Java ByteBuffer asCharBuffer()用法及代碼示例

java.nio.ByteBuffer類的asCharBuffer()方法用於創建此字節緩衝區作為char緩衝區的視圖。

新緩衝區的內容將從該緩衝區的當前位置開始。對該緩衝區內容的更改將在新緩衝區中可見，反之亦然；這兩個緩衝區的位置，限製和標記值將是獨立的。

新緩衝區的位置將為零，其容量和限製將是此緩衝區中剩餘的字節數除以2，並且其標記將不確定。當且僅當該緩衝區是直接緩衝區時，新緩衝區才是直接緩衝區；當且僅當該緩衝區是隻讀緩衝區時，新緩衝區才是隻讀緩衝區。

用法:

public abstract CharBuffer asCharBuffer()

返回值：此方法返回一個新的char緩衝區。

下麵是說明asCharBuffer()方法的示例：

示例1:

// Java program to demonstrate 
// asCharBuffer() method 
// for ByteBuffer 
  
import java.nio.*; 
import java.util.*; 
  
public class GFG { 
  
    public static void main(String[] args) 
    { 
  
        // Declaring the capacity  of the ByteBuffer 
        int capacity = 50; 
  
        // Creating the ByteBuffer 
        try { 
  
            // creating object of ByteBuffer 
            // and allocating size capacity 
            ByteBuffer bb = ByteBuffer.allocate(capacity); 
  
            // changeing bytebuffer view as char buffer 
            // and putting a string value 
            bb.asCharBuffer().put("TajMahal"); 
  
            // Declaring char variable c 
            char c; 
  
            // print the ByteBuffer 
            System.out.print("Char buffer : "); 
            while ((c = bb.getChar()) != 0) 
                System.out.print(c + " "); 
            System.out.println(); 
        } 
  
        catch (IllegalArgumentException e) { 
  
            System.out.println("Exception thrown : " + e); 
        } 
  
        catch (ReadOnlyBufferException e) { 
  
            System.out.println("Exception thrown : " + e); 
        } 
    } 
}

輸出：

Char buffer : T a j M a h a l

示例2:

// Java program to demonstrate 
// asCharBuffer() method 
// for Read only ByteBuffer 
  
import java.nio.*; 
import java.util.*; 
  
public class GFG { 
  
    public static void main(String[] args) 
    { 
  
        // Declaring the capacity  of the ByteBuffer 
        int capacity = 50; 
  
        // Creating the ByteBuffer 
        try { 
  
            // creating object of  ByteBuffer 
            // and allocating size capacity 
            ByteBuffer bb = ByteBuffer.allocate(capacity); 
  
            // changeing  bytebuffer into 
            // char buffer 
            CharBuffer cb = bb.asCharBuffer(); 
  
            // putting the value in charbuffer 
            cb.put("Tajmahal"); 
            cb.rewind(); 
  
            // Declaring variable c 
            char c; 
  
            // print the ByteBuffer 
            System.out.print("Char buffer : "); 
            while ((c = cb.get()) != 0) 
                System.out.print(c + " "); 
  
            // Creating a read-only copy of ByteBuffer 
            // using asReadOnlyBuffer() method 
            ByteBuffer bb1 = bb.asReadOnlyBuffer(); 
  
            // changeing read only bytebuffer into 
            // read only char buffer 
            CharBuffer cb1 = bb1.asCharBuffer(); 
  
            // putting the value in charbuffer 
            System.out.println("\n\nTrying to put the string"
                               + " into read only charbuffer"); 
            cb1.put("Tajmahal"); 
        } 
  
        catch (IllegalArgumentException e) { 
  
            System.out.println("Exception thrown : " + e); 
        } 
  
        catch (ReadOnlyBufferException e) { 
  
            System.out.println("Exception thrown : " + e); 
        } 
    } 
}

輸出：

Char buffer : T a j m a h a l 

Trying to put the string into read only charbuffer
Exception thrown : java.nio.ReadOnlyBufferException

相關用法

注：本文由純淨天空篩選整理自RohitPrasad3大神的英文原創作品 ByteBuffer asCharBuffer() 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。