import java.text.SimpleDateFormat;
import java.util.Calendar;
public class DateHelper {
/**
* 当前月第一天
* @return
*/
public static String getFirstDayOfMonth(){
SimpleDateFormat sdf=new SimpleDateFormat("yyyy-MM-dd 00:00:00");
Calendar lastDate = Calendar.getInstance();
lastDate.set(Calendar.DATE,1);//设为当前月的1 号
lastDate.add(Calendar.MONTH,-1);//加一个月,变为下月的1 号
return sdf.format(lastDate.getTime());
}
/**
* 计算当月最后一天
* @return
*/
public static String getLastDayOfMonth(){
SimpleDateFormat sdf=new SimpleDateFormat("yyyy-MM-dd 23:59:59");
Calendar lastDate = Calendar.getInstance();
lastDate.set(Calendar.DATE,1);//设为当前月的1 号
lastDate.add(Calendar.DATE,-1);//减去一天,变为当月最后一天
return sdf.format(lastDate.getTime());
}
/**
* 获取年月
* @return
*/
public static String getThisYearAndMonth(){
SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM");
return sdf.format(getFirstDayOfMonth());
}
}
;