java正则实现各种日期格式化

package com.st.test;
 
import java.text.DateFormat;
import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.HashMap;
import java.util.regex.Pattern;
 
public class DateFormatUtil {
   
  @SuppressWarnings("finally")
  public static String FormatDate(String dateStr){
 
    HashMap<String,String> dateRegFormat = new HashMap<String,String>();
    dateRegFormat.put(
        "^d{4}D+d{1,2}D+d{1,2}D*$","yyyy-MM-dd-HH-mm-ss");//2014年3月12日 13时5分34秒，2014-03-12 12:05:34，2014/3/12 12:5:34
    dateRegFormat.put("^d{4}D+d{2}D+d{2}D+d{2}D+d{2}$","yyyy-MM-dd-HH-mm");//2014-03-12 12:05
    dateRegFormat.put("^d{4}D+d{2}D+d{2}D+d{2}$","yyyy-MM-dd-HH");//2014-03-12 12
    dateRegFormat.put("^d{4}D+d{2}D+d{2}$","yyyy-MM-dd");//2014-03-12
    dateRegFormat.put("^d{4}D+d{2}$","yyyy-MM");//2014-03
    dateRegFormat.put("^d{4}$","yyyy");//2014
    dateRegFormat.put("^d{14}$","yyyyMMddHHmmss");//20140312120534
    dateRegFormat.put("^d{12}$","yyyyMMddHHmm");//201403121205
    dateRegFormat.put("^d{10}$","yyyyMMddHH");//2014031212
    dateRegFormat.put("^d{8}$","yyyyMMdd");//20140312
    dateRegFormat.put("^d{6}$","yyyyMM");//201403
    dateRegFormat.put("^d{2}s*:s*d{2}s*:s*d{2}$","yyyy-MM-dd-HH-mm-ss");//13:05:34 拼接当前日期
    dateRegFormat.put("^d{2}s*:s*d{2}$","yyyy-MM-dd-HH-mm");//13:05 拼接当前日期
    dateRegFormat.put("^d{2}D+d{1,2}$","yy-MM-dd");//14.10.18(年.月.日)
    dateRegFormat.put("^d{1,"yyyy-dd-MM");//30.12(日.月) 拼接当前年份
    dateRegFormat.put("^d{1,2}D+d{4}$","dd-MM-yyyy");//12.21.2013(日.月.年)
 
    String curDate =new SimpleDateFormat("yyyy-MM-dd").format(new Date());
    DateFormat formatter1 =new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
    DateFormat formatter2;
    String dateReplace;
    String strSuccess="";
    try {
      for (String key : dateRegFormat.keySet()) {
        if (Pattern.compile(key).matcher(dateStr).matches()) {
          formatter2 = new SimpleDateFormat(dateRegFormat.get(key));
          if (key.equals("^d{2}s*:s*d{2}s*:s*d{2}$")
              || key.equals("^d{2}s*:s*d{2}$")) {//13:05:34 或 13:05 拼接当前日期
            dateStr = curDate + "-" + dateStr;
          } else if (key.equals("^d{1,2}$")) {//21.1 (日.月) 拼接当前年份
            dateStr = curDate.substring(0,4) + "-" + dateStr;
          }
          dateReplace = dateStr.replaceAll("D+","-");
          // System.out.println(dateRegExpArr[i]);
          strSuccess = formatter1.format(formatter2.parse(dateReplace));
          break;
        }
      }
    } catch (Exception e) {
      System.err.println("-----------------日期格式无效:"+dateStr);
      throw new Exception( "日期格式无效");
    } finally {
      return strSuccess;
    }
  }
  public static void main(String[] args) {
    String[] dateStrArray=new String[]{
        "2014-03-12 12:05:34","2014-03-12 12:05","2014-03-12 12","2014-03-12","2014-03","2014","20140312120534","2014/03/12 12:05:34","2014/3/12 12:5:34","2014年3月12日 13时5分34秒","201403121205","1234567890","20140312","201403","2000 13 33 13 13 13","30.12.2013","12.21.2013","21.1","13:05:34","12:05","14.1.8","14.10.18" 
    };
    for(int i=0;i<dateStrArray.length;i++){
      System.out.println(dateStrArray[i] +"------------------------------".substring(1,30-dateStrArray[i].length())+ FormatDate(dateStrArray[i]));
    }
     
  }
 
}