J2EE工具类：DateUtil .java

package com.worthtech.app.util;import java.text.DateFormat;import java.text.ParseException;import java.text.SimpleDateFormat;import java.util.Calendar;import java.util.Date;import java.util.GregorianCalendar;public class DateUtil {/** * 获得当前时间，格式yyyy-MM-dd hh:mm:ss * @param format * @return */public static String getCurrentDate(){return getCurrentDate("yyyy-MM-dd hh:mm:ss");}/** * 获得当前时间，格式自定义 * @param format * @return */public static String getCurrentDate(String format){Calendar day=Calendar.getInstance(); day.add(Calendar.DATE,0); SimpleDateFormat sdf=new SimpleDateFormat(format);//"yyyy-MM-dd"String date = sdf.format(day.getTime());return date;}/** * 获得昨天时间，格式自定义 * @param format * @return */public static String getYesterdayDate(String format){Calendar day=Calendar.getInstance(); day.add(Calendar.DATE,-1); SimpleDateFormat sdf=new SimpleDateFormat(format);//"yyyy-MM-dd"String date = sdf.format(day.getTime());return date;} /** * @param date1 需要比较的时间 不能为空(null),需要正确的日期格式 ,如：2009-09-12 * @param date2 被比较的时间 为空(null)则为当前时间 * @param stype 返回值类型 0为多少天，1为多少个月，2为多少年 * @return * 举例： * compareDate("2009-09-12", null, 0);//比较天 * compareDate("2009-09-12", null, 1);//比较月 * compareDate("2009-09-12", null, 2);//比较年 */ public static int compareDate(String startDay,String endDay,int stype){ int n = 0; String[] u = {"天","月","年"}; String formatStyle = stype==1?"yyyy-MM":"yyyy-MM-dd"; endDay = endDay==null?getCurrentDate("yyyy-MM-dd"):endDay; DateFormat df = new SimpleDateFormat(formatStyle); Calendar c1 = Calendar.getInstance(); Calendar c2 = Calendar.getInstance(); try { c1.setTime(df.parse(startDay)); c2.setTime(df.parse(endDay)); } catch (Exception e3) { System.out.println("wrong occured"); } //List list = new ArrayList(); while (!c1.after(c2)) { // 循环对比，直到相等，n 就是所要的结果 //list.add(df.format(c1.getTime())); // 这里可以把间隔的日期存到数组中 打印出来 n++; if(stype==1){ c1.add(Calendar.MONTH, 1); // 比较月份，月份+1 } else{ c1.add(Calendar.DATE, 1); // 比较天数，日期+1 } } n = n-1; if(stype==2){ n = (int)n/365; } // System.out.println(startDay+" -- "+endDay+" 相差多少"+u[stype]+":"+n); return n; } /** * 判断时间是否符合时间格式 */public static boolean isDate(String date, String dateFormat) {if (date != null) {java.text.SimpleDateFormat format = new java.text.SimpleDateFormat(dateFormat);format.setLenient(false);try {format.format(format.parse(date));} catch (ParseException e) {// TODO Auto-generated catch blockreturn false;}return true;}return false;} /** * 实现给定某日期，判断是星期几 * date:必须yyyy-MM-dd格式 */ public static String getWeekday(String date){SimpleDateFormat sd = new SimpleDateFormat("yyyy-MM-dd"); SimpleDateFormat sdw = new SimpleDateFormat("E"); Date d = null; try { d = sd.parse(date); } catch (ParseException e) { e.printStackTrace(); } return sdw.format(d); } /** * 用来全局控制 上一周，本周，下一周的周数变化 */private static int weeks = 0;/** * 获得当前日期与本周一相差的天数 */ private static int getMondayPlus() { Calendar cd = Calendar.getInstance(); // 获得今天是一周的第几天，星期日是第一天，星期二是第二天...... int dayOfWeek = cd.get(Calendar.DAY_OF_WEEK); if (dayOfWeek == 1) { return -6; } else { return 2 - dayOfWeek; } } /** * 获得本周星期一的日期 */ public static String getCurrentMonday(String format) { weeks = 0; int mondayPlus = getMondayPlus(); Calendar currentDate=Calendar.getInstance(); currentDate.add(Calendar.DATE, mondayPlus); SimpleDateFormat sdf=new SimpleDateFormat(format);//"yyyy-MM-dd" String date = sdf.format(currentDate.getTime()); return date; } /** * 获得上周星期一的日期 */ public static String getPreviousMonday(String format) { weeks--; int mondayPlus = getMondayPlus(); Calendar currentDate=Calendar.getInstance(); currentDate.add(GregorianCalendar.DATE, mondayPlus + 7 * weeks); SimpleDateFormat sdf=new SimpleDateFormat(format);//"yyyy-MM-dd" String date = sdf.format(currentDate.getTime()); return date; } /** * 获得下周星期一的日期 */ public static String getNextMonday(String format) { weeks++; int mondayPlus = getMondayPlus();// GregorianCalendar currentDate = new GregorianCalendar(); Calendar currentDate=Calendar.getInstance(); currentDate.add(GregorianCalendar.DATE, mondayPlus + 7 * weeks); SimpleDateFormat sdf=new SimpleDateFormat(format);//"yyyy-MM-dd" String date = sdf.format(currentDate.getTime()); return date; } /** * 获得相应周的周日的日期 * 此方法必须写在getCurrentMonday，getPreviousMonday或getNextMonday方法之后 */ public static String getSunday(String format) { int mondayPlus = getMondayPlus(); Calendar currentDate=Calendar.getInstance(); currentDate.add(Calendar.DATE, mondayPlus + 7 * weeks + 6); SimpleDateFormat sdf=new SimpleDateFormat(format);//"yyyy-MM-dd" String date = sdf.format(currentDate.getTime()); return date; }/** *method 将字符串类型的日期转换为一个timestamp（时间戳记java.sql.Timestamp） *@param dateString 需要转换为timestamp的字符串 *@return dataTime timestamp */public final static java.sql.Timestamp string2Time(String dateString) {DateFormat dateFormat;dateFormat = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss", Locale.ENGLISH);// 设定格式dateFormat.setLenient(false);java.util.Date date = null;try {date = dateFormat.parse(dateString);} catch (ParseException e) {// TODO Auto-generated catch blocke.printStackTrace();}//java.sql.Timestamp dateTime = new java.sql.Timestamp(date.getTime());return new java.sql.Timestamp(date.getTime());// Timestamp类型,timeDate.getTime()返回一个long型}/** *method 将字符串类型的日期转换为一个Date（java.sql.Date） * * @param dateString * 需要转换为Date的字符串 *@return dataTime Date */public final static java.sql.Date string2Date(String dateString) {DateFormat dateFormat;dateFormat = new SimpleDateFormat("yyyy-MM-dd", Locale.ENGLISH);dateFormat.setLenient(false);java.util.Date date = null;try {date = dateFormat.parse(dateString);} catch (ParseException e) {// TODO Auto-generated catch blocke.printStackTrace();}//java.sql.Date dateTime = new java.sql.Date(date.getTime());// sql类型return new java.sql.Date(date.getTime());}//记录考勤， 记录迟到、早退时间public static String getState() { String state = "正常"; DateFormat df = new SimpleDateFormat("HH:mm:ss"); Date d = new Date(); try { Date d1 = df.parse("08:00:00"); Date d2 = df.parse(df.format(d)); Date d3 = df.parse("18:00:00"); int t1 = (int) d1.getTime(); int t2 = (int) d2.getTime(); int t3 = (int) d3.getTime(); if (t2 < t1) { long between = (t1 - t2) / 1000;// 除以1000是为了转换成秒 long hour1 = between % (24 * 3600) / 3600; long minute1 = between % 3600 / 60; state = "迟到 ：" + hour1 + "时" + minute1 + "分"; } else if (t2 < t3) { long between = (t3 - t2) / 1000;// 除以1000是为了转换成秒 long hour1 = between % (24 * 3600) / 3600; long minute1 = between % 3600 / 60; state = "早退 ：" + hour1 + "时" + minute1 + "分"; } return state; } catch (Exception e) { return state; } } /** * @param args */public static void main(String[] args) {// TODO Auto-generated method stub String s = getState(); System.out.println(s);}}