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     */
022    package org.granite.tide.spring.data;
023    
024    import java.util.ArrayList;
025    import java.util.List;
026    import java.util.Map;
027    import java.util.Map.Entry;
028    
029    import javax.persistence.criteria.CriteriaBuilder;
030    import javax.persistence.criteria.CriteriaQuery;
031    import javax.persistence.criteria.Predicate;
032    import javax.persistence.criteria.Root;
033    
034    import org.springframework.data.jpa.domain.Specification;
035    
036    public 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    }