IntBuffer compact() in Java

compact(): This method is available in java.nio.IntBuffer class of Java.

Syntax:

IntBuffer java.nio.IntBuffer.compact()

This method compacts this buffer.

Parameters: NA

Returns: This buffer.

Throws:

ReadOnlyBufferException - If this buffer is read-only. 

Approach 1: When no exceptions

Java

import java.nio.IntBuffer;

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

        int array[] = { 1, 2, 3, 4 };
        IntBuffer lb = IntBuffer.wrap(array);

        System.out.println(lb.compact());
    }
}

Output:

java.nio.HeapIntBuffer[pos=4 lim=4 cap=4]

Approach 2: ReadOnlyBufferException 

Java

import java.nio.IntBuffer;

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

        int array[] = { 1, 2, 3, 4 };
        IntBuffer lb = IntBuffer.wrap(array);

        IntBuffer readOnly = lb.asReadOnlyBuffer();
        System.out.println(readOnly.compact());
    }
}

Output:

Exception in thread "main" java.nio.ReadOnlyBufferException
	at java.base/java.nio.HeapIntBufferR.compact(HeapIntBufferR.java:296)