利用HtmlParser 完成含有html标签的字符截取并补全标签

wesee

截取一定长度带有HTML标签的文件内容，如果按普通文字用subtring进行截取的，当把html标签载断而非完整闭合时，整个页面都可能因此而变形， 利用HtmlParser可以很好的保留原HTML标签并将载段的标签补齐。

应该注意一点<strong>***</strong>标签需要重新定义，因为现在strong标签的getEndTag() 是null不知道是不是htmlparser的一个bug

package com.test.util;import java.util.Stack;import org.htmlparser.tags.CompositeTag;import org.htmlparser.Node;import org.htmlparser.Parser;import org.htmlparser.Tag;import org.htmlparser.nodes.TagNode;import org.htmlparser.nodes.TextNode;import org.htmlparser.util.NodeIterator;import org.htmlparser.util.ParserException;public class SubstringHTML {private final String CONTENT;private Parser parser;private Stack<TagNode> nodeStack;private int subLength;private int textLength = 0;private int pos = 0;public SubstringHTML(String content) {CONTENT = content;parser = Parser.createParser(content, "GBK");factory = new PrototypicalNodeFactory();factory.registerTag(new StrongTag());parser.setNodeFactory(factory);nodeStack = new Stack<TagNode>();}private void recusive(NodeIterator iterator) throws ParserException  {while (iterator.hasMoreNodes()) {Node node = iterator.nextNode();if (node instanceof TagNode) {TagNode tagNode = (TagNode)node;Tag tag = tagNode.getEndTag();if (tag != null) {nodeStack.push(tagNode);}}else if (node instanceof TextNode) {if (node.getText().trim().length() == 0) {continue;}                if (node.getTagName.equals("SCRIPT") {                continue;                      }String nodeText = node.getText();int tLen = nodeText.length();if ((textLength < subLength) && ((textLength + tLen) > subLength)) {pos = node.getStartPosition() + subLength - textLength;textLength = subLength;return;}else {textLength += tLen;pos = node.getEndPosition();}}if (node.getChildren() == null) {continue;}recusive(node.getChildren().elements());if (subLength <= textLength) {return;}}}public String subString(int length, String end) {if (length >= CONTENT.length() || length <= 0) {return CONTENT;}subLength = length;try {recusive(parser.elements());} catch (ParserException e) {System.out.println("parser error:" + e.getMessage());return CONTENT;}int size = nodeStack.size();StringBuffer buffer = new StringBuffer();buffer.append(CONTENT.substring(0, pos));while (size > 0) {TagNode node = nodeStack.pop();size--;if (node.getEndTag().getEndPosition() <= pos || node.getTagBegin() >= pos) {continue;}buffer.append("</");buffer.append(node.getTagName());buffer.append(">");}buffer.append(end);return buffer.toString();}private static String getContent() {byte[] con = null;InputStream in = SubstringHTML.class.getResourceAsStream("content.txt");try {int length = in.available();con = new byte[length];in.read(con, 0, length);} catch (IOException e) {e.printStackTrace();}try {return new String(con, "GBK");} catch (UnsupportedEncodingException e) {e.printStackTrace();return "";}}public static void main(String[] args) {String content = getContent();SubstringHTML app = new SubstringHTML(content);String str = app.subString(200, "");System.out.println(str);}}class StrongTag extends CompositeTag {private static final long serialVersionUID = 1L;private static final String[] mIds = new String[] { "STRONG" };        private static final String[] mEndTagEnders = new String[] {"BODY", "HTML"};public String[] getIds() {return mIds;}public String[] getEndTagEnders (){return (mEndTagEnders);}}