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 javax.persistence.criteria.CriteriaBuilder;
024import javax.persistence.criteria.Path;
025import javax.persistence.criteria.Predicate;
026
027
028public class FilterSpecUtil {
029
030        public static Predicate buildPredicate(Path<?> root, CriteriaBuilder builder, Class<?> type, String key, Object value) {
031                if (value == null)
032                        return null;
033                
034                if (type == null)
035                        type = value.getClass();
036                
037                if (type == String.class && value.toString().trim().length() == 0)
038                        return null;
039                
040                if (value instanceof String)
041                        return builder.like(root.get(key).as(String.class), "%" + value + "%");
042                
043                return builder.equal(root.get(key).as(type), value);
044        }
045}