Java regular implementation of various date formatting

Java regular implementation of various date formatting

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+\d{1,2}\D+\d{1,2}\D+\d{1,2}\D*$",
        "yyyy-MM-dd-HH-mm-ss");//March 12, 2014 13:534 seconds, 2014-03-12 12:05:34, 2014/3/12 12:5:34
    dateRegFormat.put("^\d{4}\D+\d{2}\D+\d{2}\D+\d{2}\D+\d{2}$",
        "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 splice the current date
    dateRegFormat.put("^\d{2}\s*:\s*\d{2}$", "yyyy-MM-dd-HH-mm");//13:05 splice the current date
    dateRegFormat.put("^\d{2}\D+\d{1,2}\D+\d{1,2}$", "yy-MM-dd");//14.10.18(year, month, day)
    dateRegFormat.put("^\d{1,2}\D+\d{1,2}$", "yyyy-dd-MM");//30.12(day. Month) splice the current year
    dateRegFormat.put("^\d{1,2}\D+\d{1,2}\D+\d{4}$", "dd-MM-yyyy");//12.21.2013(sun, month, year)
 
    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  or  13:05 splice the current date
            dateStr = curDate + "-" + dateStr;
          } else if (key.equals("^\d{1,2}\D+\d{1,2}$")) {//21.1 (day. Month) splice the current year
            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("----------------- Invalid date format :"+dateStr);
      throw new Exception( " Invalid date format ");
    } 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 years 3 month 12 day  13 when 5 points 34 seconds ",
        "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]));
    }
     
  }
 
}

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