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Date: 23 May 2002 00:44:57 -0000
Message-ID: <20020523004457.85689.qmail@icarus.apache.org>
From: carlson@apache.org
To: jakarta-lucene-sandbox-cvs@apache.org
Subject: cvs commit:
 jakarta-lucene-sandbox/contributions/searchbean/src/java/org/apache/lucene/beans
 HitsIterator.java

carlson     02/05/22 17:44:57

  Added:       contributions/searchbean/src/java/org/apache/lucene/beans
                        HitsIterator.java
  Log:
  Initial submit of SerachBean and related classes
  
  Revision  Changes    Path
  1.1                  jakarta-lucene-sandbox/contributions/searchbean/src/java/org/apache/lucene/beans/HitsIterator.java
  
  Index: HitsIterator.java
  ===================================================================
  /*
   * HitsIterator.java
   * Provides an Iterator class around Lucene Hits
   * It also supports paging
   * Created on November 1, 2001, 8:53 PM
   */
  
  package org.apache.lucene.beans;
  
  import org.apache.lucene.beans.SortedField;
  import org.apache.lucene.beans.CompareDocumentsByField;
  
  import org.apache.lucene.document.Document;
  import org.apache.lucene.search.Hits;
  
  import java.io.IOException;
  import java.util.Arrays;
  import java.util.Comparator;
  
  //import org.apache.log4j.Logger;
  
  /**
   *
   * @author  Peter Carlson
   * @version 1.0
   */
  public class HitsIterator {
      
      //static Logger logger = Logger.getLogger(HitsIterator.class.getName());
      
      private int currentPosition = 0;
      
      private Hits hitsCollection = null;
      private Object[] arrayOfIndividualHits = null;
      
      private int totalHits = 0;
      
      private int pageSize = 25; // default page size
      
      private int currentPage = 1; // range from 1 to totalHits%pageSize
      
      private int totalPages = -1; // set by constructor
      
      private int endPagePosition = 0; // position currentPage ends
      
      /** Creates new HitsIterator */
      private HitsIterator() {
      }
      
      public HitsIterator(Hits hits) throws IOException{
          this(hits,null);
      }
      
      public HitsIterator(Hits hits, String sortFlag) throws IOException{
          this.hitsCollection = hits;
          if (sortFlag != null){
              if ((sortFlag != "") && (sortFlag !="relevance")){
                  //logger.debug("Sorting hits by field "+sortFlag);
                  sortByField(sortFlag);
                  //logger.debug("Completed sorting by field "+sortFlag);
              }
          }
          totalHits = getTotalHits();
          setPageCount();
      }
      
      /** sorts hits by the given sort flag
       * fills an interal array
       * @param sortFlag field to sort results on
       */
      private void sortByField(String fieldName) throws IOException{
          long start = System.currentTimeMillis();
          Comparator c = null;
          if (fieldName == null){
              //logger.error("sort field is null");
              return;
          }
          
          SortedField sf = SortedField.getSortedField(fieldName);
          if (sf !=null){
              c = (Comparator) new CompareDocumentsByField();
          } else {
              //logger.error("Sort field not found");
              arrayOfIndividualHits = null;
              return;
          }
          arrayOfIndividualHits = new Object[hitsCollection.length()];
          long first = System.currentTimeMillis();
          for (int i=0; i<hitsCollection.length(); i++) {
              int id = hitsCollection.id(i);
              arrayOfIndividualHits[i] = new IndividualHit(i, sf.getFieldValue(id), hitsCollection.score(i));
          }
          long second = System.currentTimeMillis();
          //logger.debug("HitsIterator.sortByField(): filling Obj[] took "+(second-first));
          
          Arrays.sort(arrayOfIndividualHits, c);
          //logger.debug("HitsIterator.sortByField(): sort took "+(System.currentTimeMillis()-second));
          
      }
      
      
      private void setPageCount() {
          
          totalPages = totalHits / pageSize;
          
          //account for remainder if not exaxtly divisable
          if (totalHits % pageSize != 0)
          { totalPages++;}
          
          setCurrentPage(1); // reset currentPage to make sure not over the limit
      }
      
      public int getPageCount() {
          return totalPages;
      }
      
      
      public org.apache.lucene.document.Document setPosition(int position) throws IOException{
          if (position > totalHits) {
              return null;
          }
          currentPosition = position;
          return getDoc();
      }
      
      public org.apache.lucene.document.Document next() throws IOException{
          currentPosition++;
          
          if (currentPosition > totalHits) {
              currentPosition = totalHits;
              return null ;
          }
          
          return getDoc();
      }
      
      public org.apache.lucene.document.Document previous() throws IOException{
          currentPosition--;
          
          if (currentPosition < 0)
          { return null;}
          
          return getDoc();
      }
      
      public boolean hasNext() {
          if (currentPosition < endPagePosition)
          { return true; }
          
          return false;
      }
      
      public org.apache.lucene.document.Document getDoc() throws IOException {
          if (arrayOfIndividualHits == null)
              return hitsCollection.doc(currentPosition - 1);
          else {
              int i = ((IndividualHit)arrayOfIndividualHits[currentPosition - 1]).getIndex();
              return hitsCollection.doc(i);
          }
      }
      
      public int getScore() throws Exception{
          if (arrayOfIndividualHits == null)
              return (int) (hitsCollection.score(currentPosition - 1)*100.0f);
          else
              return (int) (((IndividualHit)arrayOfIndividualHits[currentPosition - 1]).getScore()*100.0f);
      }
      
      public int getTotalHits() {
          return hitsCollection.length();
      }
      
      public int getCurrentPosition() {
          return currentPosition;
      }
      
      public int getPageSize() {
          return pageSize;
      }
      
      public void setPageSize(int pageSize) {
          this.pageSize = pageSize;
          setPageCount();
      }
      
      public void setCurrentPage(int currentPage) throws IndexOutOfBoundsException{
          if (currentPage > totalPages){ 
              throw new IndexOutOfBoundsException("currentPage greater than total pages"); 
          }
          
          this.currentPage = currentPage;
          currentPosition = ((currentPage - 1) * pageSize);
          endPagePosition = Math.min( ((currentPage - 1)*pageSize) + pageSize, totalHits);
      }
      
      public int getCurrentPage() {
          return currentPage;
      }
      
      /**
       * set page number to next page, unless last page, then
       * always return last page number
       *@return current page number
       */
      public int nextPage() {
          setCurrentPage(currentPage++);
          return getCurrentPage();
      }
      
      /**
       * set page number to previous page, unless first page,
       * then always return first page number
       *@return current page number
       */
      public int previousPage() {
          setCurrentPage(currentPage--);
          return getCurrentPage();
      }
  }
  
  
  

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