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); } } } |
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); } } } |
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–
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); } } } |
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); } } } |
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-