AOP注解式拦截
1. 自己定义的拦截注解
package com.spring.aop; import java.lang.annotation.Documented; import java.lang.annotation.ElementType; import java.lang.annotation.Retention; import java.lang.annotation.RetentionPolicy; import java.lang.annotation.Target; @Retention(RetentionPolicy.RUNTIME) @Target({ElementType.ANNOTATION_TYPE,ElementType.METHOD,ElementType.TYPE}) @Documented public @interface MyAction { String value(); }
2. 定义aop切点
package com.spring.aop; import java.lang.reflect.Method; import org.aspectj.lang.JoinPoint; import org.aspectj.lang.annotation.After; import org.aspectj.lang.annotation.Aspect; import org.aspectj.lang.annotation.Before; import org.aspectj.lang.annotation.Pointcut; import org.aspectj.lang.reflect.MethodSignature; import org.springframework.stereotype.Component; @Aspect @Component public class MyAop { //切点切入自己配置的那个注解MyAction @Pointcut("@annotation(com.spring.aop.MyAction)") //注意这里的写法@annotation() 切入注解 public void annotationPointCat(){}
/*
@Pointcut("execution(* com.savage.aop.MessageSender.*(..))") //注意这里的写法execution() 切入类
private void logSender(){}
*/
@Before("annotationPointCat()")//位置为这个包下的所有类、所有方法、不论参数是什么类型 public void before(JoinPoint joinPoint){ MethodSignature signature = (MethodSignature) joinPoint.getSignature(); Method method = signature.getMethod(); MyAction myAction = method.getAnnotation(MyAction.class); System.out.println("before: "+myAction.value()); } @After("annotationPointCat()") public void after(JoinPoint joinPoint){ MethodSignature signature = (MethodSignature) joinPoint.getSignature(); Method method = signature.getMethod(); MyAction myAction = method.getAnnotation(MyAction.class); System.out.println("after: "+myAction.value()); } }
3. 编写服务类,应用切面
package com.spring.aop; import org.springframework.stereotype.Component; @Component public class MyServer {
/*
显而易见,利用注解式拦截,会提高切面的复用率
*/ @MyAction("ser01") public void ser01(){ System.out.println("call ser01"); } @MyAction("ser02") public void ser02(){ System.out.println("call ser02"); } }
4. Spring配置文件(APP.xml)
<context:component-scan base-package="com.spring.aop"></context:component-scan> <!-- 使 AspectJ 的注解起作用 ; autoproxy自动代理--> <aop:aspectj-autoproxy></aop:aspectj-autoproxy>
5. 运行
public static void main(String[] args) { BeanFactory factory = new ClassPathXmlApplicationContext("com/spring/ioc/APP.xml"); MyServer myServer = factory.getBean(MyServer.class); myServer.ser01(); myServer.ser02(); }
依赖jar包
<!-- Spring --> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-context</artifactId> <version>${org.springframework-version}</version> <exclusions> <!-- Exclude Commons Logging in favor of SLF4j --> <exclusion> <groupId>commons-logging</groupId> <artifactId>commons-logging</artifactId> </exclusion> </exclusions> </dependency> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-webmvc</artifactId> <version>${org.springframework-version}</version> </dependency> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-aop</artifactId> <version>${org.springframework-version}</version> </dependency> <!-- AspectJ --> <dependency> <groupId>org.aspectj</groupId> <artifactId>aspectjrt</artifactId> <version>${org.aspectj-version}</version> </dependency> <!-- https://mvnrepository.com/artifact/org.aspectj/aspectjweaver --> <dependency> <groupId>org.aspectj</groupId> <artifactId>aspectjweaver</artifactId> <version>${org.aspectj-version}</version> </dependency>
异常:
Caused by: java.lang.NoClassDefFoundError: org/aspectj/weaver/reflect/ReflectionWorld$ReflectionWorldException
是因为缺少 aspectjweaver 包
本文来自博客园,作者:wzyy,转载请注明原文链接:https://www.cnblogs.com/wwzyy/p/6308734.html