< 1 > 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:p="http://www.springframework.org/schema/p" 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-4.0.xsd http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-4.0.xsd" > <!-- 最简单的注入 p 命名空间 --> <bean id="person" class="spring.beans.Person" p:personName="张三" p:personSex="男" p:personAge="1" ></bean> <!-- 自动生成所有被 @Aspect 标注修饰的类 --> <aop:aspectj-autoproxy></aop:aspectj-autoproxy> <!-- 设置 Spring 容器扫描哪些包下面的 JavaBean, * 代表所有包 --> <context:component-scan base-package="spring.beans"></context:component-scan> </beans>
< 二 > 切面类的定义 ( 前置通知: @Before, 后置通知: @After, 正常返回通知: @AfterReturning, 异常返回通知: @AfterThrowing)
package spring.beans; 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.springframework.stereotype.Component; @Aspect // 声明切面类 @Component // 声明是一个 JavaBean public class MyAop { // ( 方法执行前的方法 ) execution 是切点表达式 @Before("execution (public String spring.beans.User.toString())") public void before() { System.out.println("前置方法"); } // ( 方法执行后的方法 ) 注: 不管正常执行或者抛出异常 @After("execution (public String spring.beans.User.toString())") public void after() { System.out.println("后置处理"); } // ( 方法正确执行后的方法 ) 参数(切点表达式, 返回值变量) @AfterReturning(pointcut="execution (public String spring.beans.User.toString())", returning="result") public void returning(JoinPoint join, String result){ System.out.println("方法名: " + join.getSignature().getName()); System.out.println("结果为: " + result); }
// ( 方法抛出异常时执行的方法 ) 参数(切点表达式, 抛出的异常变量) @AfterThrowing(pointcut="execution (public String spring.beans.User.toString())", throwing="ex") public void throwing(JoinPoint join, Exception ex){ System.out.println(ex.getMessage()); } }
< 3 > 切面类的定义 ( 环绕通知: @Around ) 注: 功能强大但是不常用
package spring.beans; import org.aspectj.lang.ProceedingJoinPoint; import org.aspectj.lang.annotation.Around; import org.aspectj.lang.annotation.Aspect; import org.springframework.stereotype.Component; @Aspect // 声明切面类 @Component // 声明是一个 JavaBean
@Order(0) // 声明切面顺序，越小优先级越高 public class MyAop_02 { // 环绕通知 @Around("execution (public String spring.beans.Person.toString())") public void around(ProceedingJoinPoint join){ try { System.out.println("方法调用之前"); String result = (String) join.proceed(); System.out.println("正常返回结果" + result); } catch (Throwable e) { System.out.println("出现了异常喽"); e.printStackTrace(); } finally { System.out.println("方法调用之后"); } } }