java 常用时间操作类，计算到期提醒，N年后，N月后的日期

package com.zjjerp.tool;
 
import java.text.ParseException;
import java.text.ParsePosition;
import java.text.SimpleDateFormat;
import java.util.Calendar;
import java.util.Date;
import java.util.GregorianCalendar;
 
/**
 *    @Author:Demom
 *    @Date:2013-8-2,上午9:22:05
 */
public class GetDateTimeTools {
 
    /***
     * 得到yyyy-MM-dd时间格式
     * @param date
     * @return
     */
    public static String getYYYYMMDD(Date date){
        SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd");
        return sdf.format(date);
    }
    /***
     * 得到yyyy-MM-dd hh:mm:ss时间格式
     * @param date
     * @return
     */
    public static String getYYYYMMDDHHMMSS(Date date){
        SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd hh:mm:ss");
        return sdf.format(date);
    }
    //获取当月的的10号
    public static String getnowMonthtenday(){
        Calendar cal = Calendar.getInstance();
        int month = cal.get(Calendar.MONTH) + 1;
        int year = cal.get(Calendar.YEAR);
        StringBuffer sb =new StringBuffer();
        sb.append(year);
        sb.append("-");
        if(month<10){
            sb.append("0");
            sb.append(month);
        }else{
            sb.append(month);
        }
        sb.append("-10");
        return sb.toString();
    }
    //获取当前月的下一个月的10号
    public static String getnextMonthtenday(){
        SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd hh:mm:ss");
        String strDate = sdf.format(new Date());
        int index = strDate.indexOf(" ");
        String str1 = strDate.substring(0, index);
        String[] str2 = str1.split("-");
        String nextDay="";
        if(str2[1]!="12"){
            int Month = Integer.parseInt(str2[1])+1;
            nextDay=str2[0]+"-"+Month+"-"+"10";
        }
        if(str2[1]=="12" || "12".equals(str2[1])){
            int Month = 1;
            int Year = Integer.parseInt(str2[0])+1;
            nextDay = Year+"-"+Month+"-"+"10";
        }
        return nextDay;
    }
    //获取当前年
    public static int getCurrentYear(){
        Calendar cal = Calendar.getInstance();
        int month = cal.get(Calendar.MONTH) + 1;
        int year = cal.get(Calendar.YEAR);
        return year;
    }
    //获取当前yue
    public static int getCurrentMonth(){
        Calendar cal = Calendar.getInstance();
        int month = cal.get(Calendar.MONTH) + 1;
        return month;
    }
    /**
     * 以上个月为时间轴，获取上个月的时间
     * @param status(0  代表获取月的1号，1代表获取月末）
     * @return
     */
    public static String getLastMonthDay(int status) { 
        Calendar cal = Calendar.getInstance(); 
        Date date = new Date(); 
        cal.setTime(date); 
        int year = 0; 
        int month = cal.get(Calendar.MONTH); // 上个月月份  
        String newMonth="";
       //设置年月  
        if (month == 0) { 
            year = cal.get(Calendar.YEAR) - 1; 
            month = 12; 
            newMonth=""+month;
        } else { 
            if(month<10){
                newMonth="0"+String.valueOf(month);
            }else{
                newMonth=String.valueOf(month);
            }
            year = cal.get(Calendar.YEAR); 
        } 
        //设置天数  
        String temp=year + "-" + newMonth.toString();
        SimpleDateFormat format = new SimpleDateFormat("yyyy-MM"); 
        Date d = null; 
        try { 
            d = format.parse(temp); 
        } catch (ParseException e) { 
            // TODO Auto-generated catch block  
            e.printStackTrace(); 
        } 
        cal.setTime(d); 
       
        
        int day =cal.getActualMaximum(Calendar.DAY_OF_MONTH);
        if(status==1){
            String endDay = year + "-" + newMonth + "-" + day; 
            return endDay;             
        }else{
            String endDay = year + "-" + newMonth + "-" + "01"; 
            return endDay; 
        }
    } 
    /**
     * 以上个月为时间轴，获取下个月的时间
     * @param status(0  代表获取月的1号，1代表获取月末）
     * @return
     */
    public static String getNextMonthDay(int status) { 
            Calendar cal = Calendar.getInstance(); 
            int day=cal.get(Calendar.DATE);
            SimpleDateFormat sdf =new SimpleDateFormat("yyyy-MM-dd");
            String timestr= sdf.format(new Date());
            timestr=timestr.substring(0,8);
            if(status==1){
                timestr+=String.valueOf(day);
            }else{
                timestr+="01";
            }
            return timestr;
    } 
    /***
     * 以上个月为时间轴，获取当月的时间
     * @param status(0  代表获取月的1号，1代表获取月末）
     * @return
     */
    public static String getCurrMonthDay(int status) { 
        Calendar cal = Calendar.getInstance(); 
        Date date = new Date(); 
        cal.setTime(date); 
        int year = 0; 
        int month = cal.get(Calendar.MONTH); // 上个月月份  
        String newMonth="";
       //设置年月  
        if (month == 0) { 
            year = cal.get(Calendar.YEAR) - 1; 
            month = 12; 
            newMonth=""+month;
        } else { 
            if(month<10){
                newMonth="0"+String.valueOf(month);
            }else{
                newMonth=String.valueOf(month);
            }
            year = cal.get(Calendar.YEAR); 
        } 
        //设置天数  
        String temp=year + "-" + newMonth.toString();
        SimpleDateFormat format = new SimpleDateFormat("yyyy-MM"); 
        Date d = null; 
        try { 
            d = format.parse(temp); 
        } catch (ParseException e) { 
            // TODO Auto-generated catch block  
            e.printStackTrace(); 
        } 
        cal.setTime(d); 
        int day =cal.getActualMaximum(Calendar.DAY_OF_MONTH);
        if(status==1){
            String endDay = year + "-" + newMonth + "-" + day; 
            return endDay;             
        }else{
            String endDay = year + "-" + newMonth + "-" + "01"; 
            return endDay; 
        }
        
    }
    //获取当月5号日前哦
    public static String getevery5day(){
        
        Calendar cal = Calendar.getInstance();
        int month = cal.get(Calendar.MONTH) + 1;
        int year = cal.get(Calendar.YEAR);
        StringBuffer sb =new StringBuffer();
        sb.append(year);
        sb.append("-");
        if(month<=10){
            sb.append("0");
            sb.append(month);
        }else{
            sb.append(month);
        }
        sb.append("-05");
        return sb.toString();
    }
    
    //合同续约
    public static String datexuyue(int year){
        
        SimpleDateFormat sdf =new SimpleDateFormat("yyyy-MM-dd");
        String now = sdf.format(new Date());
        String[] nowStr = now.split("-");
        int year1 = Integer.parseInt(nowStr[0])+year;
        StringBuffer sb = new StringBuffer();
        sb.append(year1+"-"+nowStr[1]+"-"+nowStr[2]);
        return sb.toString();
    }
    //得到N天后的日期
     public static String getBeforeAfterDate(String datestr, int day) {  
            SimpleDateFormat df = new SimpleDateFormat("yyyy-MM-dd");  
            java.sql.Date olddate = null;  
            try {  
                df.setLenient(false);  
                olddate = new java.sql.Date(df.parse(datestr).getTime());  
            } catch (ParseException e) {  
                throw new RuntimeException("日期转换错误");  
            }  
            Calendar cal = new GregorianCalendar();  
            cal.setTime(olddate);  
      
            int Year = cal.get(Calendar.YEAR);  
            int Month = cal.get(Calendar.MONTH);  
            int Day = cal.get(Calendar.DAY_OF_MONTH);  
      
            int NewDay = Day + day;  
      
            cal.set(Calendar.YEAR, Year);  
            cal.set(Calendar.MONTH, Month);  
            cal.set(Calendar.DAY_OF_MONTH, NewDay);  
      
            return new java.sql.Date(cal.getTimeInMillis()).toString();  
        }  
     
     
    //根据两个日期A、B计算AB之间的天数
        public static long getQuot(String time1, String time2){
            long quot = 0;  
            SimpleDateFormat ft = new SimpleDateFormat("yyyy-MM-dd");  
            try {   Date date1 = ft.parse( time1 );
            Date date2 = ft.parse( time2 ); 
            quot = date1.getTime() - date2.getTime(); 
            quot = quot / 1000 / 60 / 60 / 24;  
            } catch (ParseException e) { 
            e.printStackTrace();
            }  
            return quot; 
            }
        //得到N月后的日期
        public static   String   GetSysDate(String   format,   String   StrDate,   int   year,   int   month,   
                int   day)   {   
            Calendar   cal   =   Calendar.getInstance();   
            SimpleDateFormat   sFmt   =   new   SimpleDateFormat(format);   
            cal.setTime(sFmt.parse(   (StrDate),   new   ParsePosition(0)));   
            
            if   (day   !=   0)   {   
            cal.add(cal.DATE,   day);   
            }   
            if   (month   !=   0)   {   
            cal.add(cal.MONTH,   month);   
            }   
            if   (year   !=   0)   {   
            cal.add(cal.YEAR,   year);   
            
            }   
            return   sFmt.format(cal.getTime());   
            }   
 
        public static void main(String[] args) {  
             System.out.println(GetSysDate("yyyy-MM-dd",   "2004-01-18",   0,   13,   0));         
        }  
}