《Pro Spring》学习笔记之AOP抛出通知

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抛出同志在联结点之后运行(记住Spring所谓的联结点永远是方法调用),我们通过实现ThrowsAdvise接口来时先抛出通知,在实现ThrowsAdvise接口的方法中,有两个重载的afterThrowing方法/

 public void afterThrowing(Exception ex) throws Throwable{
   }
    public void afterThrowing(Method method,Object[] obj,Object target,IllegalArgumentException ex) throws Throwable{
   }

两个方法的调用规则如下:

(1)Spring只会运行一个afterThrowing方法
(2)当抛出Exception,运行第一个方法,抛出IllegalArgumentException ,运行第二个方法(以本文为例)/
(3)当一个参数合两个参数的抛出异常类型相同时,执行4个参数的方法
(4)Spring会选择签名与抛出异常最匹配的一个(同(2)所示)

示例代码:

WorkBean.java

 

package ch6.SimpleAOP.ExceptionAdvise;

public class WorkBean {
  
public void errorProneMethod() throws Exception{
      
throw new Exception();
  }

  
public void otherErrorProneMethod() throws IllegalArgumentException{
      
throw new IllegalArgumentException();
  }

}

 

ExceptionAdvise.java

 

package ch6.SimpleAOP.ExceptionAdvise;

import java.lang.reflect.Method;

import org.springframework.aop.ThrowsAdvice;

public class ExceptionAdvise implements ThrowsAdvice {
   
public void afterThrowing(Exception ex) throws Throwable{
        System.out.println(
"in exception advice");
   }

    
public void afterThrowing(Method method,Object[] obj,Object target,IllegalArgumentException ex) throws Throwable{
         System.out.println(
"in IllegalAccessException advice");
   }

}

 

测试代码:

 

package ch6.SimpleAOP.ExceptionAdvise;

import org.springframework.aop.framework.ProxyFactory;

public class TestExceptionAdvise {

    
/**
     * 
@param args
     
*/

    
public static void main(String[] args) {
        WorkBean workBean
=getWorkBean();
        
        
try {
            workBean.errorProneMethod();
        }
 catch (Exception e) {
            
        }

        
try {
            workBean.otherErrorProneMethod();
        }
 catch (IllegalArgumentException e) {
            
        }

        
    }

    
    
public static WorkBean getWorkBean(){
        WorkBean target
=new WorkBean();
        ProxyFactory pf
=new ProxyFactory();
        
        pf.addAdvice(
new ExceptionAdvise());
        pf.setTarget(target);

        
return (WorkBean)pf.getProxy();
    }


}

 

运行结果:

in exception advice
in IllegalAccessException advice