querybean.java

simple spider 源码 better light faster java 书籍源码.

package com.develop.ss.search;

import org.apache.lucene.search.IndexSearcher;
import org.apache.lucene.search.Query;
import org.apache.lucene.search.Hits;
import org.apache.lucene.analysis.Analyzer;
import org.apache.lucene.analysis.standard.StandardAnalyzer;
import org.apache.lucene.queryParser.QueryParser;
import org.apache.lucene.queryParser.ParseException;
import org.apache.lucene.document.Document;
import org.apache.lucene.document.Field;

import java.io.Serializable;
import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.io.IOException;
import java.util.List;
import java.util.ArrayList;

public class QueryBean implements Serializable {
  private String query;
  private String index;
  private String field;
  private List results = new ArrayList();
  private static float THRESHOLD_SCORE = 0.05f;

  public QueryBean(String index, String query, String field)
  {
      this.field = field;
      this.index = index;
      this.query = query;
  }

  public QueryBean(String index, String query)
  {
      this(index, query, "contents");
  }

  public String getQuery() {
    return query;
  }

  public HitBean[] getResults() {
    return (HitBean[]) results.toArray(new HitBean[results.size()]);
  }

  public HitBean getResult(int index) {
    return (HitBean) results.get(index);
  }

  public String getIndex() {
    return index;
  }

  public void setIndex(String index) {
    this.index = index;
  }

  public String getField() {
    return field;
  }

  public void setField(String field) {
    this.field = field;
  }

  public void setQuery(String query) {
    this.query = query;
  }

  //TODO: needed, and need, better unit tests here
  public void execute() throws IOException, ParseException {
    results.clear();
    if (query == null) return;
    if (field == null) throw new IllegalArgumentException("field cannot be null");
    if (index == null) throw new IllegalArgumentException("index cannot be null");
    IndexSearcher indexSearcher = new IndexSearcher(index);
    try {
      Analyzer analyzer = new StandardAnalyzer();
      Query q = QueryParser.parse(query, field, analyzer);
      Hits hits = indexSearcher.search(q);
      for (int n=0; n<hits.length(); n++) {
        if (hits.score(n) < THRESHOLD_SCORE) {
          return;
        }
        Document d = hits.doc(n);
        String title = safeGetFieldString(d, "title");
        results.add(new HitBean(d.getField("url").stringValue(), safeGetFieldString(d, "title"), hits.score(n)));
      }
    } finally {
      indexSearcher.close();
    }
  }
  private String safeGetFieldString(Document d, String field) {
    Field f = d.getField(field);
    return (f == null) ? "" : f.stringValue();
  }
}