ByteBuffer limit() methods in Java with Examples

The limit() method of java.nio.ByteBuffer Class is used to set this buffer’s limit. If the position is larger than the new limit then it is set to the new limit. If the mark is defined and larger than the new limit then it is discarded. 

Syntax:

public ByteBuffer limit(int newLimit)

Return Value: This method returns this buffer. 

Below are the examples to illustrate the limit() method: 

Examples 1:

Java

// Java program to demonstrate
// limit() method

import java.nio.*;
import java.util.*;

public class GFG {
    public static void main(String[] args)
    {
        // defining and allocating ByteBuffer
        // using allocate() method
        ByteBuffer byteBuffer = ByteBuffer.allocate(4);

        // put byte value in byteBuffer
        // using put() method
        byteBuffer.put((byte)20);
        byteBuffer.put((byte)30);

        // print the byte buffer
        System.out.println("ByteBuffer before compact: "
                           + Arrays.toString(byteBuffer.array())
                           + "\nPosition: " + byteBuffer.position()
                           + "\nLimit: " + byteBuffer.limit());

        // Limit the byteBuffer
        // using limit() method
        byteBuffer.limit(1);

        // print the byte buffer
        System.out.println("\nByteBuffer after compact: "
                           + Arrays.toString(byteBuffer.array())
                           + "\nPosition: " + byteBuffer.position()
                           + "\nLimit: " + byteBuffer.limit());
    }
}

Output:

ByteBuffer before compact: [20, 30, 0, 0]
Position: 2
Limit: 4

ByteBuffer after compact: [20, 30, 0, 0]
Position: 1
Limit: 1

Examples 2:

Java

// Java program to demonstrate
// limit() method

import java.nio.*;
import java.util.*;

public class GFG {
    public static void main(String[] args)
    {
        // defining and allocating ByteBuffer
        // using allocate() method
        ByteBuffer byteBuffer = ByteBuffer.allocate(5);

        // put byte value in byteBuffer
        // using put() method
        byteBuffer.put((byte)20);
        byteBuffer.put((byte)30);
        byteBuffer.put((byte)40);

        // mark will be going to discarded by limit()
        byteBuffer.mark();

        // print the byte buffer
        System.out.println("ByteBuffer before compact: "
                           + Arrays.toString(byteBuffer.array())
                           + "\nPosition: " + byteBuffer.position()
                           + "\nLimit: " + byteBuffer.limit());

        // Limit the byteBuffer
        // using limit() method
        byteBuffer.limit(4);

        // print the byte buffer
        System.out.println("\nByteBuffer after compact: "
                           + Arrays.toString(byteBuffer.array())
                           + "\nPosition: " + byteBuffer.position()
                           + "\nLimit: " + byteBuffer.limit());
    }
}

Output:

ByteBuffer before compact: [20, 30, 40, 0, 0]
Position: 3
Limit: 5

ByteBuffer after compact: [20, 30, 40, 0, 0]
Position: 3
Limit: 4

Reference: https://docs.oracle.com/javase/9/docs/api/java/nio/ByteBuffer.html#limit-int-