【转】一个lucene的官网例子

创建索引：

import java.io.BufferedReader;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.InputStreamReader;
import java.nio.charset.StandardCharsets;
import java.util.Date;

import org.apache.lucene.analysis.Analyzer;
import org.apache.lucene.analysis.standard.StandardAnalyzer;
import org.apache.lucene.document.Document;
import org.apache.lucene.document.Field;
import org.apache.lucene.document.LongField;
import org.apache.lucene.document.StringField;
import org.apache.lucene.document.TextField;
import org.apache.lucene.index.IndexWriter;
import org.apache.lucene.index.IndexWriterConfig;
import org.apache.lucene.index.Term;
import org.apache.lucene.index.IndexWriterConfig.OpenMode;
import org.apache.lucene.store.Directory;
import org.apache.lucene.store.FSDirectory;
import org.apache.lucene.util.Version;

public class CreateLuceneIndex {

    public static void main(String[] args) {
        if (args == null || args.length <= 0) {
            args = new String[] { 
                    "-index", 
                    "E:\00.学习\03.软件\JAVA\lu01\index",
                    "-docs", 
                    "E:\00.学习\03.软件\JAVA\lu01\doc" };
        }
        String indexPath = ""; 
        String docsPath = null; 
        boolean create = true;
        for (int i = 0; i < args.length; i++) {
            if ("-index".equals(args[i])) {
                indexPath = args[i + 1];
                i++;
            } else if ("-docs".equals(args[i])) {
                docsPath = args[i + 1];
                i++;
            } else if ("-update".equals(args[i])) {
                create = false;
            }
        }

        if (docsPath == null) {
            System.err.println("资源文件所在目录为空，请指定资源文件所在目录！！！");
            System.exit(1);
        }

        final File docDir = new File(docsPath);
        if (!docDir.exists() || !docDir.canRead()) {
            System.out.println("资源文件目录 '" + docDir.getAbsolutePath()
                    + "' 不存在或不可读，请检查！");
            System.exit(1);
        }

        Date start = new Date();
        try {
            System.out.println("建立索引文件到该目录 '" + indexPath + "'...");

            Directory dir = FSDirectory.open(new File(indexPath));
            Analyzer analyzer = new StandardAnalyzer();
            IndexWriterConfig iwc = new IndexWriterConfig(
                    Version.LUCENE_4_10_2, analyzer);
            if (create) {
                iwc.setOpenMode(OpenMode.CREATE);
            } else {
                iwc.setOpenMode(OpenMode.CREATE_OR_APPEND);
            }
            IndexWriter writer = new IndexWriter(dir, iwc);
            indexDocs(writer, docDir);
            writer.close();
            Date end = new Date();
            System.out.println(end.getTime() - start.getTime()
                    + " total milliseconds");
        } catch (IOException e) {
            System.out.println(" caught a " + e.getClass()
                    + "
 with message: " + e.getMessage());
        }
    }

    /**
     * 将资源文件索引到指定目录下，生成磁盘的索引文件
     * 
     * @param writer
     *            索引文件
     * @param file
     *            资源文件
     */
    static void indexDocs(IndexWriter writer, File file) throws IOException {
        if (!file.canRead()) {
            return;
        }
        if (file.isDirectory()) {
            String[] files = file.list();
            if (files != null) {
                for (int i = 0; i < files.length; i++) {
                    indexDocs(writer, new File(file, files[i]));
                }
            }
        } else {
            FileInputStream fis;
            try {
                fis = new FileInputStream(file);
            } catch (FileNotFoundException fnfe) {
                return;
            }
            try {                
                Document doc = new Document();
                Field pathField = new StringField("path", file.getPath(),
                        Field.Store.YES);
                doc.add(pathField);
                doc.add(new LongField("modified", file.lastModified(),
                        Field.Store.NO));

                doc.add(new TextField("contents", new BufferedReader(
                        new InputStreamReader(fis, StandardCharsets.UTF_8))));

                if (writer.getConfig().getOpenMode() == OpenMode.CREATE) {
                    System.out.println("adding " + file);
                    writer.addDocument(doc);
                } else {
                    System.out.println("updating " + file);
                    writer.updateDocument(new Term("path", file.getPath()), doc);
                }
            } finally {
                fis.close();
            }
        }
    }
}

全文检索：

import java.io.BufferedReader;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStreamReader;
import java.nio.charset.StandardCharsets;
import java.util.Date;

import org.apache.lucene.analysis.Analyzer;
import org.apache.lucene.analysis.standard.StandardAnalyzer;
import org.apache.lucene.document.Document;
import org.apache.lucene.index.DirectoryReader;
import org.apache.lucene.index.IndexReader;
import org.apache.lucene.queryparser.classic.QueryParser;
import org.apache.lucene.search.IndexSearcher;
import org.apache.lucene.search.Query;
import org.apache.lucene.search.ScoreDoc;
import org.apache.lucene.search.TopDocs;
import org.apache.lucene.store.FSDirectory;

public class SearchFiles {

    public static void main(String[] args) throws Exception {
        args = new String[] { 
                "-index", 
                "E:\00.学习\03.软件\JAVA\lu01\index" 
            };
        if (args.length > 0
                && ("-h".equals(args[0]) || "-help".equals(args[0]))) {
            System.exit(0);
        }

        String index = "index";
        String field = "contents";
        String queries = null;
        int repeat = 0;
        boolean raw = false;
        String queryString = null;
        int hitsPerPage = 10;

        for (int i = 0; i < args.length; i++) {
            if ("-index".equals(args[i])) {
                index = args[i + 1];
                i++;
            } else if ("-field".equals(args[i])) {
                field = args[i + 1];
                i++;
            } else if ("-queries".equals(args[i])) {
                queries = args[i + 1];
                i++;
            } else if ("-query".equals(args[i])) {
                queryString = args[i + 1];
                i++;
            } else if ("-repeat".equals(args[i])) {
                repeat = Integer.parseInt(args[i + 1]);
                i++;
            } else if ("-raw".equals(args[i])) {
                raw = true;
            } else if ("-paging".equals(args[i])) {
                hitsPerPage = Integer.parseInt(args[i + 1]);
                if (hitsPerPage <= 0) {
                    System.err.println("最少每页有1条数据");
                    System.exit(1);
                }
                i++;
            }
        }

        IndexReader reader = DirectoryReader.open(FSDirectory.open(new File(
                index)));
        IndexSearcher searcher = new IndexSearcher(reader);
        // :Post-Release-Update-Version.LUCENE_XY:
        Analyzer analyzer = new StandardAnalyzer();

        BufferedReader in = null;
        if (queries != null) {
            in = new BufferedReader(new InputStreamReader(new FileInputStream(
                    queries), StandardCharsets.UTF_8));
        } else {
            in = new BufferedReader(new InputStreamReader(System.in,
                    StandardCharsets.UTF_8));
        }
        // :Post-Release-Update-Version.LUCENE_XY:
        QueryParser parser = new QueryParser(field,
                analyzer);
        while (true) {
            if (queries == null && queryString == null) { // prompt the user
                System.out.println("输入查询关键字: ");
            }

            String line = queryString != null ? queryString : in.readLine();

            if (line == null || line.length() == -1) {
                break;
            }

            line = line.trim();
            if (line.length() == 0) {
                break;
            }

            Query query = parser.parse(line);
            System.out.println("Searching for: " + query.toString(field));

            if (repeat > 0) { // repeat & time as benchmark
                Date start = new Date();
                for (int i = 0; i < repeat; i++) {
                    searcher.search(query, null, 100);
                }
                Date end = new Date();
                System.out.println("Time: " + (end.getTime() - start.getTime())
                        + "ms");
            }

            doPagingSearch(in, searcher, query, hitsPerPage, raw,
                    queries == null && queryString == null);

            if (queryString != null) {
                break;
            }
        }
        reader.close();
    }

    public static void doPagingSearch(BufferedReader in,
            IndexSearcher searcher, Query query, int hitsPerPage, boolean raw,
            boolean interactive) throws IOException {

        // Collect enough docs to show 5 pages
        TopDocs results = searcher.search(query, 5 * hitsPerPage);
        ScoreDoc[] hits = results.scoreDocs;

        int numTotalHits = results.totalHits;
        System.out.println(numTotalHits + " total matching documents");

        int start = 0;
        int end = Math.min(numTotalHits, hitsPerPage);

        while (true) {
            if (end > hits.length) {
                System.out
                        .println("Only results 1 - " + hits.length + " of "
                                + numTotalHits
                                + " total matching documents collected.");
                System.out.println("Collect more (y/n) ?");
                String line = in.readLine();
                if (line.length() == 0 || line.charAt(0) == 'n') {
                    break;
                }

                hits = searcher.search(query, numTotalHits).scoreDocs;
            }

            end = Math.min(hits.length, start + hitsPerPage);

            for (int i = start; i < end; i++) {
                if (raw) { // output raw format
                    System.out.println("doc=" + hits[i].doc + " score="
                            + hits[i].score);
                    continue;
                }

                Document doc = searcher.doc(hits[i].doc);
                String path = doc.get("path");
                if (path != null) {
                    System.out.println((i + 1) + ". " + path);
                    String title = doc.get("title");
                    if (title != null) {
                        System.out.println("   Title: " + doc.get("title"));
                    }
                } else {
                    System.out.println((i + 1) + ". "
                            + "No path for this document");
                }

            }

            if (!interactive || end == 0) {
                break;
            }

            if (numTotalHits >= end) {
                boolean quit = false;
                while (true) {
                    System.out.print("Press ");
                    if (start - hitsPerPage >= 0) {
                        System.out.print("(p)revious page, ");
                    }
                    if (start + hitsPerPage < numTotalHits) {
                        System.out.print("(n)ext page, ");
                    }
                    System.out
                            .println("(q)uit or enter number to jump to a page.");

                    String line = in.readLine();
                    if (line.length() == 0 || line.charAt(0) == 'q') {
                        quit = true;
                        break;
                    }
                    if (line.charAt(0) == 'p') {
                        start = Math.max(0, start - hitsPerPage);
                        break;
                    } else if (line.charAt(0) == 'n') {
                        if (start + hitsPerPage < numTotalHits) {
                            start += hitsPerPage;
                        }
                        break;
                    } else {
                        int page = Integer.parseInt(line);
                        if ((page - 1) * hitsPerPage < numTotalHits) {
                            start = (page - 1) * hitsPerPage;
                            break;
                        } else {
                            System.out.println("No such page");
                        }
                    }
                }
                if (quit)
                    break;
                end = Math.min(numTotalHits, start + hitsPerPage);
            }
        }
    }
}

 //************************************************************************************************************************

新增部分基础概念的梳理：参考lucene 实战

1、基本概念

lucence 可以认为分为两大组件：

1）索引组件

a、内容获取：即将原始的内容材料，可以是数据库、网站（爬虫）、文本转换为lucence的Docment
Docment 为若干个带值得域
b、文档分析：利用分词器对文档进行分析；
c、建立索引：根据文档分析的结构建立索引文件；

2）搜索组件

a、建立查询：即将用户请求转换为搜索引擎支持的查询对象格式；
b、执行搜索查询；并反馈Document结果集；


2、官方样例代码分析

**索引组件部分工作
1、创建一个包含某个分词器的IndexWriter
private IndexWriter writer;
writer = new IndexWriter(IndexDir, new StandardAnalyzer(), true, IndexWriter.MaxFieldLength.UNLIMITED);

2、遍历被索引的文件（即原始内容）将其转换为Document
Docment doc = new Docment();
doc.add(new Field("contents", new FileReader(f));
doc.add(new Field("filename"), f.getName(), Field.Store.Yes, Field.Index.NOT_ANALYZED);

3、针对该Docment创建索引
writer.addDocment(doc);

**搜索组件部分工作
1、打开索引文件
IndexSearcher is = new IndexSearcher(IndexDir);

2、创建一个查询对象
QueryParser parser = new QueryParser(Version.LUCENE_30, "contents", new StandardAnalyzer());
Query query = parser("要找的查询关键字");

3、执行查询并返回结果
TopDocs hits = is.search(query, 10);