HtmlRegexpUtil.java

package com.cnblogs.android.utility;

import java.util.regex.Matcher;
import java.util.regex.Pattern;

/**
 * <p>
 * Title: HTML��ص�������ʽ������
 * </p>
 * <p>
 * Description: ��������HTML��ǣ�ת��HTML��ǣ��滻�ض�HTML���
 * </p>
 * <p>
 * Copyright: Copyright (c) 2006
 * </p>
 * 
 * @author hejian
 * @version 1.0
 * @createtime 2006-10-16
 */

public class HtmlRegexpUtil {
	private final static String regxpForHtml = "<([^>]*)>"; // ����������<��ͷ��>��β�ı�ǩ

	// private final static String regxpForImgTag = "<\\s*img\\s+([^>]*)\\s*>";
	// // �ҳ�IMG��ǩ

	// private final static String regxpForImaTagSrcAttrib = "src=\"([^\"]+)\"";
	// // �ҳ�IMG��ǩ��SRC����

	/**
	 * 
	 * �������ܣ��滻�����������ʾ
	 * <p>
	 * 
	 * @param input
	 * @return String
	 */
	public static String replaceTag(String input) {
		if (!hasSpecialChars(input)) {
			return input;
		}
		StringBuffer filtered = new StringBuffer(input.length());
		char c;
		for (int i = 0; i <= input.length() - 1; i++) {
			c = input.charAt(i);
			switch (c) {
				case '<' :
					filtered.append("<");
					break;
				case '>' :
					filtered.append(">");
					break;
				case '"' :
					filtered.append(""");
					break;
				case '&' :
					filtered.append("&");
					break;
				default :
					filtered.append(c);
			}

		}
		return (filtered.toString());
	}

	/**
	 * 
	 * �������ܣ��жϱ���Ƿ����
	 * <p>
	 * 
	 * @param input
	 * @return boolean
	 */
	public static boolean hasSpecialChars(String input) {
		boolean flag = false;
		if ((input != null) && (input.length() > 0)) {
			char c;
			for (int i = 0; i <= input.length() - 1; i++) {
				c = input.charAt(i);
				switch (c) {
					case '>' :
						flag = true;
						break;
					case '<' :
						flag = true;
						break;
					case '"' :
						flag = true;
						break;
					case '&' :
						flag = true;
						break;
				}
			}
		}
		return flag;
	}

	/**
	 * 
	 * �������ܣ�����������"<"��ͷ��">"��β�ı�ǩ
	 * <p>
	 * 
	 * @param str
	 * @return String
	 */
	public static String filterHtml(String str) {
		Pattern pattern = Pattern.compile(regxpForHtml);
		Matcher matcher = pattern.matcher(str);
		StringBuffer sb = new StringBuffer();
		boolean result1 = matcher.find();
		while (result1) {
			matcher.appendReplacement(sb, "");
			result1 = matcher.find();
		}
		matcher.appendTail(sb);
		return sb.toString();
	}

	/**
	 * 
	 * �������ܣ�����ָ����ǩ
	 * <p>
	 * 
	 * @param str
	 * @param tag
	 *            ָ����ǩ
	 * @return String
	 */
	public static String fiterHtmlTag(String str, String tag) {
		String regxp = "<\\s*" + tag + "\\s+([^>]*)\\s*>";
		Pattern pattern = Pattern.compile(regxp);
		Matcher matcher = pattern.matcher(str);
		StringBuffer sb = new StringBuffer();
		boolean result1 = matcher.find();
		while (result1) {
			matcher.appendReplacement(sb, "");
			result1 = matcher.find();
		}
		matcher.appendTail(sb);
		return sb.toString();
	}

	/**
	 * 
	 * �������ܣ��滻ָ���ı�ǩ
	 * <p>
	 * 
	 * @param str
	 * @param beforeTag
	 *            Ҫ�滻�ı�ǩ
	 * @param tagAttrib
	 *            Ҫ�滻�ı�ǩ����ֵ
	 * @param startTag
	 *            �±�ǩ��ʼ���
	 * @param endTag
	 *            �±�ǩ�������
	 * @return String
	 * @�磺�滻img��ǩ��src����ֵΪ[img]����ֵ[/img]
	 */
	public static String replaceHtmlTag(String str, String beforeTag,
			String tagAttrib, String startTag, String endTag) {
		String regxpForTag = "<\\s*" + beforeTag + "\\s+([^>]*)\\s*>";
		String regxpForTagAttrib = tagAttrib + "=\"([^\"]+)\"";
		Pattern patternForTag = Pattern.compile(regxpForTag);
		Pattern patternForAttrib = Pattern.compile(regxpForTagAttrib);
		Matcher matcherForTag = patternForTag.matcher(str);
		StringBuffer sb = new StringBuffer();
		boolean result = matcherForTag.find();
		while (result) {
			StringBuffer sbreplace = new StringBuffer();
			Matcher matcherForAttrib = patternForAttrib.matcher(matcherForTag
					.group(1));
			if (matcherForAttrib.find()) {
				matcherForAttrib.appendReplacement(sbreplace, startTag
						+ matcherForAttrib.group(1) + endTag);
			}
			matcherForTag.appendReplacement(sb, sbreplace.toString());
			result = matcherForTag.find();
		}
		matcherForTag.appendTail(sb);
		return sb.toString();
	}
}