Java Date processing calendar and date

Copy of the family, only for the study of use.

Java Date gets date and time seconds

　　

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();      } }

Get day, if greater than 16 + 2 months, otherwise + 1 months, output 7 months

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);      } }

Java Date processing calendar and date