Spring AOP剖析

package com.ssy.www.aspect; import com.ssy.www.anno.ReLoad; import com.ssy.www.entity.User; import com.ssy.www.service.OtherService; import com.ssy.www.service.impl.OtherServiceImpl; import com.ssy.www.util.R; import io.swagger.annotations.ApiModel; import org.aspectj.lang.JoinPoint; import org.aspectj.lang.ProceedingJoinPoint; import org.aspectj.lang.Signature; import org.aspectj.lang.annotation.*; import org.aspectj.lang.reflect.MethodSignature; import org.springframework.stereotype.Component; import java.lang.annotation.Annotation; import java.lang.reflect.Method; /** * @author ssy * @className AopAspect * @description AopAspect * @date 2023-12-13 15:23:52 */ @Component @Aspect//这个类就是切面类 public class AopAspect { /** * execution(* com.ssy.www.controller.UserController.before(..))这个就类似于切点 * 这个表达式代表所有权限下的com.ssy.www.controller.UserController.before方法 * ..表示参数可有可无 * <p/> * 前置通知 */ @Before(value = "execution(* com.ssy.www.controller.UserController.before(..))") public void before(JoinPoint jp){//这个方法就是通知 System.out.println("前置通知开始了······"); Signature signature = jp.getSignature(); String name = signature.getName(); System.out.println(name); } /** * 最终通知 */ @After(value = "execution(* com.ssy.www.controller.UserController.after(..))") public void after(JoinPoint jp){ System.out.println("最终通知开始了······"); Signature signature = jp.getSignature(); String name = signature.getName(); System.out.println(name); } /** * 环绕通知 */ @Around(value = "execution(* com.ssy.www.controller.UserController.around(..))") public Object around(ProceedingJoinPoint pjp) throws Throwable { System.out.println("环绕通知开始了······"); Signature signature = pjp.getSignature(); String name = signature.getName(); System.out.println(name); Object[] args = pjp.getArgs(); User user = null; if(args[0] instanceof User) { user = (User) args[0]; user.setName("李浩"); } Object proceed = pjp.proceed(new Object[]{user == null ? args[0] : user}); if( proceed instanceof R){ R info = (R) proceed; System.out.println(info); user.setName("王八蛋"); info.setData(user); System.out.println("环绕通知结束了······"); return info; }else { System.out.println("环绕通知结束了······"); return proceed; } } /** * 后置通知 */ @AfterReturning(value = "execution(* com.ssy.www.controller.UserController.afterReturning(..))", returning = "info") public Object afterReturning(JoinPoint jp, Object info){ System.out.println("后置通知开始了······"); Signature signature = jp.getSignature(); String name = signature.getName(); System.out.println(name); System.out.println(info); return info; } /** *异常通知 */ @AfterThrowing(value = "execution(* com.ssy.www.controller.UserController.afterThrowing(..))", throwing = "e") public void afterThrowing(JoinPoint jp, Throwable e){ System.out.println("异常通知开始了······"); Signature signature = jp.getSignature(); String name = signature.getName(); System.out.println(name); System.out.println(e.getMessage()); } @Pointcut(value = "execution(* com.ssy.www.controller.UserController.execution())") public void pointcut(){} /** * @Before(value = "execution(* com.ssy.www.controller.UserController.execution())") * 也是和@Before(value = "pointcut()")等价的， * 如果很多通知都用到同一个表达式，那么每次通知都写一大串会很臃肿，所以通过@Pointcut的形式抽取出来 */ @Before(value = "pointcut()") public void log(JoinPoint jp){ Signature signature = jp.getSignature(); System.out.println("方法名为" + signature.getName() + "开始执行了······"); } /** * 表示具体的类 * within(com.ssy.www.controller.DemoController) * 表示这个包下的所有类 * within(com.ssy.www.controller.*) * 表示这个包以及子包下的所有类 * within(com.ssy.www.controller..*) */ @Before(value = "within(com.ssy.www.controller.DemoController)") public void monitor(JoinPoint jp){ System.out.println("within测试开始执行了······"); } /** * this是作用于代理对象，指定Spring采用JDK动态代理时才有区别 * 不指定无论是this(com.ssy.www.service.UserService) * 还是this(com.ssy.www.service.impl.UserServiceImpl) * 控制层无论是UserService还是UserServiceImpl注入都是可以执行这个通知的 */ @Before(value = "this(com.ssy.www.service.UserService)") public void thisExec(JoinPoint jp){ System.out.println("this测试开始执行了······"); System.out.println("this被代理对象：" + jp.getTarget()); } /** * 参数类型匹配：args(String,String,com.ssy.www.entity.User,..) * 这种匹配方式不能在通知中添加相同类型的参数变量 * 反之 * args(username, password, user,..)可以匹配参数， * 名字随便起不影响，然而通知的方法参数必须加上具体的类型和指定的args中变量，否则切点无效 * 如： * public void argsExec(JoinPoint jp, String uasername, String password, User user){ * * } * 但是，args需要配套其他的表达式使用，太过于模糊会出问题 */ @Before(value = "args(String,String,com.ssy.www.entity.User,..) && execution(* com.ssy.www.controller.DemoController.argsOne(..))") public void argsExec(JoinPoint jp){ System.out.println("args测试开始执行了······"); } @Before(value = "bean(demoServiceImpl)") public void beanExec(JoinPoint jp){ System.out.println("bean测试开始执行了······"); } @Before(value = "@within(reLoad)") public void annoWithinExec(JoinPoint jp, ReLoad reLoad){ System.out.println("@within测试开始执行了······"); System.out.println("ReLoad注解的属性value的值：" + reLoad.value()); //第二种获取注解的方式 ReLoad annotation = jp.getTarget().getClass().getAnnotation(ReLoad.class); System.out.println("annotation：" + annotation.value()); } /** * 获取方法上注解的方式：获取到的签名就是方法的签名，强制转换为MethodSignature * 注意是org.aspectj.lang.reflect.MethodSignature这个类 */ @Before(value = "@annotation(com.ssy.www.anno.ReLoad)") public void annotationExpression(JoinPoint jp){ System.out.println("@annotation测试开始执行了······"); Signature signature = jp.getSignature(); MethodSignature methodSignature = (MethodSignature) signature; ReLoad annotation = methodSignature.getMethod().getAnnotation(ReLoad.class); System.out.println("annotation：" + annotation.value()); } @Before(value = "@args(..,io.swagger.annotations.ApiModel) " + "&& args(String,String,com.ssy.www.entity.User)" + "&& @annotation(org.springframework.web.bind.annotation.PostMapping)" + "&& @annotation(io.swagger.annotations.ApiOperation)") public void annoArgsExpression(JoinPo