Java Application File I/O
since May 10, 2000, last modified May 10, 2000

---

Java Application with File I/O

The following code reads text data in 'input.txt' file and write the result to both the std I/O and 'output.txt' file. It uses FileReader and FileWriter classes in the java.io package. See the binary I/O stream classes which respond to the classes respectively.

import java.io.*;

public class fio {
    public static void main(String[] args) throws IOException {

       FileReader in = null;
       FileWriter out = null;

       try {
           in = new FileReader("input.txt");
           out = new FileWriter("output.txt");
       } catch (FileNotFoundException e) {
           System.err.println("CheckedIOTest: " + e);
           System.exit(-1);
       } catch (IOException e) {
           System.err.println("CheckedIOTest: " + e);
           System.exit(-1);
       }

       int c;

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

       in.close();
       out.close();
    }
}

For more information of I/O stream, see The Java Tutorial "Essential Java Classes.Reading and Writing (but No 'rithmetic)" section.

---

Knowledge and Engineering Databases (c) copyright Namchul Do, 2000