Does DataInputStream.close() throw an exception?

A good answer might be:

Yes, it throws an IOException

So there is a problem. The close() method inside the catch{} block throws an IOException which is not caught.

      // Loop with problems

      try
      {
        while ( true )
          sum += instr.readInt();
      }

      catch ( EOFException eof )
      {
        System.out.println( "The sum is: " + sum );
        instr.close(); <--- throws IOException 
      }

      catch ( IOException eof ) <--- this  catch is for the try{} block 
      {                              not for the previous catch{} block
        System.out.println( "Problem reading input" );
        instr.close(); <--- throws IOException 
      }

There are various ways to deal with this. One possiblility is not to catch the exception that close() throws. Then the method header must be public static void main(String[] args) throws IOException

QUESTION 10:

Can a try{}/catch{} be nested inside an outer try{} block?