Open In App

PushbackReader read() method in Java with Examples

Last Updated : 29 Apr, 2019
Comments
Improve
Suggest changes
Like Article
Like
Report
The read() method of PushbackReader Class in Java is used to read a single character from the stream. This method blocks the stream till:
  • It has taken some input from the stream.
  • Some IOException has occurred
  • It has reached the end of the stream while reading.
Syntax:
public int read()
Parameters: This method does not accepts any parameters Return Value: This method returns an integer value which is the integer value read from the stream. It can range from 0 to 65535. Else it returns -1 if no character has been read. Exception: This method throws IOException if some error occurs while input output. Below methods illustrates the working of read() method: Program 1: Java
// Java program to demonstrate
// PushbackReader read() method

import java.io.*;
import java.util.*;

class GFG {
    public static void main(String[] args)
    {

        try {
            // Initializing a StringReader
            // and PushbackReader
            String s = "GeeksForGeeks";

            StringReader stringReader
                = new StringReader(s);
            PushbackReader pushbackReader
                = new PushbackReader(stringReader);

            // Get the character
            // to be read from the stream
            int ch;

            // Read the first 5 characters
            // to this reader using read() method
            // This will put the str in the stream
            // till it is read by the reader
            for (int i = 0; i < 5; i++) {
                ch = pushbackReader.read();
                System.out.println("\nInteger value "
                                   + "of character read: "
                                   + ch);
                System.out.println("Actual "
                                   + "character read: "
                                   + (char)ch);
            }

            // Close the stream using read()
            pushbackReader.close();
            System.out.println("Stream Closed.");
        }
        catch (Exception e) {
            System.out.println(e);
        }
    }
}
Output:
Integer value of character read: 71
Actual character read: G

Integer value of character read: 101
Actual character read: e

Integer value of character read: 101
Actual character read: e

Integer value of character read: 107
Actual character read: k

Integer value of character read: 115
Actual character read: s
Stream Closed.
Program 2: Java
// Java program to demonstrate
// PushbackReader read() method

import java.io.*;
import java.util.*;

class GFG {
    public static void main(String[] args)
    {

        try {
            // Initializing a StringReader
            // and PushbackReader
            String s = "GFG";

            StringReader stringReader
                = new StringReader(s);
            PushbackReader pushbackReader
                = new PushbackReader(stringReader);

            // Get the character
            // to be read from the stream
            int ch;

            // Read the first 2 characters
            // to this reader using read() method
            // This will put the str in the stream
            // till it is read by the reader
            for (int i = 0; i < 2; i++) {
                ch = pushbackReader.read();
                System.out.println("\nInteger value "
                                   + "of character read: "
                                   + ch);
                System.out.println("Actual "
                                   + "character read: "
                                   + (char)ch);
            }

            // Close the stream
            pushbackReader.close();
            System.out.println("Stream Closed.");
        }
        catch (Exception e) {
            System.out.println(e);
        }
    }
}
Output:
Integer value of character read: 71
Actual character read: G

Integer value of character read: 70
Actual character read: F
Stream Closed.
Reference: https://docs.oracle.com/javase/9/docs/api/java/io/PushbackReader.html#read--

Next Article

Similar Reads