1  /*
     2   * Licensed to the Apache Software Foundation (ASF) under one or more
     3   *  contributor license agreements.  The ASF licenses this file to You
     4   * under the Apache License, Version 2.0 (the "License"); you may not
     5   * use this file except in compliance with the License.
     6   * You may obtain a copy of the License at
     7   *
     8   *     http://www.apache.org/licenses/LICENSE-2.0
     9   *
    10   * Unless required by applicable law or agreed to in writing, software
    11   * distributed under the License is distributed on an "AS IS" BASIS,
    12   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    13   * See the License for the specific language governing permissions and
    14   * limitations under the License.  For additional information regarding
    15   * copyright in this work, please see the NOTICE file in the top level
    16   * directory of this distribution.
    17   */
    18  /* Created on Jul 18, 2003 */
    19  package org.apache.roller.weblogger.business.search.operations;
    20  
    21  import java.io.IOException;
    22  
    23  import org.apache.commons.logging.Log;
    24  import org.apache.commons.logging.LogFactory;
    25  import org.apache.lucene.analysis.standard.StandardAnalyzer;
    26  import org.apache.lucene.index.IndexReader;
    27  import org.apache.lucene.index.Term;
    28  import org.apache.lucene.queryParser.MultiFieldQueryParser;
    29  import org.apache.lucene.queryParser.ParseException;
    30  import org.apache.lucene.search.BooleanQuery;
    31  import org.apache.lucene.search.Hits;
    32  import org.apache.lucene.search.IndexSearcher;
    33  import org.apache.lucene.search.Query;
    34  import org.apache.lucene.search.Sort;
    35  import org.apache.lucene.search.SortField;
    36  import org.apache.lucene.search.TermQuery;
    37  import org.apache.roller.weblogger.business.search.IndexManagerImpl;
    38  import org.apache.roller.weblogger.business.search.FieldConstants;
    39  import org.apache.roller.weblogger.business.search.IndexUtil;
    40  import org.apache.roller.weblogger.business.search.IndexManager;
    41  
    42  
    43  /**
    44   * An operation that searches the index.
    45   * @author Mindaugas Idzelis (min@idzelis.com)
    46   */
    47  public class SearchOperation extends ReadFromIndexOperation {
    48      //~ Static fields/initializers =============================================
    49      
             /* 
    P/P       *  Method: org.apache.roller.weblogger.business.search.operations.SearchOperation__static_init
              * 
              *  Presumptions:
              *    org.apache.commons.logging.LogFactory:getFactory(...)@50 != null
              * 
              *  Postconditions:
              *    SEARCH_FIELDS == &new String[](SearchOperation__static_init#1)
              *    SORTER == &new Sort(SearchOperation__static_init#2)
              *    init'ed(mLogger)
              *    new Sort(SearchOperation__static_init#2) num objects == 1
              *    new String[](SearchOperation__static_init#1) num objects == 1
              *    SEARCH_FIELDS.length == 4
              *    SEARCH_FIELDS[0] == &"content"
              *    SEARCH_FIELDS[1] == &"title"
              *    SEARCH_FIELDS[2] == &"comment"
              *    SEARCH_FIELDS[3] == &"cat"
              */
    50      private static Log mLogger =
    51              LogFactory.getFactory().getInstance(SearchOperation.class);
    52      
    53      private static String[] SEARCH_FIELDS = new String[]{
    54          FieldConstants.CONTENT, FieldConstants.TITLE,
    55          FieldConstants.C_CONTENT, FieldConstants.CATEGORY
    56      };
    57      
    58      private static Sort SORTER = new Sort( new SortField(
    59              FieldConstants.PUBLISHED, SortField.STRING, true) );
    60      
    61      //~ Instance fields ========================================================
    62      
    63      private String term;
    64      private String websiteHandle;
    65      private String category;
    66      private Hits searchresults;
    67      private String parseError;
    68      
    69      //~ Constructors ===========================================================
    70      
    71      /**
    72       * Create a new operation that searches the index.
    73       */
    74      public SearchOperation(IndexManager mgr) {
    75          // TODO: finish moving  IndexManager to backend, so this cast is not needed
                 /* 
    P/P           *  Method: void org.apache.roller.weblogger.business.search.operations.SearchOperation(IndexManager)
                  * 
                  *  Postconditions:
                  *    this.manager == mgr
                  *    init'ed(this.manager)
                  */
    76          super((IndexManagerImpl)mgr);
    77      }
    78      
    79      //~ Methods ================================================================
    80      
    81      public void setTerm(String term) {
                 /* 
    P/P           *  Method: void setTerm(String)
                  * 
                  *  Postconditions:
                  *    this.term == term
                  *    init'ed(this.term)
                  */
    82          this.term = term;
    83      }
    84      
    85      /* (non-Javadoc)
    86       * @see java.lang.Runnable#run()
    87       */
    88      public void doRun() {
                 /* 
    P/P           *  Method: void doRun()
                  * 
                  *  Preconditions:
                  *    (soft) init'ed(SEARCH_FIELDS)
                  *    (soft) init'ed(SORTER)
                  *    (soft) mLogger != null
                  *    (soft) init'ed(this.manager.reader)
                  *    (soft) org/apache/roller/weblogger/business/search/IndexManagerImpl.mLogger != null
                  *    (soft) init'ed(this.category)
                  *    (soft) this.manager != null
                  *    (soft) init'ed(this.manager.fRAMindex)
                  *    (soft) init'ed(this.manager.indexDir)
                  *    (soft) init'ed(this.manager.useRAMIndex)
                  *    ...
                  * 
                  *  Postconditions:
                  *    init'ed(this.manager.reader)
                  *    possibly_updated(this.parseError)
                  *    init'ed(this.searchresults)
                  */
    89          searchresults = null;
    90          
    91          IndexSearcher searcher = null;
    92          
    93          try {
    94              IndexReader reader = manager.getSharedIndexReader();
    95              searcher = new IndexSearcher(reader);
    96              
    97              Query query =
    98                      MultiFieldQueryParser.parse(
    99                      term, SEARCH_FIELDS, new StandardAnalyzer());
   100              
   101              Term tUsername =
   102                      IndexUtil.getTerm(FieldConstants.WEBSITE_HANDLE, websiteHandle);
   103              
   104              if (tUsername != null) {
   105                  BooleanQuery bQuery = new BooleanQuery();
   106                  bQuery.add(query, true, false);
   107                  bQuery.add(new TermQuery(tUsername), true, false);
   108                  query = bQuery;
   109              }
   110              
   111              Term tCategory =
   112                      IndexUtil.getTerm(FieldConstants.CATEGORY, category);
   113              
   114              if (tCategory != null) {
   115                  BooleanQuery bQuery = new BooleanQuery();
   116                  bQuery.add(query, true, false);
   117                  bQuery.add(new TermQuery(tCategory), true, false);
   118                  query = bQuery;
   119              }
   120              searchresults = searcher.search(query, null/*Filter*/, SORTER);
   121          } catch (IOException e) {
   122              mLogger.error("Error searching index", e);
   123              parseError = e.getMessage();
   124          } catch (ParseException e) {
   125              // who cares?
   126              parseError = e.getMessage();
   127          }
   128          // don't need to close the reader, since we didn't do any writing!
   129      }
   130      
   131      public Hits getResults() {
                 /* 
    P/P           *  Method: Hits getResults()
                  * 
                  *  Preconditions:
                  *    init'ed(this.searchresults)
                  * 
                  *  Postconditions:
                  *    return_value == this.searchresults
                  *    init'ed(return_value)
                  */
   132          return searchresults;
   133      }
   134      
   135      public int getResultsCount() {
                 /* 
    P/P           *  Method: int getResultsCount()
                  * 
                  *  Preconditions:
                  *    init'ed(this.searchresults)
                  * 
                  *  Postconditions:
                  *    init'ed(return_value)
                  * 
                  *  Test Vectors:
                  *    this.searchresults: Inverse{null}, Addr_Set{null}
                  */
   136          if (searchresults == null) return -1;
   137          
   138          return searchresults.length();
   139      }
   140      
   141      public String getParseError() {
                 /* 
    P/P           *  Method: String getParseError()
                  * 
                  *  Preconditions:
                  *    init'ed(this.parseError)
                  * 
                  *  Postconditions:
                  *    return_value == this.parseError
                  *    init'ed(return_value)
                  */
   142          return parseError;
   143      }
   144      
   145      /**
   146       * @param string
   147       */
   148      public void setWebsiteHandle(String websiteHandle) {
                 /* 
    P/P           *  Method: void setWebsiteHandle(String)
                  * 
                  *  Postconditions:
                  *    this.websiteHandle == websiteHandle
                  *    init'ed(this.websiteHandle)
                  */
   149          this.websiteHandle = websiteHandle;
   150      }
   151      
   152      /**
   153       * @param parameter
   154       */
   155      public void setCategory(String category) {
                 /* 
    P/P           *  Method: void setCategory(String)
                  * 
                  *  Postconditions:
                  *    this.category == category
                  *    init'ed(this.category)
                  */
   156          this.category = category;
   157      }
   158      
   159  }