Java IntBuffer array()方法

java.nio.IntBuffer 类的 array() 方法是用来返回支持这个缓冲区的int数组。对这个缓冲区内容的修改将导致返回数组的内容被修改，反之亦然。在调用此方法之前，先使用Invoke()和hasArray()方法，以确保此缓冲区有一个可访问的支持数组。

语法

public final int[] array()

返回值： 该方法返回支持该缓冲区的数组。

异常： 该方法抛出 ReadOnlyBufferException （如果这个缓冲区是由一个数组支持的，但是是只读的）。

下面的程序说明了 array() 方法。

例子 1 :

// Java program to demonstrate
// array() method
  
import java.nio.*;
import java.util.*;
  
public class GFG {
    public static void main(String[] args)
    {
  
        // Declaring the capacity of the IntBuffer
        int capacity = 10;
  
        // Creating the IntBuffer
        try {
  
            // creating object of Intbuffer
            // and allocating size capacity
            IntBuffer ib = IntBuffer.allocate(capacity);
  
            // putting the value in Intbuffer
            ib.put(7);
            ib.put(2, 6);
            ib.rewind();
  
            // getting array from ib IntBuffer using array() method
            int[] ibb = ib.array();
  
            // printing the IntBuffer ib
            System.out.println("IntBuffer:  "
                               + Arrays.toString(ibb));
        }
  
        catch (IllegalArgumentException e) {
  
            System.out.println("IllegalArgumentException catched");
        }
  
        catch (ReadOnlyBufferException e) {
  
            System.out.println("ReadOnlyBufferException catched");
        }
    }
}

输出:

IntBuffer:  [7, 0, 6, 0, 0, 0, 0, 0, 0, 0]

例子 2 :

// Java program to demonstrate
// array() method
  
import java.nio.*;
import java.util.*;
  
public class GFG {
    public static void main(String[] args)
    {
  
        // Declaring the capacity of the ib
        int capacity1 = 10;
  
        // Declaring the capacity of the ib1
        int capacity2 = 5;
  
        // Creating the IntBuffer
        try {
            //
            // ib
            //
            // creating object of Intbuffer ib
            // and allocating size capacity
            IntBuffer ib = IntBuffer.allocate(capacity1);
  
            // putting the value in ib
            ib.put(7);
            ib.put(2, 6);
            ib.put(3, 7);
            ib.rewind();
  
            // print the IntBuffer
            System.out.println("IntBuffer ib: "
                               + Arrays.toString(ib.array()));
  
            //
            // ib1
            //
            // creating object of Intbuffer ib1
            // and allocating size capacity
            IntBuffer ib1 = IntBuffer.allocate(capacity2);
  
            // putting the value in ib1
            ib1.put(1, 4);
            ib1.put(2, 6);
            ib1.rewind();
  
            // print the IntBuffer
            System.out.println("\nIntBuffer ib1:  "
                               + Arrays.toString(ib1.array()));
  
            // Creating a read-only copy of IntBuffer
            // using asReadOnlyBuffer() method
            IntBuffer readOnlyib = ib.asReadOnlyBuffer();
  
            // print the IntBuffer
            System.out.print("\nReadOnlyBuffer IntBuffer: ");
  
            while (readOnlyib.hasRemaining())
                System.out.print(readOnlyib.get() + ", ");
  
            // try to change readOnlyib
            System.out.println("\n\nTrying to get the array"
                               + " from ReadOnlyib for editing");
  
            int[] ibarr = readOnlyib.array();
        }
        catch (IllegalArgumentException e) {
            System.out.println("IllegalArgumentException catched");
        }
        catch (ReadOnlyBufferException e) {
            System.out.println("Exception thrown: " + e);
        }
    }
}

输出:

IntBuffer ib: [7, 0, 6, 7, 0, 0, 0, 0, 0, 0]

IntBuffer ib1:  [0, 4, 6, 0, 0]

ReadOnlyBuffer IntBuffer: 7, 0, 6, 7, 0, 0, 0, 0, 0, 0, 

Trying to get the array from ReadOnlyib for editing
Exception thrown: java.nio.ReadOnlyBufferException