Reading and Writing To text file

This is the code i made to write and read from text file using java.

java code

/*
 * Main.java
 *
 * Created on November 10, 2006, 10:14 AM
 */
 

import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.DataInputStream;
import java.io.DataOutputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.FileReader;
import java.io.FileWriter;
import java.io.IOException;

/**
 *
 * @author MSI */
public class Main {
    
    /** Creates a new instance of Main */
    public Main() 
    
    {
        data="mmmmmmmmmmmmm";
        
        String ddff;
        int tt=6111;

try {

File_in=new FileInputStream(myFile);
                Data_in =new DataInputStream(File_in); 
                BufferedReader  ReadH=new BufferedReader(new FileReader("text.txt")) ;
                BufferedWriter myW=new BufferedWriter(new FileWriter("text.txt")) ;
          
          File_out=new FileOutputStream(myFile);
           Data_out=new DataOutputStream(File_out);
           Data_out.writeInt(tt);
           Data_out.flush();
           
           Data_out.close(); 
           
          System.out.println(ReadH.read());
           System.out.println(ReadH.read());
            System.out.println(ReadH.read());
            System.out.println(ReadH.read());
            System.out.println(ReadH.read());
                System.out.println((Data_in.read(buff)));
                System.out.println(buff);
        System.out.println(Byte.toString(Data_in.readByte()));
           
        } catch (FileNotFoundException ex) {
            ex.printStackTrace();
        }
         catch (IOException ex) {
                ex.printStackTrace();
            }
  
    }
    
    /**
     * @param args the command line arguments
     */
    public static void main(String[] args) {
        // TODO code application logic here
        new Main();
    }
    File myFile=new File("text.txt");
    FileInputStream File_in;
    DataInputStream Data_in ;
    FileOutputStream File_out ;
    DataOutputStream Data_out;
    String data;
   byte[] buff=new byte[100];
    byte dd;
    int x;
    
}

To Read from a file you open a logical connection to the file in this part :java code

File_in=new FileInputStream(myFile);
                Data_in =new DataInputStream(File_in);

or :
java code

BufferedReader  ReadH=new BufferedReader(new FileReader("text.txt")) ;

To Write to a file you open a logical connection to the file in this part :java code

File_out=new FileOutputStream(myFile);
           Data_out=new DataOutputStream(File_out);

or :
java code

BufferedWriter myW=new BufferedWriter(new FileWriter("text.txt")) ;

To read from the file in a buffer :
java code

System.out.println((Data_in.read(buff)));
                System.out.println(buff);

To read one charactar from the file :
java code

ReadH.read()

this function return -1 if the end of the file achivied


To write to the file

java code

Data_out.writeInt(tt);

this write integers only. There are more functions to other type of data.
or :

java code

WriteH.write(tt);

using close() and flush() functions
flush() free the buffer of the Read/Write.
close() close the logical connection.