使用aop需要在网上下载两个jar包:
- aopalliance.jar
- aspectjweaver.jar
为idea添加jar包,快捷键ctrl+shift+alt+s,打开添加jar包的对话框,将刚才下载好的jar添加进去
前置增强实例
编写TimeHandler.java
1 package com.example.spring;
2
3 public class TimeHandler {
4 public void beforTime()
5 {
6 System.out.println("前置增强:CurrentTime = " + System.currentTimeMillis());
7 }
8 }
编写HelloWorld.java
1 package com.example.spring;
2
3 public class HelloWorld {
4 public void printHello(){
5 System.out.println("Hello Aop.");
6 }
7 }
编写配置文件
1 <?xml version="1.0" encoding="UTF-8"?>
2 <beans xmlns="http://www.springframework.org/schema/beans"
3 xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
4 xmlns:aop="http://www.springframework.org/schema/aop"
5 xsi:schemaLocation="http://www.springframework.org/schema/beans
6 http://www.springframework.org/schema/beans/spring-beans-4.2.xsd
7 http://www.springframework.org/schema/aop
8 http://www.springframework.org/schema/aop/spring-aop-4.2.xsd">
9
10 <!-- bean definition & AOP specific configuration -->
11 <!-- 1 配置对象-->
12 <bean id="helloWorld" class="com.example.spring.HelloWorld"/>
13 <bean id="timeHandler" class="com.example.spring.TimeHandler"/>
14
15 <!-- 2 配置aop操作-->
16 <aop:config>
17 <!-- 2.1 配置切入点-->
18 <!-- 设置切入点id为pointcut1 -->
19 <aop:pointcut id="pointcut1" expression="execution(* com.example.spring.HelloWorld.*(..))"/>
20
21 <!-- 2.2 配置切面-->
22 <aop:aspect ref="timeHandler">
23 <!-- 配置前置增强类型 ,method:增强类()里面的方法(beforTime())作为前置-->
24 <!-- pointcut-ref设置为切入点的id:pointcut1 -->
25 <aop:before method="beforTime" pointcut-ref="pointcut1"/>
26 </aop:aspect>
27 </aop:config>
28 </beans>
编写Application.java
1 package com.example.spring;
2
3 import org.springframework.context.support.AbstractApplicationContext;
4 import org.springframework.context.support.ClassPathXmlApplicationContext;
5
6 public class Application {
7 public static void main(String[] args) {
8 //bean配置文件所在位置 D:\\IdeaProjects\\spring\\src\\Beans.xml
9 //使用AbstractApplicationContext容器
10 AbstractApplicationContext context = new ClassPathXmlApplicationContext("file:D:\\IdeaProjects\\spring\\src\\aop.xml");
11 //得到配置创建的对象
12 HelloWorld helloWorld = (HelloWorld)context.getBean("helloWorld");
13 helloWorld.printHello();
14 }
15 }
运行输出
前置增强:CurrentTime = 1510134673408
Hello Aop.
可以看到,打印Hello Aop.之前会先打印当前的时间CurrentTime = 1510132664923。
后置增强实例
修改TimeHandler.java
1 package com.example.spring;
2
3 import org.aspectj.lang.ProceedingJoinPoint;
4
5 public class TimeHandler {
6 public void beforTime()
7 {
8 System.out.println("前置增强:CurrentTime = " + System.currentTimeMillis());
9 }
10
11 public void afterTime()
12 {
13 System.out.println("后置增强:CurrentTime = " + System.currentTimeMillis());
14 }
15 }
修改配置文件aop.xml
1 <?xml version="1.0" encoding="UTF-8"?>
2 <beans xmlns="http://www.springframework.org/schema/beans"
3 xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
4 xmlns:aop="http://www.springframework.org/schema/aop"
5 xsi:schemaLocation="http://www.springframework.org/schema/beans
6 http://www.springframework.org/schema/beans/spring-beans-4.2.xsd
7 http://www.springframework.org/schema/aop
8 http://www.springframework.org/schema/aop/spring-aop-4.2.xsd">
9
10 <!-- bean definition & AOP specific configuration -->
11 <!-- 1 配置对象-->
12 <bean id="helloWorld" class="com.example.spring.HelloWorld"/>
13 <bean id="timeHandler" class="com.example.spring.TimeHandler"/>
14
15 <!-- 2 配置aop操作-->
16 <aop:config>
17 <!-- 2.1 配置切入点-->
18 <!-- 设置切入点id为pointcut1 -->
19 <aop:pointcut id="pointcut1" expression="execution(* com.example.spring.HelloWorld.*(..))"/>
20
21 <!-- 2.2 配置切面-->
22 <aop:aspect ref="timeHandler">
23 <!-- 配置前置增强类型 method:增强类()里面的方法(beforTime())作为前置-->
24 <!-- pointcut-ref设置为切入点的id:pointcut1 -->
25 <!--<aop:before method="beforTime" pointcut-ref="pointcut1"/>-->
26
27 <!-- 配置后置增强类型 method:增强类()里面的方法(afterTime())作为后置-->
28 <!-- pointcut-ref设置为切入点的id:pointcut1 -->
29 <aop:after method="afterTime" pointcut-ref="pointcut1"/>
30 </aop:aspect>
31 </aop:config>
32 </beans>
运行输出
Hello Aop.
后置增强:CurrentTime = 1510134850754
环绕增强实例
修改TimeHandler.java
1 package com.example.spring;
2
3 import org.aspectj.lang.ProceedingJoinPoint;
4
5 public class TimeHandler {
6 public void beforTime()
7 {
8 System.out.println("前置增强:CurrentTime = " + System.currentTimeMillis());
9 }
10
11 public void afterTime()
12 {
13 System.out.println("后置增强:CurrentTime = " + System.currentTimeMillis());
14 }
15
16 public void aroundTime(ProceedingJoinPoint proceedingJoinPoint) throws Throwable {
17 //方法之前
18 System.out.println("环绕增强:CurrentTime = " + System.currentTimeMillis());
19
20 //执行被增强的方法
21 proceedingJoinPoint.proceed();
22
23 //方法之后
24 System.out.println("环绕增强:CurrentTime = " + System.currentTimeMillis());
25 }
26
27 }
修改aop.xml
1 <?xml version="1.0" encoding="UTF-8"?>
2 <beans xmlns="http://www.springframework.org/schema/beans"
3 xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
4 xmlns:aop="http://www.springframework.org/schema/aop"
5 xsi:schemaLocation="http://www.springframework.org/schema/beans
6 http://www.springframework.org/schema/beans/spring-beans-4.2.xsd
7 http://www.springframework.org/schema/aop
8 http://www.springframework.org/schema/aop/spring-aop-4.2.xsd">
9
10 <!-- bean definition & AOP specific configuration -->
11 <!-- 1 配置对象-->
12 <bean id="helloWorld" class="com.example.spring.HelloWorld"/>
13 <bean id="timeHandler" class="com.example.spring.TimeHandler"/>
14
15 <!-- 2 配置aop操作-->
16 <aop:config>
17 <!-- 2.1 配置切入点-->
18 <!-- 设置切入点id为pointcut1 -->
19 <aop:pointcut id="pointcut1" expression="execution(* com.example.spring.HelloWorld.*(..))"/>
20
21 <!-- 2.2 配置切面-->
22 <aop:aspect ref="timeHandler">
23 <!-- 配置前置增强类型 method:增强类()里面的方法(beforTime())作为前置通知-->
24 <!-- pointcut-ref设置为切入点的id:pointcut1 -->
25 <!--<aop:before method="beforTime" pointcut-ref="pointcut1"/>-->
26
27 <!-- 配置后置增强类型 method:增强类()里面的方法(afterTime())作为后置通知-->
28 <!-- pointcut-ref设置为切入点的id:pointcut1 -->
29 <!--<aop:after method="afterTime" pointcut-ref="pointcut1"/>-->
30
31 <!-- 配置环绕增强类型 method:增强类()里面的方法(aroundTime())作为环绕通知-->
32 <!-- pointcut-ref设置为切入点的id:pointcut1 -->
33 <aop:around method="aroundTime" pointcut-ref="pointcut1"/>
34 </aop:aspect>
35 </aop:config>
36 </beans>
运行输出
环绕增强:CurrentTime = 1510135559066
Hello Aop.
环绕增强:CurrentTime = 1510135559074
之后就不用修改源程序,只需通过调整配置文件,就可以调整程序的逻辑。
修改配置文件
1 <?xml version="1.0" encoding="UTF-8"?>
2 <beans xmlns="http://www.springframework.org/schema/beans"
3 xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
4 xmlns:aop="http://www.springframework.org/schema/aop"
5 xsi:schemaLocation="http://www.springframework.org/schema/beans
6 http://www.springframework.org/schema/beans/spring-beans-4.2.xsd
7 http://www.springframework.org/schema/aop
8 http://www.springframework.org/schema/aop/spring-aop-4.2.xsd">
9
10 <!-- bean definition & AOP specific configuration -->
11 <!-- 1 配置对象-->
12 <bean id="helloWorld" class="com.example.spring.HelloWorld"/>
13 <bean id="timeHandler" class="com.example.spring.TimeHandler"/>
14
15 <!-- 2 配置aop操作-->
16 <aop:config>
17 <!-- 2.1 配置切入点-->
18 <!-- 设置切入点id为pointcut1 -->
19 <aop:pointcut id="pointcut1" expression="execution(* com.example.spring.HelloWorld.*(..))"/>
20
21 <!-- 2.2 配置切面-->
22 <aop:aspect ref="timeHandler">
23 <!-- 配置前置增强类型 method:增强类()里面的方法(beforTime())作为前置通知-->
24 <!-- pointcut-ref设置为切入点的id:pointcut1 -->
25 <aop:before method="beforTime" pointcut-ref="pointcut1"/>
26
27 <!-- 配置后置增强类型 method:增强类()里面的方法(afterTime())作为后置通知-->
28 <!-- pointcut-ref设置为切入点的id:pointcut1 -->
29 <aop:after method="afterTime" pointcut-ref="pointcut1"/>
30
31 <!-- 配置环绕增强类型 method:增强类()里面的方法(aroundTime())作为环绕通知-->
32 <!-- pointcut-ref设置为切入点的id:pointcut1 -->
33 <aop:around method="aroundTime" pointcut-ref="pointcut1"/>
34 </aop:aspect>
35 </aop:config>
36 </beans>
运行输出
前置增强:CurrentTime = 1510190036105
环绕增强:CurrentTime = 1510190036105
Hello Aop.
环绕增强:CurrentTime = 1510190036122
后置增强:CurrentTime = 1510190036122