What is the CharBuffer put() method in Java?

java.nio.CharBuffer is a class that can be used to store a buffer of characters. The put() method of the java.nio.CharBuffer class is used to write a character to a buffer. The CharBuffer.put() method writes the character at the current positionThe index of the next element of the buffer that will be read or written of the buffer and increments the position by one.

Declaration

The CharBuffer.put() method can be declared as:

buff1.put(x);

buff1: The CharBuffer in which the character x will be written.
x: The character that will be written to buff1.

Return value

The CharBuffer.put() method returns the CharBuffer buff1 after writing the character x to it.

Note:

If the position of buff1 is not less than the limitThe first index of the buffer that should not be read or written of buff1, the BufferOverflowException is thrown.

If buff1 is read-only, the ReadOnlyBufferException is thrown.

Example

Example 1

Consider the code snippet below, which demonstrates the use of the CharBuffer.put() method.

import java.nio.*;
import java.util.*;
public class main {
   public static void main(String[] args) {
      int n1 = 5;
      int n2 = 4;
      try {
         CharBuffer buff1 = CharBuffer.allocate(n1);
         buff1.put('a');
         buff1.put('c');
         System.out.println("buff1: " + Arrays.toString(buff1.array()));
         System.out.println("position: " + buff1.position());
         
      } catch (IllegalArgumentException e) {
         System.out.println("Error!!! IllegalArgumentException");
      } catch (ReadOnlyBufferException e) {
         System.out.println("Error!!! ReadOnlyBufferException");
      }
   }
}

Explanation

A CharBuffer buff1 is declared in line 8.
An element is written to buff1 using the CharBuffer.put() method in line 9. After adding the first element, the position of buff1 is incremented from 0 to 1.
Another element is written to buff1 using the CharBuffer.put() method in line 10. After adding the second element, the position of buff1 is incremented from 1 to 2.

Example 2

As explained above, using the CharBuffer.put() method on a read-only buffer throws the ReadOnlyBufferException. Consider the code snippet below that demonstrates this.

import java.nio.*;
import java.util.*;
public class main {
   public static void main(String[] args) {
      int n1 = 5;
      int n2 = 4;
      try {
         CharBuffer buff1 = CharBuffer.allocate(n1);
         CharBuffer buff2 = buff1.asReadOnlyBuffer();
         buff2.put('a');
         buff2.put('c');
         System.out.println("buff2: " + Arrays.toString(buff2.array()));
         System.out.println("position: " + buff2.position());
         
      } catch (IllegalArgumentException e) {
         System.out.println("Error!!! IllegalArgumentException");
      } catch (ReadOnlyBufferException e) {
         System.out.println("Error!!! ReadOnlyBufferException");
      }
   }
}