Java中的 UUID getMostSignificantBits() 方法及示例

UUID 是 128 位值。 Java中UUID 类的getMostSignificantBits()方法用于获取该 UUID 的最高有效 64 位。

句法：

public long getMostSignificantBits()

参数：该方法不带任何参数。

返回值：该方法返回一个整数值，它是这 128 个值的 UUID 的最高有效 64 位。

下面的程序说明了 getMostSignificantBits() 方法的工作：

方案一：

// Java code to illustrate
// getMostSignificantBits() method
  
import java.util.*;
  
public class UUID_Demo {
    public static void main(String[] args)
    {
        // Creating two UUIDs
        UUID UUID_1
            = UUID
                  .fromString(
                      "58e0a7d7-eebc-11d8-9669-0800200c9a66");
  
        // Displaying the UUID
        System.out.println("UUID: "
                           + UUID_1);
  
        // Displaying the value of UUID
        System.out.println("The value is: "
                           + UUID_1.clockSequence());
  
        // Getting the most significant 64 bit
        System.out.println("The most significant 64 bit: "
                           + UUID_1
                                 .getMostSignificantBits());
    }
}

输出：

UUID: 58e0a7d7-eebc-11d8-9669-0800200c9a66
The value is: 5737
The most significant 64 bit: 6404303215985955288

方案二：

// Java code to illustrate
// getMostSignificantBits() method
  
import java.util.*;
  
public class UUID_Demo {
    public static void main(String[] args)
    {
  
        // Creating two UUIDs
        UUID UUID_1
            = UUID
                  .fromString(
                      "58e0a7d7-eebc-11d8-9669-0800200c9a66");
  
        // Displaying the UUID
        System.out.println("UUID: "
                           + UUID_1);
  
        // Displaying the value of UUID
        System.out.println("The value is: "
                           + UUID_1.clockSequence());
  
        // Getting the most significant 64 bit
        System.out.println("The most significant 64 bit: "
                           + UUID_1.getMostSignificantBits());
    }
}

输出：

UUID: 58e0a7d7-eebc-11d8-9669-0800200c9a66
The value is: 5737
The most significant 64 bit: 6404303215985955288