Basic Struts 2 project setup

You can download Struts 2 from http://struts.apache.org/index.html (I used struts-2.2.1.1 here). Once you have downloaded the archive please have a look at the lib folder - it includes all the relevent Struts 2 libraries. But we do not want to add all the jar files to our project because we don't need them all.

Unfortunately the Struts 2 downloads for some reason miss the javassist library - I cannot tell you why. That means you have to download it manually as well from www.javassist.org. The download includes javassist-x.xx.x-GA.jar (in my case javassist-3.14.0-GA.jar). If you don't add this library to your project then your Struts 2 application won't run.

Since we will also add log4j support later we have to add the log4j library as well. You can get log4j from http://logging.apache.org/log4j/1.2/.

So finally we have the libraries we want to add to our project. This is the minimum setup for any Struts 2 project:

• commons-fileupload-1.2.1.jar
• commons-io-1.3.2.jar
• commons-logging-1.0.4.jar
• ognl-3.0.jar
• commons-logging-api-1.1.jar
• struts2-core-2.2.1.1.jar
• freemarker-2.3.16.jar
• xwork-core-2.2.1.1.jar
• javassist-3.14.0-GA.jar
• log4j-1.2.16.jar

The web.xml is pretty streight forward. The following web.xml has to be placed as usual into your WEB-INF directory:

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

<web-app id="WebApp_ID" version="3.0"
    xmlns="http://java.sun.com/xml/ns/javaee"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd">

    <display-name>Basic Strust 2 Project setup on Glassfish 3.0.1</display-name>

    <filter>
        <filter-name>struts2</filter-name>
        <filter-class>org.apache.struts2.dispatcher.ng.filter.StrutsPrepareAndExecuteFilter</filter-class>
    </filter>

    <filter-mapping>
        <filter-name>struts2</filter-name>
        <url-pattern>/*</url-pattern>
    </filter-mapping>

</web-app>

The struts.xml is the main configuration file for struts. Here we will define our Actions. The struts.xml file has to be placed either in your default package or it can be placed into the WEB-INF/classes/ directory (for the latter case you might have to create the classes directory yourself). I have choosen to put the file together with struts-2.1.7.dtd into the classes directory.

Hint: I guess the Struts 2 developers always forget to offer a new *.dtd file which contains the latest version number (I have monitored this the last releases). But struts-2.1.7.dtd works just fine.

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE struts PUBLIC
    "-//Apache Software Foundation//DTD Struts Configuration 2.1.7//EN"
    "/WEB-INF/classes/struts-2.1.7.dtd">

<struts>
    <!--
    You could also set the constants in the struts.properties file
    placed in the same directory as struts.xml
    -->
    <constant name="struts.devMode" value="true" />

    <package name="basicstruts2" extends="struts-default" namespace="/">

        <!--
        If no class attribute is specified the framework will assume success and
        render the result index.jsp
        If no name value for the result node is specified the success value is the default
        -->
        <action name="index">
            <result>/WEB-INF/results/index.jsp</result>
        </action>

        <action name="">
            <result>/WEB-INF/results/index.jsp</result>
        </action>

        <!--
        If the URL is hello.action then call the execute method of class HelloWorldAction.
        If the result returned by the execute method is success render the HelloWorld.jsp
        -->
        <action name="hello" class="com.nabisoft.struts2.demo.action.HelloWorldAction" method="execute">
            <result name="success">/WEB-INF/results/HelloWorld.jsp</result>
            <result name="input">/WEB-INF/results/index.jsp</result>
        </action>

    </package>

</struts>

The struts.properties file is another configuration file where we can set some struts properties. See http://struts.apache.org/2.0.14/docs/strutsproperties.html for more information. I have choosen to place this file at /WEB-INF/classes/.

struts.devMode=true
#struts.locale=en
#we don't want to show extensions
struts.action.extension= ,
struts.configuration.xml.reload=false
struts.i18n.reload=true
struts.custom.i18n.resources=global
struts.enable.DynamicMethodInvocation=false
#struts.enable.SlashesInActionNames=true

The log4j.xml file has to be placed either in your default package or it can be placed into the WEB-INF/classes/ directory. Again I have choosen to put the file together with log4j.dtd into the classes directory.

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE log4j:configuration PUBLIC "-//log4j/log4j Configuration//EN" "log4j.dtd">

<log4j:configuration xmlns:log4j="http://jakarta.apache.org/log4j/">

    <appender name="STDOUT" class="org.apache.log4j.ConsoleAppender" >
       <layout class="org.apache.log4j.PatternLayout" >
          <param name="ConversionPattern" value="%d %-5p %c.%M:%L - %m%n" />
       </layout>
    </appender>

    <!-- specify the logging level for loggers from other libraries -->
    <logger name="com.opensymphony" >
        <level value="DEBUG" />
    </logger>

    <logger name="org.apache.struts2" >
         <level value="DEBUG" />
    </logger>

    <!-- for all other loggers log only debug and above log messages -->
    <root>
       <priority value="INFO" />
       <appender-ref ref="STDOUT" />
    </root>

</log4j:configuration>

Internationalization is an easy job in Struts 2. We will simply create a global.properties file because we have defined it in our struts.properties (see above). global.properties is for the default language, for English we also create global_en.properties and for German global_de.properties files. Since I want English to be the default language global_en.properties will simply be empty. In this case you could also leave the file global_en.properties away but unfortunately I was facing some i18n issues. It seems that depending on the JRE locale struts chooses the corresponding "default"-locale. Offering an empty global_en.properties file solved my issue - it is enough for me as a workaround. All English descriptions will be in global.properties. For this tutorial it is enough to place the properties files into the default package.

submit=submit
your.message-label=Your message
welcome=Welcome to Struts 2!
error.enter.message=Please enter a Message!

submit=Absenden
your.message-label=Ihre Nachricht
welcome=Willkomen zu Struts 2!
error.enter.message=Please enter a message!

Next we will create two jsp files in /WEB-INF/results/ which will be our struts result pages we have specified in the struts.xml.

<%@ page language="java" contentType="text/html; charset=ISO-8859-1" pageEncoding="ISO-8859-1"%>
<%@ taglib prefix="s" uri="/struts-tags" %>
<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html>
    <head>
        <title>Basic Struts 2 Project Setup</title>
        <s:head/>
    </head>

    <body>

        <h1><s:text name="welcome" /></h1>

        <p>
            <s:url id="localeEN" namespace="/" action="" >
                <s:param name="request_locale" >en</s:param>
            </s:url>
            <s:url id="localeDE" namespace="/" action="" >
                <s:param name="request_locale" >de</s:param>
            </s:url>
            <s:a href="%{localeEN}" >English</s:a>
            <s:a href="%{localeDE}" >German</s:a>
        </p>

        <s:if test="hasActionErrors()">
        <div id="fieldErrors">
            <s:actionerror/>
        </div>
        </s:if>

        <s:form action="hello" namespace="/" method="post" name="myForm" theme="xhtml">
            <s:textfield name="message" size="40" maxlength="40" required="true" key="your.message-label"/>
            <s:submit key="submit" />
        </s:form>

    </body>

</html>

<%@ page language="java" contentType="text/html; charset=ISO-8859-1"
    pageEncoding="ISO-8859-1"%>
<%@ taglib prefix="s" uri="/struts-tags" %>
<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html>

    <head>
        <title>Hello World!</title>
    </head>

    <body>

        <h2>Thank you for your message on <s:property value="nowDate" /></h2>

        <p>
            Your Message was:<br/><br/>
            <s:property value="message" />
        </p>

    </body>

</html>

Now we have to implement our Action class which we have referenced from within our struts.xml file.

package com.nabisoft.struts2.demo.action;

import com.opensymphony.xwork2.ActionSupport;
import java.util.Date;

public class HelloWorldAction extends ActionSupport {


    private String message;

    private Date nowDate;

    @Override
    public void validate(){
        if (message==null || message.length()==0)
            addActionError(getText("error.enter.message"));
    }

    @Override
    public String execute() throws Exception {
        nowDate = new Date();

        return SUCCESS;
    }

    public String getMessage() {
        return message;
    }

    public void setMessage(String message) {
        this.message = message;
    }

    public Date getNowDate() {
        return nowDate;
    }

}

Please have a look at the two sceenshots above (one for Eclipse and one for Netbeans) to see where exactly all the required files are located. You could also download the preconfigured Eclipse project (configured to run on Tomcat 7) or Netbeans project (configured to run on Glassfish 3.0.1) and import it into your IDE. As you can see both in the screenshots and the preconfigured projects the i18n property files are placed right in the default Java package. The directory WEB-INF/classes/ contains the following files:

• log4j.dtd
• log4j.xml
• struts-2.1.7.dtd (shipped with the struts download)
• struts.properties
• struts.xml

I usually prefer to put *.dtd (here: struts-2.1.7.dtd) files somewhere on the local server and then referencing them there instead of referencing a remote server. In our case I have choosen to put the file struts-2.1.7.dtd into WEB-INF/classes/ and to reference it in the file struts.xml via "/WEB-INF/classes/struts-2.1.7.dtd" instead of referencing "http://struts.apache.org/dtds/struts-2.1.7.dtd" (see Step 3 ).

To see the result of your application you need to enter one of the following URLs into a browser of your choice (your URL might be different depending on your project settings):

• Eclipse project: http://localhost:8080/BasicStrust2ProjectEclipse/
• Netbeans project: http://localhost:8080/BasicStrust2Project/

Instead of creating your Eclipse/Netbeans project according to this tutorial you might prefer to download the preconfigured projects I offer. This might save you some time because you can import them into your Netbeans/Eclipse IDE and have a runnung example within only a few minutes (or even seconds). Make sure you have already installed Glassfish 3.0.1 / Tomcat 7. You should also have Glassfish 3.0.1 / Tomcat 7 added to your IDE.

• Download Eclipse project here
• Download Netbeans project here