surround "throw new Exception()" with try catch

Question

throw new Exception();

If you put this statement in a method, you should either add throws Exception after the method name. Or, you can surround the statement with try-catch.

try {
    throw new Exception();
} catch (Exception e) {
    // TODO Auto-generated catch block
    e.printStackTrace();
}

But what is it the point here? The compiler permit it, so I just want to know if it is designed intentionally. I am curious.

That looks like nonsense to me. You ask, `"But what it is point here?"` -- there is no point to that code. Where did you get it? Did you make it up yourself? Or did you see it in some tutorial? — Hovercraft Full Of Eels, Dec 27 '13 at 03:32
http://stackoverflow.com/questions/6115896/java-checked-vs-unchecked-exception-explanation check this — Sureshkumar Panneerselvan, Dec 27 '13 at 03:33
It looks like a basic Java intro to me. It's telling you that checked exceptions are a compile time error in Java (unless the method declares that it throws the Exception, and it must catch any checked exceptions from methods it calls). — Elliott Frisch, Dec 27 '13 at 03:33
There's no point catching an exception that was just thrown. You `try/catch` functions that *could* `throw` exceptions if they fail. — Trojan, Dec 27 '13 at 03:34
@HovercraftFullOfEels I made it up when I want to see if I can throw a checked Exception through other ways. — bijiDango, Dec 27 '13 at 03:35
What does the code prove though? Nothing. What use is the code? None. — Hovercraft Full Of Eels, Dec 27 '13 at 03:35
@HovercraftFullOfEels The compiler permit it, so I just want to know if it is designed intentionally. — bijiDango, Dec 27 '13 at 03:39
It is valid Java, so it will compile, but it's not good Java. — Hovercraft Full Of Eels, Dec 27 '13 at 03:41

score 3 · Accepted Answer · answered Dec 27 '13 at 03:50

Actually, this is useful in some scenarios.

Say, you want to perform a series of tasks and if any one of them fails, you want to abort the sequence and do some other task.

It is true that you can do the same with a series of if statements, but this provides another way to do it.

try{
// do task 1
// if failed, throw new Exception("Task 1 Failed");

// do task 2
// if failed, throw new Exception("Task 2 Failed");

// do task 3
// if failed, throw new Exception("Task 3 Failed");

...

}catch(Exception e){
 // System.err.println(e.getMessage());
 // do somthing else
}

surround "throw new Exception()" with try catch

1 Answers1