错误信息：
1 org.springframework.webflow.execution.ActionExecutionException: Exception thrown executing [AnnotatedAction@50b13f08 targetAction = [EvaluateAction@1e91236d expression =
authorityCacheAction.authorityCacheByST(flowRequestContext,service), resultExpression = [null]], attributes = map[[empty]]]
in state 'authorityCacheAction' of flow 'login' -- action execution attributes were 'map[[empty]]' 2 at org.springframework.webflow.execution.ActionExecutor.execute(ActionExecutor.java:60) 3 at org.springframework.webflow.engine.ActionState.doEnter(ActionState.java:101) 4 at org.springframework.webflow.engine.State.enter(State.java:194) 5 at org.springframework.webflow.engine.Transition.execute(Transition.java:227) 6 at org.springframework.webflow.engine.impl.FlowExecutionImpl.execute(FlowExecutionImpl.java:393) 7 at org.springframework.webflow.engine.impl.RequestControlContextImpl.execute(RequestControlContextImpl.java:214) 8 at org.springframework.webflow.engine.TransitionableState.handleEvent(TransitionableState.java:119) 9 at org.springframework.webflow.engine.Flow.handleEvent(Flow.java:555) 10 at org.springframework.webflow.engine.impl.FlowExecutionImpl.handleEvent(FlowExecutionImpl.java:388) 11 at org.springframework.webflow.engine.impl.RequestControlContextImpl.handleEvent(RequestControlContextImpl.java:210) 12 at org.springframework.webflow.engine.ActionState.doEnter(ActionState.java:105) 13 at org.springframework.webflow.engine.State.enter(State.java:194) 14 at org.springframework.webflow.engine.Transition.execute(Transition.java:227) 15 at org.springframework.webflow.engine.DecisionState.doEnter(DecisionState.java:51) 16 at org.springframework.webflow.engine.State.enter(State.java:194) 17 at org.springframework.webflow.engine.Transition.execute(Transition.java:227) 18 at org.springframework.webflow.engine.impl.FlowExecutionImpl.execute(FlowExecutionImpl.java:393) 19 at org.springframework.webflow.engine.impl.RequestControlContextImpl.execute(RequestControlContextImpl.java:214) 20 at org.springframework.webflow.engine.TransitionableState.handleEvent(TransitionableState.java:119) 21 at org.springframework.webflow.engine.Flow.handleEvent(Flow.java:555) 22 at org.springframework.webflow.engine.impl.FlowExecutionImpl.handleEvent(FlowExecutionImpl.java:388) 23 at org.springframework.webflow.engine.impl.RequestControlContextImpl.handleEvent(RequestControlContextImpl.java:210) 24 at org.springframework.webflow.engine.ActionState.doEnter(ActionState.java:105) 25 at org.springframework.webflow.engine.State.enter(State.java:194) 26 at org.springframework.webflow.engine.Transition.execute(Transition.java:227) 27 at org.springframework.webflow.engine.impl.FlowExecutionImpl.execute(FlowExecutionImpl.java:393) 28 at org.springframework.webflow.engine.impl.RequestControlContextImpl.execute(RequestControlContextImpl.java:214) 29 at org.springframework.webflow.engine.TransitionableState.handleEvent(TransitionableState.java:119) 30 at org.springframework.webflow.engine.Flow.handleEvent(Flow.java:555) 31 at org.springframework.webflow.engine.impl.FlowExecutionImpl.handleEvent(FlowExecutionImpl.java:388) 32 at org.springframework.webflow.engine.impl.RequestControlContextImpl.handleEvent(RequestControlContextImpl.java:210) 33 at org.springframework.webflow.engine.ActionState.doEnter(ActionState.java:105) 34 at org.springframework.webflow.engine.State.enter(State.java:194) 35 at org.springframework.webflow.engine.Transition.execute(Transition.java:227) 36 at org.springframework.webflow.engine.impl.FlowExecutionImpl.execute(FlowExecutionImpl.java:393) 37 at org.springframework.webflow.engine.impl.RequestControlContextImpl.execute(RequestControlContextImpl.java:214) 38 at org.springframework.webflow.engine.TransitionableState.handleEvent(TransitionableState.java:119) 39 at org.springframework.webflow.engine.Flow.handleEvent(Flow.java:555) 40 at org.springframework.webflow.engine.impl.FlowExecutionImpl.handleEvent(FlowExecutionImpl.java:388) 41 at org.springframework.webflow.engine.impl.RequestControlContextImpl.handleEvent(RequestControlContextImpl.java:210) 42 at org.springframework.webflow.engine.ViewState.handleEvent(ViewState.java:232) 43 at org.springframework.webflow.engine.ViewState.resume(ViewState.java:196) 44 at org.springframework.webflow.engine.Flow.resume(Flow.java:545) 45 at org.springframework.webflow.engine.impl.FlowExecutionImpl.resume(FlowExecutionImpl.java:258) 46 at org.springframework.webflow.executor.FlowExecutorImpl.resumeExecution(FlowExecutorImpl.java:169) 47 at org.springframework.webflow.mvc.servlet.FlowHandlerAdapter.handle(FlowHandlerAdapter.java:183) 48 at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:933) 49 at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:867) 50 at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:953) 51 at org.springframework.web.servlet.FrameworkServlet.doPost(FrameworkServlet.java:855) 52 at javax.servlet.http.HttpServlet.service(HttpServlet.java:648) 53 at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:829) 54 at javax.servlet.http.HttpServlet.service(HttpServlet.java:729) 55 at org.jasig.cas.web.init.SafeDispatcherServlet.service_aroundBody2(SafeDispatcherServlet.java:125) 56 at org.jasig.cas.web.init.SafeDispatcherServlet.service_aroundBody3$advice(SafeDispatcherServlet.java:54) 57 at org.jasig.cas.web.init.SafeDispatcherServlet.service(SafeDispatcherServlet.java:1) 58 at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:292) 59 at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:207) 60 at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52) 61 at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:240) 62 at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:207) 63 at edu.vt.middleware.servlet.filter.RequestDumperFilter.doFilter(RequestDumperFilter.java:86) 64 at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:240) 65 at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:207) 66 at com.github.inspektr.common.web.ClientInfoThreadLocalFilter.doFilter(ClientInfoThreadLocalFilter.java:63) 67 at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:240) 68 at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:207) 69 at edu.vt.middleware.cas.web.filter.GetSessionCookieFilter.doFilter(GetSessionCookieFilter.java:112) 70 at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:240) 71 at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:207) 72 at edu.vt.middleware.servlet.filter.CharacterEncodingFilter.doFilter(CharacterEncodingFilter.java:86) 73 at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:240) 74 at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:207) 75 at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:212) 76 at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:94) 77 at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:616) 78 at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:141) 79 at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:79) 80 at org.apache.catalina.valves.AbstractAccessLogValve.invoke(AbstractAccessLogValve.java:620) 81 at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:88) 82 at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:502) 83 at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1132) 84 at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:684) 85 at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1533) 86 at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.run(NioEndpoint.java:1489) 87 at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142) 88 at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617) 89 at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61) 90 at java.lang.Thread.run(Thread.java:748) 91 Caused by: org.springframework.binding.expression.EvaluationException:
An ELException occurred getting the value for expression 'authorityCacheAction.authorityCacheByST(flowRequestContext,service)' on context [class org.springframework.webflow.engine.impl.RequestControlContextImpl] 92 at org.springframework.binding.expression.spel.SpringELExpression.getValue(SpringELExpression.java:92) 93 at org.springframework.webflow.action.EvaluateAction.doExecute(EvaluateAction.java:75) 94 at org.springframework.webflow.action.AbstractAction.execute(AbstractAction.java:188) 95 at org.springframework.webflow.execution.AnnotatedAction.execute(AnnotatedAction.java:145) 96 at org.springframework.webflow.execution.ActionExecutor.execute(ActionExecutor.java:51) 97 ... 88 more 98 Caused by: org.springframework.expression.spel.SpelEvaluationException: EL1004E:(pos 21): Method call: Method authorityCacheByST(org.springframework.webflow.engine.impl.RequestControlContextImpl,
org.jasig.cas.authentication.principal.SimpleWebApplicationServiceImpl)cannot be found on com.sun.proxy.$Proxy46 type 99 at org.springframework.expression.spel.ast.MethodReference.findAccessorForMethod(MethodReference.java:202) 100 at org.springframework.expression.spel.ast.MethodReference.getValueInternal(MethodReference.java:118) 101 at org.springframework.expression.spel.ast.MethodReference.access$000(MethodReference.java:44) 102 at org.springframework.expression.spel.ast.MethodReference$MethodValueRef.getValue(MethodReference.java:258) 103 at org.springframework.expression.spel.ast.CompoundExpression.getValueInternal(CompoundExpression.java:82) 104 at org.springframework.expression.spel.ast.SpelNodeImpl.getTypedValue(SpelNodeImpl.java:102) 105 at org.springframework.expression.spel.standard.SpelExpression.getValue(SpelExpression.java:98) 106 at org.springframework.binding.expression.spel.SpringELExpression.getValue(SpringELExpression.java:84) 107 ... 92 more
错误信息基本上是红色部分。
场景还原：
1、cas单点登录，想自定义审计注入【@Audit()】，于是在cas登录流程加入了一个自己写的类：
1 public class AuthorityCacheAction { 2 3 private static final Logger logger = LoggerFactory.getLogger(AuthorityCacheAction.class); 4 5 private RedisUtil redisUtil; 6 7 public RedisUtil getRedisUtil() { 8 return redisUtil; 9 } 10 11 public void setRedisUtil(RedisUtil redisUtil) { 12 this.redisUtil = redisUtil; 13 } 14 15 @Audit(action = "MY_AUTHORITY_CACHE_TICKET", actionResolverName = "MY_AUTHORITY_CACHE_TICKET_RESOLVER", resourceResolverName = "MY_AUTHORITY_CACHE_TICKET_RESOURCE_RESOLVER") 16 @Transactional(readOnly = false) 17 public Event authorityCacheByST(RequestContext context, Service service) throws Exception { 18 19 看重点部分：20 21 22 23 MyServiceTicket myServiceTicket = (MyServiceTicket) attributes.get("serviceTicketId"); 24 myServiceTicket.setServiceTicketId(serviceTicketId); 25 26 redisUtil.set(serviceTicketId, attributes.get("groupAuthorities").toString()); 27 return new Event(this, "success"); 28 } 29 30 }
cas登录流程流程代码：
1 <action-state id="authorityCacheAction"> 2 <evaluate expression="authorityCacheAction.authorityCacheByST(flowRequestContext,service)" /> 3 <transition on="success" to ="warn" /> 4 </action-state>
aop切入点声明：
<aop:aspectj-autoproxy/> <bean id="authorityCacheAction" class="com.tyky.cas.web.AuthorityCacheAction" p:redisUtil-ref="redisUtil"/> ...........
差不多就是事故现场了，单点登录到这个流程，就会报以上错误！还有种错误情况情况就是redisUtil 为null，redisUtil 的bean声明在另一个xml文件中，一直以为是xml加载顺序的原因，尝试将两个bean的声明写在同一个xml中，redisUtil不为空了，但是我的审计@Audit（）方法不起作用，于是在想为什么不能注入，已经声明了
<aop:aspectj-autoproxy/>
并将class在里面声明了。
后来各种在网上尝试找方法，看到了一句 "原来Sprig AOP默认情况下创建的代理是基于接口的，所以类的属性是不能通过代理来访问的，这就是为什么前面报这样的错了!",尝试将该类添加一个接口，于是心愿了了。
1 public class AuthorityCacheAction implements IAuthorityCacheAction { 2 ....... 3 4 }
接口：
1 public interface IAuthorityCacheAction { 2 public Event authorityCacheByST(RequestContext context,Service service) throws Exception; 3 4 }
参考资料中是用另外一种方式解决的。
动态代理：
内容是摘抄的，不知最初的原作者，见谅
Java 动态代理。具体有如下四步骤：
- 通过实现 InvocationHandler 接口创建自己的调用处理器；
- 通过为 Proxy 类指定 ClassLoader 对象和一组 interface 来创建动态代理类；
- 通过反射机制获得动态代理类的构造函数，其唯一参数类型是调用处理器接口类型；
- 通过构造函数创建动态代理类实例，构造时调用处理器对象作为参数被传入。
GCLIB代理
cglib（Code Generation Library）是一个强大的,高性能,高质量的Code生成类库。它可以在运行期扩展Java类与实现Java接口。
cglib封装了asm，可以在运行期动态生成新的class。
cglib用于AOP，jdk中的proxy必须基于接口，cglib却没有这个限制。
原理区别：
java动态代理是利用反射机制生成一个实现代理接口的匿名类，在调用具体方法前调用InvokeHandler来处理。而cglib动态代理是利用asm开源包，对代理对象类的class文件加载进来，通过修改其字节码生成子类来处理。
1、如果目标对象实现了接口，默认情况下会采用JDK的动态代理实现AOP
2、如果目标对象实现了接口，可以强制使用CGLIB实现AOP
3、如果目标对象没有实现了接口，必须采用CGLIB库，spring会自动在JDK动态代理和CGLIB之间转换
如何强制使用CGLIB实现AOP？
* 添加CGLIB库，SPRING_HOME/cglib/*.jar
* 在spring配置文件中加入<aop:aspectj-autoproxy proxy-target-class="true"/>
JDK动态代理和CGLIB字节码生成的区别？
* JDK动态代理只能对实现了接口的类生成代理，而不能针对类
* CGLIB是针对类实现代理，主要是对指定的类生成一个子类，覆盖其中的方法
因为是继承，所以该类或方法最好不要声明成final。
曾尝试过使用<aop:aspectj-autoproxy proxy-target-class="true"/> ，可能因为含有这个aop声明的xml文件包含其他bean的声明导致出错，我就是用了接口的方式。
reference: http://blog.csdn.net/gxlstone/article/details/12955063