@Around是可以同时在所拦截方法的前后执行一段逻辑。
@Before是在所拦截方法执行之前执行一段逻辑。
@After 是在所拦截方法执行之后执行一段逻辑。
注意:不能拦截静态(static)方法
示例:
package com.abc.advice;
import java.util.Arrays;
import org.aspectj.lang.JoinPoint;
import org.aspectj.lang.ProceedingJoinPoint;
import org.aspectj.lang.annotation.After;
import org.aspectj.lang.annotation.AfterReturning;
import org.aspectj.lang.annotation.Around;
import org.aspectj.lang.annotation.Aspect;
import org.aspectj.lang.annotation.Before;
@Aspect
public class AdviceTest {
@Around("execution(* com.abc.service.*.many*(..))")
public Object process(ProceedingJoinPoint point) throws Throwable {
System.out.println("@Around:执行目标方法之前...");
//访问目标方法的参数:
Object[] args = point.getArgs();
if (args != null && args.length > 0 && args[0].getClass() == String.class) {
args[0] = "改变后的参数1";
}
//用改变后的参数执行目标方法
Object returnValue = point.proceed(args);
System.out.println("@Around:执行目标方法之后...");
System.out.println("@Around:被织入的目标对象为:" + point.getTarget());
return "原返回值:" + returnValue + ",这是返回结果的后缀";
}
@Before("execution(* com.abc.service.*.many*(..))")
public void permissionCheck(JoinPoint point) {
System.out.println("@Before:模拟权限检查...");
System.out.println("@Before:目标方法为:" +
point.getSignature().getDeclaringTypeName() +
"." + point.getSignature().getName());
System.out.println("@Before:参数为:" + Arrays.toString(point.getArgs()));
System.out.println("@Before:被织入的目标对象为:" + point.getTarget());
}
@AfterReturning(pointcut="execution(* com.abc.service.*.many*(..))",
returning="returnValue")
public void log(JoinPoint point, Object returnValue) {
System.out.println("@AfterReturning:模拟日志记录功能...");
System.out.println("@AfterReturning:目标方法为:" +
point.getSignature().getDeclaringTypeName() +
"." + point.getSignature().getName());
System.out.println("@AfterReturning:参数为:" +
Arrays.toString(point.getArgs()));
System.out.println("@AfterReturning:返回值为:" + returnValue);
System.out.println("@AfterReturning:被织入的目标对象为:" + point.getTarget());
}
@After("execution(* com.abc.service.*.many*(..))")
public void releaseResource(JoinPoint point) {
System.out.println("@After:模拟释放资源...");
System.out.println("@After:目标方法为:" +
point.getSignature().getDeclaringTypeName() +
"." + point.getSignature().getName());
System.out.println("@After:参数为:" + Arrays.toString(point.getArgs()));
System.out.println("@After:被织入的目标对象为:" + point.getTarget());
}
}
被拦截的方法
//将被AdviceTest的各种方法匹配
public String manyAdvices(String param1, String param2) {
System.out.println("方法:manyAdvices");
return param1 + " 、" + param2;
}
运行方法
String result = manager.manyAdvices("aa", "bb");
System.out.println("Test方法中调用切点方法的返回值:" + result);
结果
@Around:执行目标方法之前...
@Before:模拟权限检查...
@Before:目标方法为:com.abc.service.AdviceManager.manyAdvices
@Before:参数为:[改变后的参数1, bb]
@Before:被织入的目标对象为:com.abc.service.AdviceManager@1dfc617e
方法:manyAdvices
@Around:执行目标方法之后...
@Around:被织入的目标对象为:com.abc.service.AdviceManager@1dfc617e
@After:模拟释放资源...
@After:目标方法为:com.abc.service.AdviceManager.manyAdvices
@After:参数为:[改变后的参数1, bb]
@After:被织入的目标对象为:com.abc.service.AdviceManager@1dfc617e
@AfterReturning:模拟日志记录功能...
@AfterReturning:目标方法为:com.abc.service.AdviceManager.manyAdvices
@AfterReturning:参数为:[改变后的参数1, bb]
@AfterReturning:返回值为:原返回值:改变后的参数1 、 bb,这是返回结果的后缀
@AfterReturning:被织入的目标对象为:com.abc.service.AdviceManager@1dfc617e
Test方法中调用切点方法的返回值:原返回值:改变后的参数1 、bb,这是返回结果的后缀
原文地址:https://my.oschina.net/itblog/blog/211693