ByteBuffer put(ByteBuffer) in Java

put(ByteBuffer): This method is available in java.nio.ByteBuffer class of Java.

Syntax:

ByteBuffer java.nio.ByteBuffer.put(ByteBuffer src)

This method takes one argument of type ByteBuffer as its parameter. This method transfers the bytes remaining in the given source buffer into this buffer.

Note:

1. If there are more bytes remaining in the source buffer than in this buffer, that is, if src.remaining() > remaining(),then no bytes are transferred and a BufferOverflowException is thrown.

2. Otherwise, this method copies n = src.remaining() bytes from the given buffer into this buffer, starting at each buffer's current position. The positions of  both buffers are then incremented by n.

Parameters: One parameter is required for this method.

src: The source buffer from which bytes are to be read; must not be this buffer.

Returns: This buffer.

Throws:

1. BufferOverflowException - If there is insufficient space in this buffer for the remaining bytes in the source buffer.

2. IllegalArgumentException - If the source buffer is this buffer.

3. ReadOnlyBufferException - If this buffer is read-only

Approach 1: When no exceptions.

Java

import java.nio.ByteBuffer;
import java.util.Arrays;

public class ByteBufferput3 {
    public static void main(String[] args) {

        byte array[] = { 1, 2, 3, 4, 5 };
        ByteBuffer bb = ByteBuffer.wrap(array);

        byte array2[] = { 10, 20, 30, 56 };
        ByteBuffer src = ByteBuffer.wrap(array2);
        System.out.println(Arrays.toString(bb.put(src).array()));

    }
}

Output:

[10, 20, 30, 56, 5]

Approach 2: BufferOverflowException

Java

import java.nio.ByteBuffer;
import java.util.Arrays;

public class ByteBufferput3 {
    public static void main(String[] args) {

        byte array[] = { 1, 2, 3 };
        ByteBuffer bb = ByteBuffer.wrap(array);

        byte array2[] = { 10, 20, 30, 56 };
        ByteBuffer src = ByteBuffer.wrap(array2);
        System.out.println(Arrays.toString(bb.put(src).array()));

    }
}

Output:

Exception in thread "main" java.nio.BufferOverflowException
	at java.base/java.nio.ByteBuffer.put(ByteBuffer.java:957)
	at java.base/java.nio.HeapByteBuffer.put(HeapByteBuffer.java:247)
	

Approach 3: IllegalArgumentException

Java

import java.nio.ByteBuffer;
import java.util.Arrays;

public class ByteBufferput3 {
    public static void main(String[] args) {

        byte array[] = { 1, 2, 3, 4, 5 };
        ByteBuffer bb = ByteBuffer.wrap(array);
        System.out.println(Arrays.toString(bb.put(bb).array()));

    }
}

Output:

Exception in thread "main" java.lang.IllegalArgumentException: The source buffer is this buffer
	at java.base/java.nio.Buffer.createSameBufferException(Buffer.java:261)
	at java.base/java.nio.ByteBuffer.put(ByteBuffer.java:949)
	at java.base/java.nio.HeapByteBuffer.put(HeapByteBuffer.java:247)
	

Approach 4: ReadOnlyBufferException 

Java

import java.nio.ByteBuffer;
import java.util.Arrays;

public class ByteBufferput3 {
    public static void main(String[] args) {

        byte array[] = { 1, 2, 3, 4, 5 };
        ByteBuffer bb = ByteBuffer.wrap(array);

        ByteBuffer readOnly = bb.asReadOnlyBuffer();
        byte array2[] = { 10, 20, 30, 56 };
        ByteBuffer src = ByteBuffer.wrap(array2);
        System.out.println(Arrays.toString(readOnly.put(src).array()));

    }
}

Output:

Exception in thread "main" java.nio.ReadOnlyBufferException
	at java.base/java.nio.HeapByteBufferR.put(HeapByteBufferR.java:250)