Struts

Hello World Example in Eclipse

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

In the HelloWorldForm class add the following code.        

       
    package com.chennaisundays.form;

    import org.apache.struts.action.ActionForm;

    private static final long serialVersionUID = -473562596852452021L;

    private String message;public String getMessage() {

    return message;
    }

    public void setMessage(String message) {

    this.message = message;
    }
    }

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

    package com.chennaisunday.action;

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

    import org.apache.struts.action.Action;
    import org.apache.struts.action.ActionForm;
    import org.apache.struts.action.ActionForward;
    import org.apache.struts.action.ActionMapping;

    import com.chennaisunday.form.HelloWorldForm;

    public class HelloWorldAction extends Action {

    @Override
    public ActionForward execute(ActionMapping mapping, ActionForm form,     HttpServletRequest request, HttpServletResponse response) throws Exception {

    HelloWorldForm hwForm = (HelloWorldForm) form;

    hwForm.setMessage("Hello World");

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

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

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

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

    <!DOCTYPE struts-config PUBLIC
    "-//Apache Software Foundation//DTD Struts Configuration 1.3//EN"
    "http://struts.apache.org/dtds/struts-config_1_3.dtd">

    <struts-config>

    <form-beans>
    <form-bean name="helloWorldForm"     type="com.chennaisunday.form.HelloWorldForm"/>
    </form-beans>

    <global-forwards>
    <forward name="helloWorld" path="/helloWorld.do"/>
    </global-forwards>

    <action-mappings>
    <action&npath="/helloWorld"type="com.chennaisunday.action.HelloWorldAction"     name="helloWorldForm">
    <forward name="success" path="/helloWorld.jsp" />
    </action>
    </action-mappings>

    </struts-config>

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

    <?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>StrutsExample1</display-name>

    <servlet>
    <servlet-name>action</servlet-name>
    <servlet-class>org.apache.struts.action.ActionServlet</servlet-class>
    <init-param>
    <param-name>config</param-name>
    <param-value>/WEB-INF/struts-config.xml</param-value>
    </init-param>
    <load-on-startup>2</load-on-startup>
    </servlet>

    <servlet-mapping>
    <servlet-name>action</servlet-name>
    <url-pattern>*.do</url-pattern>
    </servlet-mapping>

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

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

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

    <html>
    <head>
    <meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1">
    <title>Hello World</title>
    </head>
    <body>
    <bean:write name="helloWorldForm" property="message"/>
    </body>
    </html>