java.lang.ClassNotFoundException：启动SimpleStruts2应用程序时org.apache.struts2.dispatcher.ng.filter.StrutsPrepareAndExecuteFilter

Question

我正在尝试运行一个简单的Struts2应用程序，但它始终会引发以下异常：

java.lang.ClassNotFoundException: org.apache.struts2.dispatcher.ng.filter.StrutsPrepareAndExecuteFilter

我已经按照http://struts.apache.org/development/2.x/docs/create-struts-2-web-
application-using-maven-to-manage-artifacts-and-
to中

的分步教程进行了操作-build-the-
application.html，但我无法使其工作。我还设法找到其他使用maven的Struts2教程，但都失败了。当我尝试运行应用程序时，它将引发相同的异常。

我使用了以下内容：

• Eclipse
• Maven
• Tomcat
• Struts2

根据其他讨论，依赖项jar文件（例如struts2-core）必须放在lib文件夹中，但对我而言，我正在使用Maven，因此所有依赖项都已包含在我的Maven依赖项下的构建路径中。

我什至尝试运行Struts2网站（Basic_Struts_2_Maven_2_3_1_2.zip）中给出的示例项目，但是我仍然没有运气。构建成功，但是在服务器上运行总是失败。

我有什么想念的吗？

这是web.xml：

<?xml version="1.0" encoding="UTF-8"?>
<web-app id="WebApp_ID" version="2.4" xmlns="http://java.sun.com/xml/ns/j2ee" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://java.sun.com/xml/ns/j2ee http://java.sun.com/xml/ns/j2ee/web-app_2_4.xsd">
<display-name>Basic_Struts2_Maven</display-name>
  <welcome-file-list>
    <welcome-file>index.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>

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>manning</groupId>
    <artifactId>Basic_Struts2_Mvn</artifactId>
    <packaging>war</packaging>
    <version>0.0.1-SNAPSHOT</version>
    <name>Basic Struts 2</name>
    <properties>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
    </properties>
    <build>
        <finalName>Basic_Struts2_Mvn</finalName>
        <plugins>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-compiler-plugin</artifactId>
                <version>2.3.2</version>
                <configuration>
                    <source>1.6</source>
                    <target>1.6</target>
                </configuration>
            </plugin>
        </plugins>
    </build>
    <dependencies>
        <dependency>
            <groupId>org.apache.struts</groupId>
            <artifactId>struts2-core</artifactId>
            <version>2.3.1.2</version>
        </dependency>
        <dependency>
            <groupId>log4j</groupId>
            <artifactId>log4j</artifactId>
            <version>1.2.14</version>
        </dependency>
    </dependencies>
</project>

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>
        <constant name="struts.devMode" value="true" />
        <package name="basicstruts2" extends="struts-default">
            <action name="index">
                <result>/index.jsp</result>
            </action>
        </package>
    </struts>

.classpath ：

<?xml version="1.0" encoding="UTF-8"?>
<classpath>
    <classpathentry kind="src" output="target/classes" path="src/main/java"/>
    <classpathentry excluding="**" kind="src" output="target/classes" path="src/main/resources"/>
    <classpathentry kind="src" output="target/test-classes" path="src/test/java"/>
    <classpathentry excluding="**" kind="src" output="target/test-classes" path="src/test/resources"/>
    <classpathentry kind="con" path="org.eclipse.jdt.launching.JRE_CONTAINER/org.eclipse.jdt.internal.debug.ui.launcher.StandardVMType/J2SE-1.5"/>
    <classpathentry kind="con" path="org.maven.ide.eclipse.MAVEN2_CLASSPATH_CONTAINER"/>
    <classpathentry kind="con" path="org.eclipse.jst.j2ee.internal.web.container"/>
    <classpathentry kind="con" path="org.eclipse.jst.j2ee.internal.module.container"/>
    <classpathentry kind="output" path="target/classes"/>
</classpath>

Answer 1

使用以下命令将Maven项目转换为Eclipse动态Web项目：

mvn eclipse:eclipse -Dwtpversion=3.4.2

您可以更改使用的任何WTP版本

.classpath 应该是这样的

<classpath>
  <classpathentry kind="src" path="src/main/java" including="**/*.java"/>
  <classpathentry kind="src" path="src/main/resources" excluding="**/*.java"/>
  <classpathentry kind="output" path="target/classes"/>
  <classpathentry kind="var" path="M2_REPO/asm/asm/3.3/asm-3.3.jar"/>
  <classpathentry kind="var" path="M2_REPO/asm/asm-commons/3.3/asm-commons-3.3.jar"/>
  <classpathentry kind="var" path="M2_REPO/asm/asm-tree/3.3/asm-tree-3.3.jar"/>
  <classpathentry kind="var" path="M2_REPO/commons-fileupload/commons-fileupload/1.2.2/commons-fileupload-1.2.2.jar" />
  <classpathentry kind="var" path="M2_REPO/commons-io/commons-io/2.0.1/commons-io-2.0.1.jar"/>
  <classpathentry kind="var" path="M2_REPO/commons-lang/commons-lang/2.5/commons-lang-2.5.jar"/>
  <classpathentry kind="var" path="M2_REPO/org/freemarker/freemarker/2.3.18/freemarker-2.3.18.jar"/>
  <classpathentry kind="var" path="M2_REPO/javassist/javassist/3.11.0.GA/javassist-3.11.0.GA.jar"/>
  <classpathentry kind="var" path="M2_REPO/junit/junit/3.8.1/junit-3.8.1.jar"/>
  <classpathentry kind="var" path="M2_REPO/ognl/ognl/3.0.4/ognl-3.0.4.jar"/>
  <classpathentry kind="var" path="M2_REPO/org/apache/struts/struts2-core/2.3.1.2/struts2-core-2.3.1.2.jar"/>
  <classpathentry kind="lib" path="C:/Program Files/Java/jdk1.6.0_32/lib/tools.jar"/>
  <classpathentry kind="var" path="M2_REPO/org/apache/struts/xwork/xwork-core/2.3.1.2/xwork-core-2.3.1.2.jar"/>
  <classpathentry kind="con" path="org.eclipse.jdt.launching.JRE_CONTAINER"/>
</classpath>

构建后，WAR文件应部署到%CATALINA_BASE%\webapps。