KickJava   Java API By Example, From Geeks To Geeks.

Java > Open Source Codes > org > outerj > daisy > query > model > IsNotNull


1 /*
2  * Copyright 2004 Outerthought bvba and Schaubroeck nv
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  * http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16 package org.outerj.daisy.query.model;
17
18 import org.outerj.daisy.query.QueryContext;
19 import org.outerj.daisy.repository.query.QueryException;
20 import org.outerj.daisy.repository.query.EvaluationContext;
21 import org.outerj.daisy.repository.Document;
22 import org.outerj.daisy.repository.Version;
23
24 import java.sql.PreparedStatement JavaDoc;
25 import java.sql.SQLException JavaDoc;
26
27 public class IsNotNull extends AbstractPredicateExpr {
28     private final Identifier identifier;
29
30     public IsNotNull(Identifier identifier) {
31         this.identifier = identifier;
32     }
33
34     public void prepare(QueryContext context) throws QueryException {
35         identifier.prepare(context);
36     }
37
38     public boolean evaluate(Document document, Version version, EvaluationContext evaluationContext) throws QueryException {
39         Object JavaDoc value = identifier.evaluate(null, document, version, evaluationContext);
40         return evaluate(value);
41     }
42
43     public boolean evaluate(Object JavaDoc value) {
44         return value != null;
45     }
46
47     public void generateSql(StringBuffer JavaDoc sql, SqlGenerationContext context) throws QueryException {
48         sql.append(" (");
49         String JavaDoc preCond = identifier.getSqlPreConditions(context);
50         if (preCond != null)
51             sql.append(preCond).append(" and ");
52         identifier.generateSqlValueExpr(sql, context);
53         sql.append(" IS NOT NULL)");
54     }
55
56     public int bindSql(PreparedStatement JavaDoc stmt, int bindPos, EvaluationContext evaluationContext) throws SQLException JavaDoc, QueryException {
57         bindPos = identifier.bindPreConditions(stmt, bindPos);
58         bindPos = identifier.bindValueExpr(stmt, bindPos, null, evaluationContext);
59         return bindPos;
60     }
61
62     public AclConditionViolation isAclAllowed() {
63         return identifier.isAclAllowed();
64     }
65
66     public Tristate appliesTo(Document document) throws QueryException {
67         if (identifier.canTestAppliesTo()) {
68             boolean result = evaluate(identifier.evaluate(null, document, null, new EvaluationContext()));
69             return result ? Tristate.YES : Tristate.NO;
70         } else {
71             return Tristate.MAYBE;
72         }
73     }
74 }
75
Popular Tags