java 季度的最后一天 java本月最后一天

package test;
import java.text.ParseException;
 import java.text.SimpleDateFormat;
 import java.util.Calendar;
 import java.util.Date;public class test1 {
      public static void main(String []agrs){
                    //获取当前月最后一天
            Calendar ca = Calendar.getInstance();
            ca.set(Calendar.DAY_OF_MONTH, ca.getActualMaximum(Calendar.DAY_OF_MONTH));
            String last = new SimpleDateFormat("yyyy-MM-dd").format(ca.getTime());
            System.out.println("===============last:"+last);
            
            Calendar c = Calendar.getInstance();
            try {
             c.setTime(new SimpleDateFormat("yyyy-MM-dd").parse(last));
         } catch (ParseException e) {
             // TODO Auto-generated catch block
             e.printStackTrace();
         }
            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
            String first = new SimpleDateFormat("yyyy-MM-dd").format(c.getTime());
            System.out.println("===============first:"+first);
           
      }
 }