use interceptor to log informations (J2EE 6 利用interceptor 打Log)

 

import javax.interceptor.AroundInvoke; import javax.interceptor.Interceptor; import javax.interceptor.InvocationContext;

 

 

Here is the example :

        1.Define the annotation for interceptor

//@Inheritedto specify that the annotation can //be inherited from superclasses @Inherited @InterceptorBinding @Retention(RetentionPolicy.RUNTIME) @Target({TYPE, METHOD}) public @interface Logged { }

 

2. Define the interceptor

@Logged @Interceptor public class LoggedInterceptor implements Serializable {        private static final long serialVersionUID = 274175956305979479L;          public LoggedInterceptor() {     }       @AroundInvoke     public Object logMethodEntry(InvocationContext invocationContext)             throws Exception {         System.out.println("Entering method: "                 + invocationContext.getMethod().getName() + " in class "                 + invocationContext.getMethod().getDeclaringClass().getName()+"—start”);         Object o = invocationContext.proceed();         System.out.println("Entering method: "                 + invocationContext.getMethod().getName() + " in class "                 + invocationContext.getMethod().getDeclaringClass().getName()+"--end");         return o;     } }     <interceptors>               <class>com.interceptors.LoggedInterceptor</class>         </interceptors>    add this in beans.xml to register the interceptor .

 

3.  Use the inceptor : just put the annotation upon the method you want log something

@Logged        public String redirectUrlTest (){                             return "detail.jsf";        }

 

            here is the output

Entering method: redirectUrlTest in class com.test.render.TestMB--start   15:06:18,372 INFO  [stdout] (http-localhost/127.0.0.1:8080-1) hi you are the best  James ! Gentle   15:06:18,373 INFO  [stdout] (http-localhost/127.0.0.1:8080-1) Entering method: redirectUrlTest in class com.test.render.TestMB--end