java综合日期时间处理工具类

package com.ljn.callingsimulation.util;

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

/**
* Created by 12390 on 2017/8/30.
*/
public class DateUtil {

public static String getDistanceTime(String str1, String str2) {
DateFormat df = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
Date one;
Date two;
long day = 0;
long hour = 0;
long min = 0;
long sec = 0;
try {
one = df.parse(str1);
two = df.parse(str2);
long time1 = one.getTime();
long time2 = two.getTime();
long diff;
if (time1 < time2) {
diff = time2 - time1;
} else {
diff = time1 - time2;
}
day = diff / (24 * 60 * 60 * 1000);
hour = (diff / (60 * 60 * 1000) - day * 24);
min = ((diff / (60 * 1000)) - day * 24 * 60 - hour * 60);
sec = (diff / 1000 - day * 24 * 60 * 60 - hour * 60 * 60 - min * 60);
} catch (ParseException e) {
e.printStackTrace();
}
if (day != 0) {
return day + "天" + hour + "小时" + min + "分";
} else {
if (day == 0 && hour != 0) {
return hour + "小时" + min + "分";
} else {
return min + "分";
}
}
}

public static String dateToString(Date date){
SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
return sdf.format(date);
}

public static Date stringToDate(String date){
SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
try {
return sdf.parse(date);
} catch (ParseException e) {
e.printStackTrace();
return null;
}
}

public static String getWeekOfDate(Date dt) {
String[] weekDays = {"星期日", "星期一", "星期二", "星期三", "星期四", "星期五", "星期六"};
Calendar cal = Calendar.getInstance();
cal.setTime(dt);
int w = cal.get(Calendar.DAY_OF_WEEK) - 1;
if (w < 0)
w = 0;
return weekDays[w];
}

public static String getNextTHTime(){
Date now = new Date();
return dateToString(new Date(now.getTime() + 2*60*60*1000));
}
}