如何测试一种方法是否有效？

Question

Using the code below, I need to test whether or not the method has been successful in working, and then print "false" if the method has not been successful.

private void doShowBorrower()
    {
        boolean found = false;
        System.out.println("Enter Library Number to Search: ");
        String borrowerLibraryNumber = myScanner.next();
        borrowerList.getBorrower(borrowerLibraryNumber);
    }

I was thinking about using a boolean 'found' which I can set to be true if the method worked properly, and then if it's still false then to print "false".

However, I'm not sure how to implement this. I'm assuming you need to use loops, but I'm not sure how to do it.

Anyone got an idea?

Answer 1

Answer to your question depends on what borrowerList.getBorrower(borrowerLibraryNumber) returns.

• If borrowerList.getBorrower(borrowerLibraryNumber) call returns an object, you can check for Null and if the returned object is null, then you can set the flag to true
• If borrowerList.getBorrower(borrowerLibraryNumber) call throws an exception when requested object is not found, then you can catch the exception and set the flag to true with in catch block.