Home » Java programming language

Java DataOutputStream size() Method with Example

DataOutputStream Class size() method: Here, we are going to learn about the size() method of DataOutputStream Class with its syntax and example.
Submitted by Preeti Jain, on March 30, 2020

DataOutputStream Class size() method

• size() method is available in java.io package.
• size() method is used to return the size of this stream or in other words, we can say it returns the value of the variable counter that contains written bytes.
• size() method is a non-static method, it is accessible with the class object only and if we try to access the method with the class name then we will get an error.
• size() method does not throw an exception at the time of returning size.

Syntax:

    public final int size();

Parameter(s):

• It does not accept any parameter.

Return value:

The return type of the method is int, it returns the last value of the variable counter.

Example:

// Java program to demonstrate the example 
// of int size() method of DataOutputStream

import java.io.*;

public class SizeOfDOS {
 public static void main(String[] args) throws IOException {
  InputStream is_stm = null;
  DataInputStream dis_stm = null;
  FileOutputStream fos_stm = null;
  DataOutputStream dos_stm = null;
  byte[] b_arr = {
   12,
   20,
   45,
   98,
   75,
   69,
   30,
   58,
   47,
   61,
   83,
   55
  };

  try {
   // Instantiate FileInputStream, 
   // DataInputStream, FileOutputStream
   // and DataOutputStream 

   fos_stm = new FileOutputStream("C:\\Users\\Preeti Jain\\Desktop\\programs\\includehelp.txt");
   dos_stm = new DataOutputStream(fos_stm);
   is_stm = new FileInputStream("C:\\Users\\Preeti Jain\\Desktop\\programs\\includehelp.txt");
   dis_stm = new DataInputStream(is_stm);

   // Loop to write each byte till end
   for (byte val: b_arr) {
    // By using write() method isto
    // write a byte value to the
    // DataOutputStream dos_stm
    dos_stm.write(val);
   }

   // Loop To Read Available Data till end
   while (dis_stm.available() > 0) {
    // By using read() method isto read 
    // byte from dis_stm
    int in = dis_stm.read();
    System.out.println("dis_stm.read(): " + in );
   }

   System.out.println();

   // By using size() method isto return
   // size of this stream
   int size = dos_stm.size();

   System.out.println("dos_stm.size(): " + size);
  } catch (Exception ex) {
   System.out.println(ex.toString());
  } finally {
   // To free system resources linked
   // with these streams
   if (is_stm != null)
    is_stm.close();

   if (dis_stm != null)
    dis_stm.close();

   if (dos_stm != null)
    dos_stm.close();

   if (fos_stm != null)
    fos_stm.close();
  }
 }
}

Output

dis_stm.read(): 12
dis_stm.read(): 20
dis_stm.read(): 45
dis_stm.read(): 98
dis_stm.read(): 75
dis_stm.read(): 69
dis_stm.read(): 30
dis_stm.read(): 58
dis_stm.read(): 47
dis_stm.read(): 61
dis_stm.read(): 83
dis_stm.read(): 55

dos_stm.size(): 12