嗯,我试着去理解和解读导致它的原因,但我就是不明白:

在我的代码中有这样的代码:

 try{
 ..
 m.invoke(testObject);
 ..
 } catch(AssertionError e){
 ...
 } catch(Exception e){
 ..
 }

Thing is that, when it tries to invoke some method it throws InvocationTargetException instead of some other expected exception (specifically ArrayIndexOutOfBoundsException). As I actually know what method is invoked I went straight to this method code and added a try-catch block for the line that suppose to throw ArrayIndexOutOfBoundsException and it really threw ArrayIndexOutOfBoundsException as expected. Yet when going up it somehow changes to InvocationTargetException and in the code above catch(Exception e) e is InvocationTargetException and not ArrayIndexOutOfBoundsException as expected.

是什么导致了这样的行为或者我如何检查这样的事情?


当前回答

则抛出异常

InvocationTargetException—如果底层方法抛出异常。

因此,如果用反射API调用的方法抛出异常(例如运行时异常),反射API将把异常包装到InvocationTargetException中。

其他回答

则抛出异常

InvocationTargetException—如果底层方法抛出异常。

因此,如果用反射API调用的方法抛出异常(例如运行时异常),反射API将把异常包装到InvocationTargetException中。

这将打印特定方法中的精确代码行,当调用该方法时,会引发异常:

try {

    // try code
    ..
    m.invoke(testObject);
    ..

} catch (InvocationTargetException e) {

    // Answer:
    e.getCause().printStackTrace();
} catch (Exception e) {

    // generic exception handling
    e.printStackTrace();
}

调用目标异常:

我坚信,任何命名惯例都有勤奋的思想投入 在里面。而且,很有可能我们的问题都有他们的问题 答案就在名字里,如果我们试着找出名字背后的原因。

Let's break the name up into 3 parts. "Exception" has occurred when "Invoking" a "Target" method. And, the exception is thrown with this wrapper when, a method is invoked via reflection in Java. While executing the method, there could be any type of exception raised. It is by design, that the actual cause of the exception is abstracted away, to let the end user know that the exception was one that occurred during a reflection based method access. In order to get the actual cause, it is recommended that the exception is caught and ex.getCause() is called. Best practice is to, in fact throw the cause from the catch block that caught the InvocationTargetException

try{
    method.invoke();
} catch(InvocationTargetException ite) {
    throw ite.getCause();
} catch(Exception e) {
    // handle non-reflection originated exceptions
    throw e;
}

我知道它与其他答案类似,但我想更清楚地说明Java生成这种异常类型的“何时”,因此它对任何人来说都是一个谜。

我这么做之后,错误就消失了 Clean->执行xDoclet->执行xPackaging。

在我的工作空间,在月蚀中。

来自Method.invoke()的Javadoc

如果底层方法抛出异常,则抛出:InvocationTargetException。

如果调用的方法抛出异常,则抛出此异常。