27 Kasım 2014 Perşembe

a lucene tip

Retrieving large resultsets with lucene may degrade performance as in here: http://stackoverflow.com/questions/9868419/how-to-get-total-count-in-hibernate-full-text-search 
You can choose to show the first top k results, or you can paginate lucene as follows:

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// can get the resultsize easily, so you know how many pages would be..
Integer resultSize = jpaQuery.getResultSize(); 
// I use 1000 as max results, but it depends.. just try to find the optimum.
Integer pageCount = resultSize / MAX_RESULTS + 1;
List<Object[]> rawQueryResultList = new ArrayList<>();
for(int page = 0; page < pageCount; page++) {  
 jpaQuery.setFirstResult(page * MAX_RESULTS);
 jpaQuery.setMaxResults(MAX_RESULTS);
  
 rawQueryResultList.addAll(jpaQuery.getResultList());
}