Java FloatBuffer duplicate()方法及示例

java.nio.FloatBuffer 类的 replicate() 方法用于创建一个新的 Float缓冲区 ，共享给定缓冲区的内容。

新的缓冲区的内容将是这个缓冲区的内容。这个缓冲区的内容的变化将在新的缓冲区中可见，反之亦然；两个缓冲区的位置、极限和标记值将是独立的。

新缓冲区的容量、极限、位置和标记值将与这个缓冲区的相同。当且仅当这个缓冲区是直接的，新的缓冲区将是直接的，当且仅当这个缓冲区是只读的，它将是只读的。

语法:

public abstract FloatBuffer duplicate()

返回值： 该方法返回 新的Float缓冲区 ，该缓冲区承载了 之前的Float缓冲区 内容。

下面是一些例子来说明 duplicate() 方法。

例子1： 直接使用Float缓冲区

// Java program to demonstrate
// duplicate() method
// Using direct floatbuffer
  
import java.nio.*;
import java.util.*;
  
public class GFG {
  
    public static void main(String[] args)
    {
  
        // Declaring the capacity of the FloatBuffer
        int capacity = 10;
  
        // Creating the FloatBuffer
        try {
  
            // creating object of floatbuffer
            // and allocating size capacity
            FloatBuffer fb1 = FloatBuffer.allocate(capacity);
  
            // putting the value in floatbuffer
            fb1.put(8.56F);
            fb1.put(2, 9.61F);
            fb1.rewind();
  
            // print the Original FloatBuffer
            System.out.println("Original FloatBuffer:  "
                               + Arrays.toString(fb1.array()));
  
            // Creating a duplicate copy of FloatBuffer
            // using duplicate() method
            FloatBuffer fb2 = fb1.duplicate();
  
            // print the duplicate copy of FloatBuffer
            System.out.print("\nDuplicate FloatBuffer: "
                             + Arrays.toString(fb2.array()));
        }
  
        catch (IllegalArgumentException e) {
  
            System.out.println("IllegalArgumentException catched");
        }
  
        catch (ReadOnlyBufferException e) {
  
            System.out.println("ReadOnlyBufferException catched");
        }
    }
}

输出。

Original FloatBuffer:  [8.56, 0.0, 9.61, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0]

Duplicate FloatBuffer: [8.56, 0.0, 9.61, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0]

实例2： 使用只读Float缓冲区(readlyfloatbuffer)

// Java program to demonstrate
// duplicate() method
// using read-onlyfloatbuffer
  
import java.nio.*;
import java.util.*;
  
public class GFG {
  
    public static void main(String[] args)
    {
  
        // Declaring the capacity of the FloatBuffer
        int capacity = 10;
  
        // Creating the FloatBuffer
        try {
  
            // creating object of floatbuffer
            // and allocating size capacity
            FloatBuffer fb1 = FloatBuffer.allocate(capacity);
  
            // putting the value in floatbuffer
            fb1.put(8.56F);
            fb1.put(2, 9.61F);
            fb1.rewind();
  
            // print the Original FloatBuffer
            System.out.println("Original FloatBuffer:  "
                               + Arrays.toString(fb1.array()));
  
            // Creating a read-only copy of FloatBuffer
            // using asReadOnlyBuffer() method
            FloatBuffer readonly = fb1.asReadOnlyBuffer();
  
            // print the read-only copy of FloatBuffer
            System.out.print("\nread-only FloatBuffer:  ");
            while (readonly.hasRemaining())
                System.out.print(readonly.get() + ", ");
            System.out.println("");
  
            // Rewinding the readonly FloatBuffer
            readonly.rewind();
  
            // Creating a duplicate copy of FloatBuffer
            // using duplicate() method
            FloatBuffer fb2 = readonly.duplicate();
  
            // print the duplicate copy of FloatBuffer
            System.out.print("\nduplicate copy of read-only FloatBuffer:  ");
  
            while (fb2.hasRemaining())
                System.out.print(fb2.get() + ", ");
            System.out.println("");
        }
  
        catch (IllegalArgumentException e) {
  
            System.out.println("IllegalArgumentException catched");
        }
  
        catch (ReadOnlyBufferException e) {
  
            System.out.println("ReadOnlyBufferException catched");
        }
    }
}

输出。

Original FloatBuffer:  [8.56, 0.0, 9.61, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0]

read-only FloatBuffer:  8.56, 0.0, 9.61, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 

duplicate copy of read-only FloatBuffer:  8.56, 0.0, 9.61, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0,