java 时间戳 、时间差计算（秒、分钟、小时、天数、月份、年）

以下代码就是时间差计算（秒、分钟、小时、天数、月份、年）

package me.zhengjie;

import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.Date;

import org.junit.Test;

public class DemoTest {
    @Test
    public void run1() {
        System.out.println("run1()");
        SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss.SSS");
        String startDateStr = "2012-01-20 00:00:00.000";
        String endDateStr = "2019-11-01 00:00:00.000";
        try {
            Date startDate = sdf.parse(startDateStr);
            Date endDate = sdf.parse(endDateStr);
            String timeDifference = this.convert(startDate, endDate);
            System.out.println(timeDifference);
        } catch (ParseException e) {
            e.printStackTrace();
            System.out.println("日期格式化失败");
        }
    }
    
    public String convert(Date startDate,Date endDate) {
        long startTime = startDate.getTime();//获取毫秒数
        long endTime = endDate.getTime();    //获取毫秒数
        long timeDifference = endTime-startTime;
        long second = timeDifference/1000;  //计算秒
        
        if(second<60) {
            return second+"秒前";
        }else {
            long minute = second/60;
            if(minute<60) {
                return minute+"分钟前";    
            }else {
                long hour = minute/60;
                if(hour<24) {
                    return hour+"时前";
                }else {
                    long day = hour/24;
                    if(day<30) {
                        return day+"天前";    
                    }else {
                        long month = day/30;
                        if(month<12) {
                            return day+"月前";
                        }else {
                            long year = month/12;
                            return year+"年前";
                        }
                    }
                    
                }
            }
        }
    }

}