java时间当天、昨天、本周、本月的工具类

java利用Calendar和SimpleDateFormat返回时间当天、昨天、本周、本月的工具类字符串，具体实现工具类如下：

import java.text.SimpleDateFormat;
import java.util.Calendar;
public class DataTimeUtils {

private final static String timeformat = "yyyy-MM-dd HH:mm:ss";

/**
* 今天开始时间
*
* @return
*/
public static String getTodayStartTime() {
SimpleDateFormat sdf = new SimpleDateFormat(timeformat);
Calendar todayStart = Calendar.getInstance();
todayStart.set(Calendar.HOUR_OF_DAY, 0);
todayStart.set(Calendar.MINUTE, 0);
todayStart.set(Calendar.SECOND, 0);
todayStart.set(Calendar.MILLISECOND, 0);
return sdf.format(todayStart.getTime());
}

/**
* 今天结束时间
*
* @return
*/
public static String getTodayEndTime() {
SimpleDateFormat sdf = new SimpleDateFormat(timeformat);
Calendar todayEnd = Calendar.getInstance();
todayEnd.set(Calendar.HOUR_OF_DAY, 24);
todayEnd.set(Calendar.MINUTE, 0);
todayEnd.set(Calendar.SECOND, 0);
todayEnd.set(Calendar.MILLISECOND, 0);
return sdf.format(todayEnd.getTime());
}

/**
* 昨天开始时间
*
* @return
*/
public static String getYesterdayStartTime() {
SimpleDateFormat sdf = new SimpleDateFormat(timeformat);
Calendar todayStart = Calendar.getInstance();
todayStart.add(Calendar.DATE, -1);
todayStart.set(Calendar.HOUR_OF_DAY, 0);
todayStart.set(Calendar.MINUTE, 0);
todayStart.set(Calendar.SECOND, 0);
todayStart.set(Calendar.MILLISECOND, 0);
return sdf.format(todayStart.getTime());
}

/**
* 昨天结束时间
*
* @return
*/
public static String getYesterdayEndTime() {
SimpleDateFormat sdf = new SimpleDateFormat(timeformat);
Calendar todayEnd = Calendar.getInstance();
todayEnd.add(Calendar.DATE, -1);
todayEnd.set(Calendar.HOUR_OF_DAY, 23);
todayEnd.set(Calendar.MINUTE, 59);
todayEnd.set(Calendar.SECOND, 59);
todayEnd.set(Calendar.MILLISECOND, 999);
return sdf.format(todayEnd.getTime());
}

// 获得本周一0点时间
public static String getTimesWeekmorning() {
SimpleDateFormat sdf = new SimpleDateFormat(timeformat);
Calendar cal = Calendar.getInstance();
cal.set(cal.get(Calendar.YEAR), cal.get(Calendar.MONDAY), cal.get(Calendar.DAY_OF_MONTH), 0, 0, 0);
cal.set(Calendar.DAY_OF_WEEK, Calendar.MONDAY);
return sdf.format(cal.getTime());
}

// 获得本周日24点时间
public static String getTimesWeeknight() {
SimpleDateFormat sdf = new SimpleDateFormat(timeformat);
Calendar cal = Calendar.getInstance();
Calendar cal1 = Calendar.getInstance();
cal1.set(cal.get(Calendar.YEAR), cal.get(Calendar.MONDAY), cal.get(Calendar.DAY_OF_MONTH), 0, 0, 0);
cal1.set(Calendar.DAY_OF_WEEK, Calendar.MONDAY);
cal.setTime(cal1.getTime());
cal.add(Calendar.DAY_OF_WEEK, 7);
return sdf.format(cal.getTime());
}

// 获得本月第一天0点时间
public static String getTimesMonthmorning() {
SimpleDateFormat sdf = new SimpleDateFormat(timeformat);
Calendar cal = Calendar.getInstance();
cal.set(cal.get(Calendar.YEAR), cal.get(Calendar.MONDAY), cal.get(Calendar.DAY_OF_MONTH), 0, 0, 0);
cal.set(Calendar.DAY_OF_MONTH, cal.getActualMinimum(Calendar.DAY_OF_MONTH));
return sdf.format(cal.getTime());
}

// 获得本月最后一天24点时间
public static String getTimesMonthnight() {
SimpleDateFormat sdf = new SimpleDateFormat(timeformat);
Calendar cal = Calendar.getInstance();
cal.set(cal.get(Calendar.YEAR), cal.get(Calendar.MONDAY), cal.get(Calendar.DAY_OF_MONTH), 0, 0, 0);
cal.set(Calendar.DAY_OF_MONTH, cal.getActualMaximum(Calendar.DAY_OF_MONTH));
cal.set(Calendar.HOUR_OF_DAY, 24);
return sdf.format(cal.getTime());
}

public static void main(String[] args) {

System.out.println("当天0点时间："+ getTodayStartTime());
System.out.println("当天24点时间："+ getTodayEndTime());
System.out.println("昨天0点时间："+ getYesterdayStartTime());
System.out.println("昨天24点时间："+getYesterdayEndTime());
System.out.println("本周周一0点时间："+ getTimesWeekmorning());
System.out.println("本周周日24点时间："+getTimesWeeknight());
System.out.println("本月初0点时间："+ getTimesMonthmorning());
System.out.println("本月未24点时间："+ getTimesMonthnight());
}

}