exception

[Philip Mat]

I'm new to Java and I have the below code which when compiled gives the error:- unreported exception java.io.IOexception; must be caught or declared to be thrown.
Since I'm catching the IOException in my code, I think I don't really need to declare the IOException to be thrown on main method. It compiles successfully only when I declare the IOException to be thrown on main method.

What can be done to make this code compile successfully without declaring the IOException to be thrown on main method?

import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;

public class CopyBytes {
    public static void main(String[] args) {

        FileInputStream in = null;
        FileOutputStream out = null;
    	try {        
            in = new FileInputStream("xanadu.txt");
            out = new FileOutputStream("outagain.txt");
            int c;

            while ((c = in.read()) != -1) {
                out.write(c);
            }

            } catch (IOException e) {
              System.err.println("Caught IOException: " + e.getMessage());
            } finally {
              if (in != null) {
                in.close();
            }
              if (out != null) {
                out.close();
            }
        }
    }
}

[Ernest Friedman-Hill]

Hi,

Welcome to JavaRanch!

First, a bit of business: you may not have read our naming policy on the way in. It requires that you use a full, real (sounding) first and last name for your display name. Joke names aren't acceptable. You can change your display name here. Thanks!

Now, as to your question: Those "close" calls can throw IOException, and they're not in a try block. Yes, this is a pain, and yes, everybody hates this. Solution? Another try block inside the finally block, which catches the IOException.

[Philip Mat]

Thank you ..

[Campbell Ritchie]

import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;

public class CopyBytes {
    public static void main(String[] args) {

        try
        {
             FileInputStream in = null;
             FileOutputStream out = null;
       	     try {        
                  in = new FileInputStream("xanadu.txt");
                  out = new FileOutputStream("outagain.txt");
                  int c;

                  while ((c = in.read()) != -1) {
                     out.write(c);
                  }

              } finally {
                   if (in != null) {
                      in.close();
                }
                   if (out != null) {
                      out.close();
            }
        catch (IOException e) {
             System.err.println("Caught IOException: " + e.getMessage());
                }
    }
}

What Ernest means is something like that. Only I may have got some {} unbalanced because I am not used to reading indentation with more than one brace per line.