ByteBuffer getLong() method in Java with Examples

getLong()

The getLong() method of java.nio.ByteBuffer class is used to read the next eight bytes at this buffer's current position, composing them into a long value according to the current byte order, and then increments the position by eight. Syntax:

public abstract long getLong()

Return Value: This method returns the long 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 getLong() method: Examples 1:

Java

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

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

public class GFG {

    public static void main(String[] args)
    {

        // Declaring the capacity of the ByteBuffer
        int capacity = 16;

        // Creating the ByteBuffer
        try {

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

            // putting the long value in the bytebuffer
            bb.asLongBuffer()
                .put(1233003)
                .put(2292292);

            // rewind the Bytebuffer
            bb.rewind();

            // print the ByteBuffer
            System.out.println("Original ByteBuffer: ");
            for (int i = 1; i <= capacity / 8; i++)
                System.out.print(bb.getLong() + " ");

            // rewind the Bytebuffer
            bb.rewind();

            // Reads the long at this buffer's current position
            // using getLong() method
            long value = bb.getLong();

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

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

            // print the long value
            System.out.print("\nNext Byte Value: " + value1);
        }

        catch (BufferUnderflowException e) {

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

Output:

Original ByteBuffer: 
1233003 2292292 

Byte Value: 1233003

Next Byte Value: 2292292

Examples 2:

Java

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

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

public class GFG {

    public static void main(String[] args)
    {

        // Declaring the capacity of the ByteBuffer
        int capacity = 16;

        // Creating the ByteBuffer
        try {

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

            // putting the long value in the bytebuffer
            bb.asLongBuffer()
                .put(1233003)
                .put(2292292);

            // rewind the Bytebuffer
            bb.rewind();

            // print the ByteBuffer
            System.out.println("Original ByteBuffer: ");
            for (int i = 1; i <= capacity / 8; i++)
                System.out.print(bb.getLong() + " ");

            // rewind the Bytebuffer
            bb.rewind();

            // Reads the long at this buffer's current position
            // using getLong() method
            long value = bb.getLong();

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

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

            // print the long value
            System.out.print("\nNext Byte Value: " + value1);

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

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

Output:

Original ByteBuffer: 
1233003 2292292 

Byte Value: 1233003

Next Byte Value: 2292292
there are fewer than eight bytes remaining in this buffer
Exception Thrown : java.nio.BufferUnderflowException

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

getLong(int index)

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

public abstract long getLong(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 long 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 getLong(int index) method: Examples 1:

Java

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

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

public class GFG {

    public static void main(String[] args)
    {

        // Declaring the capacity of the ByteBuffer
        int capacity = 16;

        // Creating the ByteBuffer
        try {

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

            // putting the long value in the bytebuffer
            bb.asLongBuffer()
                .put(1233003)
                .put(2292292);

            // rewind the Bytebuffer
            bb.rewind();

            // print the ByteBuffer
            System.out.println("Original ByteBuffer: ");
            for (int i = 1; i <= capacity / 8; i++)
                System.out.print(bb.getLong() + " ");

            // rewind the Bytebuffer
            bb.rewind();

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

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

            // Reads the  long at this buffer's next position
            // using getLong() method
            long value1 = bb.getLong(8);

            // print the long value
            System.out.print("\nNext 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: 
1233003 2292292 

Byte Value: 1233003

Next Byte Value: 2292292

Examples 2:

Java

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

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

public class GFG {

    public static void main(String[] args)
    {

        // Declaring the capacity of the ByteBuffer
        int capacity = 16;

        // Creating the ByteBuffer
        try {

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

            // putting the long value in the bytebuffer
            bb.asLongBuffer()
                .put(1233003)
                .put(2292292);

            // rewind the Bytebuffer
            bb.rewind();

            // print the ByteBuffer
            System.out.println("Original ByteBuffer: ");
            for (int i = 1; i <= capacity / 8; i++)
                System.out.print(bb.getLong() + " ");

            // rewind the Bytebuffer
            bb.rewind();

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

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

            // Reads the  long at this buffer's next position
            // using getLong() method
            long value1 = bb.getLong(11);

            // print the long value
            System.out.print("\nNext 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: 
1233003 2292292 

Byte Value: 1233003

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#getLong-int-

ByteBuffer getLong() method in Java with Examples

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