Java日期处理工具类DateUtils详解

本文实例为大家分享了java日期处理工具类dateutils的具体代码，供大家参考，具体内容如下

import java.sql.timestamp; 
import java.text.parseexception; 
import java.text.simpledateformat; 
import java.util.calendar; 
import java.util.date; 
 
/** 
 * <日期时间处理工具类> 
 */ 
public class dateutils { 
  
 /** 
  * date format pattern this is often used. 
  */ 
 public static final string pattern_ymd = "yyyy-mm-dd"; 
  
 /** 
  * date format pattern this is often used. 
  */ 
 public static final string pattern_ymdhms="yyyy-mm-dd hh:mm:ss"; 
  
 /** 
  * formats the given date according to the ymd pattern. 
  * 
  * @param date the date to format. 
  * @return an ymd formatted date string. 
  * 
  * @see #pattern_ymd 
  */ 
 public static string formatdate(date date) { 
  return formatdate(date, pattern_ymd); 
 } 
  
 /** 
  * formats the given date according to the specified pattern. the pattern 
  * must conform to that used by the {@link simpledateformat simple date 
  * format} class. 
  * 
  * @param date the date to format. 
  * @param pattern the pattern to use for formatting the date. 
  * @return a formatted date string. 
  * 
  * @throws illegalargumentexception if the given date pattern is invalid. 
  * 
  * @see simpledateformat 
  */ 
 public static string formatdate(date date, string pattern) { 
  if (date == null) 
   throw new illegalargumentexception("date is null"); 
  if (pattern == null) 
   throw new illegalargumentexception("pattern is null"); 
   
  simpledateformat formatter = new simpledateformat(pattern); 
  return formatter.format(date); 
 } 
  
 /** 
  * parses a date value. the format used for parsing the date value are retrieved from 
  * the default pattern_ymd. 
  * 
  * @param datevalue the date value to parse 
  * 
  * @return the parsed date 
  * 
  * @throws illegalargumentexception if the given datevalue is invalid. 
  */ 
 public static date parsedate(string datevalue) { 
  return parsedate(datevalue, null); 
 } 
  
 /** 
  * parses the date value using the given date format. 
  * 
  * @param datevalue the date value to parse 
  * @param dateformat the date format to use 
  * 
  * @return the parsed date. if parse is failed , return null 
  * 
  * @throws illegalargumentexception if the given datevalue is invalid. 
  */ 
 public static date parsedate(string datevalue, string dateformat) { 
  if (datevalue == null) { 
   throw new illegalargumentexception("datevalue is null"); 
  } 
  if (dateformat == null) { 
   dateformat = pattern_ymd; 
  } 
   
  simpledateformat df = new simpledateformat(dateformat); 
  date result = null; 
  try { 
   result = df.parse(datevalue); 
  } 
  catch (parseexception pe) { 
   pe.printstacktrace();// 日期型字符串格式错误 
  } 
  return result; 
 } 
  
 /** 
  * adds a number of years to a date returning a new object. 
  * the original date object is unchanged. 
  * 
  * @param date the date, not null 
  * @param amount the amount to add, may be negative 
  * @return the new date object with the amount added 
  * @throws illegalargumentexception if the date is null 
  */ 
 public static date addyears(date date, int amount) { 
  return add(date, calendar.year, amount); 
 } 
  
 /** 
  * adds a number of years to a timestamp returning a new object. 
  * the original timestamp object is unchanged. 
  * 
  * @param timestamp the timestamp, not null 
  * @param amount the amount to add, may be negative 
  * @return the new timestamp object with the amount added 
  * @throws illegalargumentexception if the timestamp is null 
  */ 
 public static timestamp addyears(timestamp timestamp, int amount) { 
  return add(timestamp, calendar.year, amount); 
 } 
  
 //----------------------------------------------------------------------- 
 /** 
  * adds a number of months to a date returning a new object. 
  * the original date object is unchanged. 
  * 
  * @param date the date, not null 
  * @param amount the amount to add, may be negative 
  * @return the new date object with the amount added 
  * @throws illegalargumentexception if the date is null 
  */ 
 public static date addmonths(date date, int amount) { 
  return add(date, calendar.month, amount); 
 } 
  
 /** 
  * adds a number of months to a timestamp returning a new object. 
  * the original timestamp object is unchanged. 
  * 
  * @param timestamp the timestamp, not null 
  * @param amount the amount to add, may be negative 
  * @return the new timestamp object with the amount added 
  * @throws illegalargumentexception if the timestamp is null 
  */ 
 public static timestamp addmonths(timestamp timestamp, int amount) { 
  return add(timestamp, calendar.month, amount); 
 } 
  
 //----------------------------------------------------------------------- 
 /** 
  * adds a number of days to a date returning a new object. 
  * the original date object is unchanged. 
  * 
  * @param date the date, not null 
  * @param amount the amount to add, may be negative 
  * @return the new date object with the amount added 
  * @throws illegalargumentexception if the date is null 
  */ 
 public static date adddays(date date, int amount) { 
  return add(date, calendar.date, amount); 
 } 
  
 /** 
  * adds a number of days to a timestamp returning a new object. 
  * the original timestamp object is unchanged. 
  * 
  * @param timestamp the timestamp, not null 
  * @param amount the amount to add, may be negative 
  * @return the new timestamp object with the amount added 
  * @throws illegalargumentexception if the timestamp is null 
  */ 
 public static timestamp adddays(timestamp timestamp, int amount) { 
  return add(timestamp, calendar.date, amount); 
 } 
  
 //----------------------------------------------------------------------- 
 /** 
  * adds a number of minutes to a timestamp returning a new object. 
  * the original timestamp object is unchanged. 
  * 
  * @param timestamp the timestamp, not null 
  * @param amount the amount to add, may be negative 
  * @return the new timestamp object with the amount added 
  * @throws illegalargumentexception if the timestamp is null 
  */ 
 public static timestamp addminutes(timestamp timestamp, int amount) { 
  return add(timestamp, calendar.minute, amount); 
 } 
  
 /** 
  * adds a number of days to current time returning a new object. 
  * 
  * @param amount the amount to add, may be negative 
  * @return the new timestamp object with the amount added 
  */ 
 public static timestamp adddays(int amount) { 
  calendar c = calendar.getinstance(); 
  c.add(calendar.date, amount); 
  return new timestamp(c.gettimeinmillis()); 
 } 
  
 //----------------------------------------------------------------------- 
 /** 
  * adds to a date returning a new object. 
  * the original date object is unchanged. 
  * 
  * @param date the date, not null 
  * @param calendarfield the calendar field to add to 
  * @param amount the amount to add, may be negative 
  * @return the new date object with the amount added 
  * @throws illegalargumentexception if the date is null 
  */ 
 private static date add(date date, int calendarfield, int amount) { 
  if (date == null) { 
   throw new illegalargumentexception("the date must not be null"); 
  } 
  calendar c = calendar.getinstance(); 
  c.settime(date); 
  c.add(calendarfield, amount); 
  return c.gettime(); 
 } 
  
 /** 
  * adds to a timestamp returning a new object. 
  * the original timestamp object is unchanged. 
  * 
  * @param timestamp the timestamp, not null 
  * @param calendarfield the calendar field to add to 
  * @param amount the amount to add, may be negative 
  * @return the new timestamp object with the amount added 
  * @throws illegalargumentexception if the timestamp is null 
  */ 
 private static timestamp add(timestamp timestamp, int calendarfield, int amount) { 
  if (timestamp == null) { 
   throw new illegalargumentexception("the timestamp must not be null"); 
  } 
  calendar c = calendar.getinstance(); 
  c.settime(timestamp); 
  c.add(calendarfield, amount); 
  return new timestamp(c.gettimeinmillis()); 
 } 
  
 /** 
  * <生成最小的当天日期值> 
  * @return 最小的当天日期值 
  */ 
 public static timestamp now() { 
  calendar c = calendar.getinstance(); 
  c.set(calendar.hour_of_day, 0); 
  c.set(calendar.minute, 0); 
  c.set(calendar.second, 0); 
  c.set(calendar.millisecond, 0); 
  return new timestamp(c.gettimeinmillis()); 
 } 
  
  
  
 /** this class should not be instantiated. */ 
 private dateutils() { 
 } 
} 

以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持。