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Java ObjectInputStream available() Method with Example

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

ObjectInputStream Class available() method

• available() method is available in java.io package.
• available() method is used to return the number of available bytes that can be read without blocking input from this ObjectInputStream.
• available() 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.
• available() method may throw an exception at the time of returning available bytes.
  IOException: This exception may throw when getting any input/output error while performing.

Syntax:

    public int available();

Parameter(s):

• It does not accept any parameter.

Return value:

The return type of the method is int, it returns the remaining bytes that can be read.

Example:

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


import java.io.*;

public class AvailableOfOIS {
 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 writeUTF() method is to write
  // string to the obj_out_stm stream
  obj_out_stm.writeUTF("JAVA PROGRAMMING!!");
  obj_out_stm.flush();

  obj_in_stm.skipBytes(2);

  // By using available() method is to return the
  // number of available bytes in this obj_in_stm
  int avail_bytes = obj_in_stm.available();
  System.out.println("obj_in_stm.available(): " + avail_bytes);

  for (int i = 0; i < obj_in_stm.available(); i++) {
   char ch = (char) obj_in_stm.readByte();
   System.out.println("ch:" + ch + " ");
  }
 }
}

Output

obj_in_stm.available(): 18
ch:J
ch:A
ch:V
ch:A
ch:
ch:P
ch:R
ch:O
ch:G