ClassNotFoundException：org.apache.commons.lang.xwork.StringUtils与Struts2 - JSON - JQuery

Question

我有一个使用struts2的maven web项目。它共有4个模块，2个是Web模块。所有工作都很完美。在我的JSP中，我想使用带有JSON值的JQuery ajax。

JQuery的

$(document).on('click', "#test_connection", function(event){ 
    var form = $('#genericDatabaseLoad'); 
    $.getJSON('checkDBConnection', form.serialize(),function(data) { 
     $.each(data.connectionTestStatus,function(key, value){ 
     alert("key "+ key + ", value " + value); 
     }); 
    }); 
}); 

stuts.xml

<package name="json-default-package" extends="struts-default"> 
    <result-types> 
    <result-type name="json" class="org.apache.struts2.json.JSONResult"/> 
    </result-types> 
    <interceptors> 
     <interceptor name="json" class="org.apache.struts2.json.JSONInterceptor"/> 
    </interceptors> 
</package> 

<package extends="struts-default,json-default-package" name="checkDBConnection" namespace="/"> 
      <action class="com.myconnenction.webapp.action.AAIDCADatabaseLoadAction" method="checkDBConnection" name="checkDBConnection"> 
       <result type="json"></result> 
      </action> 
    </package> 

而且JAVA方法在Action类

public String checkDBConnection() 
    { 
     String driver=null; 
     String connectionURL=null; 
     Connection connection = null; 

     connectionTestStatus = new HashMap(); 
     try 
     { 
      if(dbType.equals("mysql")) 
      { 
       driver="com.mysql.jdbc.Driver"; 
       connectionURL="jdbc:mysql://"+hostname+":"+port+"/"+dbname; 
      } 
      Class.forName(driver); 
      connection = DriverManager.getConnection (connectionURL,username,password); 
      connectionTestStatus.put("status", "success"); 
     } 
     catch(Exception e) 
     { 
      connectionTestStatus.put("status", "failure"); 
     } 
     return SUCCESS; 
    } 

当我调试项目，方法是运行并返回SUCCESS，然后向我展示了以下错误

SEVERE: Servlet.service() for servlet default threw exception 
java.lang.ClassNotFoundException: org.apache.commons.lang.xwork.StringUtils 
    at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1714) 
    at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1559) 
    at org.apache.struts2.json.SerializationParams.<init>(SerializationParams.java:57) 
    at org.apache.struts2.json.JSONResult.writeToResponse(JSONResult.java:214) 
    at org.apache.struts2.json.JSONResult.execute(JSONResult.java:204) 
    at com.opensymphony.xwork2.DefaultActionInvocation.executeResult(DefaultActionInvocation.java:367) 
    at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:271) 
    at org.apache.struts2.interceptor.debugging.DebuggingInterceptor.intercept(DebuggingInterceptor.java:256) 
    at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:242) 
    at com.opensymphony.xwork2.interceptor.DefaultWorkflowInterceptor.doIntercept(DefaultWorkflowInterceptor.java:176) 
    at com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:98) 
    at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:242) 
    at com.opensymphony.xwork2.validator.ValidationInterceptor.doIntercept(ValidationInterceptor.java:265) 
    at org.apache.struts2.interceptor.validation.AnnotationValidationInterceptor.doIntercept(AnnotationValidationInterceptor.java:68) 
    at com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:98) 
    at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:242) 
    at com.opensymphony.xwork2.interceptor.ConversionErrorInterceptor.intercept(ConversionErrorInterceptor.java:138) 
    at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:242) 
    at com.opensymphony.xwork2.interceptor.ParametersInterceptor.doIntercept(ParametersInterceptor.java:238) 
    at com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:98) 
    at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:242) 
    at com.opensymphony.xwork2.interceptor.ParametersInterceptor.doIntercept(ParametersInterceptor.java:238) 
    at com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:98) 
    at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:242) 
    at com.opensymphony.xwork2.interceptor.StaticParametersInterceptor.intercept(StaticParametersInterceptor.java:191) 
    at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:242) 
    at org.apache.struts2.interceptor.MultiselectInterceptor.intercept(MultiselectInterceptor.java:75) 
    at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:242) 
    at org.apache.struts2.interceptor.CheckboxInterceptor.intercept(CheckboxInterceptor.java:90) 
    at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:242) 
    at org.apache.struts2.interceptor.FileUploadInterceptor.intercept(FileUploadInterceptor.java:252) 
    at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:242) 
    at com.opensymphony.xwork2.interceptor.ModelDrivenInterceptor.intercept(ModelDrivenInterceptor.java:100) 
    at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:242) 
    at com.opensymphony.xwork2.interceptor.ScopedModelDrivenInterceptor.intercept(ScopedModelDrivenInterceptor.java:141) 
    at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:242) 
    at com.opensymphony.xwork2.interceptor.ChainingInterceptor.intercept(ChainingInterceptor.java:145) 
    at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:242) 
    at com.opensymphony.xwork2.interceptor.PrepareInterceptor.doIntercept(PrepareInterceptor.java:171) 
    at com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:98) 
    at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:242) 
    at com.opensymphony.xwork2.interceptor.I18nInterceptor.intercept(I18nInterceptor.java:176) 
    at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:242) 
    at org.apache.struts2.interceptor.ServletConfigInterceptor.intercept(ServletConfigInterceptor.java:164) 
    at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:242) 
    at com.opensymphony.xwork2.interceptor.AliasInterceptor.intercept(AliasInterceptor.java:193) 
    at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:242) 
    at com.opensymphony.xwork2.interceptor.ExceptionMappingInterceptor.intercept(ExceptionMappingInterceptor.java:187) 
    at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:242) 
    at org.apache.struts2.impl.StrutsActionProxy.execute(StrutsActionProxy.java:54) 
    at org.apache.struts2.dispatcher.Dispatcher.serviceAction(Dispatcher.java:544) 
    at org.apache.struts2.dispatcher.ng.ExecuteOperations.executeAction(ExecuteOperations.java:77) 
    at org.apache.struts2.dispatcher.ng.filter.StrutsExecuteFilter.doFilter(StrutsExecuteFilter.java:88) 
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:243) 
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210) 
    at com.opensymphony.sitemesh.webapp.SiteMeshFilter.obtainContent(SiteMeshFilter.java:129) 
    at com.opensymphony.sitemesh.webapp.SiteMeshFilter.doFilter(SiteMeshFilter.java:77) 
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:243) 
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210) 
    at org.apache.struts2.dispatcher.ng.filter.StrutsPrepareFilter.doFilter(StrutsPrepareFilter.java:82) 
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:243) 
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210) 
    at com.vxl.appanalytix.webapp.filter.RequestAuthentication.doFilter(RequestAuthentication.java:57) 
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:243) 
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210) 
    at org.apache.catalina.core.ApplicationDispatcher.invoke(ApplicationDispatcher.java:749) 
    at org.apache.catalina.core.ApplicationDispatcher.processRequest(ApplicationDispatcher.java:487) 
    at org.apache.catalina.core.ApplicationDispatcher.doForward(ApplicationDispatcher.java:412) 
    at org.apache.catalina.core.ApplicationDispatcher.forward(ApplicationDispatcher.java:339) 
    at org.tuckey.web.filters.urlrewrite.NormalRewrittenUrl.doRewrite(NormalRewrittenUrl.java:195) 
    at org.tuckey.web.filters.urlrewrite.RuleChain.handleRewrite(RuleChain.java:159) 
    at org.tuckey.web.filters.urlrewrite.RuleChain.doRules(RuleChain.java:141) 
    at org.tuckey.web.filters.urlrewrite.UrlRewriter.processRequest(UrlRewriter.java:90) 
    at org.tuckey.web.filters.urlrewrite.UrlRewriteFilter.doFilter(UrlRewriteFilter.java:417) 
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:243) 
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210) 
    at org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:88) 
    at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:76) 
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:243) 
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210) 
    at com.vxl.appanalytix.webapp.filter.RequestAuthentication.doFilter(RequestAuthentication.java:57) 
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:243) 
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210) 
    at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:222) 
    at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:123) 
    at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:472) 
    at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:171) 
    at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:99) 
    at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:936) 
    at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:118) 
    at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:407) 
    at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1004) 
    at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:589) 
    at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:310) 
    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:724) 

当我搜索，大多数的答案是约增加依赖于commons-lang。但我已经在我的pom.xml中添加了。

<dependency> 
    <groupId>commons-lang</groupId> 
    <artifactId>commons-lang</artifactId> 
    <version>${commons.lang.version}</version> 
</dependency> 

在父的pom.xml，我已经加入

<commons.lang.version>2.6</commons.lang.version> 

问题是什么？以及如何解决这个问题？

Answer 1

我发现了这个问题。

我用2.1.8

的Struts2的JSON的-插件版本所以在我父POM我改变Struts2的JSON的-插件版本依赖Struts2的核心版本。

<dependency> 
    <groupId>org.apache.struts</groupId> 
    <artifactId>struts2-json-plugin</artifactId> 
    <version>${struts.version}</version> 
</dependency> 

而且

<struts.version>2.3.7</struts.version> 

现在，它完美的作品。

Answer 2

如果你真的使用公共琅，类应该是org.apache.commons.lang.StringUtils而不是org.apache.commons.lang.xwork.StringUtils

http://commons.apache.org/proper/commons-lang/javadocs/api-2.6/org/apache/commons/lang/StringUtils.html

更新：添加以下依赖项：

<dependency> 
    <groupId>org.apache.struts.xwork</groupId> 
    <artifactId>xwork-core</artifactId> 
    <version>2.3.7</version> 
</dependency> 

Answer 3

在我的情况下，它是支柱，约定插件，它需要被设置为相同版本的支柱：

<dependency> 
      <groupId>org.apache.struts</groupId> 
      <artifactId>struts2-convention-plugin</artifactId> 
      <version>2.3.4.1</version> 
<!-- bugy version <version>2.2.1</version> --> 
     </dependency 

我发现各种意见的补充XWork的-2.1.3.jar除了XWork的的-core-2.3.4.1。但这只会让类加载器感到困惑，因为这两个jar包有类似的竞争。