What is the difference among the following exception handler statements?

There are 2 ways to deal with exceptions:

you can throw an exception:

public int foo() throws Exception{
  // fancy code that needs Exception handling 
  // like reading a file or parsing a int value
}

here you pass back the exception instead of the desired int-value. the method above has to deal with the exception and probably to pass it on or to deal with it.

Other version is to catch the exception direct:

public int foo() throws Exception{
  try{
    // fancy code that needs Exception handling 
    // like reading a file or parsing a int value
  }
  catch(Exception oException){
    oException.printStackTrace();
    return -1;
  }
}

in this case you catch the exception and often return a invalid int-value like -1. You can add a finally { } behind the catch to make sure certain operations are carried out no matter if the try/catch fails or not (e.g. closing file streams, making sure the database does not become invalid).

You are asking for info you may easily find yourself on the web: Google results for "Java exception handling tutorial"[^]