Java IntBuffer asReadOnlyBuffer()用法及代码示例

java.nio.IntBuffer类的asReadOnlyBuffer()方法用于使用该缓冲区的内容创建一个新的只读int缓冲区。新缓冲区是此缓冲区的副本。因此，对该缓冲区内容所做的更改将在新缓冲区中可见。

由于新缓冲区是只读缓冲区，因此不允许对其内容进行任何修改。这两个缓冲区的位置，限制和标记值将是独立的。新缓冲区的容量，限制，位置和标记值将与此缓冲区相同。如果此缓冲区本身是只读的，则此方法的行为与重复方法完全相同。

用法:

public abstract IntBuffer asReadOnlyBuffer()

返回值：此方法返回新的只读int缓冲区，其内容与此缓冲区的内容相同。

下面是说明asReadOnlyBuffer()方法的示例：

范例1：

// Java program to demonstrate 
// asReadOnlyBuffer() 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(8); 
            ib.put(2, 9); 
            ib.rewind(); 
  
            // print the IntBuffer 
            System.out.println("Original IntBuffer:  "
                               + Arrays.toString(ib.array())); 
  
            // Creating a read-only copy of IntBuffer 
            // using asReadOnlyBuffer() method 
            IntBuffer IntBuffer = ib.asReadOnlyBuffer(); 
  
            // print the IntBuffer 
            System.out.print("\nReadOnlyBuffer IntBuffer: "); 
  
            while (IntBuffer.hasRemaining()) 
                System.out.print(IntBuffer.get() + ", "); 
        } 
  
        catch (IllegalArgumentException e) { 
            System.out.println("IllegalArgumentException catched"); 
        } 
  
        catch (ReadOnlyBufferException e) { 
            System.out.println("ReadOnlyBufferException catched"); 
        } 
    } 
}

输出：

Original IntBuffer:  [8, 0, 9, 0, 0, 0, 0, 0, 0, 0]

ReadOnlyBuffer IntBuffer: 8, 0, 9, 0, 0, 0, 0, 0, 0, 0,

范例2：

// Java program to demonstrate 
// asReadOnlyBuffer() method 
  
import java.nio.*; 
import java.util.*; 
  
public class GFG { 
    public static void main(String[] args) throws Exception 
    { 
  
        // Declaring the capacity of the ib 
        int capacity1 = 10; 
  
        // Declaring the capacity of the ib1 
        int capacity2 = 5; 
  
        // Creating the IntBuffer 
        try { 
   
            // creating object of Intbuffer ib 
            // and allocating size capacity 
            IntBuffer ib = IntBuffer.allocate(capacity1); 
  
            // putting the value in ib 
            ib.put(8); 
            ib.put(2, 9); 
            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: [8, 0, 9, 0, 0, 0, 0, 0, 0, 0]

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

ReadOnlyBuffer IntBuffer: 8, 0, 9, 0, 0, 0, 0, 0, 0, 0, 

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

相关用法

注：本文由纯净天空筛选整理自nitin_sharma大神的英文原创作品 IntBuffer asReadOnlyBuffer() method in Java。非经特殊声明，原始代码版权归原作者所有，本译文未经允许或授权，请勿转载或复制。