AOP 面向切面编程 入门练习

编写过程

添加依赖

<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/maven-v4_0_0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <parent>
        <groupId>com.urfread</groupId>
        <artifactId>untitled1</artifactId>
        <version>1.0-SNAPSHOT</version>
    </parent>
    <artifactId>LearnAOP</artifactId>
    <name>Archetype - LearnAOP</name>
    <url>http://maven.apache.org</url>
    <dependencies>
        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <version>4.13.2</version>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-context</artifactId>
            <version>6.1.5</version>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-aop</artifactId>
            <version>6.1.5</version>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-aspects</artifactId>
            <version>6.1.5</version>
        </dependency>
    </dependencies>
</project>

Spring配置文件

<?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:context="http://www.springframework.org/schema/context"
       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/context
        http://www.springframework.org/schema/context/spring-context.xsd
        http://www.springframework.org/schema/aop
        http://www.springframework.org/schema/aop/spring-aop.xsd">
<!--    开启组件扫描-->
    <context:component-scan base-package="com.urfread.learnaop"/>
<!--    开启aspectj自动代理,为目标对象生成代理-->
    <aop:aspectj-autoproxy/>
</beans>

接口类和实现类

package com.urfread.learnaop;

public interface Calculator {
    int add(int a, int b);
    int sub(int a, int b);
    int mul(int a, int b);
    int div(int a, int b);
}

package com.urfread.learnaop;

import org.springframework.stereotype.Component;

@Component("calculator")
public class CalculatorImpl implements Calculator{
    @Override
    public int add(int a, int b) {
        int result = a + b;
        System.out.println(a+" + "+b+" = "+result);
        return result;
    }

    @Override
    public int sub(int a, int b) {
        int result = a - b;
        System.out.println(a+" - "+b+" = "+result);
        return result;
    }

    @Override
    public int mul(int a, int b) {
        int result = a * b;
        System.out.println(a+" * "+b+" = "+result);
        return result;
    }

    @Override
    public int div(int a, int b) {
        int result = a / b;
        System.out.println(a+" / "+b+" = "+result);
        return result;
    }
}

切面类

package com.urfread.learnaop;

import org.aspectj.lang.annotation.Aspect;
import org.aspectj.lang.annotation.Before;
import org.springframework.stereotype.Component;


@Aspect//切面类
@Component//ioc容器
public class LogAspect {
    //设置切入点和通知类型
    //切入点表达式：execution(访问修饰符 返回值类型 全类名.方法名(参数列表))

    //设置通知类型
    // 前置 @Before(value="切入点表达式配置切入点")
    @Before("execution(* com.urfread.learnaop.CalculatorImpl.*(..))")
    public void beforeMethod(){
        System.out.println("前置通知");
    }
    // 返回 @AfterReturning
    // 异常 @AfterThrowing
    // 后置 @After
    // 环绕 @Around



}

测试类

import com.urfread.learnaop.Calculator;
import org.junit.Test;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;

public class TestAop {
    @Test
    public void test(){
        ApplicationContext context = new ClassPathXmlApplicationContext("bean.xml");
        Calculator calculator = context.getBean("calculator", Calculator.class);
        calculator.add(1,2);
    }
}