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

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();
}

其他回答

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。

那个InvocationTargetException可能正在封装你的ArrayIndexOutOfBoundsException。在使用反射时,没有预先说明该方法可以抛出什么——因此,与使用抛出异常方法不同,所有异常都被捕获并封装在InvocationTargetException中。

列出Eclipse Navigator模式下的所有jar文件 验证所有jar文件都是二进制模式

我有一个java.lang.reflect.InvocationTargetException错误,来自在我的类的try / catch块内部的外部类中调用记录器对象的语句。

在Eclipse调试器中遍历代码并将鼠标悬停在记录器语句上,我看到记录器对象为空(一些外部常数需要在类的最顶部实例化)。

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();
}