Question

我可以从AspectJ中带注释 @Before 的方法返回。

@Before
public void simpleAdvice(JoinPoin joinPoint) {
    if (smth == null)
    /* return for method, which annotated */
}

如果我的问题不完整，请详细询问我。

Answer 1

@Aspect
@SuppressAjWarnings({ "adviceDidNotMatch" })
public class TestAspect {
    @Around("execution(@Monitor void *..*.* ())")
    public void aroundMethodWithMonitorAnnotation(ProceedingJoinPoint proceedingJoinPoint) throws Throwable {
        System.err.println("Around - before a()");

        String sessionId = (String) proceedingJoinPoint.getArgs()[0];

        if(sessionId != null){
            proceedingJoinPoint.proceed();
            System.err.println("Around - after a()");
        } else {
            System.err.println("Around - a() not called");
        }
    }

    public static void main(String[] args) {
        new TestAspect().a();
    }

    @Retention(RetentionPolicy.RUNTIME)
    @Target({ ElementType.METHOD })
    public @interface Monitor {
    }

    @Monitor
    public void a() {
        System.err.println("a()");
    }
}

Answer 2

您可以使用@Before，@After，@AfterReturning，@AfterThrowing，@Around来定义方法。但是您的课程可以在@Aspect注册。

您还需要定义pointcut和joinpoints。

对于示例，

@Before(value="execution(* com.pointel.aop.AopTest.beforeAspect(..))")
public void beforeAdvicing(JoinPoint joinPoint){ 

    String name = joinPoint.getSignature().getName();
    System.out.println("Name of the method : "+name);

}

@AfterReturning(value="execution(* com.pointel.aop.AopTest.beforeAspect(..))")
public void beforeAdvicing(JoinPoint joinPoint,Object result){ 

    String name = joinPoint.getSignature().getName();
    System.out.println("Name of the method : "+name);
    System.out.println("Method returned value is : " + result);

}

您的 Java 类将是，

package com.pointel.aop;

public class AopTest {

    public String beforeAspect( ) {
        return "I am a AopTest";
    }
}

就是这样。希望它有所帮助。

AspectJ之前可以从方法返回吗？

2 个答案: