Java CharBuffer allocate()用法及代码示例

java.nio.CharBuffer类的allocate()方法用于在现有缓冲区旁边分配一个新的char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 CharBuffer allocate(int capacity)

参数：此方法将以char为单位的新缓冲区的容量作为参数。

返回值：此方法返回新的char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 CharBuffer 
        char capacity = 10; 
  
        // Creating the CharBuffer 
  
        // creating object of Charbuffer 
        // and allocating size capacity 
        CharBuffer fb = CharBuffer.allocate(capacity); 
  
        // putting the value in charbuffer 
        fb.put('a'); 
        fb.put(3, 'b'); 
  
        // Printing the CharBuffer 
        System.out.println("ChartBuffer: "
                           + Arrays.toString(fb.array())); 
    } 
}

输出：

ChartBuffer: [a, , , b, , , , , , ]

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 CharBuffer 
        // by negetive integer 
        int capacity = -10; 
  
        // Creating the CharBuffer 
        try { 
  
            // creating object of CharBuffer 
            // and allocating size with negative integer 
            System.out.println("Trying to allocate a negative integer"); 
  
            CharBuffer fb = CharBuffer.allocate(capacity); 
        } 
        catch (IllegalArgumentException e) { 
            System.out.println("Exception thrown: " + e); 
        } 
    } 
}

输出：

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

相关用法

注：本文由纯净天空筛选整理自gopaldave大神的英文原创作品 CharBuffer 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。