获取常用日期

package demo;


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


public class Timeutil {


public static final String DATE_FORMAT_TIME1 = "yyyy-MM-dd HH:mm:ss";
public static final String DATE_FORMAT_TIME2 = "yyyyMMddHHmmss";
public static final String DATE_FORMAT_TIME3 = "yyyy/MM/dd HH:mm:ss";
public static final String DATE_FORMAT_DATE1 = "yyyy-MM-dd";
public static final String DATE_FORMAT_DATE2 = "yyyy/MM/dd";
public static final String DATE_FORMAT_DATE3 = "yyyyMMdd";


// 昨天
public static Date getYesterDay() {
Calendar c = Calendar.getInstance();
c.add(Calendar.DATE, -1);
return c.getTime();
}


// 第二天
public static Date getNextDay(Date date) {
Calendar c = Calendar.getInstance();
c.setTime(date);
c.add(Calendar.DATE, 1);
return c.getTime();
}


// 上一个月
public static Date getLastMonth() {
Calendar c = Calendar.getInstance();
c.add(Calendar.MONTH, -1);
return c.getTime();
}


// 上一个月末
public static Date getLastMonthEnd() {
Calendar c = Calendar.getInstance();
c.set(Calendar.DATE, 1);
c.add(Calendar.DATE, -1);
return c.getTime();
}


// 上当前月第一天
public static Date getCurMonthFirstDay() {
Calendar c = Calendar.getInstance();    
        c.add(Calendar.MONTH, 0);
        c.set(Calendar.DAY_OF_MONTH,1);//设置为1号,当前日期既为本月第一天 
return c.getTime();
}


// 格式化日期
public static String dateFormat(Date date, String format) {
SimpleDateFormat sdf = new SimpleDateFormat(format);
return sdf.format(date);
}


public static synchronized Date parseFormatDate(String dateString,
String format) {
dateString = dateString.trim();
Date date = null;
DateFormat dateFormat = new SimpleDateFormat(format);


try {
date = dateFormat.parse(dateString);
} catch (ParseException e) {
e.printStackTrace();
}
return date;
}


// 获得当天日期
public static String CurDateFormat(String format) {
Date date = new Date();
SimpleDateFormat sdf = new SimpleDateFormat(format);
return sdf.format(date);
}


public static void main(String[] args) {
System.out.println(dateFormat(getCurMonthFirstDay(),DATE_FORMAT_DATE3));
}


}