UUID 用示例比较 Java 中的方法

原文:https://www . geesforgeks . org/uuid-compare to-method-in-Java-with-examples/

Java 中 UUID 类compareTo() 方法用于将一个 UUID 值与另一个指定的 UUID 值进行比较。如果 UUID 小于该值,则返回-1;如果 UUID 等于该值,则返回 0;如果 UUID 大于该值,则返回 1。

语法:

UUID_1.compareTo(UUID_2)

参数:该方法取一个参数 UUID_2 ,与 UUID_1 进行比较。

返回值:该方法返回 -1、0 或 1 ,具体取决于该 UUID_1 是否小于、等于或大于另一个 UUID_2。

下面的程序说明了 compareTo()方法的工作原理:

程序 1: 检查两个 UUIDs 是否相等。

// Java code to illustrate compareTo() method

import java.util.*;

public class UUID_Demo {
    public static void main(String[] args)
    {

        // Creating two UUIDs
        UUID UUID_1
            = UUID
                  .fromString(
                      "5fc03087-d265-11e7-b8c6-83e29cd24f4c");

        UUID UUID_2
            = UUID
                  .fromString(
                      "5fc03087-d265-11e7-b8c6-83e29cd24f4c");

        // Displaying the UUID values
        System.out.println("UUID_1: "
                           + UUID_1.clockSequence());
        System.out.println("UUID_2: "
                           + UUID_2.clockSequence());

        // Comparing both the UUIDs
        System.out.println("Comparison Value: "
                           + UUID_1.compareTo(UUID_2));
    }
}

Output:

UUID_1: 14534
UUID_2: 14534
Comparison Value: 0

程序 2: 当 UUID_1 小于 UUID_2 时,方法返回-1。

// Java code to illustrate compareTo() 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");

        UUID UUID_2
            = UUID
                  .fromString(
                      "5fc03087-d265-11e7-b8c6-83e29cd24f4c");

        // Displaying the UUID values
        System.out.println("UUID_1: "
                           + UUID_1.clockSequence());
        System.out.println("UUID_2: "
                           + UUID_2.clockSequence());

        // Comparing both the UUIDs
        System.out.println("Comparison Value: "
                           + UUID_1.compareTo(UUID_2));
    }
}

Output:

UUID_1: 5737
UUID_2: 14534
Comparison Value: -1

程序 3: 当 UUID_1 大于 UUID_2 时,方法返回 1。

// Java code to illustrate compareTo() method

import java.util.*;

public class UUID_Demo {
    public static void main(String[] args)
    {

        // Creating two UUIDs
        UUID UUID_1
            = UUID
                  .fromString(
                      "5fc03087-d265-11e7-b8c6-83e29cd24f4c");

        UUID UUID_2
            = UUID
                  .fromString(
                      "58e0a7d7-eebc-11d8-9669-0800200c9a66");

        // Displaying the UUID values
        System.out.println("UUID_1: "
                           + UUID_1.clockSequence());
        System.out.println("UUID_2: "
                           + UUID_2.clockSequence());

        // Comparing both the UUIDs
        System.out.println("Comparison Value: "
                           + UUID_1.compareTo(UUID_2));
    }
}

Output:

UUID_1: 14534
UUID_2: 5737
Comparison Value: 1