HOW TO INTERFACE WITH FILES IN JAVA

Simple example to use string in different ways.

Syntax :

String variable_name = "Hello World!"

Example :

1. import java.io.*; 
2. public class CopyFile {
3.    public static void main(String args[]) throws IOException
4.    {
5.       FileInputStream in = null;
6.       FileOutputStream out = null;
7.        try {
8.          in = new FileInputStream("input.txt");
9.          out = new FileOutputStream("output.txt");
10.         
11.          int c;
12.          while ((c = in.read()) != -1) {
13.             out.write(c);
14.          }
15.       }finally {
16.          if (in != null) {
17.             in.close();
18.          }
19.          if (out != null) {
20.             out.close();
21.          }
22.       }
23.    }
24. }

Description :

Step 1:Starting of class

Step 2:Start of main function.

Step 3:The input or output type of exceptions that occur in main function are thrown away.

Step 4 :There are many classes for byte stream but FileInputStream and FileOutputStream are most frequently used. Here input.txt is the name of actual file that is present in your machine.

Step 5:Here output.txt is the file that will be created .
Step 12: Read every character from file "input,txt" .
Step 13:Write every character in file "output.txt" .
Step 15 - 18: "finally" keyword is used when all try catch operations are completed. If input,txt not closed then in.close closes input.txt file. Same for output.txt file,