public static DoubleBuffer allocate(int capacity)

// Java program to demonstrate
// allocate() method
 
import java.nio.*;
import java.util.*;
 
public class GFG {
    public static void main(String[] args)
    {
 
        // Declaring the capacity of the DoubleBuffer
        int capacity = 10;
 
        // Creating the DoubleBuffer
 
        // creating object of Doublebuffer
        // and allocating size capacity
        DoubleBuffer db = DoubleBuffer.allocate(capacity);
 
        // putting the value in Doublebuffer
        db.put(8.56F);
        db.put(2, 9.61F);
 
        System.out.println("DoubleBuffer: "
                           + Arrays.toString(db.array()));
    }
}

DoubleBuffer: [8.5600004196167, 0.0, 9.609999656677246, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0]

// Java program to demonstrate
// allocate() method
 
import java.nio.*;
import java.util.*;
 
public class GFG {
    public static void main(String[] args)
    {
 
        // Declaring the capacity of the DoubleBuffer
        // by negative integer
        int capacity = -10;
 
        // Creating the DoubleBuffer
        try {
 
            // creating object of Doublebuffer
            // and allocating size with negative integer
            System.out.println("Trying to allocate a negative integer");
 
            DoubleBuffer db = DoubleBuffer.allocate(capacity);
        }
        catch (IllegalArgumentException e) {
            System.out.println("Exception thrown: " + e);
        }
    }
}

Trying to allocate a negative integer
Exception thrown: java.lang.IllegalArgumentException: capacity < 0: (-10 < 0)