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 javax.persistence.criteria.CriteriaBuilder;
025    import javax.persistence.criteria.Path;
026    import javax.persistence.criteria.Predicate;
027    
028    
029    public class FilterSpecUtil {
030    
031            public static Predicate buildPredicate(Path<?> root, CriteriaBuilder builder, Class<?> type, String key, Object value) {
032                    if (value == null)
033                            return null;
034                    
035                    if (type == null)
036                            type = value.getClass();
037                    
038                    if (type == String.class && value.toString().trim().length() == 0)
039                            return null;
040                    
041                    if (value instanceof String)
042                            return builder.like(root.get(key).as(String.class), "%" + value + "%");
043                    
044                    return builder.equal(root.get(key).as(type), value);
045            }
046    }