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Java BufferedReader mark() Method with Example

BufferedReader Class mark() method: Here, we are going to learn about the mark() method of BufferedReader Class with its syntax and example.
Submitted by Preeti Jain, on March 01, 2020

BufferedReader Class mark() method

• mark() method is available in java.io package.
• mark() method is used to mark the current position in this stream and whenever we call reset() method so it will reset the stream to the given point (read_from_here).
• mark() 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.
• mark() method may throw an exception at the time of setting a limit.
  • IllegalArgumentException: This exception may throw when the given parameter is negative.
  • IOException: This exception may throw while performing input/output operation.

Syntax:

    public void mark(int read_from_here);

Parameter(s):

• int read_from_here – represents the number of bytes to read during mark() preserves.

Return value:

The return type of the method is void, it returns nothing.

Example:

// Java program to demonstrate the example 
// of void mark(int read_from_here) method of 
// BufferedReader

import java.io.*;

public class MarkBR {
    public static void main(String[] args) throws Exception {
        // To open text file by using 
        // FileInputStream
        FileInputStream fis = new FileInputStream("e:/includehelp.txt");

        // Instantiates InputStreamReader 
        InputStreamReader inp_r = new InputStreamReader(fis);

        // Instantiates BufferedReader 
        BufferedReader buff_r = new BufferedReader(inp_r);

        // Read character from the stream
        char ch1 = (char) buff_r.read();
        char ch2 = (char) buff_r.read();
        char ch3 = (char) buff_r.read();

        System.out.println("ch1: " + ch1);
        System.out.println("ch2 : " + ch2);

        // By using mark() method isto
        // set the limit the number of byte
        // to be read 
        System.out.println("buff_r.mark(5): ");
        buff_r.mark(5);
        System.out.println("ch3: " + ch3);

        // reset stream by using reset()
        System.out.println("buff_r.reset(): ");
        buff_r.reset();

        // Read from the stread
        char ch4 = (char) buff_r.read();
        char ch5 = (char) buff_r.read();

        // Display character
        System.out.println("ch4: " + ch4);
        System.out.println("ch5: " + ch5);

        fis.close();
        inp_r.close();
        buff_r.close();
    }
}

Output

ch1: H
ch2 : e
buff_r.mark(5):
ch3: l
buff_r.reset():
ch4: l
ch5: o