001/*
002  GRANITE DATA SERVICES
003  Copyright (C) 2011 GRANITE DATA SERVICES S.A.S.
004
005  This file is part of Granite Data Services.
006
007  Granite Data Services is free software; you can redistribute it and/or modify
008  it under the terms of the GNU Library General Public License as published by
009  the Free Software Foundation; either version 2 of the License, or (at your
010  option) any later version.
011
012  Granite Data Services is distributed in the hope that it will be useful, but
013  WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
014  FITNESS FOR A PARTICULAR PURPOSE. See the GNU Library General Public License
015  for more details.
016
017  You should have received a copy of the GNU Library General Public License
018  along with this library; if not, see <http://www.gnu.org/licenses/>.
019*/
020
021package org.granite.tide.spring.data;
022
023import java.util.ArrayList;
024import java.util.List;
025import java.util.Map;
026import java.util.Map.Entry;
027
028import javax.persistence.criteria.CriteriaBuilder;
029import javax.persistence.criteria.CriteriaQuery;
030import javax.persistence.criteria.Predicate;
031import javax.persistence.criteria.Root;
032
033import org.springframework.data.jpa.domain.Specification;
034
035public class FilterMapSpecification<T> implements Specification<T> {
036        
037        private Map<String, Object> filter;
038        
039        private FilterMapSpecification(Map<String, Object> filter) {
040                this.filter = filter;
041        }
042        
043        public static <T> FilterMapSpecification<T> byMap(Map<String, Object> filter) {
044                return new FilterMapSpecification<T>(filter);
045        }
046
047        public Predicate toPredicate(Root<T> root, CriteriaQuery<?> query, CriteriaBuilder builder) {
048                List<Predicate> predicates = new ArrayList<Predicate>();
049                
050                // Query by map filter
051                for (Entry<String, Object> entry : filter.entrySet()) {
052                        if (root.get(entry.getKey()) == null)
053                                throw new RuntimeException("Invalid filter mapping, path: " + entry.getKey());
054                        
055                        Predicate predicate = FilterSpecUtil.buildPredicate(root, builder, null, entry.getKey(), entry.getValue());
056                        if (predicate != null)
057                                predicates.add(predicate);
058                }
059                
060                if (predicates.size() > 0)
061                        return builder.and(predicates.toArray(new Predicate[predicates.size()]));
062                
063                return null;
064        }               
065}