使用 Spring AOP 注意事項
說實話,由於我個人某些基礎不是很牢固,所以前一段時間關於 Spring Aop 踩了一個坑,其實很簡單,今天就記錄一下,先說結論:
不能被 Spring AOP 增強的方法:
1. 基於介面的動態代理:除 public 外的其它所有的方法,此外 public static 也不能被增強
2. 基於 CGLib 的動態代理:private、static、final 的方法,也就是隻有 public 和 protected 可以,但是要注意切入點語法的配置
測試用例如下,pom 檔案:
<dependency> <groupId>org.slf4j</groupId> <artifactId>slf4j-log4j12</artifactId> <version>1.7.7</version> </dependency> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-context</artifactId> <version>4.3.11.RELEASE</version> <scope>test</scope> </dependency> <dependency> <groupId>org.aspectj</groupId> <artifactId>aspectjweaver</artifactId> <version>1.8.10</version> </dependency> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-context</artifactId> <version>4.3.11.RELEASE</version> </dependency>
配置檔案就比較簡單了:
<?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-2.5.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-2.5.xsd http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-2.5.xsd"> <context:annotation-config/> <context:component-scan base-package="cn.bridgeli"/> <aop:aspectj-autoproxy/> </beans>
切面類:
package cn.bridgeli.demo.aop; import org.aspectj.lang.ProceedingJoinPoint; import org.aspectj.lang.annotation.Around; import org.aspectj.lang.annotation.Aspect; import org.aspectj.lang.annotation.Before; import org.aspectj.lang.annotation.Pointcut; import org.springframework.stereotype.Component; @Aspect @Component public class LogInterceptor { //@Pointcut("execution(* * com.bjsxt.service..*.add(..))") @Pointcut("execution(* cn.bridgeli.demo.service..*.*(..))") public void myMethod() { } @Before("myMethod()") public void before() { System.out.println("method before"); } @Around("myMethod()") public void aroundMethod(ProceedingJoinPoint pjp) throws Throwable { System.out.println("method around start"); pjp.proceed(); System.out.println("method around end"); } }
測試類:
package cn.bridgeli.demo.service; import org.springframework.context.support.ClassPathXmlApplicationContext; import org.springframework.stereotype.Service; @Service("userService") public class UserService { /** * private方法因為修飾符訪問許可權的控制,無法被子類覆蓋 */ private void method1() { System.out.println("method1 executed"); } /** * final 方法無法被子類覆蓋 */ private final void method2() { System.out.println("method2 executed"); } /** * static 方法是類級別的方法,無法被子類覆蓋 */ private static void method3() { System.out.println("method3 executed"); } /** * public 方法可以被子類覆蓋,因此可以被動態位元組碼增強 */ public void method4() { System.out.println("method4 executed"); } /** * final 方法無法被子類覆蓋 */ public final void method5() { System.out.println("method5 executed"); } /** * protected 方法可以被子類覆蓋,因此可以被動態位元組碼增強 */ protected void method6() { System.out.println("method6 executed"); } /** * 測試 * * @param args */ public static void main(String[] args) { ClassPathXmlApplicationContext ctx = new ClassPathXmlApplicationContext("beans.xml"); UserService userService = (UserService) ctx.getBean("userService"); System.out.println("initContext successfully"); System.out.println("before method1"); userService.method1(); System.out.println("after1 method1"); System.out.println("before method2"); userService.method2(); System.out.println("after1 method2"); System.out.println("before method3"); method3(); System.out.println("after1 method3"); System.out.println("before method4"); userService.method4(); System.out.println("after1 method4"); System.out.println("before method5"); userService.method5(); System.out.println("after1 method5"); System.out.println("before method6"); userService.method6(); System.out.println("after1 method6"); if (ctx != null) { ctx.close(); } System.out.println("close context successfully"); } }
參考資料:
1. http://jinnianshilongnian.iteye.com/blog/1857189
2. https://blog.csdn.net/yangshangwei/article/details/78094196
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作 者:ofollow,noindex">BridgeLi,https://www.bridgeli.cn
原文連結:https://www.bridgeli.cn/archives/592
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