Java LongBuffer wrap()用法及代码示例

wrap(Long[] array)

java.nio.LongBuffer类的wrap()方法用于包装Long数组Longo缓冲区。新缓冲区将由给定的Long数组支持；也就是说，对缓冲区的修改将导致数组被修改，反之亦然。新缓冲区的容量和限制为array.length，位置为零，标记未定义。它的支持数组将是给定的数组，其数组偏移量将为零。

用法:

public static LongBuffer wrap(Long[] array)

参数：此方法将array(将支持此缓冲区的数组)作为参数。

返回值：此方法返回新的Long缓冲区。

以下示例程序旨在说明wrap()方法：

程序1：

// Java program to demonstrate 
// asReadOnlyBuffer() method 
  
import java.nio.*; 
import java.util.*; 
  
public class GFG { 
  
    public static void main(String[] args) 
    { 
  
        // Declare and initialize the Long array 
        long[] ibb = { 1L, 2L, 3L }; 
  
        // prLong the Long array length 
        System.out.println("Array length : " + ibb.length); 
  
        // prLong the Long array element 
        System.out.println("\nArray element : "
                           + Arrays.toString(ibb)); 
  
        // wrap the Long array Longo LongBuffer 
        // using wrap() method 
        LongBuffer longBuffer = LongBuffer.wrap(ibb, 0, ibb.length); 
  
        // Rewind the Longbuffer 
        longBuffer.rewind(); 
  
        // prLong the Long buffer 
        System.out.println("\nlongBuffer : "
                           + Arrays.toString(longBuffer.array())); 
  
        // prLong the LongBuffer capacity 
        System.out.println("\nlongbuffer capacity : "
                           + longBuffer.capacity()); 
  
        // prLong the LongBuffer position 
        System.out.println("\nlongbuffer position: "
                           + longBuffer.position()); 
    } 
}

输出：

Array length : 3

Array element : [1, 2, 3]

LongBuffer : [1, 2, 3]

Longbuffer capacity : 3

Longbuffer position:  0

wrap(Long[] array, Long offset, Long length)

新缓冲区将由给定的Long数组支持；也就是说，对缓冲区的修改将导致数组被修改，反之亦然。新缓冲区的容量将为array.length，其位置将偏移，其限制将为offset + length，其标记将是不确定的。它的支持数组将是给定的数组，其数组偏移量将为零。

用法:

public static LongBuffer wrap (Long[] array, Long offset, Long length)

参数：此方法采用以下参数：

array:将支持新缓冲区的数组。
offset:要使用的子数组的偏移量；必须为非负数，且不得大于array.length。新缓冲区的位置将设置为此值。
length:要使用的子数组的长度；必须为非负且不大于array.length –偏移量。新缓冲区的限制将设置为偏移量+长度。

返回值：此方法返回新的浮点缓冲区。

抛出：此方法抛出IndexOutOfBoundsException(如果offset和length参数的前提条件不成立)。

以下示例程序旨在说明wrap()方法：

示例1:

// Java program to demonstrate 
// asReadOnlyBuffer() method 
  
import java.nio.*; 
import java.util.*; 
  
public class GFG { 
  
    public static void main(String[] args) 
    { 
  
        // Declare and initialize the Long array 
        long[] ibb = { 1, 2, 3 }; 
  
        // prLong the Long array length 
        System.out.println("Array length : " + ibb.length); 
  
        // prLong the Long array element 
        System.out.println("\nArray element : "
                           + Arrays.toString(ibb)); 
  
        // wrap the Long array Longo LongBuffer 
        // using wrap() method 
        LongBuffer longBuffer = LongBuffer.wrap(ibb, 0, 
                                                ibb.length); 
  
        // Rewind the Longbuffer 
        longBuffer.rewind(); 
  
        // prLong the Long buffer 
        System.out.println("\nLongBuffer : "
                           + Arrays.toString(longBuffer.array())); 
  
        // prLong the LongBuffer capacity 
        System.out.println("\nLongbuffer capacity : "
                           + longBuffer.capacity()); 
  
        // prLong the LongBuffer position 
        System.out.println("\nLongbuffer position: "
                           + longBuffer.position()); 
    } 
}

输出：

Array length : 3

Array element : [1, 2, 3]

LongBuffer : [1, 2, 3]

Longbuffer capacity : 3

Longbuffer position:  0

示例2:演示NullPoLongerException。

// Java program to demonstrate 
// asReadOnlyBuffer() method 
  
import java.nio.*; 
import java.util.*; 
  
public class GFG { 
  
    public static void main(String[] args) 
    { 
  
        // Declare and initialize the float array 
        long[] ibb = { 1, 2, 3 }; 
  
        // prLong the Long array length 
        System.out.println("Array length : " + ibb.length); 
  
        // prLong the Long array element 
        System.out.println("\nArray element : " + Arrays.toString(ibb)); 
  
        try { 
            // wrap the Long array Longo LongBuffer 
            // using wrap() method 
            System.out.println("\nHere "
                               + "offset and length does not hold"
                               + " the required condition "); 
            LongBuffer longBuffer = LongBuffer.wrap(ibb, 
                                                    1, 
                                                    ibb.length); 
  
            // Rewind the Longbuffer 
            longBuffer.rewind(); 
  
            // prLong the Long buffer 
            System.out.println("\nLongBuffer : "
                               + Arrays.toString(longBuffer.array())); 
  
            // prLong the LongBuffer capacity 
            System.out.println("\nLongbuffer capacity : "
                               + longBuffer.capacity()); 
  
            // prLong the LongBuffer position 
            System.out.println("\nLongbuffer position:  "
                               + longBuffer.position()); 
        } 
        catch (IndexOutOfBoundsException e) { 
            System.out.println("Exception throws:  " + e); 
        } 
    } 
}

输出：

Array length : 3

Array element : [1, 2, 3]

Here offset and length does not hold the required condition 
Exception throws:  java.lang.IndexOutOfBoundsException

相关用法

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