Java IntBuffer asReadOnlyBuffer()用法及代碼示例

java.nio.IntBuffer類的asReadOnlyBuffer()方法用於使用該緩衝區的內容創建一個新的隻讀int緩衝區。新緩衝區是此緩衝區的副本。因此，對該緩衝區內容所做的更改將在新緩衝區中可見。

由於新緩衝區是隻讀緩衝區，因此不允許對其內容進行任何修改。這兩個緩衝區的位置，限製和標記值將是獨立的。新緩衝區的容量，限製，位置和標記值將與此緩衝區相同。如果此緩衝區本身是隻讀的，則此方法的行為與重複方法完全相同。

用法:

public abstract IntBuffer asReadOnlyBuffer()

返回值：此方法返回新的隻讀int緩衝區，其內容與此緩衝區的內容相同。

下麵是說明asReadOnlyBuffer()方法的示例：

範例1：

// Java program to demonstrate 
// asReadOnlyBuffer() method 
  
import java.nio.*; 
import java.util.*; 
  
public class GFG { 
  
    public static void main(String[] args) 
    { 
  
        // Declaring the capacity of the IntBuffer 
        int capacity = 10; 
  
        // Creating the IntBuffer 
        try { 
  
            // creating object of Intbuffer 
            // and allocating size capacity 
            IntBuffer ib = IntBuffer.allocate(capacity); 
  
            // putting the value in Intbuffer 
            ib.put(8); 
            ib.put(2, 9); 
            ib.rewind(); 
  
            // print the IntBuffer 
            System.out.println("Original IntBuffer:  "
                               + Arrays.toString(ib.array())); 
  
            // Creating a read-only copy of IntBuffer 
            // using asReadOnlyBuffer() method 
            IntBuffer IntBuffer = ib.asReadOnlyBuffer(); 
  
            // print the IntBuffer 
            System.out.print("\nReadOnlyBuffer IntBuffer: "); 
  
            while (IntBuffer.hasRemaining()) 
                System.out.print(IntBuffer.get() + ", "); 
        } 
  
        catch (IllegalArgumentException e) { 
            System.out.println("IllegalArgumentException catched"); 
        } 
  
        catch (ReadOnlyBufferException e) { 
            System.out.println("ReadOnlyBufferException catched"); 
        } 
    } 
}

輸出：

Original IntBuffer:  [8, 0, 9, 0, 0, 0, 0, 0, 0, 0]

ReadOnlyBuffer IntBuffer: 8, 0, 9, 0, 0, 0, 0, 0, 0, 0,

範例2：

// Java program to demonstrate 
// asReadOnlyBuffer() method 
  
import java.nio.*; 
import java.util.*; 
  
public class GFG { 
    public static void main(String[] args) throws Exception 
    { 
  
        // Declaring the capacity of the ib 
        int capacity1 = 10; 
  
        // Declaring the capacity of the ib1 
        int capacity2 = 5; 
  
        // Creating the IntBuffer 
        try { 
   
            // creating object of Intbuffer ib 
            // and allocating size capacity 
            IntBuffer ib = IntBuffer.allocate(capacity1); 
  
            // putting the value in ib 
            ib.put(8); 
            ib.put(2, 9); 
            ib.rewind(); 
  
            // print the IntBuffer 
            System.out.println("IntBuffer ib: "
                               + Arrays.toString(ib.array())); 
  
            // ib1 
            // creating object of Intbuffer ib1 
            // and allocating size capacity 
            IntBuffer ib1 = IntBuffer.allocate(capacity2); 
  
            // putting the value in ib1 
            ib1.put(1, 4); 
            ib1.put(2, 6); 
            ib1.rewind(); 
  
            // print the IntBuffer 
            System.out.println("\nIntBuffer ib1:  "
                               + Arrays.toString(ib1.array())); 
  
            // Creating a read-only copy of IntBuffer 
            // using asReadOnlyBuffer() method 
            IntBuffer readOnlyib = ib.asReadOnlyBuffer(); 
  
            // print the IntBuffer 
            System.out.print("\nReadOnlyBuffer IntBuffer: "); 
  
            while (readOnlyib.hasRemaining()) 
                System.out.print(readOnlyib.get() + ", "); 
  
            // try to change readOnlyib 
            System.out.println("\n\nTrying to get the array"
                               + " from ReadOnlyib for editing"); 
  
            int[] ibarr = readOnlyib.array(); 
        } 
  
        catch (IllegalArgumentException e) { 
            System.out.println("IllegalArgumentException catched"); 
        } 
  
        catch (ReadOnlyBufferException e) { 
            System.out.println("Exception thrown: " + e); 
        } 
    } 
}

輸出：

IntBuffer ib: [8, 0, 9, 0, 0, 0, 0, 0, 0, 0]

IntBuffer ib1:  [0, 4, 6, 0, 0]

ReadOnlyBuffer IntBuffer: 8, 0, 9, 0, 0, 0, 0, 0, 0, 0, 

Trying to get the array from ReadOnlyib for editing
Exception thrown: java.nio.ReadOnlyBufferException

相關用法

注：本文由純淨天空篩選整理自nitin_sharma大神的英文原創作品 IntBuffer asReadOnlyBuffer() method in Java。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。