001/**
002 *   GRANITE DATA SERVICES
003 *   Copyright (C) 2006-2013 GRANITE DATA SERVICES S.A.S.
004 *
005 *   This file is part of the Granite Data Services Platform.
006 *
007 *   Granite Data Services is free software; you can redistribute it and/or
008 *   modify it under the terms of the GNU Lesser General Public
009 *   License as published by the Free Software Foundation; either
010 *   version 2.1 of the License, or (at your option) any later version.
011 *
012 *   Granite Data Services is distributed in the hope that it will be useful,
013 *   but WITHOUT ANY WARRANTY; without even the implied warranty of
014 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser
015 *   General Public License for more details.
016 *
017 *   You should have received a copy of the GNU Lesser General Public
018 *   License along with this library; if not, write to the Free Software
019 *   Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301,
020 *   USA, or see <http://www.gnu.org/licenses/>.
021 */
022package org.granite.tide.spring.data;
023
024import java.util.ArrayList;
025import java.util.List;
026import java.util.Map;
027import java.util.Map.Entry;
028
029import javax.persistence.criteria.CriteriaBuilder;
030import javax.persistence.criteria.CriteriaQuery;
031import javax.persistence.criteria.Predicate;
032import javax.persistence.criteria.Root;
033
034import org.springframework.data.jpa.domain.Specification;
035
036public class FilterMapSpecification<T> implements Specification<T> {
037        
038        private Map<String, Object> filter;
039        
040        private FilterMapSpecification(Map<String, Object> filter) {
041                this.filter = filter;
042        }
043        
044        public static <T> FilterMapSpecification<T> byMap(Map<String, Object> filter) {
045                return new FilterMapSpecification<T>(filter);
046        }
047
048        public Predicate toPredicate(Root<T> root, CriteriaQuery<?> query, CriteriaBuilder builder) {
049                List<Predicate> predicates = new ArrayList<Predicate>();
050                
051                // Query by map filter
052                for (Entry<String, Object> entry : filter.entrySet()) {
053                        if (root.get(entry.getKey()) == null)
054                                throw new RuntimeException("Invalid filter mapping, path: " + entry.getKey());
055                        
056                        Predicate predicate = FilterSpecUtil.buildPredicate(root, builder, null, entry.getKey(), entry.getValue());
057                        if (predicate != null)
058                                predicates.add(predicate);
059                }
060                
061                if (predicates.size() > 0)
062                        return builder.and(predicates.toArray(new Predicate[predicates.size()]));
063                
064                return null;
065        }               
066}