Two different ways of closing Input/Ouput streams

Question

OK, the Sun tutorial on Exceptions [http://java.sun.com/docs/books/tutorial/essential/exceptions/putItTogether.html] shows an example where a PrintWriter is closed within a finally block.
Now, the tutorial on bute streams [http://java.sun.com/docs/books/tutorial/essential/io/bytestreams.html] shows another example which is different from the first in that the method which contains all the code has throws IOException in the method header, and no catch blocks.
As an experiment, I tried altering the second example by removing the throws IOException from the method header, and adding a catch block within the method. The code is shown below. This code does not compile, due to unreported exception errors on the close statements in the finally block.
My question is, why in the first example can we close a PrintWriter in the finally block without having the method throw IOException, but in the second example we cannot close FileInputStream in a finally block unless we throw the exception in the method header?
ok, here is my modified code from the second example...
import java.io.*;
public class CopyBytes {
     public static void main( String[] args ) {
          FileInputStream inStream = null;
          FileOutputStream outStream = null;
          try {
               inStream = new FileInputStream("xanadu.txt");
               outStream = new FileOutputStream("outfile.txt");
               int c;
               while( (c = inStream.read()) != -1 ) {
                    outStream.write(c);
          catch( IOException e ) {}
          finally {
               if( inStream != null ) inStream.close();
               if( outStream != null ) outStream.close();
}

Answer 1

endasil wrote:
Fguy wrote:
My question is, why in the first example can we close a PrintWriter in the finally block without having the method throw IOException, but in the second example we cannot close FileInputStream in a finally block unless we throw the exception in the method header?
Short answer?  Because FileOutputStream/FileInputStream.close are declared to throw an IOException.  PrintWriter.close() is not.
...Thanks, that helps. I just checked the API docs and of course they confirm what you say, So I can live with that for my current purposes.
I did notice that PrintWriter is like a wrapper for FileWriter, and close() for the FIleWriter class is inherited from OutputStreamWriter, and that close() does throw IOException. So it seems logical that there would be an exception "behind the scenes" which needs to be reported, but I guess this is not the case. Anyways, I have a direction for further investigation. Thanks again.