Java ByteBuffer asLongBuffer()用法及代碼示例

java.nio.ByteBuffer類的asLongBuffer()方法用於創建作為長緩衝區的此字節緩衝區的視圖。

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，其容量和限製將是該緩衝區中剩餘的字節數除以8，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 LongBuffer asLongBuffer()

返回值：此方法返回一個新的長緩衝區。

下麵是說明asLongBuffer()方法的示例：

範例1：

// Java program to demonstrate 
// asLongBuffer() 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 into 
            // LongBuffer 
            LongBuffer lb = bb.asLongBuffer(); 
  
            // putting the value in LongBuffer 
            lb.put(1000000); 
            lb.put(2000000); 
            lb.put(3000000); 
            lb.put(3000000); 
            lb.rewind(); 
  
            // Declaring variable c 
            long c; 
  
            // print the ByteBuffer 
            System.out.print("LongBuffer : "); 
            while ((c = lb.get()) != 0) 
                System.out.print(c + "  "); 
        } 
  
        catch (IllegalArgumentException e) { 
  
            System.out.println("Exception thrown : " + e); 
        } 
  
        catch (ReadOnlyBufferException e) { 
  
            System.out.println("Exception thrown : " + e); 
        } 
    } 
}

輸出：

LongBuffer : 1000000  2000000  3000000  3000000

範例2：

// Java program to demonstrate 
// asLongBuffer() 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 into 
            // LongBuffer 
            LongBuffer lb = bb.asLongBuffer(); 
  
            // putting the value in LongBuffer 
            lb.put(1000000); 
            lb.put(2000000); 
            lb.put(3000000); 
            lb.rewind(); 
  
            // Declaring variable c 
            long c; 
  
            // print the ByteBuffer 
            System.out.print("LongBuffer : "); 
            while ((c = lb.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 LongBuffer 
            LongBuffer lb1 = bb1.asLongBuffer(); 
  
            // putting the value in read-only LongBuffer 
            System.out.println("\n\nTrying to put the value "
                               + "in read only LongBuffer"); 
            lb1.put(10); 
            lb1.put(20); 
            lb1.put(30); 
            lb1.rewind(); 
        } 
  
        catch (IllegalArgumentException e) { 
  
            System.out.println("Exception thrown : " + e); 
        } 
  
        catch (ReadOnlyBufferException e) { 
  
            System.out.println("Exception thrown : " + e); 
        } 
    } 
}

輸出：

LongBuffer : 1000000  2000000  3000000  

Trying to put the value in read only LongBuffer
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 asLongBuffer() 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。