我想突出一些结果。我在“内容”字段中索引文档的正文（文本），当我使用highlighter.getBestFragment（...）尝试使用高亮时，我得到一个NullPointerException。
但是，例如，当我尝试突出显示fileName时，它可以正常工作。 我知道，因为我只使用了一个带有fileReader或（ParsingReader）的字段，我的文本被标记化，这与文件名不同。
这是我的代码，请帮助我。
package xxxxxx;
import java.io.File;
import java.io.FileFilter;
import java.io.FileReader;
import java.io.IOException;
import java.io.Reader;
import org.apache.lucene.analysis.standard.StandardAnalyzer;
import org.apache.lucene.document.Document;
import org.apache.lucene.document.Field;
import org.apache.lucene.index.IndexWriter;
import org.apache.lucene.store.Directory;
import org.apache.lucene.store.FSDirectory;
import org.apache.lucene.util.Version;
import org.apache.tika.parser.ParsingReader;
public class Indexer {
static long start = 0;
public static void main(String[] args) throws Exception {
System.out.println("l'index se trouve à " + args[0]);
System.out.println("le dossier ou s'effectue l'indexation est :" + args[1]);
if (args.length != 2) {
throw new IllegalArgumentException("Usage: java " + Indexer.class.getName()
+ " <index dir> <data dir>");
}
String indexDir = args[0];
String dataDir = args[1];
start = System.currentTimeMillis();
Indexer indexer = new Indexer(indexDir);
int numIndexed;
try {
numIndexed = indexer.index(dataDir, new TextFilesFilter());
} finally {
indexer.close();
}
long end = System.currentTimeMillis();
System.out.println("Indexing " + numIndexed + " files took "
+ (end - start) + " milliseconds");
}
private IndexWriter writer;
public Indexer(String indexDir) throws IOException, InterruptedException {
Directory dir = FSDirectory.open(new File(indexDir));
writer = new IndexWriter(dir, new StandardAnalyzer(Version.LUCENE_30), true,
IndexWriter.MaxFieldLength.UNLIMITED);
writer.setUseCompoundFile(true);
}
public void close() throws IOException {
writer.optimize();
writer.close();
}
public int index(String dataDir, FileFilter filter) throws Exception {
File[] files = new File(dataDir).listFiles();
for (File f : files) {
if (!f.isDirectory() && !f.isHidden() && f.exists() && f.canRead() && (filter == null || filter.accept(f))) {
if (!(f.getCanonicalPath().endsWith("~"))) {
indexFile(f);
}
} else {
index(f.toString(), filter);
}
}
return writer.numDocs();
}
private static class TextFilesFilter implements FileFilter {
public boolean accept(File path) {
return true;
}
}
protected Document getDocument(File f) throws Exception {
// FileReader frf = new FileReader(f);
Document doc = new Document();
Reader reader = new ParsingReader(f);
doc.add(new Field("contents", reader, Field.TermVector.WITH_POSITIONS_OFFSETS));
doc.add(new Field("filename", f.getName(), Field.Store.YES, Field.Index.ANALYZED ));
doc.add(new Field("fullpath", f.getCanonicalPath(),Field.Store.YES, Field.Index.NOT_ANALYZED_NO_NORMS));
return doc;
}
private void indexFile(File f) throws Exception {
System.out.println("Indexing " + f.getCanonicalPath());
Document doc = getDocument(f);
writer.addDocument(doc);
System.out.println(System.currentTimeMillis() - start);
}
}
-------------------------------------------------------------------
package xxxxxxxxxxxxxxxxxxxx;
import java.io.File;
import java.io.IOException;
import java.util.ArrayList;
import java.util.List;
import org.apache.lucene.analysis.TokenStream;
import org.apache.lucene.analysis.standard.StandardAnalyzer;
import org.apache.lucene.document.Document;
import org.apache.lucene.queryParser.MultiFieldQueryParser;
import org.apache.lucene.queryParser.ParseException;
import org.apache.lucene.queryParser.QueryParser;
import org.apache.lucene.search.DisjunctionMaxQuery;
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.search.highlight.Highlighter;
import org.apache.lucene.search.highlight.InvalidTokenOffsetsException;
import org.apache.lucene.search.highlight.QueryScorer;
import org.apache.lucene.search.highlight.SimpleSpanFragmenter;
import org.apache.lucene.search.highlight.TokenSources;
import org.apache.lucene.store.Directory;
import org.apache.lucene.store.FSDirectory;
import org.apache.lucene.util.Version;
public class Searcher {
public static void main(String[] args) throws IllegalArgumentException,
IOException, ParseException, InvalidTokenOffsetsException {
System.out.println("endroit ou se situe l'index " + args[0]);
System.out.println(args[1]);
if (args.length != 2) {
throw new IllegalArgumentException("Usage: java "
+ Searcher.class.getName()
+ " <index dir> <query>");
}
String indexDir = args[0];
String q = args[1];
search(indexDir, q);
}
public static void search(String indexDir, String q) throws IOException, ParseException, InvalidTokenOffsetsException {
Directory dir = FSDirectory.open(new File(indexDir));
IndexSearcher indexSearcher = new IndexSearcher(dir);
QueryParser parserC = new QueryParser(Version.LUCENE_30, "contents", new StandardAnalyzer(Version.LUCENE_30));
// QueryParser parserN = new QueryParser(Version.LUCENE_30, "filename", new StandardAnalyzer(Version.LUCENE_30));
QueryParser parserP = new QueryParser(Version.LUCENE_30, "fullpath", new StandardAnalyzer(Version.LUCENE_30));
parserC.setDefaultOperator(QueryParser.Operator.OR);
// parserN.setDefaultOperator(QueryParser.Operator.OR);
parserC.setPhraseSlop(10);
// parserN.setPhraseSlop(10);
DisjunctionMaxQuery dmq = new DisjunctionMaxQuery(6);
Query query = new MultiFieldQueryParser(Version.LUCENE_30, new String[]{"contents", "filename"},
new CustomAnalyzer()).parse(q);
Query queryC = parserC.parse(q);
//Query queryN = parserN.parse(q);
dmq.add(queryC);
//dmq.add(queryN);
// dmq.add(query) ;
QueryScorer scorer = new QueryScorer(dmq, "contents");
Highlighter highlighter = new Highlighter(scorer);
highlighter.setTextFragmenter(new SimpleSpanFragmenter(scorer));
System.out.println(query.toString());
long start = System.currentTimeMillis();
TopDocs hits = indexSearcher.search(dmq, 15);
System.out.println(hits.totalHits);
long end = System.currentTimeMillis();
System.err.println("Found " + hits.totalHits
+ " document(s) (in " + (end - start)
+ " milliseconds) that matched query '"
+ q + "':");
for (ScoreDoc scoreDoc : hits.scoreDocs) {
Document doc = indexSearcher.doc(scoreDoc.doc);
System.out.print(scoreDoc.score);
System.out.println(doc.get("fullpath"));
String contents = doc.get("contents"); // I am pretty sure the mistake is here , contents is always Null
//But what can I do to make this thing work ?
TokenStream stream =
TokenSources.getAnyTokenStream(indexSearcher.getIndexReader(),
scoreDoc.doc,
"contents",
doc,
new StandardAnalyzer(Version.LUCENE_30));
String fragment =
highlighter.getBestFragment(stream, contents);
System.out.println(fragment);
}
indexSearcher.close();
}
}
----------------------------------------------------------------------
答案 0 :(得分：0)
如果你想使用那个荧光笔，你需要存储它。存储“文件名”但不存在“内容”，这就是为什么你看到它们表现不同的原因：
doc.add(new Field("contents", reader, Field.TermVector.WITH_POSITIONS_OFFSETS));
doc.add(new Field("filename", f.getName(), Field.Store.YES, Field.Index.ANALYZED ));