Lucene 全文检索实践（5） 参考指数 ： 3
对于 Lucene 的初步研究已经过去一段时间，自己感觉还不是很深入，但由于时间的关系，一直也没再拿起。应网友的要求，将自己实践中写的一些代码贴出来，希望能对大家有用。程序没有做进一步的优化，只是很简单的实现功能而已，仅供参考。
在实践中，我以将 PHP 中文手册中的 HTML 文件生成索引，然后通过一个 JSP 对其进行全文检索。
生成索引的 Java 代码：
/**
* PHPDocIndexer.java
* 用于对 PHPDoc 的 HTML 页面生成索引文件。
*/
import java.io.File;
import java.io.FileReader;
import java.io.BufferedReader;
import java.io.IOException;
import java.util.Date;
import java.text.DateFormat;
import java.lang.*;
import org.apache.lucene.analysis.cjk.CJKAnalyzer;
import org.apache.lucene.index.IndexWriter;
import org.apache.lucene.document.Document;
import org.apache.lucene.document.Field;
import org.apache.lucene.document.DateField;
class PHPDocIndexer
{
public static void main(String[] args) throws ClassNotFoundException, IOException
{
try {
Date start = new Date();
IndexWriter writer = new IndexWriter("/home/nio/indexes-phpdoc", new CJKAnalyzer(), true); //索引保存目录，必须存在
indexDocs(writer, new File("/home/nio/phpdoc-zh")); //HTML 文件保存目录
System.out.println("Optimizing ....");
writer.optimize();
writer.close();
Date end = new Date();
System.out.print("Total time: ");
System.out.println(end.getTime() - start.getTime());
} catch (Exception e) {
System.out.println("Class " + e.getClass() + " throws error!\n errmsg: " + e.getMessage());
} //end try
} //end main
public static void indexDocs(IndexWriter writer, File file) throws Exception
{
if (file.isDirectory()) {
String[] files = file.list();
for (int i = 0; i < files.length; i++) {
indexDocs(writer, new File(file, files[i]));
} //end for
} else if (file.getPath().endsWith(".html")) { //只对 HTML 文件做索引
System.out.print("Add file:" + file + " ....");
// Add html file ....
Document doc = new Document();
doc.add(Field.UnIndexed("file", file.getName())); //索引文件名
doc.add(Field.UnIndexed("modified", DateFormat.getDateTimeInstance().format(new Date(file.lastModified())))); //索引最后修改时间
String title = "";
String content = "";
String status = "start";
FileReader fReader = new FileReader(file);
BufferedReader bReader = new BufferedReader(fReader);
String line = bReader.readLine();
while (line != null) {
content += line;
//截取 HTML 标题 <title>
if ("start" == status && line.equalsIgnoreCase("><TITLE")) {
status = "match";
} else if ("match" == status) {
title = line.substring(1, line.length() - 7);
doc.add(Field.Text("title", title)); //索引标题
status = "end";
} //end if
line = bReader.readLine();
} //end while
bReader.close();
fReader.close();
doc.add(Field.Text("content", content.replaceAll("<[^<>]+>", ""))); //索引内容
writer.addDocument(doc);
System.out.println(" [OK]");
} //end if
}
} //end class
索引生成完之后，就需要一个检索页面，下边是搜索页面（search.jsp）的代码：
<%@ page language="java" import="javax.servlet.*, javax.servlet.http.*, java.io.*, java.util.Date, java.util.ArrayList, java.util.regex.*, org.apache.lucene.analysis.*, org.apache.lucene.document.*, org.apache.lucene.index.*, org.apache.lucene.search.*, org.apache.lucene.queryParser.*, org.apache.lucene.analysis.Token, org.apache.lucene.analysis.TokenStream, org.apache.lucene.analysis.cjk.CJKAnalyzer, org.apache.lucene.analysis.cjk.CJKTokenizer, com.chedong.weblucene.search.WebLuceneHighlighter" %>
<%@ page contentType="text/html;charset=GB2312" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01//EN"
"http://www.w3.org/TR/html4/strict.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=gb2312" />
<title>PHPDoc - PHP 简体中文手册全文检索</title>
<base target="main"><!-- 由于使用了 Frame，所以指定 target 到 main 窗口显示 -->
<style>
body {background-color: white; margin: 4px}
body, input, div {font-family: Tahoma; font-size: 9pt}
body, div {line-height: 18px}
u {color: red}
b {color: navy}
form {padding: 0px; margin: 0px}
.txt {border: 1px solid black}
.f {padding: 4px; margin-bottom: 16px; background-color: #E5ECF9; border-top: 1px solid #3366CC; border-bottom: 1px solid #3366CC; text-align: center;}
.d, .o {padding-left: 16px}
.d {color: gray}
.o {color: green}
.o a {color: #7777CC}
</style>
<script language="JavaScript">
function gotoPage(i)
{
document.frm.page.value = i;
document.frm.submit();
} //end function
</script>
</head>
<body>
<%
String keyVal = null;
String pageVal = null;
int offset = 0;
int curPage = 0;
int pages;
final int ROWS = 50;
//获取 GET 参数
try {
byte[] keyValByte = request.getParameter("key").getBytes("ISO8859_1"); //查找关键字
keyVal = new String(keyValByte);
pageVal = request.getParameter("page"); //页码
} catch (Exception e) {
//do nothing;
}
if (keyVal == null)
keyVal = new String("");
%>
<div class="f">
<form name="frm" action="./index.jsp" method="GET" onsubmit="this.page.value='0';return true;" target="_self">
<input type="text" name="key" class="txt" size="40" value="<%=keyVal%>" />
<input type="hidden" name="page" value="<%=pageVal%>" />
<input type="submit" value="搜 索" /><br />
<font color="green">提示：可使用多个关键字（使用空格隔开）提高搜索的准确率。</font>
</form>
<script language="JavaScript">
document.frm.key.focus();
</script>
</div>
<%
if (keyVal != null && keyVal.length() > 0) {
try {
curPage = Integer.parseInt(pageVal); //将当前页转换成整数
} catch (Exception e) {
//do nothing;
} //end try
try {
Date startTime = new Date();
keyVal = keyVal.toLowerCase().replaceAll("(or|and)", "").trim().replaceAll("\\s+", " AND ");
Searcher searcher = new IndexSearcher("/home/nio/indexes-phpdoc"); //索引目录
Analyzer analyzer = new CJKAnalyzer();
String[] fields = {"title", "content"};
Query query = MultiFieldQueryParser.parse(keyVal, fields, analyzer);
Hits hits = searcher.search(query);
StringReader in = new StringReader(keyVal);
TokenStream tokenStream = analyzer.tokenStream("", in);
ArrayList al = new ArrayList();
for (Token token = tokenStream.next(); token != null; token = tokenStream.next()) {
al.add(token.termText());
} //end for
//总页数
pages = (new Integer(hits.length()).doubleValue() % ROWS != 0) ? (hits.length() / ROWS) + 1 : (hits.length() / ROWS);
//当前页码
if (curPage < 1)
curPage = 1;
else if (curPage > pages)
curPage = pages;
//起始、终止下标
offset = (curPage - 1) * ROWS;
int end = Math.min(hits.length(), offset + ROWS);
//循环输出查询结果
WebLuceneHighlighter hl = new WebLuceneHighlighter(al);
for (int i = offset; i < end; i++) {
Document doc = hits.doc(i);
%>
<div class="t"><a href="/~nio/phpdoc-zh/<%=doc.get("file")%>"><%=hl.highLight(doc.get("title"))%></a></div>
<div class="d"><%=hl.highLight(doc.get("content").replaceAll("\n", " "), 100)%> ……</div>
<div class="o">
/~nio/phpdoc-zh/<%=doc.get("file")%>
-
<%=doc.get("modified")%>
</div>
<br />
<%
} //end for
searcher.close();
Date endTime = new Date();
%>
<div class="f">
检索总共耗时 <b><%=((endTime.getTime() - startTime.getTime()) / 1000.0)%></b> 秒，约有 <b><%=hits.length()%></b> 项符合条件的记录，共 <b><%=pages%></b> 页
<%
if (curPage > 1 && pages > 1) {
%>
| <a href="javascript:gotoPage(<%=(curPage-1)%>);" target="_self">上一页</a>
<%
} //end if
if (curPage < pages && pages > 1) {
%>
| <a href="javascript:gotoPage(<%=(curPage+1)%>)" target="_self">下一页</a>
<%
} //end if
} catch (Exception e) {
%>
<!-- <%=e.getClass()%> 导致错误：<%=e.getMessage()%> -->
<%
} //end if
} //end if
%>
</body>
</html>
