从头认识Spring-3.1 简单的AOP日志实现-某方法之前的前后记录日志

Posted 2020-06-14 李灵晖

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这一章节我们引入简单的AOP日志实现。

1.domain

蛋糕类：

package com.raylee.my_new_spring.my_new_spring.ch03.topic_1_1;

public class Cake {
	
	private String name = "";

	public String getName() {
		return name;
	}

	public void setName(String name) {
		this.name = name;
	}

}

烤炉类：

package com.raylee.my_new_spring.my_new_spring.ch03.topic_1_1;

public class Oven {
	private String name = "";

	@Override
	public String toString() {
		return name;
	}

	public String getName() {
		return name;
	}

	public void setName(String name) {
		this.name = name;
	}

}

厨师类：

package com.raylee.my_new_spring.my_new_spring.ch03.topic_1_1;

public class Chief {

	private static int index = 0;

	public static int getIndex() {
		return index;
	}

	public static void setIndex(int index) {
		Chief.index = index;
	}

	private Cake cake = null;

	private final int id = index++;

	private String name = "";

	private Oven oven = null;

	public Cake getCake() {
		return cake;
	}

	public int getId() {
		return id;
	}

	public String getName() {
		return name;
	}

	public Oven getOven() {
		return oven;
	}

	public void setCake(Cake cake) {
		this.cake = cake;
	}

	public void setName(String name) {
		this.name = name;
	}

	public void setOven(Oven oven) {
		this.oven = oven;
	}

	public void makeOneCake() {
		System.out.println(getName() + " make " + getCake().getName());
	}

}

上面的几个类我们只是简单的定义了一些属性，只是在厨师类那里加上了一个简单的方法。

日志类：

package com.raylee.my_new_spring.my_new_spring.ch03.topic_1_1;

public class Log {

	public void washOven() {
		System.out.println("washOven,logging.....");
	}

	public void prepare() {
		System.out.println("prepare,logging.....");
	}

	public void after() {
		System.out.println("after someting to do,logging.....");
	}

}

我们定义了三个方法，头两个是调用方法前执行的，后面一个是调用方法后执行的

配置类：（我们这里使用基于java的配置）

package com.raylee.my_new_spring.my_new_spring.ch03.topic_1_1;

import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;

@Configuration
public class SpringBeans {
	@Bean
	public Chief jack() {
		Chief chief = new Chief();
		chief.setName("jack");
		chief.setOven(oven());
		chief.setCake(cake());
		return chief;
	}

	@Bean
	public Oven oven() {
		Oven oven = new Oven();
		oven.setName("big oven");
		return oven;
	}

	@Bean
	public Cake cake() {
		Cake cake = new Cake();
		cake.setName("blueberryCheeseCake");
		return cake;
	}

	@Bean
	public Log log() {
		return new Log();
	}

}

2.测试类：

package com.raylee.my_new_spring.my_new_spring.ch03.topic_1_1;

import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.context.ApplicationContext;
import org.springframework.test.context.ContextConfiguration;
import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;

@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration(locations = {
		"/com/raylee/my_new_spring/my_new_spring/ch03/topic_1_1/ApplicationContext-test.xml" })
public class ChiefTest {

	@Autowired
	private ApplicationContext applicationContext;

	@Test
	public void testChief() {
		Chief jack = (Chief) applicationContext.getBean(Chief.class);
		jack.makeOneCake();
	}
}

3.配置文件（重点）

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
	xmlns:context="http://www.springframework.org/schema/context" xmlns:p="http://www.springframework.org/schema/p"
	xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:tx="http://www.springframework.org/schema/tx"
	xmlns:aop="http://www.springframework.org/schema/aop" xmlns:util="http://www.springframework.org/schema/util"
	xsi:schemaLocation="
        http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.1.xsd
        http://www.springframework.org/schema/util http://www.springframework.org/schema/util/spring-util-2.0.xsd
		http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-3.1.xsd
		http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-3.1.xsd
		http://www.springframework.org/schema/util http://www.springframework.org/schema/util/spring-util-3.1.xsd
		http://www.springframework.org/schema/data/jpa http://www.springframework.org/schema/data/jpa/spring-jpa-1.0.xsd
		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.xsd">

	<context:component-scan
		base-package="com.raylee.my_new_spring.my_new_spring.ch03.topic_1_1" />
	<aop:config>
		<aop:aspect ref="log">
			<aop:pointcut
				expression="(execution(* com.raylee.my_new_spring.my_new_spring.ch03.topic_1_1.Chief.*(..)))"
				id="chiefPointCut" />
			<aop:before method="washOven" pointcut-ref="chiefPointCut" />
			<aop:before method="prepare" pointcut-ref="chiefPointCut" />
			<aop:after method="after" pointcut-ref="chiefPointCut" />
		</aop:aspect>
	</aop:config>

</beans>

解释一下配置文件的东西：

（1）我们使用<aop:config/>标签定义aop

（2）然后定义通过<aop:aspect>切面

（3）再通过<aop:pointcut/>定义切入点

（4）最后通过<aop:before/><aop:after/>等定义切点的前后方法

在这里解释一下expression里面的内容

execution(* com.raylee.my_new_spring.my_new_spring.ch03.topic_1_1.Chief.*(..))

（1）第一颗星表示返回任意类型

（2）com.raylee.my_new_spring.my_new_spring.ch03.topic_1_1代表包名

（3）Chief代表那个类

（4）*(..)代表任意方法，里面的..表示任何参数

（5）当然我们也可以简单点，全是用*这个东西来标注，不过一般不这样做，因为每一个切点对应的应该是不同的方法