Spring AOP 拦截指定方法

在Spring AOP中，有3个常用的概念，Advices、Pointcut、Advisor，解释如下，

Advices：表示一个method执行前或执行后的动作。

Pointcut：表示根据method的名字或者正则表达式去拦截一个method。

Advisor：Advice和Pointcut组成的独立的单元，并且能够传给proxy factory 对象。

package testaop;

public class CustomerService {
	 private String name;  
	    private String url;  
	      
	    public void printName(){  
	        System.out.println("Customer  name "+ name);  
	    }  
	      
	    public void printURL() {  
	        System.out.println("Customer website : " + this.url);  
	    }  
	  
	    public void printThrowException() {  
	        throw new IllegalArgumentException();  
	    }  
	  
	      
	    public String getName() {  
	        return name;  
	    }  
	    public void setName(String name) {  
	        this.name = name;  
	    }  
	    public String getUrl() {  
	        return url;  
	    }  
	    public void setUrl(String url) {  
	        this.url = url;  
	    }  
}

接着在创建一个实现了MethodInterceptor的类，必须调用“methodInvocation.proceed();” 继续在原来的方法执行，否则原来的方法将不会执行。

package testaop;

import java.util.Arrays;

import org.aopalliance.intercept.MethodInterceptor;
import org.aopalliance.intercept.MethodInvocation;

public class CustomerInterceptor implements MethodInterceptor {

	@Override
	public Object invoke(MethodInvocation methodInvocation) throws Throwable {
		 System.out.println("Method name : "  
	                + methodInvocation.getMethod().getName());  
	          
	        System.out.println("Method arguments : "  
	                + Arrays.toString(methodInvocation.getArguments()));  
	  
	        // same with MethodBeforeAdvice    相当于  MethodBeforeAdvice
	        System.out.println("CustomerService: Before method CustomerService!");  
	  
	        try {  
	            // proceed to original method call  调用原方法，即调用CustomerService中的方法
	            Object result = methodInvocation.proceed();  
	  
	            // same with AfterReturningAdvice  相当于 AfterReturningAdvice
	            System.out.println("CustomerService : Before after CustomerService!");  
	  
	            return result;  
	  
	        } catch (IllegalArgumentException e) {  
	            // same with ThrowsAdvice  相当于 ThrowsAdvice
	            System.out.println("CustomerService : Throw exception CustomerService!");  
	            throw e;  
	        }  
	}

}

配置spring-aop.xml

<?xml version="1.0" encoding="UTF-8"?>  
<beans  
    xmlns="http://www.springframework.org/schema/beans"  
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"  
    xmlns:p="http://www.springframework.org/schema/p"  
    xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.0.xsd">  
     
     
   <bean id="customerService" class="testaop.CustomerService">  
        <property name="name" value="my name is youshuai" />  
        <property name="url" value="http://www.remote3c.com" />  
    </bean>  
      
  <bean id="customerInterceptor" class="testaop.CustomerInterceptor"/>  
      
      
    <bean id="customerInterceptorProxy" class="org.springframework.aop.framework.ProxyFactoryBean">  
        <property name="target" ref="customerService" />  
        <property name="interceptorNames">  
            <list> 
<!--             	<value>customerInterceptor</value>拦截该类中所有方法 -->
                <value>customerAdvisor</value> <!-- 拦截该类中指定方法 -->
            </list>  
        </property>  
    </bean> 
    
    
    <bean id="customerYiibaicut" class="org.springframework.aop.support.NameMatchMethodPointcut">  
        <property name="mappedName" value="printName" />  
    </bean>  
  
    <bean id="customerAdvisor" class="org.springframework.aop.support.DefaultPointcutAdvisor">  
        <property name="pointcut" ref="customerYiibaicut" />  
        <property name="advice" ref="customerInterceptor" />  
    </bean>  
    
  
</beans>  

最后测试测试程序如下

package test;

import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;

import testaop.CustomerService;

/**
 * 测试类
 * @author Administrator
 *
 */
public class Test {

	public static void main(String[] args) {
		
		 // TODO Auto-generated method stub  
        ApplicationContext context = new ClassPathXmlApplicationContext("spring-aop.xml");  
        CustomerService obj = (CustomerService) context.getBean("customerInterceptorProxy");  
         
        System.out.println("****************");  
        obj.printName();  
        System.out.println("****************");  
        obj.printURL();  
        System.out.println("****************");  
		
		
	}
}

输出结果：

****************
Method name : printName
Method arguments : []
CustomerService: Before method CustomerService!
Customer  name my name is youshuai
CustomerService : Before after CustomerService!
****************
Customer website : http://www.remote3c.com
****************