ByteBuffer getDouble() method in Java with Examples
getDouble()
The getDouble() method of java.nio.ByteBuffer class is used to read the next eight bytes at this buffer’s current position, composing them into a double value according to the current byte order, and then increments the position by eight.
Syntax:
public abstract double getDouble()
Return Value: This method returns the double value at the buffer’s current position
Throws: This method throws BufferUnderflowException if the buffer’s current position is not smaller than its limit, then this exception is thrown.
Below are the examples to illustrate the getDouble() method:
Examples 1:
// Java program to demonstrate// getDouble() 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 double value in the bytebuffer            bb.asDoubleBuffer()                .put(1234.3456)                .put(2884.4444);              // 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.getDouble() + " ");              // rewind the Bytebuffer            bb.rewind();              // Reads the double at this buffer's current position            // using getDouble() method            double value = bb.getDouble();              // print the char value            System.out.println("\n\nByte Value: " + value);              // Reads the char at this buffer's next position            // using getDouble() method            double value1 = bb.getDouble();              // print the char value            System.out.print("\nNext Byte Value: " + value1);        }          catch (BufferUnderflowException e) {              System.out.println("\nException Thrown : " + e);        }    }} |
Output:
Original ByteBuffer: 1234.3456 2884.4444 Byte Value: 1234.3456 Next Byte Value: 2884.4444
Examples 2:
// Java program to demonstrate// getDouble() 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 double value in the bytebuffer            bb.asDoubleBuffer()                .put(1234.3456)                .put(2884.4444);              // 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.getDouble() + " ");              // rewind the Bytebuffer            bb.rewind();              // Reads the double at this buffer's current position            // using getDouble() method            double value = bb.getDouble();              // print the char value            System.out.println("\n\nByte Value: " + value);              // Reads the char at this buffer's next position            // using getDouble() method            double value1 = bb.getDouble();              // print the char value            System.out.println("\nNext Byte Value: " + value1);              // Reads the char at this buffer's next position            // using getDouble() method            double value2 = bb.getDouble();        }          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: 1234.3456 2884.4444 Byte Value: 1234.3456 Next Byte Value: 2884.4444 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#getDouble–
getDouble(int index)
The getDouble(int index) method of ByteBuffer is used to read eight bytes at the given index, composing them into a double value according to the current byte order.
Syntax :
public abstract double getDouble(int index)
Parameters: This method takes index as parameter which is the index from which the Byte will be read.
Return Value: This method returns The double 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 getDouble(int index) method:
Examples 1:
// Java program to demonstrate// getDouble() 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 double value in the bytebuffer            bb.asDoubleBuffer()                .put(1234.3456)                .put(2884.4444);              // rewind the Bytebuffer            bb.rewind();              // Declaring the variable            double c;              // print the ByteBuffer            System.out.println("Original ByteBuffer: ");            for (int i = 1; i <= capacity / 8; i++)                System.out.print(bb.getDouble() + " ");              // rewind the Bytebuffer            bb.rewind();              // Reads the double at this buffer's current position            // using getDouble() method            double value = bb.getDouble(0);              // print the char value            System.out.println("\n\nByte Value: " + value);              // Reads the char at this buffer's next position            // using getDouble() method            double value1 = bb.getDouble(8);              // print the char 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: 1234.3456 2884.4444 Byte Value: 1234.3456 Next Byte Value: 2884.4444
Examples 2:
// Java program to demonstrate// getDouble() 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 double value in the bytebuffer            bb.asDoubleBuffer()                .put(1234.3456)                .put(2884.4444);              // rewind the Bytebuffer            bb.rewind();              // Declaring the variable            double c;              // print the ByteBuffer            System.out.println("Original ByteBuffer: ");            for (int i = 1; i <= capacity / 8; i++)                System.out.print(bb.getDouble() + " ");              // rewind the Bytebuffer            bb.rewind();              // Reads the double at this buffer's current position            // using getDouble() method            double value = bb.getDouble(0);              // print the char value            System.out.println("\n\nByte Value: " + value);              // Reads the char at this buffer's next position            // using getDouble() method            double value1 = bb.getDouble(9);              // print the char 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: 1234.3456 2884.4444 Byte Value: 1234.3456 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#getDouble-int-
