Java实现的日期处理类完整实例

本文实例讲述了java实现的日期处理类。分享给大家供大家参考，具体如下：

开发中常常要使用日期，先小结如下，以备后用。

import java.text.parseexception;
import java.text.simpledateformat;
import java.util.calendar;
import java.util.date;
public class formattime {
  private final static simpledateformat sdf=new simpledateformat("yyyymmdd");
  private final static simpledateformat sdfymdhm = new simpledateformat("yyyymmddhhmmss");
  private final static simpledateformat sdfymdhms =  new simpledateformat("yyyy-mm-dd hh:mm:ss");
  /**
   *
  * @title: getcurrentday
  * @description: todo 获取当天时间(20161109)
  * @return
   */
  public static string getcurrentday(){
    return sdf.format(new date());
  }
  /**
   *
  * @title: ftime2
  * @description: todo 获取time这个日期以前dayago天的日期
  * @return
   */
  public static string ftime(string time,int dayago){
    date date = null;
    try {
      date = sdf.parse(time);
    } catch (parseexception e) {
        throw new runtimeexception(e);
    }
    calendar calendar = calendar.getinstance();
    calendar.settime(date);
    if(dayago>0){
      calendar.add(calendar.day_of_month, -dayago);//前15天数据
      date = calendar.gettime();
      calendar.settime(date);
    }
    int year=calendar.get(calendar.year);
    int month=calendar.get(calendar.month) + 1;
    int day = calendar.get(calendar.day_of_month);
    string mon="";
    string d="";
    if(month<10){
      mon="0"+month;
    }else{
      mon=month+"";
    }
    if(day<10){
      d="0"+day;
    }else{
      d=""+day;
    }
    string ret=year+""+mon+""+d;
    return ret;
  }
  /**
   *
  * @title: ftime2
  * @description: todo 获取time这个日期以后dayafter天的日期
  * @return
   */
  public static string ftime2(string time,int dayafter){
    date date = null;
    try {
      date = sdf.parse(time);
    } catch (parseexception e) {
        throw new runtimeexception(e);
    }
    calendar calendar = calendar.getinstance();
    calendar.settime(date);
    if(dayafter>0){
      calendar.add(calendar.day_of_month, +dayafter);//后15天数据
      date = calendar.gettime();
      calendar.settime(date);
    }
    int year=calendar.get(calendar.year);
    int month=calendar.get(calendar.month) + 1;
    int day = calendar.get(calendar.day_of_month);
    string mon="";
    string d="";
    if(month<10){
      mon="0"+month;
    }else{
      mon=month+"";
    }
    if(day<10){
      d="0"+day;
    }else{
      d=""+day;
    }
    string ret=year+""+mon+""+d;
    return ret;
  }
  /**
   *
  * @title: getdefaulttime
  * @description: todo 获取昨天的日期
  * @return
   */
  public static string getdefaulttime(){
    calendar calendar = calendar.getinstance();
    calendar.add(calendar.day_of_month, -1);//前1天
    date date = calendar.gettime();
    string time=sdf.format(date);
    return time;
  }
  /**
   *
  * @title: getsunday
  * @description: todo 获取最近一个星期天
  * @return
   */
  public static string getsunday(){
    simpledateformat f = new simpledateformat("yyyymmdd");
    calendar c = calendar.getinstance();
    c.set(calendar.day_of_week, calendar.sunday);
    return f.format(c.gettime());
  }
  /**
   *
  * @title: getmonthfirstday
  * @description: todo 获取本月第一天
  * @return
   */
  public static string getcurrentmonthfirstday(){
    calendar  cal_1=calendar.getinstance();//获取当前日期
    cal_1.add(calendar.month, 0);
    cal_1.set(calendar.day_of_month,1);//设置为1号,当前日期既为本月第一天
    string firstday = sdf.format(cal_1.gettime());
    return firstday;
  }
  /**
   *
  * @title: getmonthfirstday
  * @description: todo 获取上月第一天
  * @return
   */
  public static string getpreviousmonthfirstday(){
   //获取当前月第一天：
  calendar c = calendar.getinstance();
  c.add(calendar.month, -1);
  c.set(calendar.day_of_month,1);//设置为1号,当前日期既为本月第一天
  string first = sdf.format(c.gettime());
  return first;
  }
  /**
   *
  * @title: getmonthfirstday
  * @description: todo 获取上月最后一天
  * @return
   */
  public static string getpreviousmonthlastday(){
  //获取当前月最后一天
  calendar ca = calendar.getinstance();
  ca.set(calendar.day_of_month,0);//
  string lastday = sdf.format(ca.gettime());
  return lastday;
  }
  /**
   *
  * @title: getcurrentmonthlastday
  * @description: todo 获取指定时间最后一天
  * @return
   */
  public static string getcurrentmonthlastday(string time){
    date date =null;
   try {
    date= sdf.parse(time);
  } catch (parseexception e) {
    // todo auto-generated catch block
    e.printstacktrace();
  }
  //获取当前月最后一天
  calendar ca = calendar.getinstance();
  ca.settime(date);
  ca.set(calendar.day_of_month,
      ca.getactualmaximum(calendar.day_of_month)); //
  string lastday = sdf.format(ca.gettime());
  return lastday;
  }
  /***
   *
  * @title: getcurrentweekday
  * @description: todo 获取本周周一
   */
  public static string getcurrentmonday(){
     calendar cal = calendar.getinstance();
     cal.setfirstdayofweek(calendar.monday);//将每周第一天设为星期一，默认是星期天
     cal.add(calendar.date, 0);
     cal.set(calendar.day_of_week,calendar.monday);
     string monday = sdf.format(cal.gettime());
     return monday;
  }
  /***
   *
  * @title: getprevioussunday
  * @description: todo 获取上周周日
   */
  public static string getprevioussunday(){
     calendar cal = calendar.getinstance();
     cal.setfirstdayofweek(calendar.monday);//将每周第一天设为星期一，默认是星期天
     cal.add(calendar.date, -1*7);
     cal.set(calendar.day_of_week, calendar.sunday);
     string sunday =sdf.format(cal.gettime());
     return sunday;
  }
  /**
   *
  * @title: getminisencond
  * @description: todo 将日期转换为毫秒数
  * @param str
  * @return
   */
  public static string getminisencond(string str){
    long millionseconds=0;
    try {
      millionseconds = sdfymdhm.parse(str).gettime();//毫秒
    } catch (parseexception e) {
      // todo auto-generated catch block
      e.printstacktrace();
    }
    return millionseconds+"";
  }
   /**
   *
  * @title: getdatesencond
  * @description: todo 将日期转换为毫秒数
  * @param str
  * @return
   */
  public static long getdatesencond(string str){
    long millionseconds=0;
    try {
      millionseconds = sdfymdhms.parse(str).gettime();//毫秒
    } catch (parseexception e) {
      // todo auto-generated catch block
      e.printstacktrace();
    }
    return millionseconds;
  }
  /**
   * 计算日期相差天数
   * @param str1
   * @param str2
   * @return
   */
  public static int getdistanceoftwodate(string str1,string str2){
    int result=0;
    try{
      date date1 = sdf.parse(str1);
      date date2 =sdf.parse(str2);
      calendar acalendar = calendar.getinstance();
        acalendar.settime(date1);
        int day1 = acalendar.get(calendar.day_of_year);
        acalendar.settime(date2);
        int day2 = acalendar.get(calendar.day_of_year);
        result = day1-day2;
    }catch(exception e){
      e.printstacktrace();
    }
    return result;
  }
  /**
   *
  * @title: long2date
  * @description: todo long 转日期(年-月-日 时-分-秒)
  * @param timestamp
  * @return
   */
  public static string longtodate(long msecond){
    date date = new date(msecond);
    return sdfymdhms.format(date);
  }
}

ps：这里再为大家推荐几款关于日期与天数计算的在线工具供大家使用：

在线日期/天数计算器：

在线万年历日历：

在线阴历/阳历转换工具：

更多关于java相关内容感兴趣的读者可查看本站专题：《java日期与时间操作技巧汇总》、《java数据结构与算法教程》、《java操作dom节点技巧总结》和《java缓存操作技巧汇总》

希望本文所述对大家java程序设计有所帮助。