Java DoubleBuffer allocate()用法及代码示例

java.nio.DoubleBuffer类的allocate()方法用于在现有缓冲区旁边分配一个新的双缓冲区。新缓冲区的位置将为零。它的极限将是它的容量。其标记将是不确定的。并且其每个元素都将初始化为零。它将有一个支持数组，其数组偏移量将为零。

用法:

public static DoubleBuffer allocate(int capacity)

参数：此方法将新缓冲区的容量增加一倍，作为参数。

返回值：此方法返回新的双缓冲区。

异常：如果容量为负整数，则此方法引发IllegalArgumentException。

以下示例程序旨在说明allocate()方法：

范例1：

// Java program to demonstrate 
// allocate() method 
  
import java.nio.*; 
import java.util.*; 
  
public class GFG { 
    public static void main(String[] args) 
    { 
  
        // Declaring the capacity of the DoubleBuffer 
        int capacity = 10; 
  
        // Creating the DoubleBuffer 
  
        // creating object of Doublebuffer 
        // and allocating size capacity 
        DoubleBuffer db = DoubleBuffer.allocate(capacity); 
  
        // putting the value in Doublebuffer 
        db.put(8.56F); 
        db.put(2, 9.61F); 
  
        System.out.println("DoubleBuffer: "
                           + Arrays.toString(db.array())); 
    } 
}

输出：

DoubleBuffer: [8.5600004196167, 0.0, 9.609999656677246, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0]

范例2：演示IllegalArgumentException

// Java program to demonstrate 
// allocate() method 
  
import java.nio.*; 
import java.util.*; 
  
public class GFG { 
    public static void main(String[] args) 
    { 
  
        // Declaring the capacity of the DoubleBuffer 
        // by negetive integer 
        int capacity = -10; 
  
        // Creating the DoubleBuffer 
        try { 
  
            // creating object of Doublebuffer 
            // and allocating size with negetive integer 
            System.out.println("Trying to allocate a negetive integer"); 
  
            DoubleBuffer db = DoubleBuffer.allocate(capacity); 
        } 
        catch (IllegalArgumentException e) { 
            System.out.println("Exception thrown: " + e); 
        } 
    } 
}

输出：

Trying to allocate a negetive integer
Exception thrown: java.lang.IllegalArgumentException

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 DoubleBuffer allocate() 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。