java正则实现各种日期格式化

java各种日期格式化
"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"

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*$",
                "yyyy-MM-dd-HH-mm-ss");//2014年3月12日 13时5分34秒，2014-03-12 12:05:34，2014/3/12 12:5:34
        dateRegFormat.put("^\\d{4}\\D+\\d{2}\\D+\\d{2}\\D+\\d{2}\\D+\\d{2}$",
                "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}$", "yyyy-MM-dd-HH-mm");//13:05  拼接当前日期
        dateRegFormat.put("^\\d{2}\\D+\\d{1,2}\\D+\\d{1,2}$", "yy-MM-dd");//14.10.18(年.月.日)
        dateRegFormat.put("^\\d{1,2}\\D+\\d{1,2}$", "yyyy-dd-MM");//30.12(日.月) 拼接当前年份
        dateRegFormat.put("^\\d{1,2}\\D+\\d{1,2}\\D+\\d{4}$", "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}\\D+\\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]));
        }
         
    }
 
}

java正则实现各种日期格式化

原文：http://www.cnblogs.com/lengyao/p/4478485.html