检查Eclipse调试器中的当前异常？

Question

If a Java application throws an unhandled exception, it causes Eclipse to break at that point. Is there a way to inspect the current exception? Basically, $exception from MSVS?

Answer 1

In think the problem described occurs when making use of Exception breakpoint , in which case you don't have access to the exception variable and can't inspect it in the variables view.

I found a "solution" to this problem in the following post: Breakpoint at exception in Eclipse - how to examine Exception object?

It is:

There is an option in the Eclipse Preferences that allows inspecting of the thrown exception:

Check Java -> Debug -> Open popup when suspended on exception

With this option there will be a popup allowing inspection of the exception.

Strange that this option is not checked by default as it is very useful !

Answer 2

If you want to inspect the Exception object, set up a breakpoint inside the catch block, or set up an Exception breakpoint, and hover over the variable while at the breakpoint.

try {
    ...code...
} catch (Exception e) {
    ...
}

Hover over the e, or open the Eclipse Variables view and add the name of the exception variable.

Hope this helps!

Answer 3

我通常转到'变量'视图并查找保存异常的变量（通常是e），但我认为它取决于发生异常的特定上下文，这不是您要求的Eclipse信息。

Answer 4

In the debug perspective of eclipse find the "Breakpoints" view. Now find the tool bar icon with a little "J" and a "!", the tooltip for it should read "Add Java Exception Breakpoint". When you click this toolbar icon a window opens where you can type in an exception name and find the one you want. Make sure that "Suspend on Uncaught Exceptions" is checked. You may also want to uncheck "Suspend on Caught Exceptions" or you will probably suspend/break way to often on exceptions that are already handled appropriately in your code. Then click "OK".

You will now see your exception type in in the list of breakpoints and you can run your Java application in debug mode. Eclipse will suspend/break on the uncaught exception and you can then debug and look at variables and such. (Remember you can click on the call stack and look at other variables and methods)

In the breakpoints list you can uncheck your exception type to no longer suspend/break on that particular exception. This is convenient so you don't have to remove/add in typical exception types all the time. You can imagine that I have NullPointerException, IllegalArgumentException, ArrayIndexOutOfBoundsException, among others all added to my list and toggle them on/off as needed.