Struts的Action中不能调用两次

我会带着你远行 2022-05-31 00:46 172阅读 0赞

QuartzAction.doRunJob方法会启动一段任务运行，并等到任务运行结束才返回。如果这个任务运行需要的时间比较长，再次调用这个doRunJob会发现不起作用。

首先看看调用堆栈：

at com.nebula.commons.actions.backoffice.QuartzsAction.doRunJob(QuartzsAction.java:482)
    	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
    	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    	at java.lang.reflect.Method.invoke(Method.java:606)
    	at ognl.OgnlRuntime.invokeMethod(OgnlRuntime.java:871)
    	at ognl.OgnlRuntime.callAppropriateMethod(OgnlRuntime.java:1294)
    	at ognl.ObjectMethodAccessor.callMethod(ObjectMethodAccessor.java:68)
    	at com.opensymphony.xwork2.ognl.accessor.XWorkMethodAccessor.callMethodWithDebugInfo(XWorkMethodAccessor.java:117)
    	at com.opensymphony.xwork2.ognl.accessor.XWorkMethodAccessor.callMethod(XWorkMethodAccessor.java:108)
    	at ognl.OgnlRuntime.callMethod(OgnlRuntime.java:1370)
    	at ognl.ASTMethod.getValueBody(ASTMethod.java:90)
    	at ognl.SimpleNode.evaluateGetValueBody(SimpleNode.java:212)
    	at ognl.SimpleNode.getValue(SimpleNode.java:258)
    	at ognl.Ognl.getValue(Ognl.java:494)
    	at ognl.Ognl.getValue(Ognl.java:458)
    	at com.opensymphony.xwork2.ognl.OgnlUtil$2.execute(OgnlUtil.java:315)
    	at com.opensymphony.xwork2.ognl.OgnlUtil.compileAndExecute(OgnlUtil.java:346)
    	at com.opensymphony.xwork2.ognl.OgnlUtil.getValue(OgnlUtil.java:313)
    	at com.opensymphony.xwork2.DefaultActionInvocation.invokeAction(DefaultActionInvocation.java:430)
    	at com.opensymphony.xwork2.DefaultActionInvocation.invokeActionOnly(DefaultActionInvocation.java:290)
    	at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:251)
    	at com.opensymphony.xwork2.interceptor.DefaultWorkflowInterceptor.doIntercept(DefaultWorkflowInterceptor.java:168)
    	at com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:98)
    	at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:245)
    	at com.nebula.commons.web.struts2.JSONInterceptor.intercept(JSONInterceptor.java:193)
    	at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:245)
    	at org.apache.struts2.json.JSONValidationInterceptor.doIntercept(JSONValidationInterceptor.java:118)
    	at com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:98)
    	at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:245)
    	at com.opensymphony.xwork2.validator.ValidationInterceptor.doIntercept(ValidationInterceptor.java:265)
    	at org.apache.struts2.interceptor.validation.AnnotationValidationInterceptor.doIntercept(AnnotationValidationInterceptor.java:76)
    	at com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:98)
    	at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:245)
    	at org.apache.struts2.interceptor.DeprecationInterceptor.intercept(DeprecationInterceptor.java:41)
    	at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:245)
    	at com.opensymphony.xwork2.interceptor.ConversionErrorInterceptor.intercept(ConversionErrorInterceptor.java:138)
    	at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:245)
    	at com.opensymphony.xwork2.interceptor.ParametersInterceptor.doIntercept(ParametersInterceptor.java:229)
    	at com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:98)
    	at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:245)
    	at com.opensymphony.xwork2.interceptor.ParametersInterceptor.doIntercept(ParametersInterceptor.java:229)
    	at com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:98)
    	at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:245)
    	at org.apache.struts2.interceptor.MultiselectInterceptor.intercept(MultiselectInterceptor.java:73)
    	at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:245)
    	at org.apache.struts2.interceptor.DateTextFieldInterceptor.intercept(DateTextFieldInterceptor.java:125)
    	at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:245)
    	at org.apache.struts2.interceptor.CheckboxInterceptor.intercept(CheckboxInterceptor.java:91)
    	at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:245)
    	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:245)
    	at org.apache.struts2.interceptor.ServletConfigInterceptor.intercept(ServletConfigInterceptor.java:164)
    	at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:245)
    	at com.opensymphony.xwork2.interceptor.ExceptionMappingInterceptor.intercept(ExceptionMappingInterceptor.java:189)
    	at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:245)
    	at org.apache.struts2.impl.StrutsActionProxy.execute(StrutsActionProxy.java:54)
    	at org.apache.struts2.dispatcher.Dispatcher.serviceAction(Dispatcher.java:564)
    	at org.apache.struts2.dispatcher.ng.ExecuteOperations.executeAction(ExecuteOperations.java:81)
    	at org.apache.struts2.dispatcher.ng.filter.StrutsPrepareAndExecuteFilter.doFilter(StrutsPrepareAndExecuteFilter.java:99)
    	at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1212)
    	at com.nebula.commons.interceptor.FormDataFilter.doFilter(FormDataFilter.java:50)
    	at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1212)
    	at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:311)
    	at org.springframework.security.web.access.intercept.FilterSecurityInterceptor.invoke(FilterSecurityInterceptor.java:116)
    	at org.springframework.security.web.access.intercept.FilterSecurityInterceptor.doFilter(FilterSecurityInterceptor.java:83)
    	at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:323)
    	at org.springframework.security.web.access.ExceptionTranslationFilter.doFilter(ExceptionTranslationFilter.java:113)
    	at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:323)
    	at org.springframework.security.web.session.SessionManagementFilter.doFilter(SessionManagementFilter.java:101)
    	at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:323)
    	at org.springframework.security.web.authentication.AnonymousAuthenticationFilter.doFilter(AnonymousAuthenticationFilter.java:113)
    	at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:323)
    	at org.springframework.security.web.servletapi.SecurityContextHolderAwareRequestFilter.doFilter(SecurityContextHolderAwareRequestFilter.java:54)
    	at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:323)
    	at org.springframework.security.web.savedrequest.RequestCacheAwareFilter.doFilter(RequestCacheAwareFilter.java:45)
    	at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:323)
    	at org.springframework.security.web.authentication.www.BasicAuthenticationFilter.doFilter(BasicAuthenticationFilter.java:150)
    	at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:323)
    	at org.springframework.security.web.authentication.ui.DefaultLoginPageGeneratingFilter.doFilter(DefaultLoginPageGeneratingFilter.java:91)
    	at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:323)
    	at org.springframework.security.web.authentication.AbstractAuthenticationProcessingFilter.doFilter(AbstractAuthenticationProcessingFilter.java:182)
    	at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:323)
    	at org.springframework.security.web.authentication.AbstractAuthenticationProcessingFilter.doFilter(AbstractAuthenticationProcessingFilter.java:182)
    	at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:323)
    	at org.springframework.security.web.authentication.logout.LogoutFilter.doFilter(LogoutFilter.java:105)
    	at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:323)
    	at org.springframework.security.web.context.SecurityContextPersistenceFilter.doFilter(SecurityContextPersistenceFilter.java:87)
    	at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:323)
    	at org.springframework.security.web.FilterChainProxy.doFilter(FilterChainProxy.java:173)
    	at org.springframework.web.filter.DelegatingFilterProxy.invokeDelegate(DelegatingFilterProxy.java:346)
    	at org.springframework.web.filter.DelegatingFilterProxy.doFilter(DelegatingFilterProxy.java:259)
    	at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1212)
    	at org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:88)
    	at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:76)
    	at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1212)
    	at org.mortbay.jetty.servlet.ServletHandler.handle(ServletHandler.java:399)
    	at org.mortbay.jetty.security.SecurityHandler.handle(SecurityHandler.java:216)
    	at org.mortbay.jetty.servlet.SessionHandler.handle(SessionHandler.java:182)
    	at org.mortbay.jetty.handler.ContextHandler.handle(ContextHandler.java:766)
    	at org.mortbay.jetty.webapp.WebAppContext.handle(WebAppContext.java:450)
    	at org.mortbay.jetty.handler.HandlerWrapper.handle(HandlerWrapper.java:152)
    	at org.mortbay.jetty.Server.handle(Server.java:322)
    	at org.mortbay.jetty.HttpConnection.handleRequest(HttpConnection.java:542)
    	at org.mortbay.jetty.HttpConnection$RequestHandler.content(HttpConnection.java:945)
    	at org.mortbay.jetty.HttpParser.parseNext(HttpParser.java:756)
    	at org.mortbay.jetty.HttpParser.parseAvailable(HttpParser.java:218)
    	at org.mortbay.jetty.HttpConnection.handle(HttpConnection.java:404)
    	at org.mortbay.jetty.bio.SocketConnector$Connection.run(SocketConnector.java:228)
    	at org.mortbay.thread.BoundedThreadPool$PoolThread.run(BoundedThreadPool.java:451)

然后沿着堆栈打断点，最后看到ognl.OgnlRuntime.invokeMethod方法中：

public static Object invokeMethod(Object target, Method method, Object[] argsArray)
                throws InvocationTargetException, IllegalAccessException
        {
            ...
    
            if (syncInvoke)
            {
                synchronized(method)
                {
                    ...
                    result = method.invoke(target, argsArray);
    								...
                }
            } else
            {
               ...

至此原因就清楚了，原来Struts调用Action的一个方法时，对这个方法进行了synchronize，这样这个方法的一次调用结束以后，才能发起下一次调用。这样就可以理解我们上面发现的问题了。原因知道了，解决方法也就出来了：QuartzAction.doRunJob中生成一个线程，在线程中调用实际的任务，这样doRunJob就能快速结束而不影响下一次调用。