Java DoubleBuffer allocate()用法及代碼示例

java.nio.DoubleBuffer類的allocate()方法用於在現有緩衝區旁邊分配一個新的雙緩衝區。新緩衝區的位置將為零。它的極限將是它的容量。其標記將是不確定的。並且其每個元素都將初始化為零。它將有一個支持數組，其數組偏移量將為零。

用法:

public static DoubleBuffer allocate(int capacity)

參數：此方法將新緩衝區的容量增加一倍，作為參數。

返回值：此方法返回新的雙緩衝區。

異常：如果容量為負整數，則此方法引發IllegalArgumentException。

以下示例程序旨在說明allocate()方法：

範例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())); 
    } 
}

輸出：

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

範例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); 
        } 
    } 
}

輸出：

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

相關用法

注：本文由純淨天空篩選整理自pawan_asipu大神的英文原創作品 DoubleBuffer allocate() method in Java With Examples。非經特殊聲明，原始代碼版權歸原作者所有，本譯文未經允許或授權，請勿轉載或複製。