Java FloatBuffer asReadOnlyBuffer()用法及代码示例

java.nio.FloatBuffer类的asReadOnlyBuffer()方法用于使用该缓冲区的内容创建一个新的只读float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 FloatBuffer asReadOnlyBuffer()

返回值：此方法返回新的只读float缓冲区，其内容与此缓冲区相同。

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 FloatBuffer 
        int capacity = 10; 
  
        // Creating the FloatBuffer 
        try { 
  
            // creating object of floatbuffer 
            // and allocating size capacity 
            FloatBuffer fb = FloatBuffer.allocate(capacity); 
  
            // putting the value in floatbuffer 
            fb.put(8.56F); 
            fb.put(2, 9.61F); 
            fb.rewind(); 
  
            // print the FloatBuffer 
            System.out.println("Original FloatBuffer:  "
                               + Arrays.toString(fb.array())); 
  
            // Creating a read-only copy of FloatBuffer 
            // using asReadOnlyBuffer() method 
            FloatBuffer floatBuffer = fb.asReadOnlyBuffer(); 
  
            // print the FloatBuffer 
            System.out.print("\nReadOnlyBuffer FloatBuffer: "); 
  
            while (floatBuffer.hasRemaining()) 
                System.out.print(floatBuffer.get() + ", "); 
        } 
  
        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]

ReadOnlyBuffer FloatBuffer: 8.56, 0.0, 9.61, 0.0, 0.0, 0.0, 0.0, 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 fb 
        int capacity1 = 10; 
  
        // Declaring the capacity of the fb1 
        int capacity2 = 5; 
  
        // Creating the FloatBuffer 
        try { 
  
            // 
            // fb 
            // 
            // creating object of floatbuffer fb 
            // and allocating size capacity 
            FloatBuffer fb = FloatBuffer.allocate(capacity1); 
  
            // putting the value in fb 
            fb.put(8.56F); 
            fb.put(2, 9.61F); 
            fb.rewind(); 
  
            // print the FloatBuffer 
            System.out.println("FloatBuffer fb: "
                               + Arrays.toString(fb.array())); 
  
            // 
            // fb1 
            // 
            // creating object of floatbuffer fb1 
            // and allocating size capacity 
            FloatBuffer fb1 = FloatBuffer.allocate(capacity2); 
  
            // putting the value in fb1 
            fb1.put(1, 4.56F); 
            fb1.put(2, 6.45F); 
            fb1.rewind(); 
  
            // print the FloatBuffer 
            System.out.println("\nFloatBuffer fb1:  "
                               + Arrays.toString(fb1.array())); 
  
            // Creating a read-only copy of FloatBuffer 
            // using asReadOnlyBuffer() method 
            FloatBuffer readOnlyFb = fb.asReadOnlyBuffer(); 
  
            // print the FloatBuffer 
            System.out.print("\nReadOnlyBuffer FloatBuffer: "); 
  
            while (readOnlyFb.hasRemaining()) 
                System.out.print(readOnlyFb.get() + ", "); 
  
            // try to change readOnlyFb 
            System.out.println("\n\nTrying to get the array"
                               + " from ReadOnlyFb for editing"); 
  
            float[] fbarr = readOnlyFb.array(); 
        } 
        catch (IllegalArgumentException e) { 
            System.out.println("IllegalArgumentException catched"); 
        } 
        catch (ReadOnlyBufferException e) { 
            System.out.println("Exception thrown: " + e); 
        } 
    } 
}

输出：

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

FloatBuffer fb1:  [0.0, 4.56, 6.45, 0.0, 0.0]

ReadOnlyBuffer FloatBuffer: 8.56, 0.0, 9.61, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 

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

相关用法

注：本文由纯净天空筛选整理自RohitPrasad3大神的英文原创作品 FloatBuffer asReadOnlyBuffer() method in Java with Examples。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。