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Java ByteBuffer putChar()用法及代碼示例


putChar(char value)

java.nio.ByteBuffer類的putChar(char value)方法用於以當前字節順序將包含給定char值的兩個字節寫入當前位置的此緩衝區中，然後將該位置加2。

用法:

public abstract ByteBuffer putChar(char value)

參數：此方法將要寫入的char值。


返回值：此方法返回此緩衝區。

異常：此方法引發以下異常：

  • BufferOverflowException-如果此緩衝區的當前位置不小於其限製
  • ReadOnlyBufferException-如果此緩衝區是隻讀的

以下示例說明了putChar(char value)方法：

範例1：

// Java program to demonstrate 
// putChar() method 
  
import java.nio.*; 
import java.util.*; 
  
public class GFG { 
    public static void main(String[] args) 
    { 
  
        // Declaring the capacity of the ByteBuffer 
        int capacity = 6; 
  
        // Creating the ByteBuffer 
        try { 
  
            // creating object of ByteBuffer 
            // and allocating size capacity 
            ByteBuffer bb = ByteBuffer.allocate(capacity); 
  
            // putting the value in ByteBuffer 
            // using putChar() method 
            bb.putChar('a') 
                .putChar('b') 
                .putChar('c') 
                .rewind(); 
  
            // print the ByteBuffer 
            System.out.print("Original ByteBuffer:[ "); 
            for (int i = 1; i <= capacity / 2; i++) 
                System.out.print(bb.getChar() + " "); 
            System.out.print("]"); 
        } 
  
        catch (BufferOverflowException e) { 
  
            System.out.println("Exception throws:" + e); 
        } 
  
        catch (ReadOnlyBufferException e) { 
  
            System.out.println("Exception throws:" + e); 
        } 
    } 
}
輸出： 
Original ByteBuffer:[ a b c ]

範例2：演示BufferOverflowException。

// Java program to demonstrate 
// putChar() method 
  
import java.nio.*; 
import java.util.*; 
  
public class GFG { 
    public static void main(String[] args) 
    { 
  
        // Declaring the capacity of the ByteBuffer 
        int capacity = 6; 
  
        // Creating the ByteBuffer 
        try { 
  
            // creating object of ByteBuffer 
            // and allocating size capacity 
            ByteBuffer bb = ByteBuffer.allocate(capacity); 
  
            // putting the value in ByteBuffer 
            // using putChar() method 
            bb.putChar('a') 
                .putChar('b') 
                .putChar('c') 
                .rewind(); 
  
            // print the ByteBuffer 
            System.out.print("Original ByteBuffer:[ "); 
            for (int i = 1; i <= capacity / 2; i++) 
                System.out.print(bb.getChar() + " "); 
            System.out.print("]\n\n"); 
  
            // putting the value in ByteBuffer 
            // using putChar() method 
            bb.putChar('d'); 
        } 
  
        catch (BufferOverflowException e) { 
            System.out.println("buffer's current position"
                               + " is not smaller than"
                               + " its limit"); 
            System.out.println("Exception throws:" + e); 
        } 
  
        catch (ReadOnlyBufferException e) { 
  
            System.out.println("Exception throws:" + e); 
        } 
    } 
}
輸出： 
Original ByteBuffer:[ a b c ]

buffer's current position is not smaller than its limit
Exception throws:java.nio.BufferOverflowException

範例3：演示ReadOnlyBufferException。

// Java program to demonstrate 
// putChar() method 
  
import java.nio.*; 
import java.util.*; 
  
public class GFG { 
    public static void main(String[] args) 
    { 
  
        // Declaring the capacity of the ByteBuffer 
        int capacity = 6; 
  
        // Creating the ByteBuffer 
        try { 
  
            // creating object of ByteBuffer 
            // and allocating size capacity 
            ByteBuffer bb = ByteBuffer.allocate(capacity); 
  
            // putting the value in ByteBuffer 
            // using putChar() method 
            bb.putChar('a') 
                .putChar('b') 
                .putChar('c') 
                .rewind(); 
  
            // print the ByteBuffer 
            System.out.print("Original ByteBuffer:[ "); 
            for (int i = 1; i <= capacity / 2; i++) 
                System.out.print(bb.getChar() + " "); 
            System.out.print("]\n"); 
  
            // Creating a read-only copy of ByteBuffer 
            // using asReadOnlyBuffer() method 
            ByteBuffer bb1 = bb.asReadOnlyBuffer(); 
  
            System.out.println("\nTrying to put the char value"
                               + " in read-only buffer"); 
  
            // putting the value in readonly ByteBuffer 
            // using putChart() method 
            bb1.putChar('d'); 
        } 
  
        catch (BufferOverflowException e) { 
            System.out.println("Exception throws:" + e); 
        } 
        catch (ReadOnlyBufferException e) { 
            System.out.println("Exception throws:" + e); 
        } 
    } 
}
輸出： 
Original ByteBuffer:[ a b c ]

Trying to put the char value in read-only buffer
Exception throws:java.nio.ReadOnlyBufferException

putChar(int index, char value)

java.nio.ByteBuffer類的putChar(int index，char value)方法用於將包含給定char值的兩個字節(按當前字節順序)寫入給定索引處的此緩衝區中。


用法:

public abstract ByteBuffer putChar(int index, char value)

參數：此方法將以下參數作為參數：

  • index：將寫入字節的索引
  • value：要寫入的char值

返回值：此方法返回此緩衝區。

異常：此方法引發以下異常：

  • IndexOutOfBoundsException-如果索引為負或不小於緩衝區的限製
  • ReadOnlyBufferException-如果此緩衝區是隻讀的

以下示例說明了putChar(int index，char value)方法：

範例1：

// Java program to demonstrate 
// putChar() method 
  
import java.nio.*; 
import java.util.*; 
  
public class GFG { 
  
    public static void main(String[] args) 
    { 
  
        // Declaring the capacity of the ByteBuffer 
        int capacity = 6; 
  
        // Creating the ByteBuffer 
        try { 
  
            // creating object of ByteBuffer 
            // and allocating size capacity 
            ByteBuffer bb = ByteBuffer.allocate(capacity); 
  
            // putting the value in ByteBuffer 
            // using putChar() at  index 0 
            bb.putChar(0, 'a'); 
  
            // putting the value in ByteBuffer 
            // using putChar() at  index 2 
            bb.putChar(2, 'b'); 
  
            // putting the value in ByteBuffer 
            // using putChar() at  index 1 
            bb.putChar(4, 'c'); 
  
            // rewinding the ByteBuffer 
            bb.rewind(); 
  
            // print the ByteBuffer 
            System.out.print("Original ByteBuffer:[ "); 
            for (int i = 1; i <= capacity / 2; i++) 
                System.out.print(bb.getChar() + " "); 
            System.out.print("]\n"); 
        } 
  
        catch (IndexOutOfBoundsException e) { 
  
            System.out.println("Exception throws:" + e); 
        } 
  
        catch (ReadOnlyBufferException e) { 
  
            System.out.println("Exception throws:" + e); 
        } 
    } 
}
輸出： 
Original ByteBuffer:[ a b c ]

範例2：演示IndexOutOfBoundsException。

// Java program to demonstrate 
// putChar() method 
  
import java.nio.*; 
import java.util.*; 
  
public class GFG { 
  
    public static void main(String[] args) 
    { 
  
        // Declaring the capacity of the ByteBuffer 
        int capacity = 6; 
  
        // Creating the ByteBuffer 
        try { 
  
            // creating object of ByteBuffer 
            // and allocating size capacity 
            ByteBuffer bb = ByteBuffer.allocate(capacity); 
  
            // putting the value in ByteBuffer 
            // using putChar() at  index 0 
            bb.putChar(0, 'a'); 
  
            // putting the value in ByteBuffer 
            // using putChar() at  index 2 
            bb.putChar(2, 'b'); 
  
            // putting the value in ByteBuffer 
            // using putChar() at  index 1 
            bb.putChar(4, 'c'); 
  
            // rewinding the ByteBuffer 
            bb.rewind(); 
  
            // print the ByteBuffer 
            System.out.print("Original ByteBuffer:[ "); 
            for (int i = 1; i <= capacity / 2; i++) 
                System.out.print(bb.getChar() + " "); 
            System.out.print("]\n"); 
  
            // putting the value in ByteBuffer 
            // using put() at  index -1 
            bb.putChar(-1, 'd'); 
        } 
  
        catch (IndexOutOfBoundsException e) { 
            System.out.println("\nindex is negative or not smaller "
                               + "than the buffer's limit"); 
            System.out.println("Exception throws:" + e); 
        } 
  
        catch (ReadOnlyBufferException e) { 
  
            System.out.println("Exception throws:" + e); 
        } 
    } 
}
輸出： 
Original ByteBuffer:[ a b c ]

index is negative or not smaller than the buffer's limit
Exception throws:java.lang.IndexOutOfBoundsException

範例3：演示ReadOnlyBufferException。

// Java program to demonstrate 
// putChar() method 
  
import java.nio.*; 
import java.util.*; 
  
public class GFG { 
  
    public static void main(String[] args) 
    { 
  
        // Declaring the capacity of the ByteBuffer 
        int capacity = 6; 
  
        // Creating the ByteBuffer 
        try { 
  
            // creating object of ByteBuffer 
            // and allocating size capacity 
            ByteBuffer bb = ByteBuffer.allocate(capacity); 
  
            // Creating a read-only copy of ByteBuffer 
            // using asReadOnlyBuffer() method 
            ByteBuffer bb1 = bb.asReadOnlyBuffer(); 
  
            System.out.println("Trying to put the byte value"
                               + " in read-only buffer"); 
  
            // putting the value in readonly ByteBuffer 
            // using putChar() method 
            bb1.putChar(4, 'c'); 
        } 
  
        catch (IndexOutOfBoundsException e) { 
  
            System.out.println("Exception throws:" + e); 
        } 
  
        catch (ReadOnlyBufferException e) { 
  
            System.out.println("Exception throws:" + e); 
        } 
    } 
}
輸出： 
Trying to put the byte value in read-only buffer
Exception throws:java.nio.ReadOnlyBufferException

參考：



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