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Java ObjectInputStream readUTF() Method with Example

ObjectInputStream Class readUTF() method: Here, we are going to learn about the readUTF() method of ObjectInputStream Class with its syntax and example.
Submitted by Preeti Jain, on April 05, 2020

ObjectInputStream Class readUTF() method

• readUTF() method is available in java.io package.
• readUTF() method is used to read the string in an updated encoding scheme UTF-8 format.
• readUTF() 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.
• readUTF() method may throw an exception at the time of reading string.
  • IOException: This exception may throw when getting any input/output error while performing.
  • UTFDataFormatExeption: This exception may throw when the read bytes denote invalid UTF-8 encoding of a string.

Syntax:

    public String readUTF();

Parameter(s):

• It does not accept any parameter.

Return value:

The return type of the method is String, it returns the Unicode string.

Example:

// Java program to demonstrate the example 
// of String readUTF() method of 
// ObjectInputStream

import java.io.*;

public class ReadUTFOfOIS {
 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
  // the encoded string in UTF-8 to the 
  // obj_out_stm stream
  obj_out_stm.writeUTF("JAVA");
  obj_out_stm.writeUTF("C");
  obj_out_stm.writeUTF("C++");
  obj_out_stm.writeUTF("SFDC");

  obj_out_stm.flush();

  while (obj_in_stm.available() > 0) {
   // By using readUTF() method is to read
   // encoded string from the obj_in_stm 
   String val = (String) obj_in_stm.readUTF();
   System.out.println("obj_in_stm.readUTF(): " + 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.readUTF(): JAVA
obj_in_stm.readUTF(): C
obj_in_stm.readUTF(): C++
obj_in_stm.readUTF(): SFDC