LongBuffer holds a sequence of long values to be used in an I/O operation. The LongBuffer class provides the following four categories of operations upon long buffers:
- Absolute and relative get and put methods that read and write single longs.
- Relative bulk get methods that transfer contiguous sequences of longs from this buffer into an array.
- Relative bulk put methods that transfer contiguous sequences of longs from a long array or some other long buffer into this buffer.
- A method for compacting a long buffer.
Long buffers can be created by:
- allocate() method, which allocates space for the buffer’s content,
- wrap() method, which wraps an existing long array into a buffer, or
- by creating a view of an existing byte buffer.
Most of the methods of LongBuffer class are directly analogous to the methods defined by ByteBuffer.
Syntax: Class Declaration
public abstract class LongBuffer extends Buffer implements Comparable<LongBuffer>
All of the methods of LongBuffer class are listed below as follows:
Method | Description |
---|---|
allocate(int capacity) | This method allocates a new long buffer. |
array() | This method returns the long array that backs this buffer. |
arrayOffset() | This method returns the offset within this buffer’s backing array of the first element of the buffer. |
asReadOnlyBuffer() | This method creates a new, read-only long buffer that shares this buffer’s content. |
clear() | This method clears this buffer. |
compact() | This method compacts this buffer. |
compareTo(LongBuffer that) | This method compares this buffer to another. |
duplicate() | This method creates a new long buffer that shares this buffer’s content. |
equals(Object ob) | This method tells whether or not this buffer is equal to another object. |
flip() | This method flips this buffer. |
get() | This method is a relative get method and returns the long at the buffer’s current position. |
get(int index) | This method is an absolute get method and returns the long at the given index. |
get(long[] dst) | This method is a relative bulk get method and returns this buffer. |
get(long[] dst, int offset, int length) | This method is a relative bulk get method and returns this buffer. |
hasArray() | This method tells whether this buffer is backed by an accessible long array. |
hashCode() | This method returns the current hash code of this buffer. |
isDirect() | This method tells whether this long buffer is direct. |
limit(int newLimit) | This method sets this buffer’s limit. |
mark() | This method sets this buffer’s mark at its position. |
order() | This method retrieves this buffer’s byte order. |
position(int newPosition) | This method sets this buffer’s position. |
put(int index, long l) | This method is an absolute put method and returns this buffer. |
put(long l) | This method is a relative put method and returns this buffer. |
put(long[] src) | This method is a relative bulk put method and returns this buffer. |
put(long[] src, int offset, int length) | This method is a relative bulk put method and returns this buffer. |
put(LongBuffer src) | This method is a relative bulk put method and returns this buffer. |
reset() | This method resets this buffer’s position to the previously-marked position. |
rewind() | This method rewinds this buffer. |
slice() | This method creates a new long buffer whose content is a shared subsequence of this buffer’s content. |
toString() | This method returns a string summarizing the state of this buffer. |
wrap(long[] array) | This method wraps a long array into a buffer. |
wrap(long[] array, int offset, int length) | This method wraps a long array into a buffer. |
Following are some programs to demonstrate LongBuffer class and its methods:
Example 1:
Java
// Java program to demonstrate LongBuffer class // Importing input output classes import java.nio.*;
// Importing all utility classes import java.util.*;
// Main Class public class GFG {
// Main driver method
public static void main(String[] args)
{
// Declaring and initializing variable to
// the capacity of the LongBuffer
int capacity = 5 ;
// try block to check for exceptions
try {
// creating object of Longbuffer
// and allocating size capacity
LongBuffer ib = LongBuffer.allocate(capacity);
// Adding elements to the objects of Longbuffer
// class
// using the pur() method
ib.put( 9 );
ib.put( 8 );
ib.put( 5 );
ib.rewind();
// print the original LongBuffer
// using standard toString() method
System.out.println(
"Original LongBuffer: "
+ Arrays.toString(ib.array()));
// Reads the Long at this buffer's current
// position using get() method
Long value = ib.get();
// Print the Long value
System.out.println( "Long Value: " + value);
// Reads the Long at this buffer's next position
// using get() method
Long value1 = ib.get();
// Agan, now print the Long value
System.out.print( "Next Long Value: " + value1);
}
// Catch blocks to handle the exceptions
// Catch block 1
catch (IllegalArgumentException e) {
// Print the message when there is illegal
// arguments
System.out.println(
"IllegalArgumentException catched" );
}
// Catch block 2
catch (ReadOnlyBufferException e) {
// Print statement when an exception is encountered
System.out.println(
"ReadOnlyBufferException catched" );
}
// Catch block 3
catch (BufferUnderflowException e) {
// Print statement when an exception is encountered
System.out.println( "Exception throws: " + e);
}
}
} |
Output
Original LongBuffer: [9, 8, 5, 0, 0] Long Value: 9 Next Long Value: 8
Example 2:
Java
// Java program to demonstrate LongBuffer class // Importing required libraries import java.nio.*;
import java.util.*;
// Main Class public class GFG {
public static void main(String[] args)
{
// Declaring and initializing variable to
// capacity of the LongBuffer
int Capacity = 10 ;
// Creating the LongBuffer
// creating object of Longbuffer
// and allocating size capacity
LongBuffer ib = LongBuffer.allocate(Capacity);
// Inserting the value in Longbuffer
// Custom entries
ib.put( 11 );
ib.put( 5 , 22 );
// Print all the elements inside Longbuffer by
// use of Arrays.toString() method
System.out.println( "LongBuffer: "
+ Arrays.toString(ib.array()));
}
} |
Output
LongBuffer: [11, 0, 0, 0, 0, 22, 0, 0, 0, 0]
Article Tags :