自定義註解(一)

package com.example.annotation;

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;

/*
 *  CONSTRUCTOR：構造器的聲明
 *  FIELD：域聲明（包括enum實例）
 *	LOCAL_VARIABLE：局部變量聲明
 *	METHOD：方法聲明
 *	PACKAGE：包聲明
 *	PARAMETER：參數聲明
 *	TYPE：類、接口（包括註解類型）或enum聲明
 */
@Target({ElementType.PARAMETER,ElementType.METHOD}) //作用在參數聲明 和方法聲明

@Documented //註解是否包含在javadoc中
/*
 * SOURCE：註解將被編譯器丟棄
 *	CLASS：註解在class文件中可用，但會被VM丟棄
 *	RUNTIME：VM將在運行期間保留註解，因此可以通過反射機制讀取註解的信息
 */
@Retention(RetentionPolicy.RUNTIME)//定義該註解的聲明週期
public @interface ParamLog {
	
	String descrityption() default "";
}

package com.example.annotation;


import java.util.Map;


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.aspectj.lang.annotation.Pointcut;
import org.springframework.stereotype.Component;

import com.example.utile.Utiles;


@Aspect
@Component
public class SysParamLog {
	
	@Pointcut("@annotation(com.example.annotation.ParamLog)")
	public void controllerAspect(){
		System.out.println("I am Point");
	}
	
	@Before("controllerAspect()")
	public void doBefor(JoinPoint point) throws Exception{
		
		Map<String,String> befor = (Map<String, String>) point.getArgs()[0];
		System.out.println(befor);
		
	}
	
	@After("controllerAspect()")
	public void doAfter(){
		
		System.out.println("結束切點");
	}
	
	@SuppressWarnings("unchecked")
	@AfterReturning(pointcut=("controllerAspect()"),returning="rvt")
	public void afterReturn(JoinPoint point,Object rvt) throws Exception{
		
	
		Map<String,Object> befor = (Map<String, Object>) point.getArgs()[0];
		Map<String,Object> after = (Map<String, Object>) rvt;
		
		Utiles.compare(befor, after);
	}
	
	/*@Around("controllerAspect()")
	public void around(ProceedingJoinPoint point) throws Throwable{
		
		
		Object[] args = point.getArgs();
		Object rvt = point.proceed(args);
		Map<String,String> befor = (Map<String, String>) args[0];
		Map<String,String> after = (Map<String, String>) rvt;
		System.out.println("afterReturn"+befor);
		System.out.println("afterReturn"+after);
		Utiles.compare(befor, after);
		
		
	}*/
	
	@AfterThrowing(pointcut="controllerAspect()",throwing="e")
	public void doAfterThrowing(JoinPoint point,Throwable e) throws Exception{
		
		System.out.println("方法出出錯"+e.getStackTrace()[0].getMethodName());
	}
	
	
	
	
	/**
	 * 獲取自定義註解內容
	 * @return
	 * @throws ClassNotFoundException 
	 */
	/*public Map<String,Object> getAnnotationDescription(JoinPoint point) throws ClassNotFoundException{
		Map<String,Object> map = new HashMap<String,Object>();
		String targetName = point.getTarget().getClass().getName();
		String targetMethod = point.getSignature().getName();
		Object[] args = point.getArgs();
		Class targetClass = Class.forName(targetName);
		Method[] methods  = targetClass.getMethods();
		for(Method method:methods){
			if(method.getName().equals(targetMethod)){
				Class[] clazzs = method.getParameterTypes();
				if(clazzs.length==args.length){
					map.put("desctription", method.getAnnotation(ParamLog.class).descrityption());
					break;
				}
			}
		}
		return map;
	}*/
}