當前位置: 首頁>>代碼示例 >>用法及示例精選 >>正文

Java ByteBuffer getInt()用法及代碼示例


getInt()

java.nio.ByteBuffer類的getInt()方法用於讀取此緩衝區當前位置的下四個字節，並根據當前字節順序將它們組成一個int值，然後將該位置加4。

用法:

public abstract int getInt()

返回值：此方法返回緩衝區當前位置的int值


拋出：此方法引發BufferUnderflowException-如果此緩衝區中剩餘的字節數少於四個。
下麵是說明getInt()方法的示例：

範例1：

// Java program to demonstrate 
// getInt() method 
  
import java.nio.*; 
import java.util.*; 
  
public class GFG { 
  
    public static void main(String[] args) 
    { 
  
        // Declaring the capacity of the ByteBuffer 
        int capacity = 12; 
  
        // Creating the ByteBuffer 
        try { 
  
            // creating object of ByteBuffer 
            // and allocating size capacity 
            ByteBuffer bb = ByteBuffer.allocate(capacity); 
  
            // putting the int value in the bytebuffer 
            bb.asIntBuffer() 
                .put(10) 
                .put(20) 
                .put(30); 
  
            // rewind the Bytebuffer 
            bb.rewind(); 
  
            // print the ByteBuffer 
            System.out.println("Original ByteBuffer: "); 
            for (int i = 1; i <= capacity / 4; i++) 
                System.out.print(bb.getInt() + " "); 
  
            // rewind the Bytebuffer 
            bb.rewind(); 
  
            // Reads the Int at this buffer's current position 
            // using getInt() method 
            int value = bb.getInt(); 
  
            // print the int value 
            System.out.println("\n\nByte Value: " + value); 
  
            // Reads the int at this buffer's next position 
            // using getInt() method 
            int value1 = bb.getInt(); 
  
            // print the int value 
            System.out.println("Next Byte Value: " + value1); 
        } 
  
        catch (BufferUnderflowException e) { 
  
            System.out.println("\nException Thrown : " + e); 
        } 
    } 
}
輸出： 
Original ByteBuffer: 
10 20 30 

Byte Value: 10
Next Byte Value: 20

範例2：

// Java program to demonstrate 
// getInt() method 
  
import java.nio.*; 
import java.util.*; 
  
public class GFG { 
  
    public static void main(String[] args) 
    { 
  
        // Declaring the capacity of the ByteBuffer 
        int capacity = 8; 
  
        // Creating the ByteBuffer 
        try { 
  
            // creating object of ByteBuffer 
            // and allocating size capacity 
            ByteBuffer bb = ByteBuffer.allocate(capacity); 
  
            // putting the int value in the bytebuffer 
            bb.asIntBuffer() 
                .put(10) 
                .put(20); 
  
            // rewind the Bytebuffer 
            bb.rewind(); 
  
            // print the ByteBuffer 
            System.out.println("Original ByteBuffer: "); 
            for (int i = 1; i <= capacity / 4; i++) 
                System.out.print(bb.getInt() + " "); 
  
            // rewind the Bytebuffer 
            bb.rewind(); 
  
            // Reads the Int at this buffer's current position 
            // using getInt() method 
            int value = bb.getInt(); 
  
            // print the int value 
            System.out.println("\n\nByte Value: " + value); 
  
            // Reads the int at this buffer's next position 
            // using getInt() method 
            int value1 = bb.getInt(); 
  
            // print the int value 
            System.out.println("Next Byte Value: " + value1); 
  
            // Reads the int at this buffer's next position 
            // using getInt() method 
            int value2 = bb.getInt(); 
        } 
  
        catch (BufferUnderflowException e) { 
            System.out.println("\nthere are fewer than "
                               + "four bytes remaining in this buffer"); 
            System.out.println("Exception Thrown : " + e); 
        } 
    } 
}
輸出： 
Original ByteBuffer: 
10 20 

Byte Value: 10
Next Byte Value: 20

there are fewer than four bytes remaining in this buffer
Exception Thrown : java.nio.BufferUnderflowException

參考： https://docs.oracle.com/javase/9/docs/api/java/nio/ByteBuffer.html#getInt–

getInt(int索引)

ByteBuffer的getInt(int index)方法用於讀取給定索引處的四個字節，並根據當前字節順序將它們組成一個int值。

用法:

public abstract int getInt(int index)

參數：此方法將索引(將從中讀取Byte的索引)作為參數。

返回值：此方法返回給定索引處的int值。


異常：此方法引發IndexOutOfBoundsException。如果index為負或不小於緩衝區的限製，則拋出此異常。

以下示例說明了getInt(int index)方法：

範例1：

// Java program to demonstrate 
// getInt() method 
  
import java.nio.*; 
import java.util.*; 
  
public class GFG { 
  
    public static void main(String[] args) 
    { 
  
        // Declaring the capacity of the ByteBuffer 
        int capacity = 8; 
  
        // Creating the ByteBuffer 
        try { 
  
            // creating object of ByteBuffer 
            // and allocating size capacity 
            ByteBuffer bb = ByteBuffer.allocate(capacity); 
  
            // putting the int value in the bytebuffer 
            bb.asIntBuffer() 
                .put(10) 
                .put(20); 
  
            // rewind the Bytebuffer 
            bb.rewind(); 
  
            // print the ByteBuffer 
            System.out.println("Original ByteBuffer: "); 
            for (int i = 1; i <= capacity / 4; i++) 
                System.out.print(bb.getInt() + " "); 
  
            // rewind the Bytebuffer 
            bb.rewind(); 
  
            // Reads the Int at this buffer's current position 
            // using getInt() method 
            int value = bb.getInt(0); 
  
            // print the int value 
            System.out.println("\n\nByte Value: " + value); 
  
            // Reads the int at this buffer's next position 
            // using getInt() method 
            int value1 = bb.getInt(4); 
  
            // print the int value 
            System.out.println("Next Byte Value: " + value1); 
        } 
  
        catch (IndexOutOfBoundsException e) { 
  
            System.out.println("\nindex is negative or smaller "
                               + "than the buffer's limit, minus seven"); 
            System.out.println("Exception Thrown : " + e); 
        } 
    } 
}
輸出： 
Original ByteBuffer: 
10 20 

Byte Value: 10
Next Byte Value: 20

範例2：

// Java program to demonstrate 
// getInt() method 
  
import java.nio.*; 
import java.util.*; 
  
public class GFG { 
  
    public static void main(String[] args) 
    { 
  
        // Declaring the capacity of the ByteBuffer 
        int capacity = 8; 
  
        // Creating the ByteBuffer 
        try { 
  
            // creating object of ByteBuffer 
            // and allocating size capacity 
            ByteBuffer bb = ByteBuffer.allocate(capacity); 
  
            // putting the int value in the bytebuffer 
            bb.asIntBuffer() 
                .put(10) 
                .put(20); 
  
            // rewind the Bytebuffer 
            bb.rewind(); 
  
            // print the ByteBuffer 
            System.out.println("Original ByteBuffer: "); 
            for (int i = 1; i <= capacity / 4; i++) 
                System.out.print(bb.getInt() + " "); 
  
            // rewind the Bytebuffer 
            bb.rewind(); 
  
            // Reads the Int at this buffer's current position 
            // using getInt() method 
            int value = bb.getInt(0); 
  
            // print the int value 
            System.out.println("\n\nByte Value: " + value); 
  
            // Reads the int at this buffer's next position 
            // using getInt() method 
            int value1 = bb.getInt(7); 
  
            // print the int value 
            System.out.println("Next Byte Value: " + value1); 
        } 
  
        catch (IndexOutOfBoundsException e) { 
  
            System.out.println("\nindex is negative or smaller"
                               + " than the buffer's limit, minus seven"); 
            System.out.println("Exception Thrown : " + e); 
        } 
    } 
}
輸出： 
Original ByteBuffer: 
10 20 

Byte Value: 10

index is negative or smaller than the buffer's limit, minus seven
Exception Thrown : java.lang.IndexOutOfBoundsException

參考： https://docs.oracle.com/javase/9/docs/api/java/nio/ByteBuffer.html#getInt-int-



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 getInt() 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。