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Java ObjectInputStream readInt() Method with Example

ObjectInputStream Class readInt() method: Here, we are going to learn about the readInt() method of ObjectInputStream Class with its syntax and example.
Submitted by Preeti Jain, on April 04, 2020

ObjectInputStream Class readInt() method

• readInt() method is available in java.io package.
• readInt() method is used to read 4 bytes (i.e. 32 bit) of data from this ObjectInputStream stream and returned a integer.
• readInt() 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.
• readInt() method may throw an exception at the time of reading integer.
  • IOException: This exception may throw when getting any input/output error while performing.
  • EOFException: This exception may throw when this stream has reached its end of the file.

Syntax:

    public int readInt();

Parameter(s):

• It does not accept any parameter.

Return value:

The return type of the method is int, it returns the 4 bytes integer value read.

Example:

// Java program to demonstrate the example 
// of int readInt() method of ObjectInputStream

import java.io.*;

public class ReadIntOfOIS {
 public static void main(String[] args) throws Exception {
  // Instantiates ObjectOutputStream , ObjectInputStream 
  // FileInputStream and FileOutputStream

  FileOutputStream file_out_stm = new FileOutputStream("D:\\includehelp.txt");
  ObjectOutputStream obj_out_stm = new ObjectOutputStream(file_out_stm);
  FileInputStream file_in_stm = new FileInputStream("D:\\includehelp.txt");
  ObjectInputStream obj_in_stm = new ObjectInputStream(file_in_stm);

  // By using writeInt() method is to write
  // integer to the obj_out_stm stream
  obj_out_stm.writeInt(100);
  obj_out_stm.writeInt(200);
  obj_out_stm.writeInt(300);
  obj_out_stm.writeInt(400);

  obj_out_stm.flush();

  while (obj_in_stm.available() > 0) {
   // By using readInt() method is to read
   //  integer from the obj_in_stm
   int val = (int) obj_in_stm.readInt();
   System.out.println("obj_in_stm.readInt(): " + val);
  }
  // By using close() method is to 
  // close all the streams 
  file_in_stm.close();
  file_out_stm.close();
  obj_in_stm.close();
  obj_out_stm.close();
 }
}

Output

obj_in_stm.readInt(): 100
obj_in_stm.readInt(): 200
obj_in_stm.readInt(): 300
obj_in_stm.readInt(): 400