ByteBuffer getInt() method in Java with Examples

getInt()

The getInt() method of java.nio.ByteBuffer class is used to read the next four bytes at this buffer’s current position, composing them into an int value according to the current byte order, and then increments the position by four.

Syntax:

public abstract int getInt()

Return Value: This method returns the int value at the buffer’s current position

Throws: This method throws BufferUnderflowException – If there are fewer than four bytes remaining in this buffer.
Below are the examples to illustrate the getInt() method:

Examples 1:

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

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

public class GFG {

    public static void main(String[] args)
    {

        // Declaring the capacity of the ByteBuffer
        int capacity = 12;

        // Creating the ByteBuffer
        try {

            // creating object of ByteBuffer
            // and allocating size capacity
            ByteBuffer bb = ByteBuffer.allocate(capacity);

            // putting the int value in the bytebuffer
            bb.asIntBuffer()
                .put(10)
                .put(20)
                .put(30);

            // rewind the Bytebuffer
            bb.rewind();

            // print the ByteBuffer
            System.out.println("Original ByteBuffer: ");
            for (int i = 1; i <= capacity / 4; i++)
                System.out.print(bb.getInt() + " ");

            // rewind the Bytebuffer
            bb.rewind();

            // Reads the Int at this buffer's current position
            // using getInt() method
            int value = bb.getInt();

            // print the int value
            System.out.println("\n\nByte Value: " + value);

            // Reads the int at this buffer's next position
            // using getInt() method
            int value1 = bb.getInt();

            // print the int value
            System.out.println("Next Byte Value: " + value1);
        }

        catch (BufferUnderflowException e) {

            System.out.println("\nException Thrown : " + e);
        }
    }
}

Output:

Original ByteBuffer: 
10 20 30 

Byte Value: 10
Next Byte Value: 20

Examples 2:

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

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

public class GFG {

    public static void main(String[] args)
    {

        // Declaring the capacity of the ByteBuffer
        int capacity = 8;

        // Creating the ByteBuffer
        try {

            // creating object of ByteBuffer
            // and allocating size capacity
            ByteBuffer bb = ByteBuffer.allocate(capacity);

            // putting the int value in the bytebuffer
            bb.asIntBuffer()
                .put(10)
                .put(20);

            // rewind the Bytebuffer
            bb.rewind();

            // print the ByteBuffer
            System.out.println("Original ByteBuffer: ");
            for (int i = 1; i <= capacity / 4; i++)
                System.out.print(bb.getInt() + " ");

            // rewind the Bytebuffer
            bb.rewind();

            // Reads the Int at this buffer's current position
            // using getInt() method
            int value = bb.getInt();

            // print the int value
            System.out.println("\n\nByte Value: " + value);

            // Reads the int at this buffer's next position
            // using getInt() method
            int value1 = bb.getInt();

            // print the int value
            System.out.println("Next Byte Value: " + value1);

            // Reads the int at this buffer's next position
            // using getInt() method
            int value2 = bb.getInt();
        }

        catch (BufferUnderflowException e) {
            System.out.println("\nthere are fewer than "
                               + "four bytes remaining in this buffer");
            System.out.println("Exception Thrown : " + e);
        }
    }
}

Output:

Original ByteBuffer: 
10 20 

Byte Value: 10
Next Byte Value: 20

there are fewer than four bytes remaining in this buffer
Exception Thrown : java.nio.BufferUnderflowException

Reference: https://docs.oracle.com/javase/9/docs/api/java/nio/ByteBuffer.html#getInt–

getInt(int index)

The getInt(int index) method of ByteBuffer is used to read four bytes at the given index, composing them into a int value according to the current byte order.

Syntax :

public abstract int getInt(int index)

Parameters: This method takes index (The index from which the Byte will be read) as a parameter.

Return Value: This method returns The int value at the given index.

Exception: This method throws IndexOutOfBoundsException. If index is negative or not smaller than the buffer’s limit this exception is thrown.

Below are the examples to illustrate the getInt(int index) method:

Examples 1:

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

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

public class GFG {

    public static void main(String[] args)
    {

        // Declaring the capacity of the ByteBuffer
        int capacity = 8;

        // Creating the ByteBuffer
        try {

            // creating object of ByteBuffer
            // and allocating size capacity
            ByteBuffer bb = ByteBuffer.allocate(capacity);

            // putting the int value in the bytebuffer
            bb.asIntBuffer()
                .put(10)
                .put(20);

            // rewind the Bytebuffer
            bb.rewind();

            // print the ByteBuffer
            System.out.println("Original ByteBuffer: ");
            for (int i = 1; i <= capacity / 4; i++)
                System.out.print(bb.getInt() + " ");

            // rewind the Bytebuffer
            bb.rewind();

            // Reads the Int at this buffer's current position
            // using getInt() method
            int value = bb.getInt(0);

            // print the int value
            System.out.println("\n\nByte Value: " + value);

            // Reads the int at this buffer's next position
            // using getInt() method
            int value1 = bb.getInt(4);

            // print the int value
            System.out.println("Next Byte Value: " + value1);
        }

        catch (IndexOutOfBoundsException e) {

            System.out.println("\nindex is negative or smaller "
                               + "than the buffer's limit, minus seven");
            System.out.println("Exception Thrown : " + e);
        }
    }
}

Output:

Original ByteBuffer: 
10 20 

Byte Value: 10
Next Byte Value: 20

Examples 2:

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

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

public class GFG {

    public static void main(String[] args)
    {

        // Declaring the capacity of the ByteBuffer
        int capacity = 8;

        // Creating the ByteBuffer
        try {

            // creating object of ByteBuffer
            // and allocating size capacity
            ByteBuffer bb = ByteBuffer.allocate(capacity);

            // putting the int value in the bytebuffer
            bb.asIntBuffer()
                .put(10)
                .put(20);

            // rewind the Bytebuffer
            bb.rewind();

            // print the ByteBuffer
            System.out.println("Original ByteBuffer: ");
            for (int i = 1; i <= capacity / 4; i++)
                System.out.print(bb.getInt() + " ");

            // rewind the Bytebuffer
            bb.rewind();

            // Reads the Int at this buffer's current position
            // using getInt() method
            int value = bb.getInt(0);

            // print the int value
            System.out.println("\n\nByte Value: " + value);

            // Reads the int at this buffer's next position
            // using getInt() method
            int value1 = bb.getInt(7);

            // print the int value
            System.out.println("Next Byte Value: " + value1);
        }

        catch (IndexOutOfBoundsException e) {

            System.out.println("\nindex is negative or smaller"
                               + " than the buffer's limit, minus seven");
            System.out.println("Exception Thrown : " + e);
        }
    }
}

Output:

Original ByteBuffer: 
10 20 

Byte Value: 10

index is negative or smaller than the buffer's limit, minus seven
Exception Thrown : java.lang.IndexOutOfBoundsException

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