如何在Java中的catch块中调用方法？

Question

Requirement: If there are any exceptions, call a method that re verifies data

My implementation:

private void one() {
    try {
        //Valid data
    }catch(Exception e) {
    two();
    }
}

private void two() {
     //Process data with another input
     //On entry,
     one();
}

I realize that my usage is incorrect. How should I be handling this?

Answer 1

You can do it exactly the way you suggest, using recursion. I don't see what the problem is. Personally, using a loop is usually simpler than using recursion. I wouldn't just catch all Exception's however. You are likely to want to handle different exceptions differently.

private void one() {
  while(true) {
    try {
        //Valid data
        break;
    }catch(InvalidArgumentException e) { // or what ever you expect.
        two();
    }
  }
}

private void two() {
     //Process data with another input
     //On entry,
}

or even

private void one() {
  while(true) {
    try {
        //Valid data
        break;
    } catch(InvalidArgumentException e) { // or what ever you expect.
        // Process data with another input
        // On entry,
    }
  }
}

Answer 2

Better way of doing it would be, Check data in a while loop somewhere else before you use data in method one() , While it's not valid keep correcting until it's valid and than give it to one() .

After your comments in question

make your error variable to be an class level and reset it in method two() like this,

private void two() {
     this.error = false;
     //Process data with another input
     //On entry,
     one();
}

Good luck!

Answer 3

The usage you showed in the code is correct - What makes you think this is not correct ?

However, I see that you are recalling the original method in the catch on which I have comments -

1. If it keeps on throwing the exception, it will lead to Stack overflow.
2. You would like to have some preventive / different logic to check unless this is time dependent or the per-conditions changed itself during the calls.
3. You should consider an exit condition in case you stuck into loop.