java.util.Date.getTime() testNG

java

package com.corning.demo.util;

import org.testng.annotations.BeforeMethod;
import org.testng.annotations.Test;

import java.util.Date;

import static org.testng.Assert.assertEquals;

public class DateGetTimeTest {

    private Date date;
    private long time;

    @BeforeMethod
    public void setUp() {
        date = new Date();
        time = date.getTime();
    }

    @Test(threadPoolSize = 1, invocationCount = 10000)
    public void testDateGetTime() {
        assertEquals(time, date.getTime());
    }
    // threadPoolSize = 1 all passed

    @Test(threadPoolSize = 20, invocationCount = 10000)
    public void testDateGetTime2() {
        assertEquals(time, date.getTime());
    }
    // threadPoolSize = 20 有概率会失败，结果相差几毫秒
    //      java.lang.AssertionError: expected [1615537139497] but found [1615537139498]
    //      Expected :1615537139497
    //      Actual   :1615537139498

}

// JDK 1.8
  java version "1.8.0_161"
  Java(TM) SE Runtime Environment (build 1.8.0_161-b12)
  Java HotSpot(TM) 64-Bit Server VM (build 25.161-b12, mixed mode)

// mvn dependency
    <dependency>
        <groupId>org.testng</groupId>
        <artifactId>testng</artifactId>
        <version>6.10</version>
        <scope>test</scope>
    </dependency>