java - @AfterThrowing 没有按预期工作

Question

我想使用AOP来拦截所有在服务层抛出的运行时异常，并作为领域异常重新抛出。

@Aspect
@Component
public class ExceptionWrapperInterceptor {

    @Pointcut("within(*.service.*)")
    public void onlyServiceClasses() {}

    @AfterThrowing(pointcut = "onlyServiceClasses()", throwing = "ex")
    public void intercept(DataAccessException ex) throws Exception {
        //throw DatabaseException
    }

    @AfterThrowing(pointcut = "onlyServiceClasses()", throwing = "ex")
    public void intercept(RuntimeException ex) throws Exception {
        //throw ServiceException
    }

}

这里的问题是，对于 DataAccessException 的子类，运行时会执行错误的方法。有一个优雅的解决方案吗？

Spring 版本:4.2.4.RELEASE

附言具有大量 instanceof 的单个通用方法(从其他问题中读取)对我来说并不优雅；-)

谢谢弗朗切斯科

Answer 1

如何使用 @Around 建议？您可以在其中简单地使用类型安全的 try-catch，无需使用任何 instanceof 或反射。

这是我使用 AspectJ 而不是 Spring AOP 编译的一些示例代码，因为我不是 Spring 用户。无论如何，切入点应该是相同的。

辅助类:

package de.scrum_master.service;

public class DatabaseException extends RuntimeException {
    public DatabaseException(Throwable arg0) {
        super(arg0);
    }
}

package de.scrum_master.service;

public class ServiceException extends RuntimeException {
    public ServiceException(Throwable arg0) {
        super(arg0);
    }
}

驱动程序应用程序(纯 Java，无需使用 Spring):

package de.scrum_master.service;

import java.util.Random;
import org.springframework.jdbc.datasource.init.ScriptParseException;

public class Application {
    private static final Random RANDOM = new Random();

    public static void main(String[] args) {
        Application application = new Application();
        for (int i = 0; i < 10; i++) {
            try {
                application.doSomething();
            }
            catch (Exception e) {
                System.out.println(e);
            }
        }
    }

    public void doSomething() {
        switch (RANDOM.nextInt(3)) {
            case 1: throw new ScriptParseException("uh-oh", null);
            case 2: throw new IllegalArgumentException("WTF");
            default: System.out.println("doing something");
        }
    }
}

看点:

package de.scrum_master.aspect;

import org.aspectj.lang.ProceedingJoinPoint;
import org.aspectj.lang.annotation.Around;
import org.aspectj.lang.annotation.Aspect;
import org.aspectj.lang.annotation.Pointcut;
import org.springframework.dao.DataAccessException;
import org.springframework.stereotype.Component;
import de.scrum_master.service.DatabaseException;
import de.scrum_master.service.ServiceException;

@Aspect
@Component
public class ExceptionWrapperInterceptor {
    @Pointcut("within(*..service..*) && execution(* *(..))")
    public void onlyServiceClasses() {}

    @Around("onlyServiceClasses()")
    public Object intercept(ProceedingJoinPoint thisJoinPoint) {
        try {
            return thisJoinPoint.proceed();
        }
        catch (DataAccessException dae) {
            throw new DatabaseException(dae);
        }
        catch (RuntimeException re) {
            throw new ServiceException(re);
        }
    }
}

控制台日志:

doing something
de.scrum_master.service.DatabaseException: org.springframework.jdbc.datasource.init.ScriptParseException: Failed to parse SQL script from resource [<unknown>]: uh-oh
doing something
de.scrum_master.service.DatabaseException: org.springframework.jdbc.datasource.init.ScriptParseException: Failed to parse SQL script from resource [<unknown>]: uh-oh
doing something
de.scrum_master.service.ServiceException: java.lang.IllegalArgumentException: WTF
de.scrum_master.service.ServiceException: java.lang.IllegalArgumentException: WTF
de.scrum_master.service.ServiceException: java.lang.IllegalArgumentException: WTF
de.scrum_master.service.ServiceException: java.lang.IllegalArgumentException: WTF
doing something