package com.common.util;

import java.util.regex.Matcher;  
import java.util.regex.Pattern;  
  
/** 
 * <p> 
 * Title: HTML相关的正则表达式工具类 
 * </p> 
 * <p> 
 * Description: 包括过滤HTML标记，转换HTML标记，替换特定HTML标记 
 * </p> 
 * <p> 
 * Copyright: Copyright (c) 2010 
 * </p>
 * @author tgl 
 * @version 1.0 
 * @createtime 2009-10-16 
 */  
  
public class HtmlRegexpUtil {  
    private final static String regxpForHtml = "<([^>]*)>"; // 过滤所有以<开头以>结尾的标签  
  
//    private final static String regxpForImgTag = "<\\s*img\\s+([^>]*)\\s*>"; // 找出IMG标签  
  
//    private final static String regxpForImaTagSrcAttrib = "src=\"([^\"]+)\""; // 找出IMG标签的SRC属性  
  
    public static void main(String args[]){
    	String html = "<DIV>\n<DIV>内容提要测试\n<DIV>内容提要测试\n<DIV>内容提要测试\n<DIV>内容提要测试\n<DIV>内容提要测试\n<DIV>内容提要测试\n<DIV>内容提要测试</DIV></DIV></DIV></DIV></DIV></DIV></DIV></DIV>";
    	
    	System.out.println(replaceTag(html));
    	
    }
    /** 
     *  
     */  
    public HtmlRegexpUtil() {  
        // TODO Auto-generated constructor stub  
    }  
  
    /** 
     *  
     * 基本功能：替换标记以正常显示 
     * <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("&lt;");
                break;
            case '>':  
                filtered.append("&gt;");  
                break;
            case '"':  
                filtered.append("&quot;");
                break;  
            case '&':  
                filtered.append("&amp;");
                break;  
            default:  
                filtered.append(c);  
            }  
  
        }  
        return (filtered.toString());  
    }  
  
    /** 
     *  
     * 基本功能：判断标记是否存在 
     * <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;  
    }  
  
    /** 
     *  
     * 基本功能：过滤所有以"<"开头以">"结尾的标签 
     * <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();  
    }  
  
    /** 
     *  
     * 基本功能：过滤指定标签 
     * <p> 
     *  
     * @param str 
     * @param tag 
     *            指定标签 
     * @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();  
    }  
  
    /** 
     *  
     * 基本功能：替换指定的标签 
     * <p> 
     *  
     * @param str 
     * @param beforeTag 
     *            要替换的标签 
     * @param tagAttrib 
     *            要替换的标签属性值 
     * @param startTag 
     *            新标签开始标记 
     * @param endTag 
     *            新标签结束标记 
     * @return String 
     * @如：替换img标签的src属性值为[img]属性值[/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();  
    }  
}