Java日期工具类

/**
* Java日期处理工具类
* @author baron
*
*/
public class DateUtils {
@SuppressLint("SimpleDateFormat")
public static SimpleDateFormat format = new SimpleDateFormat("yyyy-MM-dd");

public static SimpleDateFormat format_Y_M_D_H_m_S = new SimpleDateFormat("yyyy-MM-dd hh:mm:ss");

//获取当天日期
public static String getToday(){
return format.format(new Date())+"";
}
//获取前月的第一天
public static String getFirstDayForwardMonth(){
//获取当前日期
Calendar cal_1=Calendar.getInstance();
cal_1.add(Calendar.MONTH, -1);
//设置为1号,当前日期既为本月第一天
cal_1.set(Calendar.DAY_OF_MONTH,1);
String firstDay = format.format(cal_1.getTime());
return firstDay ;
}
//获取前月的最后一天
public static String getEndDayForwardMonth(){
Calendar cale = Calendar.getInstance();
//设置为1号,当前日期既为本月第一天
cale.set(Calendar.DAY_OF_MONTH,0);
String lastDay = format.format(cale.getTime());
return lastDay;
}
//获取当前月第一天
public static String getFirstDayNowMonth(SimpleDateFormat  format_this){
Calendar c = Calendar.getInstance();
c.add(Calendar.MONTH, 0);
//设置为1号,当前日期既为本月第一天
c.set(Calendar.DAY_OF_MONTH,1);
String first = format_this.format(c.getTime());
return first;
}
//获取当前月最后一天
public static String getEndDayNowMonth(SimpleDateFormat  format_this){
Calendar ca = Calendar.getInstance();
ca.set(Calendar.DAY_OF_MONTH,
ca.getActualMaximum(Calendar.DAY_OF_MONTH));
String last = format_this.format(ca.getTime());
return last;
}
//获取某月最后一天
public static String getEndDayOneMonth(SimpleDateFormat  format_this,int year,int month){
Calendar cal = Calendar.getInstance();
cal.set(Calendar.YEAR,year);
cal.set(Calendar.MONTH,month);
cal.set(Calendar.DAY_OF_MONTH, 1);
cal.add(Calendar.DAY_OF_MONTH, -1);
Date lastDate = cal.getTime();
String last = format_this.format( lastDate);
return last;
}
//获取某月第一天
public static String getFirstDayOneMonth(SimpleDateFormat  format_this,int year,int month){
Calendar cal = Calendar.getInstance();
cal.set(Calendar.YEAR, year);
cal.set(Calendar.MONTH, month-1);
cal.set(Calendar.DAY_OF_MONTH, 1);
Date firstDate = cal.getTime();
String first = format_this.format(firstDate);
return first;
}
}