Java ByteBuffer hashCode()方法及示例

java.nio.ByteBuffer 类的 hashCode() 方法是用来返回这个缓冲区的当前哈希代码。字节缓冲区的哈希代码只取决于它的剩余元素；也就是说，取决于从position()到limit()-1的元素。因为缓冲区的哈希码是取决于内容的，所以除非知道缓冲区的内容不会改变，否则不宜使用缓冲区作为哈希图或类似数据结构的键。

语法

public int hashCode()

返回值： 该方法返回该缓冲区的当前哈希代码。下面是说明hashCode()方法的例子：

例子1 :

// Java program to demonstrate
// hashCode() method
 
import java.nio.*;
import java.util.*;
 
public class GFG {
 
    public static void main(String[] args)
    {
        // creating object of ByteBuffer
        // and allocating size capacity
        ByteBuffer bb = ByteBuffer.allocate(12);
 
        // 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 <= 3; i++)
            System.out.print(bb.getInt() + " ");
 
        // rewind the Bytebuffer
        bb.rewind();
 
        // Reads the Int at this buffer's current position
        // using hashCode() method
        int value = bb.hashCode();
 
        // print the int value
        System.out.println("\n\nByte Value: " + value);
    }
}

输出

Original ByteBuffer: 
10 20 30 

Byte Value: -219122491

例子 2 :

// Java program to demonstrate
// hashCode() method
 
import java.nio.*;
import java.util.*;
 
public class GFG {
 
    public static void main(String[] args)
    {
        // creating object of ByteBuffer
        // and allocating size capacity
        ByteBuffer bb = ByteBuffer.allocate(12);
 
        // Reads the Int at this buffer's current position
        // using hashCode() method
        int value = bb.hashCode();
 
        // print the int value
        System.out.println("Byte Value: " + value);
    }
}

输出