Spring AOP实践-优快云博客

在Spring框架中，有一个重要的内容——Aop，即面向切面编程，今天写一下怎么通过注解去实现Aop；
首先呢，我们需要配置pom.xml

<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>

    <groupId>com.yc</groupId>
    <artifactId>spring-aop</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <packaging>jar</packaging>


    <properties>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <junit.version>4.12</junit.version>
        <log4j.version>2.5</log4j.version>
        <spring.version>4.3.2.RELEASE</spring.version>
        <aspectj.version>1.8.9</aspectj.version>
    </properties>

    <dependencies>
        <!-- 单元测试包 -->
        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <version>${junit.version}</version>
        </dependency>

        <!-- 日志包 -->
        <dependency>
            <groupId>org.apache.logging.log4j</groupId>
            <artifactId>log4j-core</artifactId>
            <version>${log4j.version}</version>
        </dependency>

        <dependency>
            <groupId>org.apache.logging.log4j</groupId>
            <artifactId>log4j-slf4j-impl</artifactId>
            <version>2.6.2</version>
        </dependency>

        <!-- 引入spring框架的依赖 -->
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-context</artifactId>
            <version>${spring.version}</version>
            <scope>runtime</scope>
        </dependency>

        <!-- spring-test框架包 -->
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-test</artifactId>
            <version>${spring.version}</version>
            <scope>runtime</scope>
        </dependency>

        <!-- aop框架aspectj的依赖坐标 -->
        <dependency>
            <groupId>org.aspectj</groupId>
            <artifactId>aspectjweaver</artifactId>
            <version>${aspectj.version}</version>
            <scope>runtime</scope>
        </dependency>
    </dependencies>
</project>

然后写一个计算器Calculator类

//这里只写了加法和除法
package com.yc.spring.aop;

public interface Calculator {

    int sum(int num01,int num02);

    int divid(int num01,int num02);
}

接着呢写一个实现类CalculatorImpl

package com.yc.spring.aop.impl;

import org.springframework.stereotype.Component;

import com.yc.spring.aop.Calculator;

@Component("calculator")
public class CalculatorImpl implements Calculator {

    @Override
    public int sum(int num01, int num02) {
        int result = num01 + num02;
        System.out.println(num01 + " + " + num02 + " = " + result);
        return result;
    }

    @Override
    public int divid(int num01, int num02) {
        int result = num01 / num02;
        System.out.println(num01 + " / " + num02 + " = " + result);
        return result;
    }
}

现在到了核心部分，编写一个计算器的日志类CalculatorLogging，即切面类

package com.yc.spring.aop.impl;

import java.util.Arrays;

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

@Component("calculatorlogging")
@Aspect //指定切面
public class CalculatorLogging {

    /**
     * 一个切点不一定对应一个连接点，可能多个(使用通配符"*",.)
     */
    @Pointcut("execution(public * com.yc.spring.aop..*.*(..))") //定义切点的变量
    public void pointCut(){}

    @Before("pointCut()")
    public void beforeMethod(JoinPoint jp){
        String method = jp.getSignature().getName();
        Object[] objs = jp.getArgs();
        System.out.println("开始执行"+method+ ",计算数据是:" + Arrays.toString(objs));
    }

    @AfterReturning(pointcut="pointCut()",returning="result")
    public void afterReturingMethod(JoinPoint jp, Object result){
        String method = jp.getSignature().getName();
        System.out.println("执行"+method + "获得的结果是" + result);
    }

    @AfterThrowing(pointcut="pointCut()",throwing="e")
    public void afterThrowingMethod(JoinPoint jp,Throwable e){
        String method = jp.getSignature().getName();
        System.out.println("执行"+method + "发生"+ e.getMessage());
    }

    @After("pointCut()")
    public void afterMethod(JoinPoint jp){
        String method = jp.getSignature().getName();
        System.out.println("执行"+method + "完成...");
    }
}

最后bean.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:util="http://www.springframework.org/schema/util"
    xmlns:aop="http://www.springframework.org/schema/aop" xmlns:tx="http://www.springframework.org/schema/tx"
    xmlns:context="http://www.springframework.org/schema/context"
    xmlns:mvc="http://www.springframework.org/schema/mvc"
    xsi:schemaLocation="http://www.springframework.org/schema/beans
        http://www.springframework.org/schema/beans/spring-beans.xsd
        http://www.springframework.org/schema/util 
        http://www.springframework.org/schema/util/spring-util.xsd
        http://www.springframework.org/schema/aop
        http://www.springframework.org/schema/aop/spring-aop.xsd
        http://www.springframework.org/schema/tx
        http://www.springframework.org/schema/tx/spring-tx.xsd
        http://www.springframework.org/schema/context
        http://www.springframework.org/schema/context/spring-context.xsd
        http://www.springframework.org/schema/mvc
        http://www.springframework.org/schema/mvc/spring-mvc.xsd">

    <!-- bean就由spring容器创建好的对象 -->

    <!-- 指定可以做为spring容器管理的对象的包 -->
    <context:component-scan base-package="com.yc.spring" />

    <aop:aspectj-autoproxy/><!-- 自动切入 -->

</beans>