Java ShortBuffer compact()用法及代码示例

java.nio.ShortBuffer类的compact()方法用于压缩给定的缓冲区。缓冲区当前位置与其极限(如果有)之间的空头将复制到缓冲区的开头。也就是说，将索引p = position()的空缺复制到索引零，将索引p + 1的短缺复制到索引一，依此类推，直到索引limit() – 1的短缺复制到索引n = limit() – 1 – p。然后将缓冲区的位置设置为n + 1，并将其限制设置为其容量。如果定义了该标记，则将其丢弃。缓冲区的位置设置为复制的空头数量，而不是零，以便在调用此方法后可以立即调用另一个相对的put方法。

用法：

public abstract ShortBuffer compact()

返回值：此方法返回具有与此缓冲区相同内容的新ShortBuffer。

异常：如果此缓冲区是只读的，则此方法将引发ReadOnlyBufferException。

以下示例程序旨在说明compact()方法：

程序1：

// Java program to demonstrate 
// compact() method 
  
import java.nio.*; 
import java.util.*; 
  
public class GFG { 
    public static void main(String[] args) 
    { 
  
        // Declaring the capacity of the ShortBuffer 
        int capacity = 10; 
  
        // Creating the ShortBuffer 
  
        // creating object of shortbuffer 
        // and allocating size capacity 
        ShortBuffer sb = ShortBuffer.allocate(capacity); 
  
        // putting the value in shortbuffer 
        sb.put((short)856); 
        sb.put((short)961); 
        sb.put((short)54); 
  
        // print the ShortBuffer 
        System.out.println("Original ShortBuffer: "
                           + Arrays.toString(sb.array())); 
  
        System.out.println("Position: " + sb.position()); 
  
        System.out.println("limit: " + sb.limit()); 
  
        // Creating a compacted ShortBuffer of same ShortBuffer 
        // using compact() method 
        ShortBuffer shortBuffer = sb.compact(); 
  
        // print the ShortBuffer 
        System.out.println("\nCompacted ShortBuffer: "
                           + Arrays.toString(shortBuffer.array())); 
  
        System.out.println("Position: " + shortBuffer.position()); 
  
        System.out.println("limit: " + shortBuffer.limit()); 
  
        // putting the value in compacted shortbuffer 
        shortBuffer.put((short)961); 
  
        // print the ShortBuffer 
        System.out.println("\nUpdated Compacted ShortBuffer: "
                           + Arrays.toString(shortBuffer.array())); 
        System.out.println("Position: " + shortBuffer.position()); 
        System.out.println("limit: " + shortBuffer.limit()); 
    } 
}

输出：

Original ShortBuffer: [856, 961, 54, 0, 0, 0, 0, 0, 0, 0]
Position: 3
limit: 10

Compacted ShortBuffer: [0, 0, 0, 0, 0, 0, 0, 0, 0, 0]
Position: 7
limit: 10

Updated Compacted ShortBuffer: [0, 0, 0, 0, 0, 0, 0, 961, 0, 0]
Position: 8
limit: 10

示例2:演示ReadOnlyBufferException。

// Java program to demonstrate 
// compact() method 
  
import java.nio.*; 
import java.util.*; 
  
public class GFG { 
    public static void main(String[] args) 
    { 
  
        // Declaring the capacity of the ShortBuffer 
        int capacity = 10; 
  
        // Creating the ShortBuffer 
        try { 
  
            // creating object of ShortBuffer 
            // and allocating size capacity 
            ShortBuffer sb = ShortBuffer.allocate(capacity); 
  
            // putting the value in floatbuffer 
            sb.put((short)856); 
            sb.put((short)961); 
            sb.put((short)6010); 
            sb.rewind(); 
  
            // Creating a read-only copy of ShortBuffer 
            // using asReadOnlyBuffer() method 
            ShortBuffer sb1 = sb.asReadOnlyBuffer(); 
  
            // print the ReadOnlyBuffer 
            System.out.print("ReadOnlyBuffer ShortBuffer: "); 
            while (sb1.hasRemaining()) 
                System.out.print(sb1.get() + ", "); 
            System.out.println(""); 
  
            // print the Position of ShortBuffer sb 
            System.out.println("\nPosition: " + sb.position()); 
  
            // print the Limit of ShortBuffer fb 
            System.out.println("\nlimit: " + sb.limit()); 
  
            // Creating a compacted ShortBuffer of same ReadOnlyBuffer 
            // using compact() method 
            System.out.println("\nTrying to compact the ReadOnlyBuffer sb1"); 
  
            ShortBuffer floatBuffer = sb1.compact(); 
        } 
  
        catch (IllegalArgumentException e) { 
            System.out.println("Exception throws " + e); 
        } 
  
        catch (ReadOnlyBufferException e) { 
            System.out.println("Exception throws " + e); 
        } 
    } 
}

输出：

ReadOnlyBuffer ShortBuffer: 856, 961, 6010, 0, 0, 0, 0, 0, 0, 0, 

Position: 0

limit: 10

Trying to compact the ReadOnlyBuffer sb1
Exception throws java.nio.ReadOnlyBufferException

相关用法

注：本文由纯净天空筛选整理自IshwarGupta大神的英文原创作品 ShortBuffer compact() 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。