Java尽量精确地抽取网页的发布时间

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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