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.internal.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                 private static final long serialVersionUID = 8231534219451938847L;
  29
  30
  31                 protected RandomHibernateOrder() {
  32                         super(RandomOrder.PROPERTY_NAME, true);
  33                 }
  34
  35
  36                 @Override
  37                 public String toSqlString(Criteria criteria, CriteriaQuery criteriaQuery)
  38                 throws HibernateException {
  39                 StringBuilder fragment = new StringBuilder();
  40                 fragment.append(" rand()");
  41                 return StringHelper.replace(fragment.toString(), "{alias}",
  42                 criteriaQuery.getSQLAlias(criteria));
  43                 }
  44         }
  45
  46         @Override
  47         public void add(AuditQuery query) {
  48                         throw new OperationNotSupportedInPriorViewException("You cannot sort in a random order in the history view");
  49         }
  50 }