Java DoubleBuffer duplicate()方法及示例

java.nio.DoubleBuffer 类的 replicate() 方法用于创建一个新的浮动缓冲区，共享给定的缓冲区的内容。

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 DoubleBuffer duplicate()

返回值： 该方法返回 新的双缓冲区 ，该缓冲区承载了之前的双缓冲区内容。

下面是一些例子来说明double()方法。

程序1:

// Java program to demonstrate// duplicate() method// Using direct Doublebuffer  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        try {              // creating object of Doublebuffer            // and allocating size capacity            DoubleBuffer db1 = DoubleBuffer.allocate(capacity);              // putting the value in Doublebuffer            db1.put(8.56F);            db1.put(2, 9.61F);            db1.rewind();              // print the Original DoubleBuffer            System.out.println("Original DoubleBuffer:  "                               + Arrays.toString(db1.array()));              // Creating a duplicate copy of DoubleBuffer            // using duplicate() method            DoubleBuffer db2 = db1.duplicate();              // print the duplicate copy of DoubleBuffer            System.out.print("\nDuplicate DoubleBuffer: "                             + Arrays.toString(db2.array()));        }          catch (IllegalArgumentException e) {              System.out.println("IllegalArgumentException catched");        }          catch (ReadOnlyBufferException e) {              System.out.println("ReadOnlyBufferException catched");        }    }}

输出:

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

例2 :

// Java program to demonstrate// duplicate() method// using read-onlyDoublebuffer  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        try {              // creating object of Doublebuffer            // and allocating size capacity            DoubleBuffer db1 = DoubleBuffer.allocate(capacity);              // putting the value in Doublebuffer            db1.put(8.56F);            db1.put(2, 9.61F);            db1.rewind();              // print the Original DoubleBuffer            System.out.println("Original DoubleBuffer:  "                               + Arrays.toString(db1.array()));              // Creating a read-only copy of DoubleBuffer            // using asReadOnlyBuffer() method            DoubleBuffer readonly = db1.asReadOnlyBuffer();              // print the read-only copy of DoubleBuffer            System.out.print("\nread-only DoubleBuffer:  ");            while (readonly.hasRemaining())                System.out.print(readonly.get() + ", ");            System.out.println("");              // Rewinding the readonly DoubleBuffer            readonly.rewind();              // Creating a duplicate copy of DoubleBuffer            // using duplicate() method            DoubleBuffer db2 = readonly.duplicate();              // print the duplicate copy of DoubleBuffer            System.out.print("\nduplicate copy of read-only DoubleBuffer:  ");              while (db2.hasRemaining())                System.out.print(db2.get() + ", ");            System.out.println("");        }          catch (IllegalArgumentException e) {              System.out.println("IllegalArgumentException catched");        }          catch (ReadOnlyBufferException e) {              System.out.println("ReadOnlyBufferException catched");        }    }}

输出:

Original DoubleBuffer:  [8.5600004196167, 0.0, 9.609999656677246, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0]read-only DoubleBuffer:  8.5600004196167, 0.0, 9.609999656677246, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, duplicate copy of read-only DoubleBuffer:  8.5600004196167, 0.0, 9.609999656677246, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0,