자바 날짜계산 유틸리티 구현

자바 날짜계산 유틸리티 구현

구현 조건

startDate 와 endDate를 hashMap 변수로 받는다. 

그런다음 해당 날짜들의 리스트를 출력한다.

현재 java8 로 변하면서 Date 에서 LocalDate를 사용한다. 리팩토링 했으므로 둘 다 작성하면 얼마나 개선됬는지 한눈에 볼 수 있겠다..

클래스는 static 으로 할까 그냥 인스턴스로 할까 고민을 했는데 범용적으로 쓸 걸 고려해서 static으로 했다.

LocalDate로 구현

package com.waug.cube.v1.openapi.goods.item.util;

import java.time.LocalDate;
import java.time.Period;
import java.time.format.DateTimeFormatter;
import java.util.ArrayList;
import java.util.List;
import java.util.Map;
import com.waug.cube.v1.openapi.goods.exception.DateTypeInValidException;

public class CalculateLocalDate {

    private final static int DEFAULT_DATE = 10;


    public static List<LocalDate> initDate(Map<String, String> requestMap)
            throws DateTypeInValidException {


        if(!requestMap.containsKey("startDate") && !requestMap.containsKey("endDate")) {

            // 현재시간을 기준으로 날짜 맞춘다.
            LocalDate startDate = LocalDate.now();
            LocalDate endDate = startDate.plusDays(DEFAULT_DATE);

            return getDaysBetweenDates(startDate, endDate);

        } else if(requestMap.containsKey("startDate") && !requestMap.containsKey("endDate")) {

            LocalDate startDate =
                    LocalDate.parse(requestMap.get("startDate"), DateTimeFormatter.ISO_LOCAL_DATE);
            LocalDate endDate = startDate.plusDays(DEFAULT_DATE);

            return getDaysBetweenDates(startDate, endDate);
        } else if(!requestMap.containsKey("startDate") && requestMap.containsKey("endDate")) {

            LocalDate endDate =
                    LocalDate.parse(requestMap.get("endDate"), DateTimeFormatter.ISO_LOCAL_DATE);
            LocalDate startDate = endDate.minusDays(DEFAULT_DATE);
            return getDaysBetweenDates(startDate, endDate);

        } else {

            LocalDate startDate =
                    LocalDate.parse(requestMap.get("startDate"), DateTimeFormatter.ISO_LOCAL_DATE);
            LocalDate endDate = checkValidDate(startDate,
                    LocalDate.parse(requestMap.get("endDate"), DateTimeFormatter.ISO_LOCAL_DATE));

            return getDaysBetweenDates(startDate, endDate);
        }
    }


    private static LocalDate checkValidDate(LocalDate startDate, LocalDate endDate)
            throws DateTypeInValidException {

        Period period = startDate.until(endDate);

        if(period.getDays() > DEFAULT_DATE) {
            throw new DateTypeInValidException(
                    "if you invest endDate before now you must put startDate parameter");
        }
        return endDate;
    }


public static List<LocalDate> getDaysBetweenDates(LocalDate startDate, LocalDate endDate) {

    List<LocalDate> localDates = new ArrayList<>();

    while(startDate.isBefore(endDate)) {
        localDates.add(startDate);
        startDate = startDate.plusDays(1);
    }

    return localDates;
}
}

TestCode

package v1.openapi.goods.item;

import java.text.ParseException;
import java.time.LocalDate;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import com.waug.cube.v1.openapi.goods.exception.DateTypeInValidException;
import com.waug.cube.v1.openapi.goods.item.util.CalculateLocalDate;
import static org.hamcrest.Matchers.is;
import static org.hamcrest.Matchers.notNullValue;
import static org.junit.Assert.assertThat;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;

@RunWith(SpringJUnit4ClassRunner.class)
public class CalculateLocalDateTests {


    private Map<String, String> requestMap;


    @Test
    public void startDate_endDate_모두_입력안했을시() throws DateTypeInValidException {
        requestMap = new HashMap<>();
        List<LocalDate> dateList = CalculateLocalDate.initDate(requestMap);
        assertThat(dateList, is(notNullValue()));
    }


    @Test
    public void startDate_압력_endDate_입력안했을시() throws DateTypeInValidException {
        requestMap = new HashMap<>();
        requestMap.put("startDate", "2019-01-02");
        List<LocalDate> dateList = CalculateLocalDate.initDate(requestMap);
        assertThat(dateList, is(notNullValue()));
    }


    @Test
    public void startDate_입력안하고_endDate_입력했을시() throws DateTypeInValidException {
        requestMap = new HashMap<>();
        requestMap.put("endDate", "2019-01-02");
        List<LocalDate> dateList = CalculateLocalDate.initDate(requestMap);
        assertThat(dateList, is(notNullValue()));

    }


    @Test(expected = ParseException.class)
    public void startDate_endDate_둘중하나_오타로_입력했을시() throws DateTypeInValidException {
        requestMap = new HashMap<>();
        requestMap.put("startDate", "2019-01-0e2");
        List<LocalDate> dateList = CalculateLocalDate.initDate(requestMap);
    }


}

기존 Date로 구현

public class CalculateDate {

    private final static int DEFAULT_DATE = 10;

    public static List<Date> initDate(Map<String, String> requestMap)
            throws ParseException, DateTypeInValidException {

        SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd");

        if(!requestMap.containsKey("startDate") && !requestMap.containsKey("endDate")) {

            // 현재시간을 기준으로 날짜 맞춘다.
            String startDate = sdf.format(new Date());
            Calendar cal = Calendar.getInstance();
            cal.add(Calendar.DATE, DEFAULT_DATE);
            String endDate = sdf.format(cal.getTime());

            return getDaysBetweenDates(startDate, endDate);

        } else if(requestMap.containsKey("startDate") && !requestMap.containsKey("endDate")) {

            String startDateString = requestMap.get("startDate");
            Date startDate = checkValidDate(startDateString);
            Calendar cal = Calendar.getInstance();
            cal.setTime(startDate);
            cal.add(Calendar.DATE, DEFAULT_DATE);
            String endDateString = sdf.format(cal.getTime());

            return getDaysBetweenDates(startDateString, endDateString);
        } else {

            String startDateString;
            String endDateString = requestMap.get("endDate");
            Date startDate;
            Date endDate = checkValidDate(endDateString);
            if(requestMap.containsKey("startDate")) {
                startDateString = requestMap.get("startDate");
                startDate = checkValidDate(startDateString);
            } else {
                startDate = new Date();
            }


            if(isValidTerm(startDate, endDate)) {
                return getDaysBetweenDates(sdf.format(startDate), endDateString);
            } else {
                throw new DateTypeInValidException(
                        "if you invest endDate before now you must put startDate parameter");
            }
        }
    }


    private static boolean isValidTerm(Date startDate, Date endDate)
            throws DateTypeInValidException {
        if(startDate.compareTo(endDate) > 0) {
            return false;
        } else if(startDate.compareTo(endDate) <= 0) {
            long diffDay = (startDate.getTime() - endDate.getTime()) / (24 * 60 * 60 * 1000);
            if(diffDay <= DEFAULT_DATE) {
                return true;
            } else {
                throw new DateTypeInValidException(
                        "if you invest endDate you must put short endDate than now");
            }
        }

        return false;
    }


    private static Date checkValidDate(String startDate) throws ParseException {
        SimpleDateFormat format = new SimpleDateFormat("yyyy-MM-dd");
        return format.parse(startDate);
    }


    public static List<Date> getDaysBetweenDates(String startDate, String endDate)
            throws ParseException {

        SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd");
        List<Date> dates = new ArrayList<>();
        Date currentDate = sdf.parse(startDate);
        Date beforeDate = sdf.parse(endDate);

        Calendar calendar = new GregorianCalendar();
        calendar.setTime(currentDate);

        while(calendar.getTime().before(beforeDate)) {
            Date result = calendar.getTime();
            dates.add(result);
            calendar.add(Calendar.DATE, 1);
        }
        return dates;
    }
}