java Date获取年月日时分秒

package com.util;
 
import java.text.DateFormat;
import java.util.Calendar;
import java.util.Date;
 
 
public class Test {
    public void getTimeByDate(){
        Date date = new Date();
        DateFormat df1 = DateFormat.getDateInstance();//日期格式，精确到日
        System.out.println(df1.format(date));
        DateFormat df2 = DateFormat.getDateTimeInstance();//可以精确到时分秒
        System.out.println(df2.format(date));
        DateFormat df3 = DateFormat.getTimeInstance();//只显示出时分秒
        System.out.println(df3.format(date));
        DateFormat df4 = DateFormat.getDateTimeInstance(DateFormat.FULL,DateFormat.FULL); //显示日期，周，上下午，时间（精确到秒） 
        System.out.println(df4.format(date));  
        DateFormat df5 = DateFormat.getDateTimeInstance(DateFormat.LONG,DateFormat.LONG); //显示日期,上下午，时间（精确到秒） 
        System.out.println(df5.format(date));
        DateFormat df6 = DateFormat.getDateTimeInstance(DateFormat.SHORT,DateFormat.SHORT); //显示日期，上下午,时间（精确到分） 
        System.out.println(df6.format(date));
        DateFormat df7 = DateFormat.getDateTimeInstance(DateFormat.MEDIUM,DateFormat.MEDIUM); //显示日期，时间（精确到分）
        System.out.println(df7.format(date));
    }
    public void getTimeByCalendar(){
        Calendar cal = Calendar.getInstance();
        int year = cal.get(Calendar.YEAR);//获取年份
        int month=cal.get(Calendar.MONTH);//获取月份 
        int day=cal.get(Calendar.DATE);//获取日 
        int hour=cal.get(Calendar.HOUR);//小时 
        int minute=cal.get(Calendar.MINUTE);//分            
        int second=cal.get(Calendar.SECOND);//秒 
        int WeekOfYear = cal.get(Calendar.DAY_OF_WEEK);//一周的第几天
        System.out.println("现在的时间是：公元"+year+"年"+month+"月"+day+"日      "+hour+"时"+minute+"分"+second+"秒       星期"+WeekOfYear);
    }
    public static void main(String[] args) {
        Test t=new Test();
        t.getTimeByDate();
        System.out.println("****************************");
        t.getTimeByCalendar();
    }
}

获取日，如果大于16则+2个月，否则+1个月，输出7个月

public static void main(String[] as) throws Exception {
    int j;
    Calendar cc = Calendar.getInstance();
    int myYear = cc.get(Calendar.YEAR); 
    int myMonth = cc.get(Calendar.MONTH);
    j=cc.get(Calendar.DATE)>16?3:2;
    cc.set(Calendar.MONTH, myMonth+j);
    System.out.println(myYear+"-"+cc.get(cc.MONTH));
    for(int i=0;i<7;i++){
        cc.add(cc.MONTH, 1);
        int mm = cc.get(cc.MONTH);
        int mmm=mm==0?12:mm;
        System.out.println(myYear+"-"+mmm);
    }
}