Posts Tagged ‘ddlutils

09
Feb
12

ALTERing Database Schema Using DDLUtils

This page describes how to use DDLUtils to only prints out alter statements instead of making the changes automatically.

Requirements

Background

My previous article described how to use DDLUtils to automatically make changes to a database. Since we were using an in-memory/temporary database, it wouldn’t be a big deal if DDLUtils made a mistake.

Shortcut: If you have not implemented the “In memory database” in the requirements section and you have your own database. Then you can skip to the short cut section below. the return here.

DDLUtils has functionality to fetch the current DDL and dump it into an XML file. Once we modify the xml we can have DDLUtils compare the xml against the current database and only print “ALTER” statements to the screen. We can take those alter statements and manually run them against the database.

Create the Java Code

The following class is designed to be run from the command line. You can wrap it into a shell script. Take some time to review the java source below. It is pretty much self explanatory. Please be sure to name your xml file different from the prior project. In the example below its called “ddl-draft.xml”.

vi src/main/java/com/test/DDLUtils.java

package com.test;

import java.io.InputStreamReader;
import java.io.StringWriter;

import javax.sql.DataSource;

import org.apache.ddlutils.Platform;
import org.apache.ddlutils.PlatformFactory;
import org.apache.ddlutils.io.DatabaseIO;
import org.apache.ddlutils.model.Database;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;

/**
 * <p>
 * Dumps or generates schema information for the batch project. This class is
 * only designed to output information. Although the framework is capabile, It
 * should not make any alterations to the database since automated alterations
 * could be risky.
 * </p>
 * 
 * <p>
 * The Dump command takes the existing database schema and creates an xml file.
 * You can choose to redirect this output to a file so you can modify the
 * schema.
 * </p>
 * 
 * <p>
 * The alter command takes the xml located in the /ddl.xml file and generates
 * alter statements to standard output. You can redirect this to a file and use
 * it to alter the database manually.
 * </p>
 * 
 * <p>
 * mvn -q exec:java -Dexec.mainClass=com.test.DDLUtils -Dexec.args="dump"
 * </p> language
 * <p>
 * mvn -q exec:java -Dexec.mainClass=com.test.DDLUtils -Dexec.args="alter"
 * </p>
 * 
 */
public class DDLUtils {
	private DataSource dataSource;

	public DDLUtils() {
		super();
		ApplicationContext context = new 
		ClassPathXmlApplicationContext("com/test/app-config.xml");
		dataSource = (DataSource) context.getBean("dataSource");		
	}
	
	public static void main(String args[]) {
		(new DDLUtils()).contextInitialized(args);
	}
	
    public void contextInitialized(String args[]) {
        Platform platform = PlatformFactory
                .createNewPlatformInstance(dataSource);
 
        Database database = new DatabaseIO().read(new InputStreamReader(
                getClass().getResourceAsStream("/ddl-draft.xml")));
        if(args.length < 1) {
        	usage();
        	return;
        }
        if("dump".equals(args[0])) {
    		StringWriter writer = new StringWriter();
    		new DatabaseIO().write(platform.readModelFromDatabase("batch"), writer);
    		System.out.println(writer.toString());        	
        } else if("alter".equals(args[0])) {
        	System.out.println(platform.getAlterTablesSql(database));
        } else {
        	usage();
        	return;
        }
    }

	private void usage() {
    	System.out.println("usage: ");
    	System.out.println("\t\t"+getClass().getName()+" (dump|alter)\n\n");    
	}
    
}

Testing the Application

The following command takes the current schema and creates an xml file to standard output.

mvn -q exec:java -Dexec.mainClass=com.test.DDLUtils -Dexec.args="dump"

The following prints to standard out the DDL that will get the current database to resemble what is documented in the xml file.

mvn -q exec:java -Dexec.mainClass=com.test.DDLUtils -Dexec.args="alter"

Shortcut

Read this section if you already have a database and simply want to use DDL utils to query the schema or help modify it.

Step 1: Create a Maven Project with all the necessary dependencies listed below + the JDBC driver specific to your database.
mkdir ddlutil
cd ddlutil
vi pom.xml

<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
  xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
  <modelVersion>4.0.0</modelVersion>
  <groupId>com.test</groupId>
  <artifactId>ddlutil</artifactId>
  <packaging>jar</packaging>
  <version>1.0-SNAPSHOT</version>
  <name>ddlutil Maven Webapp</name>
  <url>http://maven.apache.org</url>
  <dependencies>
    <dependency>
      <groupId>junit</groupId>
      <artifactId>junit</artifactId>
      <version>3.8.1</version>
      <scope>test</scope>
    </dependency>
    <dependency>
		<groupId>org.apache.ddlutils</groupId>
		<artifactId>ddlutils</artifactId>
		<version>1.0</version>    
    </dependency>
		<dependency>
			<groupId>org.springframework</groupId>
			<artifactId>spring</artifactId>
			<version>2.5.6</version>
		</dependency>                
  </dependencies>
  <build>
    <finalName>ddlutil</finalName>
    
		<plugins>
			<plugin>
				<groupId>org.apache.maven.plugins</groupId>
				<artifactId>maven-compiler-plugin</artifactId>
				<version>2.0.2</version>
				<configuration>
					<source>1.5</source>
					<target>1.5</target>
				</configuration>
			</plugin>
		</plugins>    
  </build>
</project>

Step 2: Create the spring configuration file with the information necessary to connect to your datasource.

src/main/resources/applicationContext.xml

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
        xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
        xmlns:context="http://www.springframework.org/schema/context"
        xsi:schemaLocation="http://www.springframework.org/schema/beans
  
http://www.springframework.org/schema/beans/spring-beans-2.5.xsd
  
http://www.springframework.org/schema/context
  
http://www.springframework.org/schema/context/spring-context-2.5.xsd">
  
<context:annotation-config/>
<context:component-scan base-package="com.test"/>
<bean name="dataSource" class="org.springframework.jdbc.datasource.DriverManagerDataSource">
        <property name="driverClassName" value="xxxreplace with your database driverxxx"/>
        <property name="url" value="xxxreplace with your database urlxxx"/>
        <property name="username" value="xxx_username_xxx"/>
        <property name="password" value="xxx"/>
</bean>
</beans>

See the following URL to setup data connectivity using spring and help fill in the values above.

Step 3: Create sample DDL and return the the Background section on this page.

src/main/resources/ddl.xml

<?xml version="1.0"?>
<!DOCTYPE database SYSTEM "http://db.apache.org/torque/dtd/database.dtd">
<database name="testdb">
  <table name="author">
    <column name="author_id"
            type="INTEGER"
            primaryKey="true"
            required="true"/>
    <column name="name"
            type="VARCHAR"
            size="50"
            required="true"/>
    <column name="organization"
            type="VARCHAR"
            size="50"
            required="false"/>
  </table>

  <table name="book">
    <column name="book_id"
            type="INTEGER"
            required="true"
            primaryKey="true"
            autoIncrement="true"/>
    <column name="isbn"
            type="VARCHAR"
            size="15"
            required="true"/>
    <column name="author_id"
            type="INTEGER"
            required="true"/>
    <column name="title"
            type="VARCHAR"
            size="255"
            required="true"/>

    <foreign-key foreignTable="author">
      <reference local="author_id" foreign="author_id"/>
    </foreign-key>  

    <index name="book_isbn">
      <index-column name="isbn"/>
    </index>
  </table>
</database>

References

07
Apr
11

RESTful CRUD using extJS

This page describes how to create an extJS based web application that performs RESTful CRUD operations on resources in a Java JEE web application. For those that want instant gratification, a complete working version of the project is available at the following SVN location. http://ext-jsf.googlecode.com/svn/trunk/wordpress/2011/04/restful-crud-using-extjs/. Get the project and skip to the Test The Application section of this page.

Background

Each Entity object (resource) suppose to have a unique URL in a REST based application. This design consideration makes it easy for JavaScript frameworks like extJS to perform CRUD operations on the resource based on user’s actions.

This tutorial builds from an article about ExtJS + Spring MVC validation using commons-validator. While that page only allowed you to create new items by issuing a HTTP POST, this page will complete the CRUD concept allowing the browser to issue GET, PUT, and DELETE methods to manage items in the database.

CRUD is composed of the following parts:

Create(aka. HTTP POST)

The extJS component issues a HTTP POST to the URL listed in the data store. HTTP POST is neither safe or omnipotent. This means that the HTTP POST can change the state of the object and also multiple invocations can be disruptive (it will create an extra object if called twice by mistake). The component is expecting a JSON “success” string and a representation of the object at a minimum. The id of the item is not passed in the URL because it is not known yet.

Read (aka. HTTP GET)

The extJS component is expecting a list of objects to be returned when it issues a GET to the URL. The list of items are displayed on the grid based on the configuration of the reader or metaData. HTTP GET is a “safe” operation. This means that calls to a resource using GET will not change the state of the resource. The component is expecting a JSON “success” string at a minimum.

Update (aka. HTTP PUT)

The extJS component sends the id in the URL path and the representation of the modified object in the body of the PUT. HTTP PUT is not “safe” however it is “omnipotent”. This means that an HTTP PUT can change the state of the object however multiple submissions of this PUT will not will not be disruptive. The component is expecting a JSON “success” and a representation of the object at a minimum.

Destroy (aka. HTTP DELETE)

The extJS component sends the id in the URL path. HTTP DELETE is not safe however it is omnipotent. This means that DELETE operations will change the state of the object on the server side however multiple invocations of this will not be disruptive. (since deleting the same id the second time will not do anything). The component is expecting a JSON “success” string at a minimum.

This page describes all you need to create and configure a self-contained java application that interacts with an in-memory Java database.

Requirements

Procedure

Verify The Existing Project

Open up a console with to the project’s base directory.

Convert XML to POJO

The Grid on this page uses a XmlWriter to submit the Item as XML in the Request Body. In order to convert the XML into a JavaBean we will be using JAXB.

Converting XML to JavaBeans using JAXB was covered on the following page “using jaxb to convert between xml and pojo“.

Modify Item.java and define “@XmlRootElement” right above the class name and add the extra import statement.

src/main/java/com/test/Item.java

...
import javax.xml.bind.annotation.XmlRootElement;

@XmlRootElement
public class Item {
...

The following class is used by JAXB to create an instance of an Item Bean.

src/main/java/com/test/ObjectFactory.java

package com.test;

import javax.xml.bind.annotation.XmlRegistry;

@XmlRegistry
public class ObjectFactory {
 
    public ObjectFactory() {
    }
 
    public Item createItem() {
        return new Item();
    }
}

Binding the Bean from the Request Body

The request body contains XML representation of beans. Spring MVC 2.5 has a @ModelAttribute annotation that does this for us. However the default implementation expects the input as HTTP form attributes. For example (“itemId=1&name=testName&description=TestDescription”). Since the Grid will be posting the Bean as XML we need to override a few classes.

The following 4 classes need to be created:

  1. CustomAnnotationMethodHandlerAdapter.java
  2. XMLServletRequestDataBinder.java
  3. ServletRequestBodyXMLPropertyValues.java
  4. XMLWebUtils.java

src/main/java/com/test/fw/CustomAnnotationMethodHandlerAdapter.java

package com.test.fw;

import javax.servlet.http.HttpServletRequest;

import org.springframework.web.bind.ServletRequestDataBinder;
import org.springframework.web.servlet.mvc.annotation.AnnotationMethodHandlerAdapter;

/**
 * The whole purpose of this class it to allow it to specify XMLServletRequestDataBinder
 * instead of the ServletRequestDataBinder as defined in the parent class.
 */
public class CustomAnnotationMethodHandlerAdapter extends AnnotationMethodHandlerAdapter {
	@Override
	protected ServletRequestDataBinder createBinder(HttpServletRequest request,
			Object target, String objectName) throws Exception {		
		return new XMLServletRequestDataBinder(target, objectName);
	}
}

src/main/java/com/test/fw/XMLServletRequestDataBinder.java

package com.test.fw;

import javax.servlet.ServletRequest;

import org.springframework.beans.MutablePropertyValues;
import org.springframework.web.bind.ServletRequestDataBinder;
import org.springframework.web.multipart.MultipartHttpServletRequest;

/**
 * The purpose of this class it call ServletRequestBodyXMLPropertyValues instead
 * of ServletRequestPropertyValues in the bind method.
 */
public class XMLServletRequestDataBinder extends ServletRequestDataBinder {

	public XMLServletRequestDataBinder(Object target, String objectName) {
		super(target, objectName);
	}

	@Override
	public void bind(ServletRequest request) {
		MutablePropertyValues mpvs = new ServletRequestBodyXMLPropertyValues(request);
		if (request instanceof MultipartHttpServletRequest) {
			MultipartHttpServletRequest multipartRequest = (MultipartHttpServletRequest) request;
			bindMultipartFiles(multipartRequest.getFileMap(), mpvs);
		}
		doBind(mpvs);
	}

}

src/main/java/com/test/fw/ServletRequestBodyXMLPropertyValues.java

package com.test.fw;

import javax.servlet.ServletRequest;

import org.springframework.beans.MutablePropertyValues;


/**
 * PropertyValues implementation created from XML in the ServletRequest body. This 
 * implementation uses the XMLWebUtils instead of WebUtils to extract property values
 * from the ServletRequest body.
 */
public class ServletRequestBodyXMLPropertyValues extends MutablePropertyValues {
	private static final long serialVersionUID = 1L;

	public ServletRequestBodyXMLPropertyValues(ServletRequest request) {
		this(request, null, null);
	}
	
	public ServletRequestBodyXMLPropertyValues(ServletRequest request, String prefix, String prefixSeparator) {
		super(XMLWebUtils.getElementsStartingWith(
				request, (prefix != null) ? prefix + prefixSeparator : null));
	}

}

src/main/java/com/test/fw/XMLWebUtils.java

package com.test.fw;

import java.io.IOException;
import java.util.Map;
import java.util.TreeMap;

import javax.servlet.ServletRequest;
import javax.xml.parsers.ParserConfigurationException;
import javax.xml.parsers.SAXParser;
import javax.xml.parsers.SAXParserFactory;

import org.springframework.util.Assert;
import org.xml.sax.Attributes;
import org.xml.sax.SAXException;
import org.xml.sax.helpers.DefaultHandler;

/**
 * This class offers some enhanced features relating to REST processing
 * XML submitted by extJS component as part of a form submission.
 */
public class XMLWebUtils {
	static class MyDefaultHandler extends DefaultHandler {
		private String tempVal;
		
		final private Map<String, String> params;
		private String rootElement;
		private String prefix;
		
		public MyDefaultHandler(Map<String, String> map, String prefix) {
			this.params = map;
			this.prefix = prefix;
		}
		
		@Override
		public void startElement(String uri, String localName, String qName,
				Attributes attributes) throws SAXException {
			if(qName == null) {
				return;
			}
			
			if(rootElement == null) {
				rootElement = qName;
			} 
			
		}
	    
		public void characters(char[] ch, int start, int length) throws SAXException {
	        tempVal = new String(ch,start,length);
	    }
	    
		@Override
		public void endElement(String uri, String localName, String qName)
				throws SAXException {

			if(qName.equalsIgnoreCase(rootElement)) {
				rootElement = null;
			} else {
				params.put(qName, tempVal);
				tempVal = null;
			}
		}
	}
	
	/**
	 * This method creates a map of element values submitted by the extJS component.
	 * The extjs component has been set to submit an xml representation of the data. 
	 * This method uses SAX API that is built into the JDK 1.5 and above.
	 * 
	 * @param request
	 * @param prefix
	 * @return
	 */
	public static Map<String, String> getElementsStartingWith(ServletRequest request, String prefix) {
		Assert.notNull(request, "Request must not be null");
		
		Map<String, String> params = new TreeMap<String, String>();

		if (prefix == null) {
			prefix = "";
		}
        //get a factory
        SAXParserFactory spf = SAXParserFactory.newInstance();
        try {
            SAXParser sp = spf.newSAXParser();
            sp.parse(request.getInputStream(), new MyDefaultHandler(params, prefix));
        }catch(SAXException se) {
            se.printStackTrace();
        }catch(ParserConfigurationException pce) {
            pce.printStackTrace();
        }catch (IOException ie) {
            ie.printStackTrace();
        }
		return params;
	}
}

Configure SpringMVC to use the Custom Annotation Method Handler Adapter

The AnnotationMethodHandlerAdapters is configured using the spring-servlet.xml file. You can only have one HandlerAdapter per URL mapping. We will configure an alternate HandlerAdapter using another mapping.

Modify the web.xml and add an additional DispatcherServlet.

src/main/webapp/WEB-INF/web.xml

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xmlns="http://java.sun.com/xml/ns/javaee" xmlns:web="http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd"
    xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd"
    id="WebApp_ID" version="2.5">
 
    <display-name>Archetype Created Web Application</display-name>
 
    <context-param>
        <param-name>contextConfigLocation</param-name>
        <param-value>classpath:applicationContext.xml</param-value>
    </context-param>
 
    <listener>
        <listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
    </listener>
 
    <listener>
        <listener-class>com.test.DBLifecycleContextListener</listener-class>
    </listener>
 
    <servlet>
        <servlet-name>spring</servlet-name>
        <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
    </servlet>
    <servlet>
        <servlet-name>springdata</servlet-name>
        <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
    </servlet>
 
    <servlet-mapping>
        <servlet-name>spring</servlet-name>
        <url-pattern>/app/*</url-pattern>
    </servlet-mapping>
    <servlet-mapping>
        <servlet-name>springdata</servlet-name>
        <url-pattern>/appdata/*</url-pattern>
    </servlet-mapping>
 
</web-app>

The following is the configuration file for the new DispatcherServlet we defined above. Spring MVC follows a standard naming convention with reading xml configurations. If the servlet name is “springdata” then the springdata-servlet.xml file in the WEB-INF folder will be read. The below configuration file is similar to the original one except we have swapped out the HandlerAdapter for “com.test.CustomAnnotationMethodHandlerAdapter”.

src/main/webapp/WEB-INF/springdata-servlet.xml

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:context="http://www.springframework.org/schema/context"
    xsi:schemaLocation="http://www.springframework.org/schema/beans
 
http://www.springframework.org/schema/beans/spring-beans-2.5.xsd
 
http://www.springframework.org/schema/context
 
http://www.springframework.org/schema/context/spring-context-2.5.xsd">
 
    <context:annotation-config />
    <context:component-scan base-package="com.test" />
 
    <bean
        class="org.springframework.web.servlet.mvc.annotation.DefaultAnnotationHandlerMapping" />
    <bean
        class="com.test.fw.CustomAnnotationMethodHandlerAdapter" />
 
    <bean id="viewResolver"
        class="org.springframework.web.servlet.view.InternalResourceViewResolver">
        <property name="prefix" value="/WEB-INF/jsp/" />
        <property name="suffix" value=".jsp" />
    </bean>
 
</beans>

Setup the ExtJS Front End JavaScript/HTML

Lastly we will set-up the extJS Front End.

The following enhances the extJS editor grid to display validation failures. Thanks to Oskar Johansson for providing a excellent solution.

src/main/webapp/gridValidation.js

// Oskar Johansson, http://onkelborg.com
    activateGridValidation = function (grid) {
        var store = grid.getStore();
        var mapRecordToRequestJsonData = [];
        var mapRecordToRequestRecord = [];
        var storeOnBeforeSave = function (store, data) {
            mapRecordToRequestJsonData = [];
            mapRecordToRequestRecord = [];
        };
        var storeOnBeforeWrite = function (dataProxy, action, rs, params) {
            mapRecordToRequestJsonData.push(params.jsonData);
            mapRecordToRequestRecord.push(rs);
        };
        var storeOnException = function (dataProxy, type, action, options, response, arg) {
            if (action == "create" || action == "update") {
                var erroneousObject = mapRecordToRequestRecord[mapRecordToRequestJsonData.indexOf(options.jsonData)];
                var rowIndex = store.indexOf(erroneousObject);
                var colModel = grid.getColumnModel();
                var gridView = grid.getView();
                var errorsInner;
                var errors = response.raw ? response.raw.errors : ((errorsInner = Ext.decode(response.responseText)) ? errorsInner.errors : null);
                var editableColumns = [];
                for (var i = 0; i < colModel.getColumnCount(); i++) {
                    var column = colModel.getColumnById(colModel.getColumnId(i));
                    if (column.getCellEditor(rowIndex)) {
                        editableColumns.push(colModel.getDataIndex(i));
                    }
                }
                if (errors) {
                    var erroneousColumns = [];
                    for (var x in errors) {
                        erroneousColumns.push(x);
                    }
                    for (var i = 0; i < erroneousColumns.length; i++) {
                        editableColumns.splice(editableColumns.indexOf(erroneousColumns[i]), 1);
                    }
                    for (var i = 0; i < erroneousColumns.length; i++) {
                        var errKey = erroneousColumns[i];
                        var colIndex = colModel.findColumnIndex(errKey);
                        var msg = errors[errKey];
                        var cell = gridView.getCell(rowIndex, colIndex);
                        var cellElement = Ext.get(cell);
                        var cellInnerElement = cellElement.first();
                        cellInnerElement.addClass("x-form-invalid");
                        cellInnerElement.set({ qtip: msg });
                    }
                }
                for (var i = 0; i < editableColumns.length; i++) {
                    var colIndex = colModel.findColumnIndex(editableColumns[i]);
                    var cell = gridView.getCell(rowIndex, colIndex);
                    var cellElement = Ext.get(cell);
                    var cellInnerElement = cellElement.first();
                    cellInnerElement.removeClass("x-form-invalid");
                    cellInnerElement.set({ qtip: "" });
                }
            }
        };
        store.proxy.on("exception", storeOnException);
        store.proxy.on("beforewrite", storeOnBeforeWrite);
        store.on("beforesave", storeOnBeforeSave);
        grid.on("destroy", function () {
            store.proxy.un("exception", storeOnException);
            store.proxy.un("beforewrite", storeOnBeforeWrite);
            store.un("beforesave", storeOnBeforeSave);
        });
    }; 

The next file contains the JavaScript code that sets up the editor grid panel.
src/main/webapp/restful.js

MyApp={};
MyApp.getContext = function() {
	var base = document.getElementsByTagName('base')[0];
	if (base && base.href && (base.href.length > 0)) {
		base = base.href;
	} else {
		base = document.URL;
	}
	return base.substr(0, base.indexOf("/", base.indexOf("/", base.indexOf("//") + 2) + 1));
};

var App = new Ext.App({});
 
var proxy = new Ext.data.HttpProxy({
	url: MyApp.getContext() + '/appdata/itemresource'
});

var reader = new Ext.data.JsonReader({
    totalProperty: 'total',
    successProperty: 'success',
    idProperty: 'itemId',
    root: 'data',
    record: 'item',
    messageProperty: 'message',  // <-- New "messageProperty" meta-data
    fields : [
              {name: 'itemId'},
              {name: 'name', allowBlank: false},
              {name: 'description', allowBlank: true},
              {name: 'stockQty', allowBlank: true},
              {name: 'color', allowBlank: true}
    ]
});

// The new DataWriter component.
var writer = new Ext.data.XmlWriter({
    encode : false,
    writeAllFields : true,
    xmlEncoding : "UTF-8"
});

// Typical Store collecting the Proxy, Reader and Writer together.
var store = new Ext.data.Store({
    id: 'item',
    restful: true,     // <-- This Store is RESTful
    proxy: proxy,
    reader: reader,
    writer: writer    // <-- plug a DataWriter into the store
});

// load the store
store.load();

// The following is necessary to map the Record Fields to the grid columns.
var userColumns =  [
    {header: "Item Id", width: 40, sortable: true, dataIndex: 'itemId'},
    {header: "Item Name", width: 100, sortable: true, dataIndex: 'name', editor: new Ext.form.TextField({})},
    {header: "Description", width: 100, sortable: true, dataIndex: 'description', editor: new Ext.form.TextField({})},
    {header: "Quantity", width: 100, sortable: true, dataIndex: 'stockQty', editor: new Ext.form.TextField({})},
    {header: "Color", width: 100, sortable: true, dataIndex: 'color', editor: new Ext.form.TextField({})}
];

Ext.onReady(function() {
    Ext.QuickTips.init();

    // use RowEditor for editing
    var editor = new Ext.ux.grid.RowEditor({
        saveText: 'Save'
    });

    // Create a typical GridPanel with RowEditor plugin
    var userGrid = new Ext.grid.GridPanel({
        renderTo: 'user-grid',
        iconCls: 'icon-grid',
        frame: true,
        title: 'Fun with RESTful CRUD',
        height: 300,
        store: store,
        plugins: [editor],
        columns : userColumns,
    	enableColumnHide: false,
        tbar: [{
        	id: 'addBtn',
            text: 'Add',
            iconCls: 'silk-add',
            handler: onAdd
        }, '-', {
        	id: 'deleteBtn',
            text: 'Delete',
            iconCls: 'silk-delete',
            handler: onDelete
        }, '-'],
        viewConfig: {
            forceFit: true
        }
    });

    function onAdd(btn, ev) {
        var u = new userGrid.store.recordType({
            first : '',
            last: '',
            email : ''
        });
        editor.stopEditing();
        userGrid.store.insert(0, u);
        editor.startEditing(0);
    }

    // Disable the buttons when editing.
    editor.addListener('beforeedit', function(roweditor, rowIndex){
        Ext.getCmp('addBtn').disable();
        Ext.getCmp('deleteBtn').disable();
    });
    editor.addListener('afteredit', function(roweditor, rowIndex){
        Ext.getCmp('addBtn').enable();
        Ext.getCmp('deleteBtn').enable();
    });
    editor.addListener('canceledit', function(roweditor, rowIndex){
    	// get fresh records from the database.
        userGrid.store.reload({});
        Ext.getCmp('addBtn').enable();
        Ext.getCmp('deleteBtn').enable();
    });     

    function onDelete() {
        var rec = userGrid.getSelectionModel().getSelected();
        if (!rec) {
            return false;
        }
        userGrid.store.remove(rec);
    }
    activateGridValidation(userGrid);
});

The following file pulls everything together.
src/main/webapp/grid.html

<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1">
<title>RESTful Store Example</title>

<!-- extJS JavaScript files -->
<script type="text/javascript"
    src="http://dev.sencha.com/deploy/ext-3.3.1/adapter/ext/ext-base-debug.js">
</script> 
<script type="text/javascript"
    src="http://dev.sencha.com/deploy/ext-3.3.1/ext-all-debug.js">
</script>
<!-- extJS example JavaScript files -->
<script type="text/javascript"
	src="http://dev.sencha.com/deploy/ext-3.3.1/examples/shared/extjs/App.js"></script>
<script type="text/javascript"
	src="http://dev.sencha.com/deploy/ext-3.3.1/examples/ux/RowEditor.js"></script>

<!-- My JavaScript Files -->
<script type="text/javascript" src="restful.js"></script>
<script type="text/javascript" src="gridValidation.js"></script>
 
<!-- Common Styles -->
<link rel="stylesheet" type="text/css"
    href="http://dev.sencha.com/deploy/ext-3.3.1/resources/css/ext-all.css"/>
<link rel="stylesheet" type="text/css" href="restful.css" />
<!-- Example Styles -->
<link rel="stylesheet"
	href="http://dev.sencha.com/deploy/ext-3.3.1/examples/ux/css/RowEditor.css" />
<link rel="stylesheet" type="text/css"
	href="http://dev.sencha.com/deploy/ext-3.3.1/examples/shared/examples.css" />
<link rel="stylesheet" type="text/css"
	href="http://dev.sencha.com/deploy/ext-3.3.1/examples/shared/icons/silk.css" />

</head>
<body>
<h1>RESTful Editor Grid with Validation</h1>
<h3>About This Example:</h3>
    <div><ul>
    <li>Uses HyperSQL, IBATIS, Spring</li>
    </ul></div>

<div class="container" style="width:500px">
    <div id="user-grid"></div>
</div>
<h3>Tips:</h3>
    <div><ul>
    <li>1. Use Firebug to inspect RESTful operations</li>
    <li>2. Validation rules are modified by editing src/main/webapp/WEB-INF/validation.xml</li>
    </ul></div>

<h3>Steps to Add a new Column:</h3>
    <div><ul>
    <li>1. Add column to the database src/main/resources/ddl.xml</li>
    <li>2. Add column to the grid located in restful.js</li>
    <li>3. Add the new attribute to Item.java Bean (create getters/setters as well)</li>
    <li>4. Change IBATIS config file located in src/main/resources/com/test/ItemDataManager.xml</li>
    <li>5. Optionally Add column validation to src/main/webapp/WEB-INF/validation.xml</li>
    </ul></div>

</body>
</html>

Modify the index.html file and add the link to the above page.

The index.html should look like this.

src/main/webapp/index.html

<html>
<body>
<h3><a href="http://localhost:8080/crud/app/item">Part I - Simple form.</a></h3>
<h3><a href="form.html">Part II - Click here for the ExtJS Form</a></h3>
<h3><a href="grid.html">Part III -Click here for the ExtJS Editor Grid</a></h3>
</body>
</html>

Start Jetty Servlet Engine

mvn clean compile jetty:run

Test the application

Navigate to: http://localhost:8080/crud/ and enter some data

Test the following as well.
1. then shutting down jetty – CTRL-C
2. verify the data survived in the src/main/webapp/WEB-INF/db directory.

Create a WAR file

If you want to run the application in another environment you can create a war file and drop it into a server of your choice. This method will also package up any runtime dependencies and put them in the /WEB-INF/lib folder of the WAR file.

mvn clean compile package

The war file should appear in the target/ folder.

Note: If you have any suggestions to improve the code please send me a comment below. I read every comment and appreciate constructive feedback.

31
Mar
11

Schema Maintenance Using DDLUtils

This page describes the process of creating in memory database and maintaining the schema using Apache DDLUtils within your web application. Since we will be using a pure java database it allows developers to rapidly develop and unit test database driven applications in isolation.

There is no need to maintain an external mysql or Oracle database. The database is self contained within the application. Once you are finished with development you would just remove the HSQLDB dependency from the pom file and change the connect string to connect with a live database.

The primary motivation for writing this was so that I could use this as a base for writing CRUD type web applications.

This page is part of a series of Rapid Development and prototyping tutorials.

Background

HyperSQL DataBase (HSQLDB) is a Java based in-memory database that allows you to develop and unit test your web application in isolation. It supports stored procedures (callable statements) as well.

Schema maintenance is a common problem for in-memory or sandbox databases. Changes to the data model need to be applied to your test database using DDL statements often during application development.

This page describes the process of using the Apache DDLUtils framework to incrementally apply the changes kept in an XML file each time the application restarts. Since the changes are incremental (ALTER TABLE etc..) and every effort is made to preserve the existing data.

The application below will create 2 tables when the application initializes. The DDL will be generated and executed from an xml file located in the classpath. The application initialization and shut-down are handled by writing ContextLoaderListeners.

Requirements

  • Maven
  • Basic understanding of the Spring Framework
  • Basic understanding of JDBC and SQL

Procedure

Start a new project

mvn archetype:generate -DarchetypeArtifactId=maven-archetype-webapp

groupId: com.test
artifactId: ddlutil

Answer the rest of the questions with defaults “Just hit the enter key”,

cd to the project base folder.

cd ddlutil

Since this is a web project maven2 does not create the java source folder.

Create missing folder
mkdir -p src/main/java/com/test

Modify the pom.xml file to look like this.

<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
  xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
  <modelVersion>4.0.0</modelVersion>
  <groupId>com.test</groupId>
  <artifactId>ddlutil</artifactId>
  <packaging>war</packaging>
  <version>1.0-SNAPSHOT</version>
  <name>ddlutil Maven Webapp</name>
  <url>http://maven.apache.org</url>
  <dependencies>
    <dependency>
      <groupId>junit</groupId>
      <artifactId>junit</artifactId>
      <version>3.8.1</version>
      <scope>test</scope>
    </dependency>
    <dependency>
		<groupId>org.apache.ddlutils</groupId>
		<artifactId>ddlutils</artifactId>
		<version>1.0</version>    
    </dependency>
		<dependency>
			<groupId>org.hsqldb</groupId>
			<artifactId>hsqldb</artifactId>
			<version>1.8.0.10</version>
		</dependency>
		    
		<dependency>
            <groupId>org.apache.geronimo.specs</groupId>
            <artifactId>geronimo-servlet_2.5_spec</artifactId>
            <version>1.2</version>
            <scope>provided</scope>
        </dependency>

		<dependency>
			<groupId>org.springframework</groupId>
			<artifactId>spring</artifactId>
			<version>2.5.6</version>
		</dependency>
                
  </dependencies>
  <build>
    <finalName>ddlutil</finalName>
    
		<plugins>
			<plugin>
				<groupId>org.apache.maven.plugins</groupId>
				<artifactId>maven-compiler-plugin</artifactId>
				<version>2.0.2</version>
				<configuration>
					<source>1.5</source>
					<target>1.5</target>
				</configuration>
			</plugin>
			<plugin>
				<groupId>org.mortbay.jetty</groupId>
				<artifactId>jetty-maven-plugin</artifactId>
				<version>7.0.0.v20091005</version>
				<configuration>
					<scanIntervalSeconds>2</scanIntervalSeconds>
				</configuration>
			</plugin>
		</plugins>    
  </build>
</project>

Spring configuration

The following contains a single bean that represents a un-pooled data source.

src/main/resources/applicationContext.xml

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
        xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
        xmlns:context="http://www.springframework.org/schema/context"
        xsi:schemaLocation="http://www.springframework.org/schema/beans
 
http://www.springframework.org/schema/beans/spring-beans-2.5.xsd
 
http://www.springframework.org/schema/context
 
http://www.springframework.org/schema/context/spring-context-2.5.xsd">
 
<context:annotation-config/>
<context:component-scan base-package="com.test"/>
<bean name="dataSource" class="org.springframework.jdbc.datasource.DriverManagerDataSource">
        <property name="driverClassName" value="org.hsqldb.jdbcDriver"/>
        <property name="url" value="jdbc:hsqldb:file:src/main/resources/db/testdb"/>
        <property name="username" value="sa"/>
        <property name="password" value=""/>
</bean>
</beans>

Servlet Context Listener

The following class listens to application life-cycle events like start-up and shut-down. It executes code to initialize and shut-down the database based on these events. Using listeners over Servlets is that the contextListeners will execute before any Servlets get a chance to run.

src/main/java/com/test/DBLifecycleContextListener.java

package com.test;

import java.io.InputStreamReader;

import javax.servlet.ServletContextEvent;
import javax.servlet.ServletContextListener;
import javax.sql.DataSource;

import org.apache.ddlutils.Platform;
import org.apache.ddlutils.PlatformFactory;
import org.apache.ddlutils.io.DatabaseIO;
import org.apache.ddlutils.model.Database;
import org.springframework.jdbc.core.simple.SimpleJdbcTemplate;
import org.springframework.web.context.WebApplicationContext;
import org.springframework.web.context.support.WebApplicationContextUtils;

/**
 * This listener initializes or gracefully shuts down the database based on
 * events from the web application.
 */
public class DBLifecycleContextListener implements ServletContextListener {
	private DataSource dataSource = null;
	private WebApplicationContext springContext = null;

	public void contextDestroyed(ServletContextEvent event) {
		SimpleJdbcTemplate template = new SimpleJdbcTemplate(dataSource);
		template.update("SHUTDOWN;");
		System.out.println("HSQLDB was shutdown. ");
	}

	public void contextInitialized(ServletContextEvent event) {
		springContext = WebApplicationContextUtils
				.getWebApplicationContext(event.getServletContext());
		dataSource = (DataSource) springContext.getBean("dataSource");

		Platform platform = PlatformFactory
				.createNewPlatformInstance(dataSource);

		Database database = new DatabaseIO().read(new InputStreamReader(
				getClass().getResourceAsStream("/ddl.xml")));

		System.out.println(database);

		platform.alterTables(database, false);

		System.out.println("HSQLDB is ready: " + platform);

	}

}

Database Schema (DDL)

The following file contains the schema that will be generated in the HSQLDB database. Any changes made to this file will result in “ALTER” table statements when the server restarts.

src/main/resources/ddl.xml

<?xml version="1.0"?>
<!DOCTYPE database SYSTEM "http://db.apache.org/torque/dtd/database.dtd">
<database name="testdb">
  <table name="author">
    <column name="author_id"
            type="INTEGER"
            primaryKey="true"
            required="true"/>
    <column name="name"
            type="VARCHAR"
            size="50"
            required="true"/>
    <column name="organization"
            type="VARCHAR"
            size="50"
            required="false"/>
  </table>

  <table name="book">
    <column name="book_id"
            type="INTEGER"
            required="true"
            primaryKey="true"
            autoIncrement="true"/>
    <column name="isbn"
            type="VARCHAR"
            size="15"
            required="true"/>
    <column name="author_id"
            type="INTEGER"
            required="true"/>
    <column name="title"
            type="VARCHAR"
            size="255"
            required="true"/>

    <foreign-key foreignTable="author">
      <reference local="author_id" foreign="author_id"/>
    </foreign-key>  

    <index name="book_isbn">
      <index-column name="isbn"/>
    </index>
  </table>
</database>

Web Application Configuration

The following loads both the spring and the DBLifecycle ContextLoaderListeners. The ordering is critical as you want the spring application context to initialize before anything else.

src/main/webapp/WEB-INF/web.xml

<!DOCTYPE web-app PUBLIC
 "-//Sun Microsystems, Inc.//DTD Web Application 2.3//EN"
 "http://java.sun.com/dtd/web-app_2_3.dtd" >

<web-app>
	<display-name>Archetype Created Web Application</display-name>

	<context-param>
		<param-name>contextConfigLocation</param-name>
		<param-value>classpath:applicationContext.xml</param-value>
	</context-param>

	<listener>
		<listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
	</listener>

	<listener>
		<listener-class>com.test.DBLifecycleContextListener</listener-class>
	</listener>
</web-app>

Run the application

Return to the project main folder and run the following on the command line to start the jetty servlet engine.

mvn clean compile jetty:run

You should see the following at the console

Database [name=testdb; 2 tables]
Mar 31, 2011 10:12:38 PM org.apache.ddlutils.alteration.ModelComparator compare
INFO: Table author needs to be added
Mar 31, 2011 10:12:38 PM org.apache.ddlutils.alteration.ModelComparator compare
INFO: Table book needs to be added
Mar 31, 2011 10:12:38 PM org.apache.ddlutils.platform.SqlBuilder getForeignKeyName
WARNING: Encountered a foreign key in table book that has no name. DdlUtils will use the auto-generated and shortened name book_FK_author_id_author instead.
Mar 31, 2011 10:12:38 PM org.apache.ddlutils.platform.PlatformImplBase evaluateBatch
INFO: Executed 4 SQL command(s) with 0 error(s)
HSQLDB is ready: org.apache.ddlutils.platform.hsqldb.HsqlDbPlatform@10e9c592
2011-03-31 22:12:38.392:INFO::Started SelectChannelConnector@0.0.0.0:8080
[INFO] Started Jetty Server
[INFO] Starting scanner at interval of 2 seconds.

There is no need to open a browser to view the web application since all the work that was needed has already been done when the application initialized.

Shutdown the server by typing CTRL-C.

View the results

The server will initiate a graceful shut-down when you type CTRL-C at the console. The HSQLDB will write all data from the memory to a file located in the src/main/resources/db/ folder.

During runtime the data is kept in memory. Saving the data to a file-system allows the server to resume where it left of without loosing data when the server starts up again. We can use this to our advantage to peek into the file to see what is the state of the database.

After the first run the following file should look like this. Note the length of the AUTHOR.NAME field.

src/main/resources/db/testdb.script

CREATE SCHEMA PUBLIC AUTHORIZATION DBA
CREATE MEMORY TABLE BOOK(BOOK_ID INTEGER GENERATED BY DEFAULT AS IDENTITY(START WITH 0) NOT NULL PRIMARY KEY,ISBN VARCHAR(15) NOT NULL,AUTHOR_ID INTEGER NOT NULL,TITLE VARCHAR(255) NOT NULL)
CREATE INDEX BOOK_ISBN ON BOOK(ISBN)
CREATE MEMORY TABLE AUTHOR(AUTHOR_ID INTEGER NOT NULL PRIMARY KEY,NAME VARCHAR(50) NOT NULL,ORGANISATION VARCHAR(50))
ALTER TABLE BOOK ADD CONSTRAINT BOOK_FK_AUTHOR_ID_AUTHOR FOREIGN KEY(AUTHOR_ID) REFERENCES AUTHOR(AUTHOR_ID)
ALTER TABLE BOOK ALTER COLUMN BOOK_ID RESTART WITH 0
CREATE USER SA PASSWORD ""
GRANT DBA TO SA
SET WRITE_DELAY 10

Altering the schema

Open up ddl.xml and increase the length of the name field of the “AUTHOR” table to VARCHAR(100) line 11 (highlighted).

1. Restart the jetty
2. shut it back down by typing CTRL-C.

Re-open the file below. You will notice that the auther.name field has been expanded to 100 characters.

src/main/resources/db/testdb.script

CREATE SCHEMA PUBLIC AUTHORIZATION DBA
CREATE MEMORY TABLE BOOK(BOOK_ID INTEGER GENERATED BY DEFAULT AS IDENTITY(START WITH 0) NOT NULL PRIMARY KEY,ISBN VARCHAR(15) NOT NULL,AUTHOR_ID INTEGER NOT NULL,TITLE VARCHAR(255) NOT NULL)
CREATE INDEX BOOK_ISBN ON BOOK(ISBN)
CREATE MEMORY TABLE AUTHOR(AUTHOR_ID INTEGER NOT NULL PRIMARY KEY,NAME VARCHAR(100) NOT NULL,ORGANISATION VARCHAR(50))
ALTER TABLE BOOK ADD CONSTRAINT BOOK_FK_AUTHOR_ID_AUTHOR FOREIGN KEY(AUTHOR_ID) REFERENCES AUTHOR(AUTHOR_ID)
ALTER TABLE BOOK ALTER COLUMN BOOK_ID RESTART WITH 0
CREATE USER SA PASSWORD ""
GRANT DBA TO SA
SET WRITE_DELAY 10

That’s all for now!

28
Mar
11

Using Spring to perform CRUD on an HSQLDB using Ibatis

The following page describes how to create a simple web application that performs CRUD operations against the database using Ibatis SQL Mapper and the Spring Framework and an in-memory Java database called HyperSQL. Since we are using HSQLDB there is no need to set-up an external database. This page contains all the code you need to have a working database driven application.

Note: This page was originally written on Nov 6 2009.

Full downloadable source for this page is available here. Corrections and enhancements are welcome, fork, change and push back to GitHub.

Background

CRUD = Create Read Update Delete.

The application described here presents the user with a simple html form that allows them to create read update and delete items in the database. The Spring JDBC template and Ibatis is used to execute SQL statements.

Requirements

  1. Maven 2
  2. Java 6
  3. Servlet 2.5
  4. Ibatis 2
  5. Spring 2.5
  6. Basic understanding of Spring and Ibatis

Procedure

Outline

  1. Create a new Project
  2. Database Setup and Configuration
  3. Spring Application
  4. Integration with Ibatis
  5. Tying it all Together with Spring MVC
  6. Web Application Configuration
  7. Test the application

Create a new project

mvn archetype:generate -DarchetypeArtifactId=maven-archetype-webapp

groupId: com.test
artifactId: crud

Answer the rest of the questions with defaults “Just hit the enter key”,

cd to the project base folder.

cd crud

Since this is a web project maven2 does not create the java source folder.

Create missing folders now.
mkdir -p src/main/java/com/test
mkdir -p src/main/resources/com/test
mkdir -p src/main/webapp/WEB-INF/jsp

Modify the project Configuration

The pom.xml file should look something like this.

vi pom.xml

<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <groupId>com.test</groupId>
    <artifactId>crud</artifactId>
    <packaging>war</packaging>
    <version>1.0-SNAPSHOT</version>
    <name>crud Maven Webapp</name>
    <url>http://maven.apache.org</url>
    <pluginRepositories>
      <pluginRepository>
        <id>numberformat-releases</id>
        <url>https://raw.github.com/numberformat/20130213/master/repo</url>
      </pluginRepository>
    </pluginRepositories>

    <dependencies>
        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <version>3.8.1</version>
            <scope>test</scope>
        </dependency>
        <dependency>
            <groupId>org.json</groupId>
            <artifactId>json</artifactId>
            <version>20090211</version>
        </dependency>
        <dependency>
            <groupId>org.apache.ibatis</groupId>
            <artifactId>ibatis-sqlmap</artifactId>
            <version>2.3.4.726</version>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring</artifactId>
            <version>2.5.6</version>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-webmvc</artifactId>
            <version>2.5.6</version>
        </dependency>
        <dependency>
            <groupId>log4j</groupId>
            <artifactId>log4j</artifactId>
            <version>1.2.14</version>
        </dependency>
        <dependency>
            <groupId>org.hsqldb</groupId>
            <artifactId>hsqldb</artifactId>
            <version>1.8.0.10</version>
        </dependency>
        <dependency>
            <groupId>org.apache.ddlutils</groupId>
            <artifactId>ddlutils</artifactId>
            <version>1.0</version>
        </dependency>
        <dependency>
            <groupId>javax.servlet</groupId>
            <artifactId>servlet-api</artifactId>
            <version>2.5</version>
            <scope>provided</scope>
        </dependency>
        <dependency>
            <groupId>javax.servlet</groupId>
            <artifactId>jsp-api</artifactId>
            <version>2.0</version>
            <scope>provided</scope>
        </dependency>
    </dependencies>
    <build>
        <finalName>crud</finalName>
        <plugins>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-compiler-plugin</artifactId>
                <version>2.0.2</version>
                <configuration>
                    <source>1.6</source>
                    <target>1.6</target>
                </configuration>
            </plugin>
            <plugin>
                <groupId>org.mortbay.jetty</groupId>
                <artifactId>jetty-maven-plugin</artifactId>
                <version>7.0.0.v20091005</version>
                <configuration>
                    <scanIntervalSeconds>2</scanIntervalSeconds>
                    <webAppConfig>
                        <contextPath>/crud</contextPath>
                    </webAppConfig>
                    <stopKey>s</stopKey>
                </configuration>
            </plugin>
            <plugin>
                <groupId>github.numberformat</groupId>
                <artifactId>blog-plugin</artifactId>
                <version>1.0-SNAPSHOT</version>
                <configuration>
                <gitUrl>https://github.com/numberformat/20110328</gitUrl>
                </configuration>
            <executions>
              <execution>
                <id>1</id>
                <phase>site</phase>
                <goals>
                  <goal>generate</goal>
                </goals>
              </execution>
            </executions>
            </plugin>
        </plugins>

    </build>
</project>

Database Setup and Configuration

The following configuration file is used by Apache DDLUtils to generate apply the schema changes each time the application restarts. Changes are made incrementally and every attempt is made to preserve the data. For more information about DDLUtils please see my other tutorial.

vi src/main/resources/ddl.xml

<?xml version="1.0"?>
<!DOCTYPE database SYSTEM "http://db.apache.org/torque/dtd/database.dtd">

<database name="testdb">

    <table name="item">
        <column name="item_id" type="INTEGER" required="true"
            primaryKey="true" autoIncrement="true" />
        <column name="category_id" type="INTEGER" />
        <column name="oem_id" type="VARCHAR" size="50"/>
        <column name="item_x" type="VARCHAR" size="100" />
        <column name="special_f" type="CHAR" size="1" />
        <column name="description" type="VARCHAR" size="1000" />
        <column name="color" type="VARCHAR" size="20" />
        <column name="image_url" type="VARCHAR" size="100" />
        <column name="price" type="DECIMAL" size="15" />
        <column name="length" type="DECIMAL" size="10" />
        <column name="width" type="DECIMAL" size="10" />
        <column name="height" type="DECIMAL" size="10" />
        <column name="weight" type="DECIMAL" size="10" />
        <column name="stock_qty" type="DECIMAL" size="10" />
        <index name="item_item_x">
            <index-column name="item_x" />
        </index>
    </table>

</database>

Since we are working with HSQLDB, it is critical that we gracefully shut-down the database when the application stops. Otherwise the data that was cached in memory will be lost.

We will use a “ServletContextListener” to listen for the application shut-down event. This will allow us to execute code to graceful shut-down the HSQLDB database.

vi src/main/java/com/test/DBLifecycleContextListener.java

package com.test;

import java.io.InputStreamReader;

import javax.servlet.ServletContextEvent;
import javax.servlet.ServletContextListener;
import javax.sql.DataSource;

import org.apache.ddlutils.Platform;
import org.apache.ddlutils.PlatformFactory;
import org.apache.ddlutils.io.DatabaseIO;
import org.apache.ddlutils.model.Database;
import org.springframework.jdbc.core.simple.SimpleJdbcTemplate;
import org.springframework.web.context.WebApplicationContext;
import org.springframework.web.context.support.WebApplicationContextUtils;

/**
 * This listener initializes or gracefully shuts down the database based on
 * events from the web application.
 */
public class DBLifecycleContextListener implements ServletContextListener {
    private DataSource dataSource = null;
    private WebApplicationContext springContext = null;

    public void contextDestroyed(ServletContextEvent event) {
        SimpleJdbcTemplate template = new SimpleJdbcTemplate(dataSource);
        template.update("SHUTDOWN;");
        System.out.println("Database Successfully Shutdown.");
    }

    public void contextInitialized(ServletContextEvent event) {
        springContext = WebApplicationContextUtils
                .getWebApplicationContext(event.getServletContext());
        dataSource = (DataSource) springContext.getBean("dataSource");

        Platform platform = PlatformFactory
                .createNewPlatformInstance(dataSource);

        Database database = new DatabaseIO().read(new InputStreamReader(
                getClass().getResourceAsStream("/ddl.xml")));

        platform.alterTables(database, false);
    }
}

Spring Application

The Spring application consists of a

  • Item – POJO that represents the individual item
  • ItemModel – Service Interface
  • ItemModelImpl – Implementation of the Service
  • ItemDataManager – DataManager Interface
  • ItemDataManagerImpl – DataManager Implementation

The majority of the configuration is Annotation Based. For more information on annotation based spring configuration please see my other tutorial “using annotations in the spring framework“. Also checkout the following: “hello world spring mvc with annotations“.

Item Bean

vi src/main/java/com/test/Item.java

package com.test;

import java.math.BigDecimal;

/**
 * Represents an item in inventory or in a shopping cart.
 */
public class Item {
    private Integer itemId;
    private String oemId;
    private String name;
    private String description;
    private String imageURL;
    private String color;
    private BigDecimal price;
    private BigDecimal length;
    private BigDecimal width;
    private BigDecimal height;

    /**
     * Weight in grams
     */
    private BigDecimal weight;
    /**
     * Quantity in stock.
     */
    private Integer stockQty;

    public Item() {
        super();
    }

    public Item(Integer id, String name) {
        this.name = name;
        this.itemId = id;
    }

    public Integer getItemId() {
        return itemId;
    }
    public void setItemId(Integer itemId) {
        this.itemId = itemId;
    }
    public String getOemId() {
        return oemId;
    }
    public void setOemId(String oemId) {
        this.oemId = oemId;
    }
    public String getName() {
        return name;
    }
    public void setName(String name) {
        this.name = name;
    }
    public String getDescription() {
        return description;
    }
    public void setDescription(String description) {
        this.description = description;
    }
    public String getColor() {
        return color;
    }
    public void setColor(String color) {
        this.color = color;
    }
    public String getImageURL() {
        return imageURL;
    }
    public void setImageURL(String imageURL) {
        this.imageURL = imageURL;
    }
    public BigDecimal getPrice() {
        return price;
    }
    public void setPrice(BigDecimal price) {
        this.price = price;
    }
    public BigDecimal getLength() {
        return length;
    }
    public void setLength(BigDecimal length) {
        this.length = length;
    }
    public BigDecimal getWidth() {
        return width;
    }
    public void setWidth(BigDecimal width) {
        this.width = width;
    }
    public BigDecimal getHeight() {
        return height;
    }
    public void setHeight(BigDecimal height) {
        this.height = height;
    }
    public BigDecimal getWeight() {
        return weight;
    }
    public void setWeight(BigDecimal weight) {
        this.weight = weight;
    }

    public Integer getStockQty() {
        return stockQty;
    }

    public void setStockQty(Integer stockQty) {
        this.stockQty = stockQty;
    }

}

Spring Model classes

The following interface and implementation classes are currently being used a pass-thru to the data manager. Its not adding any value to the application but once we start using Spring Transactions we will be glad we did it this way.

vi src/main/java/com/test/ItemModel.java

package com.test;

import java.util.List;

public interface ItemModel {
    /**
     * This is a pass-thru method that just calls the DataManager.
     */
    public Item getItemInfo(Integer itemId);

    public Item createItem(Item item);

    public void updateItem(Item item);

    public void deleteItem(Integer itemId);

    /**
     * This is a pass-thru method that just calls the DataManager.
     */
    public List<Item> getAllItems(int skipResults, int maxItems);

    /**
     * This is a pass-thru method that just calls the DataManager.
     */
    public int getItemCount();

    public void deleteItemImage(Integer itemId);

}

The following is the implementation class.

vi src/main/java/com/test/ItemModelImpl.java

package com.test;

import java.util.List;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Qualifier;
import org.springframework.beans.factory.annotation.Required;
import org.springframework.stereotype.Service;

@Service
public class ItemModelImpl implements ItemModel {

    @Autowired
    @Qualifier("simpleItemDataManager")
    private ItemDataManager itemDataManager;   

    @Override
    public Item createItem(Item item) {
        return itemDataManager.createItem(item);
    }

    @Override
    public void deleteItem(Integer itemId) {
        itemDataManager.deleteItem(itemId);
    }

    @Override
    public void deleteItemImage(Integer itemId) {
        itemDataManager.deleteItemImage(itemId);
    }

    @Override
    public List<Item> getAllItems(int skipResults, int maxItems) {
        return itemDataManager.getAllItems(skipResults, maxItems);
    }

    @Override
    public int getItemCount() {
        return itemDataManager.getItemCount();
    }

    @Override
    public Item getItemInfo(Integer itemId) {
        return itemDataManager.getItemInfo(itemId);
    }

    @Override
    public void updateItem(Item item) {
        itemDataManager.updateItem(item);
    }

    public void setItemDataManager(ItemDataManager itemDataManager) {
        this.itemDataManager = itemDataManager;
    }

    public ItemDataManager getItemDataManager() {
        return itemDataManager;
    }

}

Spring Data Managers

Data Managers isolate the Model from the implementation of the data store.

vi src/main/java/com/test/ItemDataManager.java

package com.test;

import java.util.List;

public interface ItemDataManager {

    public Item getItemInfo(Integer itemId);

    public Item createItem(Item item);

    public void updateItem(Item item);

    public void deleteItem(Integer itemId);

    List<Item> getAllItems(int skipResults, int maxItems);

    int getItemCount();

    public void deleteItemImage(Integer itemId);
}

The following is the data manager implementation class.

vi src/main/java/com/test/ItemDataManagerImpl.java

package com.test;

import java.util.List;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Required;
import org.springframework.orm.ibatis.SqlMapClientTemplate;
import org.springframework.stereotype.Repository;

/**
 * This is the non-ibatis implementation.
 */
@Repository("itemDataManager")
public class ItemDataManagerImpl implements ItemDataManager {
    private final Log logger = LogFactory.getLog(ItemDataManagerImpl.class);
    private SqlMapClientTemplate sqlMapClientTemplate;

    public SqlMapClientTemplate getSqlMapClientTemplate() {
        return sqlMapClientTemplate;
    }

    @Autowired
    @Required
    public void setSqlMapClientTemplate(SqlMapClientTemplate sqlMapClientTemplate) {
        this.sqlMapClientTemplate = sqlMapClientTemplate;
    }

    @Override
    public Item getItemInfo(Integer itemId) {
        return (Item)getSqlMapClientTemplate().queryForObject("getItemInfo", itemId);
    }

    @Override
    public Item createItem(Item item) {
        Integer id = (Integer) getSqlMapClientTemplate().insert("itemInsert", item);
        item.setItemId(id);
        return item;
    }

    @Override
    public void deleteItem(Integer itemId) {
        if(itemId != null) {
            getSqlMapClientTemplate().delete("deleteItem", itemId);
        }
    }
    @Override
    public void deleteItemImage(Integer itemId) {
        if(itemId != null) {
            getSqlMapClientTemplate().delete("deleteItemImage", itemId);
        }
    }

    @Override
    public void updateItem(Item item) {
        getSqlMapClientTemplate().update("updateItem", item);
    }

    @Override
    public int getItemCount() {
        return 0;
    }

    @Override
    public List<Item> getAllItems(int skipResults, int maxItems) {
        List<Item> list = null;

        list = getSqlMapClientTemplate().queryForList("allItems", null, skipResults, maxItems);

        return list;
    }

}

Spring Configuration

Most of the spring configuration was done using Java Annotations, therefore this file is not too large.

vi src/main/resources/applicationContext.xml

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
        xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
        xmlns:context="http://www.springframework.org/schema/context"
        xsi:schemaLocation="http://www.springframework.org/schema/beans

http://www.springframework.org/schema/beans/spring-beans-2.5.xsd

http://www.springframework.org/schema/context

http://www.springframework.org/schema/context/spring-context-2.5.xsd">

    <context:annotation-config/>
    <context:component-scan base-package="com.test"/>

    <bean name="dataSource" class="org.springframework.jdbc.datasource.DriverManagerDataSource">
        <property name="driverClassName" value="org.hsqldb.jdbcDriver"/>
        <property name="url" value="jdbc:hsqldb:file:src/main/webapp/WEB-INF/db/testdb"/>
        <property name="username" value="sa"/>
        <property name="password" value=""/>
    </bean>

<!-- Used for Ibatis -->
    <bean id="sqlMapClient" class="org.springframework.orm.ibatis.SqlMapClientFactoryBean">
        <property name="configLocation" value="/WEB-INF/mapper-config.xml"/>
        <property name="dataSource" ref="dataSource"/>
        <property name="useTransactionAwareDataSource" value="true"/>
    </bean>
    <bean id="sqlMapClientTemplate" class="org.springframework.orm.ibatis.SqlMapClientTemplate">
        <property name="sqlMapClient" ref="sqlMapClient"/>
    </bean>

</beans>

Configure simple logging to the console.

vi src/main/resources/log4j.properties

# Set root logger level to DEBUG and its only appender to A1.
log4j.rootLogger=INFO, A1

log4j.appender.A1=org.apache.log4j.ConsoleAppender
log4j.appender.A1.layout=org.apache.log4j.PatternLayout
log4j.appender.A1.layout.ConversionPattern=%d %-5p %c - %m%n

Integration with IBATIS

The following needs to be defined in the spring configuration. The SQLMapClientTemplate is the primary class that will be used by our data-mangers to query the database thru SQL statements and stored procedure calls. It needs a reference to sqlMapClient that we just created.

The following is the ibatis main configuration file. Since we are using spring framework there is not much configuration that you need to put in here. All that is required is that ibatis knows where the xml files for all the Data Managers are located.

For more information on ibatis please see my other tutorial “ibatis 2.3 spring 2.5 hello world

vi src/main/webapp/WEB-INF/mapper-config.xml

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE sqlMapConfig
        PUBLIC "-//ibatis.apache.org//DTD SQL Map Config 2.0//EN"
        "http://ibatis.apache.org/dtd/sql-map-config-2.dtd">
<sqlMapConfig>
    <sqlMap resource="com/test/ItemDataManager.xml"/>
</sqlMapConfig>

vi src/main/resources/com/test/ItemDataManager.xml

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE sqlMap
        PUBLIC "-//ibatis.apache.org//DTD SQL Map 2.0//EN"
        "http://ibatis.apache.org/dtd/sql-map-2.dtd">
<sqlMap namespace="Item">

<typeAlias alias="Item" type="com.test.Item" />

    <select id="allItems" resultClass="Item">
        select item_id as itemId,
        oem_id as oemId,
        item_x as name,
        description as description,
        color as color,
        image_url as imageURL,
        price as price,
        length as length,
        width as width,
        height as height,
        weight as weight,
        stock_qty as stockQty
        from item;
    </select>
    <select id="getItemInfo" parameterClass="int" resultClass="Item">
        select item_id as itemId,
        oem_id as oemId,
        item_x as name,
        description as description,
        color as color,
        image_url as imageURL,
        price as price,
        length as length,
        width as width,
        height as height,
        weight as weight,
        stock_qty as stockQty
        from item where item_id = #id#;
    </select>

    <insert id="itemInsert" parameterClass="Item">
        insert into item (oem_id,
            item_x,
            description,
            color,
            image_url,
            price,
            length,
            width,
            height,
            weight,
            stock_qty)
        values ( #oemId#, #name#, #description#, #color#,
            #imageURL#, #price#, #length#, #width#,
            #height#, #weight#, #stockQty# );
        <selectKey resultClass="int" >
            <!-- HSQLDB -->
            CALL IDENTITY();
            <!-- MySQL -->
            <!-- SELECT LAST_INSERT_ID(); -->
        </selectKey>
    </insert>
    <update id="updateItem" parameterClass="Item">
        update item set oem_id = #oemId#, item_x = #name#, description=#description#,
            color = #color#, image_url = #imageURL#, price = #price#, length = #length#,
            width = #width#, height = #height#, weight = #weight#, stock_qty = #stockQty#
        where item_id = #itemId#;
    </update>
    <delete id="deleteItem" parameterClass="java.lang.Integer">
        delete from item where item_id = #itemId#;
    </delete>
</sqlMap>

Tying it all Together with Spring MVC

The following is the controller class that handles the http form submissions.

vi src/main/java/com/test/ItemController.java

package com.test;

import java.util.Date;
import java.util.List;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Required;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;

@Controller
@RequestMapping("/item")
public class ItemController {

    private ItemModel itemModel;

    @RequestMapping(method = RequestMethod.GET)
    public String itemInfo(HttpServletRequest request) {
        List <Item> items = itemModel.getAllItems(0, 100);
        request.setAttribute("items", items);
        return "index";
    }

    @RequestMapping(method = RequestMethod.POST)
    public String createItem(HttpServletRequest request,
            HttpServletResponse response) {

        if ("C".equals(request.getParameter("operation"))) {
            System.out.println("create");
            Item item = new Item();
            item.setName("item created: " + new Date());
            itemModel.createItem(item);
            String message = "newly created item: " + item.getItemId();
            System.out.println(message);
            request.setAttribute("message", message);

        } else if ("R".equals(request.getParameter("operation"))) {
            // left for the reader to implement
            Integer id = new Integer(request.getParameter("id"));

        	System.out.println(itemModel.getItemInfo(id));
        } else if ("U".equals(request.getParameter("operation"))) {
            // left for the reader to implement
            Integer id = new Integer(request.getParameter("id"));
        	Item item = itemModel.getItemInfo(id);
        	item.setName("item updated: " + new Date());
        	itemModel.updateItem(item);
        } else if ("D".equals(request.getParameter("operation"))) {
            Integer id = new Integer(request.getParameter("id"));
            itemModel.deleteItem(id);
            String message = "item deleted: " + id;
            System.out.println(message);
            request.setAttribute("message", message);
        }

        request.setAttribute("items", itemModel.getAllItems(0, 100));
        return "index";
    }

    public ItemModel getItemModel() {
        return itemModel;
    }

    @Required
    @Autowired
    public void setItemModel(ItemModel itemModel) {
        this.itemModel = itemModel;
    }

}

Create the Test HTML Form

The following form issues a POST request to the spring MVC controller. The form is missing the “action” attribute because by default the form posts back to the originating URL. In this case the originating URL is “/apps/item”

vi src/main/webapp/WEB-INF/jsp/index.jsp

<%@ taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN"
 "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">

<html xmlns="http://www.w3.org/1999/xhtml" lang="en" xml:lang="en">
<head>
<title>DB Parameters</title>
<meta http-equiv="Content-type" content="text/html; charset=iso-8859-1" />
<meta http-equiv="Content-Language" content="en-us" />

</head>
<body>
<h3><c:out  value="${message}"/></h3>

<h3>Items:</h3>
<table border="1">
<thead>
    <td>Id</td>
    <td>Name</td>
</thead>
<tbody>
<c:forEach items="${items}" var="item" >
    <tr>
    <td><c:out value="${item.itemId}"/></td>
    <td><c:out value="${item.name}"/></td>
    </tr>
</c:forEach>
</tbody>
</table>

    <form method="post">
        <label>Operation: </label>
        <select name="operation">
            <option value="C">Create</option>
            <option value="R">Read</option>
            <option value="U">Update</option>
            <option value="D">Delete</option>
        </select>
        <br/>
        <label>ID: </label><input type="text" name="id"/><br/>
        <input type="submit" value="submit"/><br/>
    </form>

This page saves data to an HyperSQL database located in the src/main/webapp/WEB-INF/db folder.
</body>
</html>

Web Application Configuration

The ordering of the listeners are important. You want to make sure that the spring application context is initialized before the DBLifecycleListener.

vi src/main/webapp/WEB-INF/web.xml

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xmlns="http://java.sun.com/xml/ns/javaee" xmlns:web="http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd"
    xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd"
    id="WebApp_ID" version="2.5">

    <display-name>Archetype Created Web Application</display-name>

    <context-param>
        <param-name>contextConfigLocation</param-name>
        <param-value>classpath:applicationContext.xml</param-value>
    </context-param>

    <listener>
        <listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
    </listener>

    <listener>
        <listener-class>com.test.DBLifecycleContextListener</listener-class>
    </listener>

    <servlet>
        <servlet-name>spring</servlet-name>
        <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
    </servlet>

    <servlet-mapping>
        <servlet-name>spring</servlet-name>
        <url-pattern>/app/*</url-pattern>
    </servlet-mapping>

</web-app>

vi src/main/webapp/WEB-INF/spring-servlet.xml

<?xml version="1.0" encoding="UTF-8"?>
<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:context="http://www.springframework.org/schema/context"
    xsi:schemaLocation="http://www.springframework.org/schema/beans

http://www.springframework.org/schema/beans/spring-beans-2.5.xsd

http://www.springframework.org/schema/context

http://www.springframework.org/schema/context/spring-context-2.5.xsd">

    <context:annotation-config />
    <context:component-scan base-package="com.test" />

    <bean
        class="org.springframework.web.servlet.mvc.annotation.DefaultAnnotationHandlerMapping" />
    <bean
        class="org.springframework.web.servlet.mvc.annotation.AnnotationMethodHandlerAdapter" />

    <bean id="viewResolver"
        class="org.springframework.web.servlet.view.InternalResourceViewResolver">
        <property name="prefix" value="/WEB-INF/jsp/" />
        <property name="suffix" value=".jsp" />
    </bean>

</beans>

Start Jetty Servlet Engine

mvn clean compile jetty:run

Test the application

 

 

Test the following as well.

  1. then shutting down jetty – CTRL-C
  2. verify the data survived in the src/main/webapp/WEB-INF/db directory.

Creating a WAR file

If you want to run the application in another environment you can create a war file and drop it into a server of your choice. This method will also package up any runtime dependencies and put them in the /WEB-INF/lib folder of the WAR file.

mvn clean compile package

The war file should appear in the following location…

target/crud-1.0-SNAPSHOT.war

Next Steps

Full downloadable source for this page is available here.



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