Classes in this File | Line Coverage | Branch Coverage | Complexity | ||||
ScalarHandler |
|
| 1.8;1.8 |
1 | /* | |
2 | * Licensed to the Apache Software Foundation (ASF) under one or more | |
3 | * contributor license agreements. See the NOTICE file distributed with | |
4 | * this work for additional information regarding copyright ownership. | |
5 | * The ASF licenses this file to You under the Apache License, Version 2.0 | |
6 | * (the "License"); you may not use this file except in compliance with | |
7 | * the License. You may obtain a copy of the License at | |
8 | * | |
9 | * http://www.apache.org/licenses/LICENSE-2.0 | |
10 | * | |
11 | * Unless required by applicable law or agreed to in writing, software | |
12 | * distributed under the License is distributed on an "AS IS" BASIS, | |
13 | * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. | |
14 | * See the License for the specific language governing permissions and | |
15 | * limitations under the License. | |
16 | */ | |
17 | package org.apache.commons.dbutils.handlers; | |
18 | ||
19 | import java.sql.ResultSet; | |
20 | import java.sql.SQLException; | |
21 | ||
22 | import org.apache.commons.dbutils.ResultSetHandler; | |
23 | ||
24 | /** | |
25 | * <code>ResultSetHandler</code> implementation that converts one | |
26 | * <code>ResultSet</code> column into an Object. This class is thread safe. | |
27 | * | |
28 | * @see org.apache.commons.dbutils.ResultSetHandler | |
29 | */ | |
30 | public class ScalarHandler implements ResultSetHandler { | |
31 | ||
32 | /** | |
33 | * The column number to retrieve. | |
34 | */ | |
35 | private final int columnIndex; | |
36 | ||
37 | /** | |
38 | * The column name to retrieve. Either columnName or columnIndex | |
39 | * will be used but never both. | |
40 | */ | |
41 | private final String columnName; | |
42 | ||
43 | /** | |
44 | * Creates a new instance of ScalarHandler. The first column will | |
45 | * be returned from <code>handle()</code>. | |
46 | */ | |
47 | public ScalarHandler() { | |
48 | 0 | this(1, null); |
49 | 0 | } |
50 | ||
51 | /** | |
52 | * Creates a new instance of ScalarHandler. | |
53 | * | |
54 | * @param columnIndex The index of the column to retrieve from the | |
55 | * <code>ResultSet</code>. | |
56 | */ | |
57 | public ScalarHandler(int columnIndex) { | |
58 | 0 | this(columnIndex, null); |
59 | 0 | } |
60 | ||
61 | /** | |
62 | * Creates a new instance of ScalarHandler. | |
63 | * | |
64 | * @param columnName The name of the column to retrieve from the | |
65 | * <code>ResultSet</code>. | |
66 | */ | |
67 | public ScalarHandler(String columnName) { | |
68 | 0 | this(1, columnName); |
69 | 0 | } |
70 | ||
71 | // Helper constructor | |
72 | 0 | private ScalarHandler(int columnIndex, String columnName){ |
73 | 0 | this.columnIndex = columnIndex; |
74 | 0 | this.columnName = columnName; |
75 | 0 | } |
76 | ||
77 | /** | |
78 | * Returns one <code>ResultSet</code> column as an object via the | |
79 | * <code>ResultSet.getObject()</code> method that performs type | |
80 | * conversions. | |
81 | * | |
82 | * @return The column or <code>null</code> if there are no rows in | |
83 | * the <code>ResultSet</code>. | |
84 | * | |
85 | * @throws SQLException if a database access error occurs | |
86 | * | |
87 | * @see org.apache.commons.dbutils.ResultSetHandler#handle(java.sql.ResultSet) | |
88 | */ | |
89 | public Object handle(ResultSet rs) throws SQLException { | |
90 | ||
91 | 0 | if (rs.next()) { |
92 | 0 | if (this.columnName == null) { |
93 | 0 | return rs.getObject(this.columnIndex); |
94 | } else { | |
95 | 0 | return rs.getObject(this.columnName); |
96 | } | |
97 | ||
98 | } else { | |
99 | 0 | return null; |
100 | } | |
101 | } | |
102 | } |