CharArrayReader read(CharBuffer) method in Java with Examples
Last Updated :
11 Jul, 2025
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The read(CharBuffer) method of CharArrayReader Class in Java is used to read the specified characters into a CharBuffer instance. This method blocks the stream till:
Java
Java
- It has taken some input from the stream.
- Some IOException has occurred
- It has reached the end of the stream while reading.
public int read(CharBuffer charBuffer)Parameters: This method accepts a mandatory parameter charBuffer which is the CharBuffer instance to be written in the Stream. Return Value: This method returns an integer value which is the number of characters read from the stream. It returns -1 if no character has been read. Exception: This method throws following exceptions:
- IOException: if some error occurs while input output.
- NullPointerException: if the CharBuffer instance to be filled is null
- ReadOnlyBufferException: if the CharBuffer instance to be filled is a read only buffer
// Java program to demonstrate
// CharArrayReader read(CharBuffer) method
import java.io.*;
import java.util.*;
import java.nio.CharBuffer;
class GFG {
public static void main(String[] args)
{
try {
char[] str = { 'G', 'e', 'e', 'k', 's',
'F', 'o', 'r',
'G', 'e', 'e', 'k', 's' };
// Create a CharArrayReader instance
CharArrayReader reader
= new CharArrayReader(str);
// Get the CharBuffer instance
// to be read from the stream
CharBuffer charBuffer
= CharBuffer.allocate(5);
// Read the charBuffer
// to this reader using read() method
// This will put the str in the stream
// till it is read by the reader
reader.read(charBuffer);
// Print the read charBuffer
System.out.println(charBuffer
.flip()
.toString());
reader.close();
}
catch (Exception e) {
System.out.println(e);
}
}
}
// Java program to demonstrate// CharArrayReader read(CharBuffer) methodimport java.io.*;import java.util.*;import java.nio.CharBuffer;class GFG { public static void main(String[] args) { try { char[] str = { 'G', 'e', 'e', 'k', 's', 'F', 'o', 'r', 'G', 'e', 'e', 'k', 's' }; // Create a CharArrayReader instance CharArrayReader reader = new CharArrayReader(str); // Get the CharBuffer instance // to be read from the stream CharBuffer charBuffer = CharBuffer.allocate(5); // Read the charBuffer // to this reader using read() method // This will put the str in the stream // till it is read by the reader reader.read(charBuffer); // Print the read charBuffer System.out.println(charBuffer .flip() .toString()); reader.close(); } catch (Exception e) { System.out.println(e); } }}
Output:
Program 2:
Geeks
// Java program to demonstrate
// CharArrayReader read(CharBuffer) method
import java.io.*;
import java.util.*;
import java.nio.CharBuffer;
class GFG {
public static void main(String[] args)
{
try {
char[] str = { 'G', 'e', 'e', 'k', 's',
'F', 'o', 'r',
'G', 'e', 'e', 'k', 's' };
// Create a CharArrayReader instance
CharArrayReader reader
= new CharArrayReader(str);
// Get the CharBuffer instance
// to be read from the stream
CharBuffer charBuffer
= CharBuffer
.allocate(13);
// Read the charBuffer
// to this reader using read() method
// This will put the str in the stream
// till it is read by the reader
reader.read(charBuffer);
// Print the read charBuffer
System.out.println(charBuffer
.flip()
.toString());
reader.close();
}
catch (Exception e) {
System.out.println(e);
}
}
}
// Java program to demonstrate// CharArrayReader read(CharBuffer) methodimport java.io.*;import java.util.*;import java.nio.CharBuffer;class GFG { public static void main(String[] args) { try { char[] str = { 'G', 'e', 'e', 'k', 's', 'F', 'o', 'r', 'G', 'e', 'e', 'k', 's' }; // Create a CharArrayReader instance CharArrayReader reader = new CharArrayReader(str); // Get the CharBuffer instance // to be read from the stream CharBuffer charBuffer = CharBuffer .allocate(13); // Read the charBuffer // to this reader using read() method // This will put the str in the stream // till it is read by the reader reader.read(charBuffer); // Print the read charBuffer System.out.println(charBuffer .flip() .toString()); reader.close(); } catch (Exception e) { System.out.println(e); } }}
Output:
Reference: https://docs.oracle.com/javase/9/docs/api/java/io/Reader.html#read-java.nio.CharBuffer-
GeeksForGeeks
