您是否应该在主方法中捕获所有异常

Question

Is it correct to catch everything into the main? If not, why?

public static void main(String[] args) {

    try {
        // A lot
        // of
        // calls
    } catch (Exception e) {
        e.printStackTrace();
    }           
}   

Answer 1

Generally it's better to separate out the catches IMO, so that you can handle each separately even if you end up handling these the same. It's also easier to see what the risks are, what the catch is, when you come back to your code. Just a quick example:

try {

} catch (URISyntaxException e) {
    e.printStackTrace();
} catch (IOException e) {
    request.abort();
} finally {
    client.close();
}

Answer 2

If all you do is call e.printStacktrace () , I do not think it is worthwhile. The JVM will do something like that anyway. But I believe it is worthwhile if you output a meaningful message; stacktraces are meaningful only to programmers.

Answer 3

它会捕获try{}块中的每个Exception ，如果内部代码中还有另一个catch捕获，则可能不会捕获

Answer 4

It depends. If you only need to show some error messages when an exception arise, I guess it's ok. But if you find the need to make some kind of processing depending on the type of exception, then you'll be better off try-catching in the inner code.

Answer 5

In your case it makes no sense since you do not process the exception you catch but simply print it. If you declare main throws checked_exceptions_your_code_throws_list you will get the same result (JVM will print exception) and a cleaner code. And if your code throws no checked exception then do not declare any exceptions at all.