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
021 package org.granite.tide.spring.data;
022
023 import java.beans.BeanInfo;
024 import java.beans.Introspector;
025 import java.beans.PropertyDescriptor;
026 import java.util.ArrayList;
027 import java.util.List;
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 FilterBeanSpecification<T> implements Specification<T> {
037
038 private Object filter;
039
040 private FilterBeanSpecification(Object filter) {
041 this.filter = filter;
042 }
043
044 public static <T> FilterBeanSpecification<T> byBean(Object filter) {
045 return new FilterBeanSpecification<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 bean filter
052 PropertyDescriptor[] pds = null;
053 try {
054 BeanInfo info = Introspector.getBeanInfo(filter.getClass());
055 pds = info.getPropertyDescriptors();
056 }
057 catch (Exception e) {
058 throw new RuntimeException("Could not introspect filter bean", e);
059 }
060
061 for (PropertyDescriptor pd : pds) {
062 if (pd.getWriteMethod() == null || !pd.getReadMethod().isAnnotationPresent(FilterMapping.class) || pd.getReadMethod().getAnnotation(FilterMapping.class).mode() == FilterMode.EXCLUDE)
063 continue;
064
065 FilterMapping mapping = pd.getReadMethod().getAnnotation(FilterMapping.class);
066 if (root.get(mapping.value()) == null)
067 throw new RuntimeException("Invalid filter mapping, path: " + mapping.value());
068
069 Object value = null;
070 try {
071 value = pd.getReadMethod().invoke(filter);
072 }
073 catch (Exception e) {
074 throw new RuntimeException("Could not get filter property " + pd.getName(), e);
075 }
076
077 Predicate predicate = FilterSpecUtil.buildPredicate(root, builder, pd.getReadMethod().getReturnType(), mapping.value(), value);
078 if (predicate != null)
079 predicates.add(predicate);
080 }
081
082 if (predicates.size() > 0)
083 return builder.and(predicates.toArray(new Predicate[predicates.size()]));
084
085 return null;
086 }
087 }