How to catch exceptions in Java.

Hey,

When a method throws an exception. It's throwing to to the calling method. That calling method needs to catch it, throw it again and or do nothing with it, which makes troubleshooting hard.

Let's take your method for example. The one that throws an IOException. If this method fails to work, it's going to produce an error. Let's say it fails.

public void doSomething() throws IOException {
    //code goes here
}

Let's call that method and catch the IOExecption.

public void catchError() {

     try {
           doSomething();

      } catch (IOException e) {
               System.err.println("Caught IOException: " + e.getMessage());
}

What happens is that I call doSomething(), which throws an error if it fails. catchError is calling doSomething, so I need to catch the error thrown from doSomething inside my catchError method.

Now, the catch I used a generic example of printing out the output given to the catchError when doSomething throws it back. But where this really comes in handy, is with custom exceptions. Or I can pretty much do anything I want in the catch block. I can say (Hey, I called doSomething, so whatever failed is inisde the method(go write a unit test)). I can say something like that.

Does this help explain it better? Let me know and if not I can try another way.

Thanks!