HtmlUtils.java

package com.hundsun.jresplus.common.util;

import java.io.IOException;
import java.io.LineNumberReader;
import java.io.Reader;
import java.io.StringReader;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import com.hundsun.jresplus.common.util.html.HTMLParser;

/**
 * @author LeoHu copy by sagahl copy by fish
 * @version $Id: HtmlUtils.java,v 1.1 2011/06/20 08:04:35 fish Exp $
 */
public final class HtmlUtils {

	private static final Logger logger = LoggerFactory
			.getLogger(HtmlUtils.class);

	private static final Pattern scriptTag = Pattern
			.compile("(?i)(?s)(<script.+?</script>)|(on.+?=)");

	private static final String emptyString = "";

	/**
	 * 去掉禁止输入的html标签,比如说script等
	 * 
	 * @param s
	 * @return
	 */
	public static final String escapeForbiddenHtml(String s) {
		return escapeScriptTag(s);
	}

	/**
	 * 去掉禁止输入的script标签,以及 onclick这样的函数
	 * 
	 * @param s
	 * @return
	 */
	public static final String escapeScriptTag(String s) {
		if (s == null) {
			return null;
		}
		Matcher m = scriptTag.matcher(s);
		return m.replaceAll(emptyString);
	}

	/**
	 * 得到去除html标签后的文字
	 * 
	 * @param s
	 * @return
	 */
	public static final String parseHtml(String s) {
		if (s == null) {
			return null;
		}
		StringBuffer sb = new StringBuffer();
		try {
			Reader r = new StringReader(s);
			HTMLParser parser = new HTMLParser(r);
			LineNumberReader reader = new LineNumberReader(parser.getReader());
			for (String l = reader.readLine(); l != null; l = reader.readLine()) {
				sb.append(l);
			}
			r.close();
		} catch (IOException e) {
			logger.error("error than parse html string", e);
		}
		return sb.toString();
	}

	/**
	 * 得到去除html标签后的文字
	 * 
	 * @param s
	 * @param maxLength
	 *            最大长度,
	 * @return s.length <= maxLength
	 */
	public static final String parseHtml(String s, int maxLength) {
		if (maxLength <= 0) {
			throw new java.lang.IllegalArgumentException(
					"maxLength must greate than zero");
		}
		if (s == null) {
			return null;
		}
		StringBuffer sb = new StringBuffer();
		try {
			Reader r = new StringReader(s);
			HTMLParser parser = new HTMLParser(r);
			LineNumberReader reader = new LineNumberReader(parser.getReader());
			for (String l = reader.readLine(); l != null; l = reader.readLine()) {
				sb.append(l);
				if (sb.length() >= maxLength) {
					break;
				}
			}
			r.close();
		} catch (IOException e) {
			logger.error("error than parse html string", e);
		}
		if (sb.length() >= maxLength) {
			return sb.substring(0, maxLength);
		}
		return sb.toString();
	}
}