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-