java日期格式处理及月份第一天和最后一天

最新推荐文章于 2024-07-09 10:46:05 发布

原创最新推荐文章于 2024-07-09 10:46:05 发布 · 1.1k 阅读

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#java #calendar #string #integer #date #null

本文介绍了一个Java实用工具类，用于获取月份的第一天和最后一天的日期字符串，并提供了灵活的日期格式化方法。该工具类利用了Java的Calendar和SimpleDateFormat类来实现日期的灵活处理。

import java.text.SimpleDateFormat;
import java.util.Calendar;
import java.util.Date;
import java.util.GregorianCalendar;

public class HandleDateUtil {

//日期格式化
private static SimpleDateFormat simpleFormate = new SimpleDateFormat(" yyyy-MM-dd ");

/**
*
* @description: 按日期格式返回月份第一天.
* @author: liuxmi
* @Date:Sep 9, 2009
* @return
* @return:String
*/
public static String getFirstDayOfMonth() {
  Calendar calendar = new GregorianCalendar();
  calendar.set(Calendar.DATE, 1);
  System.out.println(simpleFormate.format(calendar.getTime()));
  return simpleFormate.format(calendar.getTime());
}

/**
*
* @description: 按日期格式返回月份最后天.
* @author: liuxmi
* @Date:Sep 9, 2009
* @return
* @return:String
*/
public static String getLastDayOfMonth() {
  Calendar calendar = new GregorianCalendar();
  calendar.set(Calendar.DATE, 1);
  calendar.roll(Calendar.DATE, -1);
  System.out.println(simpleFormate.format(calendar.getTime()));
  return simpleFormate.format(calendar.getTime());
}
/**

* 返回当前格式日期

*/
public static String getDateFormat(Date date) {
return simpleFormate.format(date);
}
/**

*返回特定格式的日期

*/
public static String getDateFormat(Date date,SimpleDateFormat dateFormat) {
  return dateFormat.format(date);
}
/**
*
* @description: 返回指定年月的月的第一天.
* @author: liuxmi
* @Date:Sep 11, 2009
* @param year
* @param month
* @return
* @return:String
*/
public static String getFirstDayOfMonth(Integer year,Integer month){
  Calendar calendar = new GregorianCalendar();
  if(year == null){
   year = calendar.get(Calendar.YEAR);
  }
  if(month == null){
   month = calendar.get(Calendar.MONTH);
  }
  calendar.set(year, month, 1);
  System.out.println(simpleFormate.format(calendar.getTime()));
  return simpleFormate.format(calendar.getTime());
}
/**
*
* @description: 返回指定年月的月的最后一天.
* @author: liuxmi
* @Date:Sep 11, 2009
* @param year
* @param month
* @return
* @return:String
*/
public static String getLastDayOfMonth(Integer year,Integer month) {
  Calendar calendar = new GregorianCalendar();
  if(year == null){
   year = calendar.get(Calendar.YEAR);
  }
  if(month == null){
   month = calendar.get(Calendar.MONTH);
  }
  calendar.set(year, month, 1);
  calendar.roll(Calendar.DATE, -1);
  System.out.println(simpleFormate.format(calendar.getTime()));
  return simpleFormate.format(calendar.getTime());
}

}