The rewind() method of java.nio.FloatBuffer Class is used to rewind this buffer. This method sets the position to zero and limit remains unaffected and if there is any position which was previously marked, will be discarded. This method should be invoked when there is any necessity of sequence of channel-write or get operations. It means that if buffer data is already written then it is needed to be copied into another array. For example:
out.write(buf); // Writes the remaining data buf.rewind(); // Rewind the buffer buf.get(array); // Copy data into array
Syntax:
public final FloatBuffer rewind()
Parameters: The method does not take any parameters.
Return Value: The method returns this buffer.
Below are the examples to illustrate the rewind() method:
Examples 1:
// Java program to demonstrate// rewind() method import java.nio.*;import java.util.*; public class GFG { public static void main(String[] args) { // defining and allocating FloatBuffer // using allocate() method FloatBuffer floatBuffer = FloatBuffer.allocate(4); // put char value in FloatBuffer // using put() method floatBuffer.put(10.5f); floatBuffer.put(20.5f); // print the float buffer System.out.println("Buffer before operation: " + Arrays.toString( floatBuffer.array()) + "\nPosition: " + floatBuffer.position() + "\nLimit: " + floatBuffer.limit()); // rewind the Buffer // using rewind() method floatBuffer.rewind(); // print the floatbuffer System.out.println("\nBuffer after operation: " + Arrays.toString( floatBuffer.array()) + "\nPosition: " + floatBuffer.position() + "\nLimit: " + floatBuffer.limit()); }} |
Output:
Buffer before operation: [10.5, 20.5, 0.0, 0.0] Position: 2 Limit: 4 Buffer after operation: [10.5, 20.5, 0.0, 0.0] Position: 0 Limit: 4
Examples 2:
// Java program to demonstrate// rewind() method import java.nio.*;import java.util.*; public class GFG { public static void main(String[] args) { // defining and allocating FloatBuffer // using allocate() method FloatBuffer floatBuffer = FloatBuffer.allocate(5); // put float value in floatBuffer // using put() method floatBuffer.put(10.5f); floatBuffer.put(20.5f); floatBuffer.put(30.5f); // mark will be going to discarded by rewind() floatBuffer.mark(); // print the buffer System.out.println("Buffer before operation: " + Arrays.toString( floatBuffer.array()) + "\nPosition: " + floatBuffer.position() + "\nLimit: " + floatBuffer.limit()); // Rewind the Buffer // using rewind() method floatBuffer.rewind(); // print the buffer System.out.println("\nBuffer after operation: " + Arrays.toString( floatBuffer.array()) + "\nPosition: " + floatBuffer.position() + "\nLimit: " + floatBuffer.limit()); }} |
Output:
Buffer before operation: [10.5, 20.5, 30.5, 0.0, 0.0] Position: 3 Limit: 5 Buffer after operation: [10.5, 20.5, 30.5, 0.0, 0.0] Position: 0 Limit: 5
Reference: https://docs.oracle.com/javase/9/docs/api/java/nio/FloatBuffer.html#rewind–
