Program to Write DOUBLE data type in file using DataOutputStream and Read DOUBLE from file using DataInputStream - java file IO



In this post we’ll write following programs -

  • Program 1 to Write DOUBLE data type in file using DataOutputStream
  • Program 2 to Read DOUBLE from file using DataInputStream - java file IO




Program 1 to Write DOUBLE data type in file using DataOutputStream >

import java.io.DataOutputStream;
import java.io.FileOutputStream;
import java.io.IOException;
/** JavaMadeSoEasy.com */
public class WriteDoubleToFileUsingDataOutputStream {
   public static void main(String... args) {
          FileOutputStream fos = null;
          DataOutputStream dos = null;
         
          try {
                 // create FileOutputStream for writing in file
                 fos = new FileOutputStream("c:/myFile.txt");
                 dos = new DataOutputStream(fos);
                 double doubleToBeWrittenInFile = 16d;
                 // write double data type in file using writeDouble(double) method
                 dos.writeDouble(doubleToBeWrittenInFile);
                
                 System.out.println("double data type to be written in file = "
                              + doubleToBeWrittenInFile);
                 System.out.println("double data type has been written in file");
                 dos.flush(); // bytes in buffer are written in file
          } catch (IOException e) {
                 e.printStackTrace();
          } finally {
                 try {
                       if (dos != null){
                              dos.close(); //close DataOutputStream
                       }
                       if (fos != null){
                              fos.close(); //close FileOutputStream
                       }
                
                 } catch (IOException e) {
                       e.printStackTrace();
                 }
          }
   }
}
/* OUTPUT
double data type to be written in file = 16.0
double data type has been written in file
*/



Program 2 to Read DOUBLE from file using DataInputStream - java file IO >

import java.io.DataInputStream;
import java.io.FileInputStream;
import java.io.IOException;
/** JavaMadeSoEasy.com */
public class ReadDoubleFromFileUsingDataInputStream {
   public static void main(String... args) {
          FileInputStream fis = null;
          DataInputStream dis = null;
         
          try {
                 // create FileInputStream for reading from file
                 fis = new FileInputStream("c:/myFile.txt");
                 dis = new DataInputStream(fis);
                 while (dis.available() > 0) {
                       // read double data type from file using readDouble() method.
                       double doubleReadFromFile = dis.readDouble();
                       System.out.print("double data type read from file = "
                                     + doubleReadFromFile);
                 }
          } catch (IOException e) {
                 e.printStackTrace();
          } finally {
                 try {
                       if (dis != null){
                              dis.close(); //close DataInputStream
                       }
                       if (fis != null){
                              fis.close(); //close FileInputStream
                       }
                
                 } catch (IOException e) {
                       e.printStackTrace();
                 }
          }
   }
}
/* OUTPUT
double data type read from file = 16.0
*/


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