The compact() method of java.nio.CharBuffer Class is used to compact the given buffer.
The values between the buffer’s current position and its limit are copied to the beginning of the buffer. The buffer’s position is then set to n+1 and its limit is set to its capacity. The buffer’s position is set to the number of floats copied.
Syntax:
public abstract CharBuffer compact()
Return Value: This method returns the new CharBuffer with the same content as that of this buffer.
Exception: This method throws the ReadOnlyBufferException, If this buffer is read-only.
Below program illustrates the compact() method:
Example 1:
// Java program to demonstrate // compact() method import java.nio.*;
import java.util.*;
public class GFG {
public static void main(String[] args)
{
// Declaring the capacity of the CharBuffer
int capacity = 10 ;
// Creating the CharBuffer
// creating object of Intbuffer
// and allocating size capacity
CharBuffer ic = CharBuffer.allocate(capacity);
// putting the value in Intbuffer
ic.put( 'a' );
ic.put( 'b' );
ic.put( 'c' );
// print the CharBuffer
System.out.println( "Original CharBuffer: "
+ Arrays.toString(ic.array()));
System.out.println( "Position: " + ic.position());
System.out.println( "limit: " + ic.limit());
// Creating a compacted CharBuffer of same CharBuffer
// using compact() method
CharBuffer CharBuffer = ic.compact();
// print the CharBuffer
System.out.println( "\nCompacted CharBuffer: "
+ Arrays.toString(CharBuffer.array()));
System.out.println( "Position: " + CharBuffer.position());
System.out.println( "limit: " + CharBuffer.limit());
// putting the value in compacted Intbuffer
CharBuffer.put( 'g' );
// print the CharBuffer
System.out.println( "\nUpdated Compacted CharBuffer: "
+ Arrays.toString(CharBuffer.array()));
System.out.println( "Position: " + CharBuffer.position());
System.out.println( "limit: " + CharBuffer.limit());
}
} |
Original CharBuffer: [a, b, c, , , , , , , ] Position: 3 limit: 10 Compacted CharBuffer: [, , , , , , , , , ] Position: 7 limit: 10 Updated Compacted CharBuffer: [, , , , , , , g, , ] Position: 8 limit: 10
Example 2:
// Java program to demonstrate // compact() method import java.nio.*;
import java.util.*;
public class GFG {
public static void main(String[] args)
{
// Declaring the capacity of the CharBuffer
int capacity = 10 ;
// Creating the CharBuffer
try {
// creating object of CharBuffer
// and allocating size capacity
CharBuffer cb = CharBuffer.allocate(capacity);
// putting the value in CharBuffer
cb.put( 'a' );
cb.put( 'b' );
cb.put( 'b' );
cb.rewind();
// Creating a read-only copy of CharBuffer
// using asReadOnlyBuffer() method
CharBuffer cb1 = cb.asReadOnlyBuffer();
// print the ReadOnlyBuffer
System.out.print( "ReadOnlyBuffer CharBuffer: " );
while (cb1.hasRemaining())
System.out.print(cb1.get() + ", " );
System.out.println( "" );
// print the Position of CharBuffer cb
System.out.println( "\nPosition: " + cb.position());
// print the Limit of CharBuffer cb
System.out.println( "\nlimit: " + cb.limit());
// Creating a compacted CharBuffer of same ReadOnlyBuffer
// using compact() method
System.out.println( "\nTrying to compact the ReadOnlyBuffer cb1" );
CharBuffer CharBuffer = cb1.compact();
}
catch (IllegalArgumentException e) {
System.out.println( "Exception throws " + e);
}
catch (ReadOnlyBufferException e) {
System.out.println( "Exception throws " + e);
}
}
} |
ReadOnlyBuffer CharBuffer: a, b, b, , , , , , , , Position: 0 limit: 10 Trying to compact the ReadOnlyBuffer cb1 Exception throws java.nio.ReadOnlyBufferException