ClassNotFoundException：带有Struts2的org.apache.commons.lang.xwork.StringUtils – JSON – JQuery

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。 一切都很完美。 在我的JSP中，我想使用返回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

和Action类中的JAVA方法

 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; } 

当我调试项目时，该方法正在运行，它返回SUCCESS ，然后显示以下错误

 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.(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) 

当我搜索时，大多数答案都是关于为commons-lang添加依赖commons-lang 。 但是我已经在我的pom.xml中添加了它。

  commons-lang commons-lang ${commons.lang.version}  

在父pom.xml中 ，我添加了

 2.6 

问题是什么？ 以及如何解决这个问题？

Answer 1

如果你真的使用commons-lang，那么该类应该是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：

  org.apache.struts.xwork xwork-core 2.3.7  

Answer 2

我发现了问题。

struts2-json-plugin版本我使用的是2.1.8

所以在我的父pom中，我将struts2-json-plugin依赖的版本更改为struts2-core版本。

  org.apache.struts struts2-json-plugin ${struts.version}  

和

 2.3.7 

现在它完美无缺。

Answer 3

在我的例子中，它是struts-convention插件，需要设置为与struts相同的版本：

  org.apache.struts struts2-convention-plugin 2.3.4.1   

除了xwork-core-2.3.4.1.jar之外，我发现了添加xwork-2.1.3.jar的各种建议，但这只会混淆类加载器，因为这两个jar有一组有竞争力的类。