How to propagate an exception in java

Question

I am a C programmer and just learning some java recently because I am developing one android application. Currently I am in a situation. Following is the one.

Answer 1

Just don't catch the exception in the first place, and change your method declaration so that it can propagate them:

public void myMethod() throws ExceptionType1, ExceptionType2 {
    // Some code here which can throw exceptions
}

If you need to take some action and then propagate, you can rethrow it:

public void myMethod() throws ExceptionType1, ExceptionType2 {
    try {
        // Some code here which can throw exceptions
    } catch (ExceptionType1 e) {
        log(e);
        throw e;
    }
}

Here ExceptionType2 isn't caught at all - it'll just propagate up automatically. ExceptionType1 is caught, logged, and then rethrown.

It's not a good idea to have catch blocks which just rethrow an exception - unless there's some subtle reason (e.g. to prevent a more general catch block from handling it) you should normally just remove the catch block instead.