phrasequerytest.java

来自「Lucene in Action 中文版代码下载」· Java 代码 · 共 77 行

package lia.searching;

import junit.framework.TestCase;
import org.apache.lucene.analysis.WhitespaceAnalyzer;
import org.apache.lucene.document.Document;
import org.apache.lucene.document.Field;
import org.apache.lucene.index.IndexWriter;
import org.apache.lucene.index.Term;
import org.apache.lucene.search.Hits;
import org.apache.lucene.search.IndexSearcher;
import org.apache.lucene.search.PhraseQuery;
import org.apache.lucene.store.RAMDirectory;

import java.io.IOException;

public class PhraseQueryTest extends TestCase {
  private IndexSearcher searcher;

  protected void setUp() throws IOException {
    // set up sample document
    RAMDirectory directory = new RAMDirectory();
    IndexWriter writer = new IndexWriter(directory,
        new WhitespaceAnalyzer(), true);
    Document doc = new Document();
    doc.add(Field.Text("field",
              "the quick brown fox jumped over the lazy dog"));
    writer.addDocument(doc);
    writer.close();

    searcher = new IndexSearcher(directory);
  }

  private boolean matched(String[] phrase, int slop)
      throws IOException {
    PhraseQuery query = new PhraseQuery();
    query.setSlop(slop);

    for (int i=0; i < phrase.length; i++) {
      query.add(new Term("field", phrase[i]));
    }

    Hits hits = searcher.search(query);
    return hits.length() > 0;
  }

  public void testSlopComparison() throws Exception {
    String[] phrase = new String[] {"quick", "fox"};

    assertFalse("exact phrase not found", matched(phrase, 0));

    assertTrue("close enough", matched(phrase, 1));
  }

  public void testReverse() throws Exception {
    String[] phrase = new String[] {"fox", "quick"};

    assertFalse("hop flop", matched(phrase, 2));
    assertTrue("hop hop slop", matched(phrase, 3));
  }

  public void testMultiple() throws Exception {
    assertFalse("not close enough",
        matched(new String[] {"quick", "jumped", "lazy"}, 3));

    assertTrue("just enough",
        matched(new String[] {"quick", "jumped", "lazy"}, 4));

    assertFalse("almost but not quite",
        matched(new String[] {"lazy", "jumped", "quick"}, 7));

    assertTrue("bingo",
        matched(new String[] {"lazy", "jumped", "quick"}, 8));

  }

}