是否有可能在Java中构造一段代码,使假设的Java .lang. chucknorrisexception无法捕获?
我想到的是使用拦截器或面向方面的编程。
是否有可能在Java中构造一段代码,使假设的Java .lang. chucknorrisexception无法捕获?
我想到的是使用拦截器或面向方面的编程。
当前回答
在finalize中调用System.exit(1),并抛出来自所有其他方法的异常副本,以便程序退出。
其他回答
Two fundamental problems with exception handling in Java are that it uses the type of an exception to indicate whether action should be taken based upon it, and that anything which takes action based upon an exception (i.e. "catch"es it) is presumed to resolve the underlying condition. It would be useful to have a means by which an exception object could decide which handlers should execute, and whether the handlers that have executed so far have cleaned things up enough for the present method to satisfy its exit conditions. While this could be used to make "uncatchable" exceptions, two bigger uses would be to (1) make exceptions which will only be considered handled when they're caught by code that actually knows how to deal with them, and (2) allow for sensible handling of exceptions which occur in a finally block (if a FooException during a finally block during the unwinding of a BarException, both exceptions should propagate up the call stack; both should be catchable, but unwinding should continue until both have been caught). Unfortunately, I don't think there would be any way to make existing exception-handling code work that way without breaking things.
抛出的任何异常都必须扩展Throwable,因此总是可以捕获它。所以答案是否定的。
如果你想让它难以处理,你可以重写方法getCause(), getMessage(), getStackTrace(), toString()抛出另一个java.lang.ChuckNorrisException。
任何代码都可以捕获Throwable。所以不,无论你创建什么异常都会是Throwable的子类并且会被捕获。
你可以把ChuckNorris隐藏起来,也可以把他封装起来,也可以把他吞下去……
try {doChuckAction();} catch(ChuckNorrisException cne){/*做其他事情*/}
在当前线程上模拟一个未捕获的异常是很容易的。这将触发未捕获异常的常规行为,从而在语义上完成工作。然而,它并不一定会停止当前线程的执行,因为实际上并没有抛出异常。
Throwable exception = /* ... */;
Thread currentThread = Thread.currentThread();
Thread.UncaughtExceptionHandler uncaughtExceptionHandler =
currentThread.getUncaughtExceptionHandler();
uncaughtExceptionHandler.uncaughtException(currentThread, exception);
// May be reachable, depending on the uncaught exception handler.
这实际上在(非常罕见的)情况下很有用,例如当需要适当的错误处理时,但该方法从捕获(并丢弃)任何Throwable的框架中调用。