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; }}以上就是本文的全部内容，希望对大家学习java程序设计有所帮助。