package cn.z201.io.annotation.aop;

import java.lang.annotation.ElementType;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;

/**
 * @author z201.coding@gmail.com
 **/
@Target(ElementType.METHOD)
@Retention(RetentionPolicy.RUNTIME)
public @interface AnnotationAop {

    String value();

}

package cn.z201.io.annotation.aop;

import org.aspectj.lang.JoinPoint;
import org.aspectj.lang.annotation.*;
import org.aspectj.lang.reflect.MethodSignature;
import org.springframework.stereotype.Component;

import java.lang.reflect.Method;

/**
 * @author z201.coding@gmail.com
 **/
@Component
@Aspect
public class LogsAspect {

    @Pointcut("@annotation(cn.z201.io.annotation.aop.AnnotationAop)")
    private void cutMethod() {

    }

    /**
     * 异常通知：目标方法抛出异常时执行
     */
    @AfterThrowing("cutMethod()")
    public void afterThrowing(JoinPoint joinPoint) {
        System.out.println("  after throwing");
    }

    /**
     * 环绕通知：灵活自由的在目标方法中切入代码
     */
    @Before("cutMethod()")
    public void around(JoinPoint joinPoint) throws Throwable {
        // 获取目标方法的名称
        String methodName = joinPoint.getSignature().getName();
        // 获取方法传入参数
        Object[] params = joinPoint.getArgs();
        if (null != params && params.length != 0) {
            System.out.println(" method name " + methodName + " args " + params[0]);
        }
        // 执行源方法
        AnnotationAop annotationAop = getDeclaredAnnotation(joinPoint);
        System.out.println("  annotationAop  value " + annotationAop.value());
    }

    /**
     * 获取方法中声明的注解
     *
     * @param joinPoint
     * @return
     * @throws NoSuchMethodException
     */
    public AnnotationAop getDeclaredAnnotation(JoinPoint joinPoint) throws NoSuchMethodException {
        // 获取方法名
        String methodName = joinPoint.getSignature().getName();
        // 反射获取目标类
        Class<?> targetClass = joinPoint.getTarget().getClass();
        // 拿到方法对应的参数类型
        Class<?>[] parameterTypes = ((MethodSignature) joinPoint.getSignature()).getParameterTypes();
        // 根据类、方法、参数类型（重载）获取到方法的具体信息
        Method objMethod = targetClass.getMethod(methodName, parameterTypes);
        // 拿到方法定义的注解信息
        AnnotationAop annotation = objMethod.getDeclaredAnnotation(AnnotationAop.class);
        // 返回
        return annotation;
    }

}


package cn.z201.io.annotation.aop;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.context.annotation.EnableAspectJAutoProxy;

/**
 * @author z201.coding@gmail.com
 **/
@SpringBootApplication
@EnableAspectJAutoProxy
public class AnnotationApp {

    public static void main(String[] args) {
        SpringApplication.run(AnnotationApp.class, args);
    }

}


package cn.z201.io.annotation.aop;

import org.springframework.web.bind.annotation.*;
import org.springframework.web.servlet.ModelAndView;

/**
 * @author z201.coding@gmail.com
 **/
@RestController
@RequestMapping
public class HelloController {

    @GetMapping("")
    @AnnotationAop("Aop")
    public Object index() {
        ModelAndView modelAndView = new ModelAndView();
        modelAndView.addObject("value", "hello annotationApp  ");
        return modelAndView.getModelMap();
    }
}