飞的更高

Why Finally?

A Finally block will be executed after a try block if no exception has been thrown or after a catch if an exception was thrown. This means that a finally block can be used as 'clean up' - a place to close files or connections etc, whether an exception is thrown or not.

If a try block throws an exception and the catch block propagates the exception (throws it again), the finally clause will still execute. If the finally clause executes a return statement, it overides a thrown exception (so the exception will not be thrown; instead the return will occur).

1。finally块在以下情况下执行：

     try块执行完毕且没有抛出异常;

     try块执行，抛出异常，catch块自己处理该异常后；

     try块执行，抛出异常，catch块将该异常向上抛出；（如果fanally块中有返回的声明，那么该异常将不被抛出，相反，将该声明返回）

    注意：无论try块，还是catch块中是否有语句 return； fanally块都会在return到主程序之前，执行。