Explication détaillée d'exemples de développement de classes de dates de base en Java-javaDidacticiel-php.cn

Cet article présente principalement le contenu pertinent de la classe date de base dans le développement Java. Le code utilise la classe d'outils date pour obtenir la correspondance entre le jour de la semaine et la date du mois spécifié, et pour obtenir l'ensemble des toutes les dates et jours du mois spécifié, etc., qui ont une certaine valeur de référence, peuvent le découvrir.

En raison du travail, je n'ai pas mis à jour mon blog depuis longtemps. Aujourd'hui, je vais vous proposer un article sur l'obtention de la relation correspondante entre le jour de la semaine et la date du mois spécifié en Java. Bon, sans plus attendre, passons directement au code :

1. Classe d'outil de date

package com.lyz.date;
import java.text.SimpleDateFormat;
import java.util.ArrayList;
import java.util.Calendar;
import java.util.Date;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import com.chwl.medical.utils.common.CollectionUtils;
import com.chwl.medical.utils.common.ObjectUtils;
/**
 * 日期工具类，获取指定月份的星期与日期的对应关系
 * @author liuyazhuang
 *
 */
public class DateUtils {
	public static final String DATE_FORMAT = "yyyy-MM-dd";
	public enum Type{
		Year, Month, Date
	}
	/**
	 * 获取两个时间之间的年份
	 * @param startDate
	 * @param endDate
	 * @return
	 */
	public static int getYears(Date startDate, Date endDate, Type type){
		int count = 0;
		 Calendar calBegin = Calendar.getInstance(); //获取日历实例 
		 Calendar calEnd = Calendar.getInstance(); 
		 calBegin.setTime(startDate);
		 calEnd.setTime(endDate);
		 if(Type.Year == type){
			 count = calEnd.get(Calendar.YEAR) - calBegin.get(Calendar.YEAR); 
		 }else if(Type.Month == type){
			 count = calEnd.get(Calendar.MONTH) - calBegin.get(Calendar.MONTH); 
		 }else{
			 count = calEnd.get(Calendar.DATE) - calBegin.get(Calendar.DATE); 
		 }
		 return count;
	}
	/**
	 * 获取指定月份的所有日期和星期集合
	 * @param offset:起止月份, 0：当前月, 1:下一个月; 2下下月； 以此类推... -1:上一个月; -2:上上一个月 ; 以此类推....
	 * @param length:终止月份, 0：当前月, 1:下一个月; 2下下月； 以此类推... -1:上一个月; -2:上上一个月 ; 以此类推....
	 * @return:日期和星期集合:星期为key 日期为value
	 */
	public static Map<String, List<String>> getKeyFromMapByValue(int offset, int length){
		return getKeyFromMapByValue(getDateKeyWeekValue(offset, length));
	}
	/**
	 * 将以date为key, week为value的map转化为以week为key, date为value的map
	 * @param dateWeek
	 * @return
	 */
	public static Map<String, List<String>> getKeyFromMapByValue(Map<String, String> dateWeek){
		Map<String, List<String>> weekDate = new HashMap<String, List<String>>();
		if(!CollectionUtils.isEmpty(dateWeek)){
			for(Map.Entry<String, String> entry : dateWeek.entrySet()){
				//获取日期集合
				List<String> list = weekDate.get(entry.getValue());
				if(ObjectUtils.isEmpty(list)){
					list = new ArrayList<String>();
				}
				list.add(entry.getKey());
				weekDate.put(entry.getValue(), list);
			}
		}
		return weekDate;
	}
	/**
	 * 获取指定月份的所有日期和星期集合
	 * @param offset:起止月份, 0：当前月, 1:下一个月; 2下下月； 以此类推... -1:上一个月; -2:上上一个月 ; 以此类推....
	 * @param length:终止月份, 0：当前月, 1:下一个月; 2下下月； 以此类推... -1:上一个月; -2:上上一个月 ; 以此类推....
	 * @return:日期和星期集合:日期为key 星期为value
	 */
	public static Map<String, String> getDateKeyWeekValue(int offset, int length){
		Map<String, String> map = new HashMap<String, String>();
		for(int i = offset; i <= length; i++){
			List<Date> list = getAllTheDateOftheMonth(new Date(),i);
			for(Date date: list){
				String weekDay = getDateOfWeek(date);
				map.put(parseDateToString(date, DATE_FORMAT), weekDay);
			}
		}
		return map;
	}
	/**
	 * 获取当前日期所在月份的所有日期，指定月份的所有日期
	 * @param date:当前日期
	 * @param n:1下一月;2:下下月..以此类推; -1:上月,-2:上上月...以此类推
	 * @return:返回指定月份的所有日期
	 */
	public static List<Date> getAllTheDateOftheMonth(Date date, int n) {
		List<Date> list = new ArrayList<Date>();
		Calendar cal = Calendar.getInstance();
		cal.setTime(date);
		cal.set(Calendar.DATE, 1);
		cal.add(Calendar.MONTH, n);
		int month = cal.get(Calendar.MONTH);
		while(cal.get(Calendar.MONTH) == month){
			list.add(cal.getTime());
			cal.add(Calendar.DATE, 1);
		}
		return list;
	}
	/**
	 * 根据日期获得星期
	 * @param date
	 * @return
	 */
	public static String getDateOfWeek(Date date) {
		//String[] weekDaysName = { "星期日", "星期一", "星期二", "星期三", "星期四", "星期五", "星期六" };
		String[] weekDaysCode = { "0", "1", "2", "3", "4", "5", "6" };
		Calendar calendar = Calendar.getInstance();
		calendar.setTime(date);
		int intWeek = calendar.get(Calendar.DAY_OF_WEEK) - 1;
		if(intWeek < 0) intWeek = 0;
		return weekDaysCode[intWeek];
	}
	public static String parseDateToString(Date date, String formatString) {
		return getSimpleDateFormat(formatString).format(date);
	}
	public static SimpleDateFormat getSimpleDateFormat(String formatString) {
		return new SimpleDateFormat(formatString);
	}
}

Copier après la connexion

2. Classe de test

package com.lyz.date; 
import net.sf.json.JSONObject; 
/** 
 * 测试工具类 
 * @author liuyazhuang 
 * 
 */ 
public class TestDate { 
  public static void main(String[] args) { 
    System.out.println(JSONObject.fromObject(DateUtils.getDateKeyWeekValue(-1, 1))); 
    System.out.println(JSONObject.fromObject(DateUtils.getKeyFromMapByValue(-1,1))); 
  } 
}

Copier après la connexion

3. Résultats des tests

{
  "2017-02-28": "2",
  "2017-04-19": "3",
  "2017-04-17": "1",
  "2017-02-25": "6",
  "2017-04-18": "2",
  "2017-02-24": "5",
  "2017-04-15": "6",
  "2017-02-27": "1",
  "2017-04-16": "0",
  "2017-02-26": "0",
  "2017-04-13": "4",
  "2017-02-21": "2",
  "2017-04-14": "5",
  "2017-02-20": "1",
  "2017-04-11": "2",
  "2017-02-23": "4",
  "2017-04-12": "3",
  "2017-02-22": "3",
  "2017-04-21": "5",
  "2017-04-20": "4",
  "2017-04-08": "6",
  "2017-04-09": "0",
  "2017-04-04": "2",
  "2017-04-05": "3",
  "2017-04-06": "4",
  "2017-04-07": "5",
  "2017-04-01": "6",
  "2017-04-02": "0",
  "2017-04-03": "1",
  "2017-04-10": "1",
  "2017-02-07": "2",
  "2017-02-06": "1",
  "2017-02-09": "4",
  "2017-02-08": "3",
  "2017-03-29": "3",
  "2017-03-25": "6",
  "2017-03-26": "0",
  "2017-03-27": "1",
  "2017-02-01": "3",
  "2017-03-28": "2",
  "2017-03-21": "2",
  "2017-02-03": "5",
  "2017-03-22": "3",
  "2017-02-02": "4",
  "2017-03-23": "4",
  "2017-02-05": "0",
  "2017-03-24": "5",
  "2017-02-04": "6",
  "2017-03-31": "5",
  "2017-03-30": "4",
  "2017-04-23": "0",
  "2017-04-22": "6",
  "2017-02-19": "0",
  "2017-04-25": "2",
  "2017-02-18": "6",
  "2017-04-24": "1",
  "2017-02-17": "5",
  "2017-04-27": "4",
  "2017-04-26": "3",
  "2017-04-29": "6",
  "2017-03-18": "6",
  "2017-04-28": "5",
  "2017-03-19": "0",
  "2017-02-12": "0",
  "2017-03-16": "4",
  "2017-02-11": "6",
  "2017-03-17": "5",
  "2017-02-10": "5",
  "2017-03-14": "2",
  "2017-03-15": "3",
  "2017-02-16": "4",
  "2017-03-12": "0",
  "2017-02-15": "3",
  "2017-03-13": "1",
  "2017-02-14": "2",
  "2017-03-10": "5",
  "2017-02-13": "1",
  "2017-03-11": "6",
  "2017-03-20": "1",
  "2017-03-09": "4",
  "2017-03-08": "3",
  "2017-03-07": "2",
  "2017-03-06": "1",
  "2017-03-05": "0",
  "2017-03-04": "6",
  "2017-03-03": "5",
  "2017-03-02": "4",
  "2017-04-30": "0",
  "2017-03-01": "3"
}

Copier après la connexion

{
  "3": [
    "2017-04-19",
    "2017-04-12",
    "2017-02-22",
    "2017-04-05",
    "2017-02-08",
    "2017-03-29",
    "2017-02-01",
    "2017-03-22",
    "2017-04-26",
    "2017-03-15",
    "2017-02-15",
    "2017-03-08",
    "2017-03-01"
  ],
  "2": [
    "2017-02-28",
    "2017-04-18",
    "2017-02-21",
    "2017-04-11",
    "2017-04-04",
    "2017-02-07",
    "2017-03-28",
    "2017-03-21",
    "2017-04-25",
    "2017-03-14",
    "2017-02-14",
    "2017-03-07"
  ],
  "1": [
    "2017-04-17",
    "2017-02-27",
    "2017-02-20",
    "2017-04-03",
    "2017-04-10",
    "2017-02-06",
    "2017-03-27",
    "2017-04-24",
    "2017-03-13",
    "2017-02-13",
    "2017-03-20",
    "2017-03-06"
  ],
  "0": [
    "2017-04-16",
    "2017-02-26",
    "2017-04-09",
    "2017-04-02",
    "2017-03-26",
    "2017-02-05",
    "2017-04-23",
    "2017-02-19",
    "2017-03-19",
    "2017-02-12",
    "2017-03-12",
    "2017-03-05",
    "2017-04-30"
  ],
  "6": [
    "2017-02-25",
    "2017-04-15",
    "2017-04-08",
    "2017-04-01",
    "2017-03-25",
    "2017-02-04",
    "2017-04-22",
    "2017-02-18",
    "2017-04-29",
    "2017-03-18",
    "2017-02-11",
    "2017-03-11",
    "2017-03-04"
  ],
  "5": [
    "2017-02-24",
    "2017-04-14",
    "2017-04-21",
    "2017-04-07",
    "2017-02-03",
    "2017-03-24",
    "2017-03-31",
    "2017-02-17",
    "2017-04-28",
    "2017-03-17",
    "2017-02-10",
    "2017-03-10",
    "2017-03-03"
  ],
  "4": [
    "2017-04-13",
    "2017-02-23",
    "2017-04-20",
    "2017-04-06",
    "2017-02-09",
    "2017-02-02",
    "2017-03-23",
    "2017-03-30",
    "2017-04-27",
    "2017-03-16",
    "2017-02-16",
    "2017-03-09",
    "2017-03-02"
  ]
}

Copier après la connexion

Résumé

Cet article vous montre plusieurs utilisations de la classe d'outils de date à travers des exemples de code. J'espère qu'il vous sera utile. à tous ceux qui apprennent Java.

Ce qui précède est le contenu détaillé de. pour plus d'informations, suivez d'autres articles connexes sur le site Web de PHP en chinois!