cdmlib-persistence/src/main/java/eu/etaxonomy/cdm/persistence/query/RandomOrder.java

   1 package eu.etaxonomy.cdm.persistence.query;
   2
   3 import java.util.Map;
   4
   5 import org.hibernate.Criteria;
   6 import org.hibernate.HibernateException;
   7 import org.hibernate.criterion.CriteriaQuery;
   8 import org.hibernate.criterion.Order;
   9 import org.hibernate.envers.query.AuditQuery;
  10 import org.hibernate.util.StringHelper;
  11
  12 import eu.etaxonomy.cdm.persistence.dao.common.OperationNotSupportedInPriorViewException;
  13
  14
  15 public class RandomOrder extends OrderHint {
  16         private final static String PROPERTY_NAME = "uselessAnyways";
  17
  18         public RandomOrder() {
  19                 super(RandomOrder.PROPERTY_NAME,SortOrder.ASCENDING);
  20     }
  21
  22         @Override
  23         public void add(Criteria criteria, Map<String, Criteria> criteriaMap) {
  24                 criteria.addOrder(new RandomHibernateOrder());
  25         }
  26
  27         public class RandomHibernateOrder extends Order {
  28
  29                 protected RandomHibernateOrder() {
  30                         super(RandomOrder.PROPERTY_NAME, true);
  31                 }
  32
  33
  34                 @Override
  35                 public String toSqlString(Criteria criteria, CriteriaQuery criteriaQuery)
  36                 throws HibernateException {
  37                 StringBuilder fragment = new StringBuilder();
  38                 fragment.append(" rand()");
  39                 return StringHelper.replace(fragment.toString(), "{alias}",
  40                 criteriaQuery.getSQLAlias(criteria));
  41                 }
  42         }
  43         @Override
  44         public void add(AuditQuery query) {
  45                         throw new OperationNotSupportedInPriorViewException("You cannot sort in a random order in the history view");
  46         }
  47 }