Java精确抽取网页发布时间

对网页中各种不同格式的发布时间进行抽取，将发布时间以规整的“yyyy-MM-dd HH:mm:ss”格式表示出来，只能尽量追求精确，但是因为网络发布时间的格式十分灵活，所以做不到百分百地正确抽取

package whu.extract.pubtime.core;

import java.util.ArrayList;
import java.util.Calendar;
import java.util.Collections;
import java.util.List;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

import whu.utils.TimeUtil;

/**
 * Created On 2014年3月13日 下午2:49:05
 * @description 获取网页的发布时间
 */
public class FetchPubTime {
  /** 表示url中连续的8位日期，例如http://www.baidu.com/20140311/2356.html */
  private static String url_reg_whole= "([-|/|_]{1}20\\d{6})";
  /** 表示 用-或者/隔开的日期,有年月日的，例如 http://www.baidu.com/2014-3-11/2356.html */
  private static String url_reg_sep_ymd = "([-|/|_]{1}20\\d{2}[-|/|_]{1}\\d{1,2}[-|/|_]{1}\\d{1,2})";
  /** 表示 用-或者/隔开的日期,只有年和月份的，例如 http://www.baidu.com/2014-3/2356.html */
  private static String url_reg_sep_ym = "([-|/|_]{1}20\\d{2}[-|/|_]{1}\\d{1,2})";
  private static Calendar current = Calendar.getInstance();
  /** 格式正确的时间正则表达式*/
  private static String rightTimeReg = "^((\\d{2}(([02468][048])|([13579][26]))[\\-\\/\\s]?((((0?[13578])|(1[02]))[\\-\\/\\s]?((0?[1-9])|([1-2][0-9])|(3[01])))|(((0?[469])|(11))[\\-\\/\\s]?((0?[1-9])|([1-2][0-9])|(30)))|(0?2[\\-\\/\\s]?((0?[1-9])|([1-2][0-9])))))|(\\d{2}(([02468][1235679])|([13579][01345789]))[\\-\\/\\s]?((((0?[13578])|(1[02]))[\\-\\/\\s]?((0?[1-9])|([1-2][0-9])|(3[01])))|(((0?[469])|(11))[\\-\\/\\s]?((0?[1-9])|([1-2][0-9])|(30)))|(0?2[\\-\\/\\s]?((0?[1-9])|(1[0-9])|(2[0-8]))))))(\\s(((0?[0-9])|([1-2][0-3]))\\:([0-5]?[0-9])((\\s)|(\\:([0-5]?[0-9])))))?$";

  /**
   * @param url
   * @param urlContent
   * @return
   */
  public static String getPubTimeVarious(String url,String urlContent) {

    String pubTime = getPubTimeFromUrl(url);

   //链接里面没有，匹配文本中的
    if(pubTime == null)
    {
      if(urlContent!=null&&!urlContent.trim().equals(""))
        return extractPageDate(urlContent);
    }

    return pubTime;
  }

  /**从url里面抽取出发布时间，返回YYYY-MM-DD HH:mm:ss格式的字符串
   * @param url
   * @return
   */
  public static String getPubTimeFromUrl(String url)
  {
    Pattern p_whole = Pattern.compile(url_reg_whole);
    Matcher m_whole = p_whole.matcher(url);
    if(m_whole.find(0)&&m_whole.groupCount()>0)
    {
      String time = m_whole.group(0);
      time = time.substring(1,time.length());
      //每一步都不能够超出当前时间
    if(current.compareTo(TimeUtil.strToCalendar(time, "yyyyMMdd"))>=0)
    {

      return time.substring(0,4)+"-"+time.substring(4,6)+"-"+
         time.substring(6,8)+" "+"00:00:00";
    }
    }

    p_whole = null;
    m_whole = null;
    Pattern p_sep = Pattern.compile(url_reg_sep_ymd);
    Matcher m_sep = p_sep.matcher(url);
    if(m_sep.find(0)&&m_sep.groupCount()>0)
    {
       String time = m_sep.group(0);
       time = time.substring(1,time.length());
       String[] seg = time.split("[-|/|_]{1}");
       Calendar theTime = Calendar.getInstance();
       theTime.set(Calendar.YEAR,Integer.parseInt(seg[0]));
       theTime.set(Calendar.MONTH, Integer.parseInt(seg[1]));
       theTime.set(Calendar.DAY_OF_MONTH, Integer.parseInt(seg[2]));
       if(current.compareTo(theTime)>=0)
        {

      return seg[0]+"-"+seg[1]+"-"+seg[2]+" "+"00:00:00";
        }
    }
    p_sep = null;
    m_sep = null;
    Pattern p_sep_ym = Pattern.compile(url_reg_sep_ym);
    Matcher m_sep_ym = p_sep_ym.matcher(url);
    if(m_sep_ym.find(0)&&m_sep_ym.groupCount()>0)
    {
       String time = m_sep_ym.group(0);
       time = time.substring(1,time.length());
       Calendar theTime = Calendar.getInstance();
       String[] seg = time.split("[-|/|_]{1}");
       theTime.set(Calendar.YEAR,Integer.parseInt(seg[0]));
       theTime.set(Calendar.MONTH, Integer.parseInt(seg[1]));
       theTime.set(Calendar.DAY_OF_MONTH, 1);
       if(current.compareTo(theTime)>=0)
      {

      return seg[0]+"-"+seg[1]+"-"+"01"+" "+"00:00:00";
      }
    }

    return null;
  }

  /** 从网页源码中取出发布时间
   * java中正则表达式提取字符串中日期实现代码
   * 2013年12月19日15:58:42
   * 读取出2013-12-19 15:48:33或者2013-12-19或者2012/3/05形式的时间
   * @param text 待提取的字符串
   * @return 返回日期
   * @author: oschina
   * @Createtime: Jan 21, 2013
   */
  public static String extractPageDate(String text) {
    boolean containsHMS =false;
    String dateStr = text.replaceAll("r?n", " ");
    try {
      List matches = null;
      Pattern p_detail = Pattern.compile("(20\\d{2}[-/]\\d{1,2}[-/]\\d{1,2} \\d{1,2}:\\d{1,2}:\\d{1,2})|(20\\d{2}年\\d{1,2}月\\d{1,2}日)", Pattern.CASE_INSENSITIVE|Pattern.MULTILINE);
      //如果是仅仅抽取年月日，则按照上面的，如果是抽取年月日-时分秒，则按照下面的
      Pattern p = Pattern.compile("(20\\d{2}[-/]\\d{1,2}[-/]\\d{1,2})|(20\\d{2}年\\d{1,2}月\\d{1,2}日)", Pattern.CASE_INSENSITIVE|Pattern.MULTILINE);
      //Matcher matcher = p.matcher(dateStr);
      Matcher matcher_detail = p_detail.matcher(dateStr);

      if(!(matcher_detail.find(0) && matcher_detail.groupCount() >= 1))
      {
        matcher_detail = p.matcher(dateStr);
        containsHMS = true;
      }else
        matcher_detail = p_detail.matcher(dateStr);
      if (matcher_detail.find() && matcher_detail.groupCount() >= 1) {
        matches = new ArrayList();
        for (int i = 1; i <= matcher_detail.groupCount(); i++) {
          String temp = matcher_detail.group(i);
          matches.add(temp);
        }
      } else {
        matches = Collections.EMPTY_LIST;
      }      

      if (matches.size() > 0) {
        for(int i=0;i<matches.size();i++)
        {
          String pubTime = matches.get(i).toString().trim();
          //取出第一个值
          pubTime = pubTime.replace("/", "-").replace("年", "-").replace("月", "-").replace("日", "-");
          if(current.compareTo(TimeUtil.strToCalendar(pubTime, "yyyy-MM-dd"))>=0)
          {
            if(containsHMS)
              pubTime+=" "+"00:00:00";
            if(pubTime.matches(rightTimeReg))
            {
              return pubTime;
            }
          }
        }
      } else {
        return null;
      } 

    } catch (Exception e) {
      return null;
    }
    return null;
  }
}

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