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Resource not available error using Eclipse Kepler with Struts 2 + Tomcat 7

This is my first app written in Java and my first time using Eclipse Kepler, Tomcat 7, and Struts2, so I'm surprised that I even got this far since all I know is JS and Rails. Anyway, this basic web app literally is just supposed to output the string "Success Page!" when you enter that URL in the IDE while running Tomcat 7.

I viewed the Tomcat success page so I know the runtime server is working. Also, I am getting no red x marks in my IDE. The tutorial told me to add to the URL getTutorial.action of my completed web app in order to render the success.jsp view.

However, I get this error at the URL localhost:8080/Struts2Starter/getTutorial.action:

message /Struts2Starter/getTutorial.action

description The requested resource is not available.

The error log tells me this :

    SEVERE: Dispatcher initialization failed
    Unable to load configuration. - action - file:/Users/jasonrodriguez/Java/apache-tomcat-7.0.47/wtpwebapps/Struts2Starter/WEB-INF/classes/struts.xml:10:76

SEVERE: Dispatcher initialization failed
Unable to load configuration. - action - file:/Users/jasonrodriguez/Java/apache-tomcat-7.0.47/wtpwebapps/Struts2Starter/WEB-INF/classes/struts.xml:10:76
    at com.opensymphony.xwork2.config.ConfigurationManager.getConfiguration(ConfigurationManager.java:70)
    at org.apache.struts2.dispatcher.Dispatcher.init_PreloadConfiguration(Dispatcher.java:446)
    at org.apache.struts2.dispatcher.Dispatcher.init(Dispatcher.java:490)
    at org.apache.struts2.dispatcher.ng.InitOperations.initDispatcher(InitOperations.java:74)
    at org.apache.struts2.dispatcher.ng.filter.StrutsPrepareAndExecuteFilter.init(StrutsPrepareAndExecuteFilter.java:57)
    at org.apache.catalina.core.ApplicationFilterConfig.initFilter(ApplicationFilterConfig.java:281)
    at org.apache.catalina.core.ApplicationFilterConfig.getFilter(ApplicationFilterConfig.java:262)
    at org.apache.catalina.core.ApplicationFilterConfig.<init>(ApplicationFilterConfig.java:107)
    at org.apache.catalina.core.StandardContext.filterStart(StandardContext.java:4775)
    at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:5452)
    at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150)
    at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1559)
    at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1549)
    at java.util.concurrent.FutureTask.run(FutureTask.java:262)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
    at java.lang.Thread.run(Thread.java:744)
Caused by: Action class [org.koushik.javabrains.TutorialAction] not found - action - file:/Users/jasonrodriguez/Java/apache-tomcat-7.0.47/wtpwebapps/Struts2Starter/WEB-INF/classes/struts.xml:10:76
    at com.opensymphony.xwork2.config.providers.XmlConfigurationProvider.verifyAction(XmlConfigurationProvider.java:482)
    at com.opensymphony.xwork2.config.providers.XmlConfigurationProvider.addAction(XmlConfigurationProvider.java:426)
    at com.opensymphony.xwork2.config.providers.XmlConfigurationProvider.addPackage(XmlConfigurationProvider.java:552)
    at com.opensymphony.xwork2.config.providers.XmlConfigurationProvider.loadPackages(XmlConfigurationProvider.java:292)
    at org.apache.struts2.config.StrutsXmlConfigurationProvider.loadPackages(StrutsXmlConfigurationProvider.java:112)
    at com.opensymphony.xwork2.config.impl.DefaultConfiguration.reloadContainer(DefaultConfiguration.java:250)
    at com.opensymphony.xwork2.config.ConfigurationManager.getConfiguration(ConfigurationManager.java:67)
    ... 16 more

SEVERE: Error filterStart

My 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" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd" id="WebApp_ID" version="3.0">
  <display-name>Struts2Starter</display-name>
  <welcome-file-list>
    <welcome-file>index.html</welcome-file>
    <welcome-file>index.htm</welcome-file>
    <welcome-file>index.jsp</welcome-file>
    <welcome-file>default.html</welcome-file>
    <welcome-file>default.htm</welcome-file>
    <welcome-file>default.jsp</welcome-file>
  </welcome-file-list>

<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>

My struts.xml:

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE struts PUBLIC
    "-//Apache Software Foundation//DTD Struts Configuration 2.0//EN"
    "http://struts.apache.org/dtds/struts-2.0.dtd">

<struts>

    <package name="default" extends="struts-default">

        <action name="getTutorial" class="org.koushik.javabrains.TutorialAction">
            <result name="success">/success.jsp</result>
            <result name="failure">/error.jsp</result>
        </action>

    </package>

</struts>

My TutorialAction.java:

package org.koushik.javabrains.action;

public class TutorialAction {

    public String execute() {
        System.out.println("Hello from execute");
        return"success";
    }
}

My success.jsp view:

<%@ page language="java" contentType="text/html; charset=US-ASCII"
    pageEncoding="US-ASCII"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=US-ASCII">
<title>Insert title here</title>
</head>
<body>
    Success Page!
</body>
</html>

I am struggling to troubleshoot this. In Rails I'd throw in a binding.pry but here I am not the slightest clue how to troubleshoot. Best I can tell, perhaps the routing got messed up somewhere.

Solution

  • When struts2 app bootstraps it load the configuration from struts.xml. It parses that document and create config related objects and put them into the internal container. Then used this config objects to instantiate real objects like actions, results, interceptors, etc. It's important to specify classes in the configuration that exist in the application. Eclipse can only compile a Java files and even validate DTD of struts.xml but it will not resolve configuration errors. Struts2 is doing it on bootstrap. As a result you got the error that action class is not resolvable. To fix the error you should provide the class reference that exist on the classpath. 

    <action name="getTutorial" class="org.koushik.javabrains.action.TutorialAction">
    <result>/success.jsp</result>
    <result name="failure">/error.jsp</result>
</action>

    Note, the result name "success" is the default name of the result and could be omitted.