Spring初学之xml实现AOP前置通知后置通知返回通知异常通知等

Posted 2020-09-10

实现两个整数的加减乘除，在每个方法执行前后打印日志。

ArithmeticCalculator.java:

package spring.aop.impl.xml;

public interface ArithmeticCalculator {
    
    int add(int i,int j);
    int sub(int i,int j);
    int mul(int i,int j);
    int div(int i,int j);
    
}

ArithmeticCalculatorImpl.java：

package spring.aop.impl.xml;


public class ArithmeticCalculatorImpl implements ArithmeticCalculator {

    public int add(int i, int j) {
        int result = i+j;
        return result;
    }

    public int sub(int i, int j) {
        int result = i-j;
        return result;
    }

    public int mul(int i, int j) {
        int result = i*j;
        return result;
    }

    public int div(int i, int j) {
        int result = i/j;
        return result;
    }

}

LoggingAspect.java：

package spring.aop.impl.xml;

import java.util.Arrays;
import java.util.List;

import org.aspectj.lang.JoinPoint;
import org.aspectj.lang.ProceedingJoinPoint;
import org.aspectj.lang.annotation.After;
import org.aspectj.lang.annotation.AfterReturning;
import org.aspectj.lang.annotation.AfterThrowing;
import org.aspectj.lang.annotation.Around;
import org.aspectj.lang.annotation.Aspect;
import org.aspectj.lang.annotation.Before;
import org.aspectj.lang.annotation.Pointcut;
import org.springframework.core.annotation.Order;
import org.springframework.stereotype.Component;

public class LoggingAspect {
    

    public void beforeMethod(JoinPoint joinPoint){
        String methodName=joinPoint.getSignature().getName();
        List<Object> args=Arrays.asList(joinPoint.getArgs());
        System.out.println("The method "+methodName+" begins "+args);
    }
    
    public void afterMethod(JoinPoint joinPoint){
        String methodName=joinPoint.getSignature().getName();
        List<Object> args=Arrays.asList(joinPoint.getArgs());
        System.out.println("The method "+methodName+" ends ");
    }
    

    public void afterReturnMethod(JoinPoint joinPoint,Object result){
        String methodName=joinPoint.getSignature().getName();
        System.out.println("The method "+methodName+" ends with afterReturning "+ result);
    }
    

    public  void afterThrowing(JoinPoint joinPoint,Exception ex){
        String methodName=joinPoint.getSignature().getName();
        System.out.println("The method "+methodName+" occurs exection: "+ ex);
    }
    

    public Object aroundMethod(ProceedingJoinPoint joinPoint){
        
        Object result=null;
        String methodName=joinPoint.getSignature().getName();
        try {
            //前置通知
            System.out.println("---->The method "+methodName+" begins with" +Arrays.asList(joinPoint.getArgs()));
            //执行目标方法
            result=joinPoint.proceed();
            //返回通知
            System.out.println("---->"+result);
        } catch (Throwable e) {
            e.printStackTrace();
            //异常通知
            System.out.println("---->"+e);
        }
        
        //后置通知
        System.out.println("---->The method "+methodName+ "ends");
        return result;
    }
}

ApplicationContext.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:aop="http://www.springframework.org/schema/aop"
    xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd
        http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-4.3.xsd">

    <!-- 配置bean  -->
    <bean id="arithmeticCalculator" class="spring.aop.impl.xml.ArithmeticCalculatorImpl">
    </bean>
    
    <!-- 配置切面的bean -->
    <bean id="loggingAspect" class="spring.aop.impl.xml.LoggingAspect">
    </bean>
    
    <!-- 配置AOP -->
    <aop:config>
        <!-- 配置切点表达式 -->
        <aop:pointcut expression="execution(* spring.aop.impl.xml.ArithmeticCalculator.*(..))" 
        id="pointcut"/>
        
        <!-- 配置切面及通知 -->
        <aop:aspect ref="loggingAspect" order="1">
             <aop:before method="beforeMethod" pointcut-ref="pointcut"/>
             <aop:after method="afterMethod" pointcut-ref="pointcut"/>
             <aop:after-throwing method="afterThrowing" pointcut-ref="pointcut" throwing="ex"/>
        </aop:aspect>
    </aop:config>
    
</beans>

测试：

package spring.aop.impl.xml.test;

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

import spring.aop.impl.xml.ArithmeticCalculator;


public class Main {

    public static void main(String[] args) {

        ApplicationContext ctx=new ClassPathXmlApplicationContext("applicationContext-xml.xml");
        ArithmeticCalculator arithmeticCalculator=(ArithmeticCalculator) ctx.getBean("arithmeticCalculator");
    
        int result=arithmeticCalculator.add(10, 20);
        System.out.println("result:"+result);
        
        result=arithmeticCalculator.div(10, 0);
        System.out.println("result:"+result);
    }

}

输出：

The method add begins [10, 20]
The method add ends
result:30
The method div begins [10, 0]
The method div ends
The method div occurs exection: java.lang.ArithmeticException: / by zero
Exception in thread "main" java.lang.ArithmeticException: / by zero
at spring.aop.impl.xml.ArithmeticCalculatorImpl.div(ArithmeticCalculatorImpl.java:22)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:497)
at org.springframework.aop.support.AopUtils.invokeJoinpointUsingReflection(AopUtils.java:333)
at org.springframework.aop.framework.ReflectiveMethodInvocation.invokeJoinpoint(ReflectiveMethodInvocation.java:190)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:157)
at org.springframework.aop.framework.adapter.MethodBeforeAdviceInterceptor.invoke(MethodBeforeAdviceInterceptor.java:52)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179)
at org.springframework.aop.aspectj.AspectJAfterAdvice.invoke(AspectJAfterAdvice.java:47)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179)
at org.springframework.aop.aspectj.AspectJAfterThrowingAdvice.invoke(AspectJAfterThrowingAdvice.java:62)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179)
at org.springframework.aop.interceptor.ExposeInvocationInterceptor.invoke(ExposeInvocationInterceptor.java:92)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179)
at org.springframework.aop.framework.JdkDynamicAopProxy.invoke(JdkDynamicAopProxy.java:213)
at com.sun.proxy.$Proxy2.div(Unknown Source)
at spring.aop.impl.xml.test.Main.main(Main.java:19)