2 Struts Hello World Example in Eclipse

玄范 2012-08-21

展開全文

06.13.2012

File Source : http://www./tutorials/java/struts/struts-tutorial/struts-tutorial-using-eclipse-1.html

In this tutorial you will learn how to create a Struts hello world application in eclipse. First create a new project, go to File->New and select

DynamicWebProject.

Enter the project name and click the Finish button.

Add the following jar files to the WEB-INF\lib directory.

Right click the src folder and select New->Package.

Enter the package name as com.vaannila.form and click Finish.

Now right click the newly created package and select New->Class.

Enter the class name as HelloWorldForm and the superclass name asorg.apache.struts.action.ActionForm and click Finish.

In the HelloWorldForm class add the following code.

01.package com.vaannila.form;

02.

03.import org.apache.struts.action.ActionForm;

04.

05.public class HelloWorldForm extends ActionForm {

06.

07.private static final long serialVersionUID = -473562596852452021L;

08.

09.private String message;

10.

11.public String getMessage() {

12.return message;

13.}

14.

15.public void setMessage(String message) {

16.this.message = message;

17.}

18.}

In the same way create a new package com.vaannila.action and create a HelloWorldAction class extending org.apache.struts.action.Action. Add the following code to the action class and save it.

01.package com.vaannila.action;

02.

03.import javax.servlet.http.HttpServletRequest;

04.import javax.servlet.http.HttpServletResponse;

05.

06.import org.apache.struts.action.Action;

07.import org.apache.struts.action.ActionForm;

08.import org.apache.struts.action.ActionForward;

09.import org.apache.struts.action.ActionMapping;

10.

11.import com.vaannila.form.HelloWorldForm;

12.

13.public class HelloWorldAction extends Action {

14.

15.@Override

16.public ActionForward execute(ActionMapping mapping, ActionForm form, HttpServletRequest request, HttpServletResponse response) throwsException {

17.HelloWorldForm hwForm = (HelloWorldForm) form;

18.hwForm.setMessage("Hello World");

19.return mapping.findForward("success");

20.}

21.}

Here we typecast the ActionForm to HelloWorldForm and set the message value.

Add the following entries in the struts-config.xml file.

01.<?xml version="1.0" encoding="ISO-8859-1" ?>

02.

03.<!DOCTYPE struts-config PUBLIC

04."-//Apache Software Foundation//DTD Struts Configuration 1.3//EN"

05."http://struts./dtds/struts-config_1_3.dtd">

06.

07.<struts-config>

08.

09.<form-beans>

10.<form-bean name="helloWorldForm"type="com.vaannila.form.HelloWorldForm"/>

11.</form-beans>

12.

13.<global-forwards>

14.<forward name="helloWorld" path="/helloWorld.do"/>

15.</global-forwards>

16.

17.<action-mappings>

18.<action path="/helloWorld"type="com.vaannila.action.HelloWorldAction" name="helloWorldForm">

19.<forward name="success" path="/helloWorld.jsp" />

20.</action>

21.</action-mappings>

22.

23.</struts-config>

Now configure the deployment descriptor. Add the following configuration information in the web.xml file.

01.<?xml version="1.0" encoding="UTF-8"?>

02.<web-app xmlns:xsi="http://www./2001/XMLSchema-instance"xmlns="http://java./xml/ns/javaee"xmlns:web="http://java./xml/ns/javaee/web-app_2_5.xsd"xsi:schemaLocation="http://java./xml/ns/javaee http://java./xml/ns/javaee/web-app_2_5.xsd" id="WebApp_ID"version="2.5">

03.<display-name>StrutsExample1</display-name>

04.

05.<servlet>

06.<servlet-name>action</servlet-name>

07.<servlet-class>org.apache.struts.action.ActionServlet</servlet-class>

08.<init-param>

09.<param-name>config</param-name>

10.<param-value>/WEB-INF/struts-config.xml</param-value>

11.</init-param>

12.<load-on-startup>2</load-on-startup>

13.</servlet>

14.

15.<servlet-mapping>

16.<servlet-name>action</servlet-name>

17.<url-pattern>*.do</url-pattern>

18.</servlet-mapping>

19.

20.<welcome-file-list>

21.<welcome-file>index.jsp</welcome-file>

22.</welcome-file-list>

23.</web-app>

When we run the application the index.jsp page will be executed first. In the index.jsp page we redirect the request to the helloWorld.do URI, which inturn invokes the HelloWorldAction.

1.<%@ taglib uri="http://struts./tags-logic" prefix="logic" %>

2.<logic:redirect forward="helloWorld"/>

In the action class we return the ActionForward "success" which is mapped to the helloWorld.jsp page. In the helloWorld.jsp page we display the "Hello World" message.

01.<%@taglib uri="http://struts./tags-bean" prefix="bean" %>

02.<html>

03.<head>

04.<meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1">

05.<title>Hello World</title>

06.</head>

07.<body>

08.<bean:write name="helloWorldForm" property="message"/>

09.</body>

10.</html>

After creating all the files the directory structure of the application looks like this.