页面日期时间抽取

DateUtils.java

package com.cyhone;

import java.text.SimpleDateFormat;
import java.util.Calendar;
import java.util.Date;
import java.util.concurrent.TimeUnit;

/**
 * @author cyhone
 * @date 2017/3/28
 */
public class DateUtils {
    private static final String DATE_PATTEN = "yyyy-MM-dd";

    /**
     * @param year  年，格式为2017
     * @param month 正常月份 如1为1月份，2为2月份
     * @param day   日期，如01、31等
     * @return 若时间正确，则返回Date对象 ，若错误则返回null
     */
    public static Date formatDate(Integer year, Integer month, Integer day) {
        Calendar cal = Calendar.getInstance();
        cal.setLenient(false);
        cal.set(year, month - 1, day);

        try {
            return cal.getTime();
        } catch (Exception e) {
            return null;
        }
    }

    public static Date formatDate(String year, String month, String day) {
        return formatDate(Integer.valueOf(year), Integer.valueOf(month), Integer.valueOf(day));
    }

    public static String toString(Date date) {
        SimpleDateFormat formater = new SimpleDateFormat(DATE_PATTEN);
        return formater.format(date);
    }

    public static int minusDate(Date date1, Date date2) {
        if (date1 == null || date2 == null)
            throw new IllegalArgumentException("date1 or date2 cannot be null");
        return (int) TimeUnit.DAYS.convert(date1.getTime() - date2.getTime(), TimeUnit.MILLISECONDS);
    }
    public static String thisYear() {
        return String.valueOf(Calendar.getInstance().get(Calendar.YEAR));
    }

}

PublishedDate.java

package com.cyhone;

import java.util.ArrayList;
import java.util.Date;
import java.util.List;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

/**
 * @author cyhone
 * @date 2017/3/28
 */
public class PublishedDate {
    private PublishedDate() {
    }

    public static Date parse(String url, String html) {
        Date urlDate = parseFromUrl(url);
        Date contentDate = parseFromHTML(html);
        return chooseLastestDate(urlDate, contentDate);
    }

    private static List<Pattern> urlPatterns = new ArrayList<Pattern>();
    private static List<Pattern> contentPatterns = new ArrayList<Pattern>();

    private static final String YEAR_REGEX = "(?<year>20[01]\\d{1})";  //仅抽取200x或者201x年的日期
    private static final String MONTH_REGEX = "(?<month>(?:1[012])|(?:0?[1-9]))";
    private static final String DAY_REGEX = "(?<day>(?:[12][0-9])|(?:3[01])|(?:0?[1-9]))";

    static {
        initUrlRegex();
        initContentRegex();
    }


    /**
     * 装配url正则表达式
     */
    private static void initUrlRegex() {
        /*
         1. /201612/08/
         2. /201703/
         3. /20170321/
         4. /2017-2-28/
         5. /2016/1114/
         6. /2016-12-31-600479.html
         */
        String urlReg1 = "/" + YEAR_REGEX + "[/\\-]?" + MONTH_REGEX + "(?:[/\\-]?" + DAY_REGEX + ")?[/\\-]";
        /*
         7. /3/6/2005/
         */
        String urlReg2 = "/" + MONTH_REGEX + "[/\\-]?" + DAY_REGEX + "[/\\-]?" + YEAR_REGEX + "[/\\-]";

        urlPatterns.add(Pattern.compile(urlReg1));
        urlPatterns.add(Pattern.compile(urlReg2));

    }

    public static Date parseFromUrl(String url) {
        Date result = null;
        for (Pattern pattern : urlPatterns) {
            Matcher matcher = pattern.matcher(url);

            String year = null, month = null, day = null;
            if (matcher.find()) {
                year = matcher.group("year");
                month = matcher.group("month");
                day = matcher.group("day");
            }
            result = formatDate(year, month, day);
            if (result != null) return result;
        }

        return null;

    }

    private static void initContentRegex() {

        /*
          1. 2016年11月23日
          2. 2016-12-20
          3. 2016/12/20
          4. 2016\12\20

         */
        String contentReg1 = YEAR_REGEX + "\\s*[年/\\-_:：\\\\]\\s*"
                + MONTH_REGEX + "\\s*[月/\\-_:：\\\\]\\s*"
                + DAY_REGEX + "\\s*[日/\\-_:：\\\\]?\\s*";

        /*
          5. 10-16 08:23
         */
        String contentReg2 = "(" + YEAR_REGEX + "\\s*[年/\\-_:：\\\\]\\s*)?"
                + MONTH_REGEX + "\\s*[月/\\-_:：\\\\]\\s*"
                + DAY_REGEX + "\\s*[日/\\-_:：\\\\]?\\s*"
                + "[0-2]\\d[:：][0-6]\\d";
        contentPatterns.add(Pattern.compile(contentReg1));
        contentPatterns.add(Pattern.compile(contentReg2));
    }

    public static Date parseFromText(String content) {

        Date result = null;
        for (Pattern pattern : contentPatterns) {
            Matcher matcher = pattern.matcher(content);
            String year = null, month = null, day = null;
            while (matcher.find()) {

                month = matcher.group("month");
                day = matcher.group("day");
                year = matcher.group("year");
                year = year == null ? DateUtils.thisYear() : year;
                result = chooseLastestDate(result, formatDate(year, month, day));
            }
        }
        return result;
    }

    /**
     * 选择最晚的日期
     *
     * @param date1 date
     * @param date2 date
     * @return
     */
    private static Date chooseLastestDate(Date date1, Date date2) {
        if (date1 == null)
            return date2;

        if (date2 == null)
            return date1;

        return DateUtils.minusDate(date1, date2) > 0 ? date1 : date2;
    }

    public static Date parseFromHTML(String html) {
        // 预处理，去除标签、script，仅留取body里面的数据
        html = html.replaceAll("(?is)<script.*?>.*?</script>", "")
                .replaceAll("(?is)<head.*?>.*?</head>", "");
        return parseFromText(html);
    }

    private static Date formatDate(String year, String month, String day) {
        if (day == null)
            day = "01";

        if (year == null || month == null)
            return null;

        return DateUtils.formatDate(year, month, day);
    }

}