KM-Server-Milestone2/src/main/java/com/redxun/knowledge/utils/DateUtils.java

package com.redxun.knowledge.utils;

import org.apache.commons.lang.time.DateFormatUtils;

import java.time.LocalDate;
import java.time.format.DateTimeFormatter;
import java.time.temporal.TemporalAdjusters;
import java.util.Calendar;
import java.util.Date;

/**
 * 文件名: DateUtils
 * 作者: zizg
 * 时间: 2023/3/20
 * 描述:
 * 修改人:
 * 修改时间:
 * 修改内容:
 */
public class DateUtils {

    private static String datePattern = "yyyy-MM-dd";

    private DateUtils(){

    }

    /**
     * 时间转时间字符串
     * @param date  日期
     * @return String
     */
    public static String format(Date date) {
        if (date == null)
            return "";
        return DateFormatUtils.format(date,datePattern);
    }

    /**
     * 获取某年第一天日期
     * @param year 年份
     * @return Date
     */
    public static Date getFirstOfYear(int year){
        Calendar calendar = Calendar.getInstance();
        calendar.clear();
        calendar.set(Calendar.YEAR, year);
        return calendar.getTime();
    }



    /**
     * 获取某年最后一天日期
     * @param year 年份
     * @return Date
     */
    public static Date getLastOfYear(int year){
        Calendar calendar = Calendar.getInstance();
        calendar.clear();
        calendar.set(Calendar.YEAR, year);
        calendar.roll(Calendar.DAY_OF_YEAR, -1);
        return calendar.getTime();
    }

    /**
     * 获取指定年月日的第一天
     * @param year
     * @param month
     * @param day
     * @return
     */
    public static String getFirstOfMonth(int year,int month,int day){
        LocalDate date = LocalDate.of(year, month, day);
        LocalDate firstDay = date.with(TemporalAdjusters.firstDayOfMonth());
        DateTimeFormatter df = DateTimeFormatter.ofPattern(datePattern);
        String dateStr = firstDay.format(df);
        return dateStr;
    }

    /**
     * 获取指定年月日的最后一天
     * @param year
     * @param month
     * @param day
     * @return
     */
    public static String getLastOfMonth(int year,int month,int day){
        LocalDate date = LocalDate.of(year, month, day);
        LocalDate lastDay = date.with(TemporalAdjusters.lastDayOfMonth());
        DateTimeFormatter df = DateTimeFormatter.ofPattern(datePattern);
        String dateStr = lastDay.format(df);
        return dateStr;
    }
}