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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;
18  
19  import java.sql.ResultSet;
20  import java.sql.ResultSetMetaData;
21  import java.sql.SQLException;
22  import java.util.HashMap;
23  import java.util.Iterator;
24  import java.util.List;
25  import java.util.Map;
26  
27  /**
28   * Basic implementation of the <code>RowProcessor</code> interface.
29   * 
30   * <p>
31   * This class is thread-safe.
32   * </p>
33   * 
34   * @see RowProcessor
35   */
36  public class BasicRowProcessor implements RowProcessor {
37  
38      /**
39       * The default BeanProcessor instance to use if not supplied in the
40       * constructor.
41       */
42      private static final BeanProcessor defaultConvert = new BeanProcessor();
43  
44      /**
45       * The Singleton instance of this class.
46       */
47      private static final BasicRowProcessor instance = new BasicRowProcessor();
48  
49      /**
50       * Returns the Singleton instance of this class.
51       *
52       * @return The single instance of this class.
53       * @deprecated Create instances with the constructors instead.  This will 
54       * be removed after DbUtils 1.1.
55       */
56      public static BasicRowProcessor instance() {
57          return instance;
58      }
59  
60      /**
61       * Use this to process beans.
62       */
63      private BeanProcessor convert = null;
64  
65      /**
66       * BasicRowProcessor constructor.  Bean processing defaults to a 
67       * BeanProcessor instance.
68       */
69      public BasicRowProcessor() {
70          this(defaultConvert);
71      }
72      
73      /**
74       * BasicRowProcessor constructor.
75       * @param convert The BeanProcessor to use when converting columns to 
76       * bean properties.
77       * @since DbUtils 1.1
78       */
79      public BasicRowProcessor(BeanProcessor convert) {
80          super();
81          this.convert = convert;
82      }
83  
84      /**
85       * Convert a <code>ResultSet</code> row into an <code>Object[]</code>.
86       * This implementation copies column values into the array in the same 
87       * order they're returned from the <code>ResultSet</code>.  Array elements
88       * will be set to <code>null</code> if the column was SQL NULL.
89       *
90       * @see org.apache.commons.dbutils.RowProcessor#toArray(java.sql.ResultSet)
91       */
92      public Object[] toArray(ResultSet rs) throws SQLException {
93          ResultSetMetaData meta = rs.getMetaData();
94          int cols = meta.getColumnCount();
95          Object[] result = new Object[cols];
96  
97          for (int i = 0; i < cols; i++) {
98              result[i] = rs.getObject(i + 1);
99          }
100 
101         return result;
102     }
103 
104     /**
105      * Convert a <code>ResultSet</code> row into a JavaBean.  This 
106      * implementation delegates to a BeanProcessor instance.
107      * @see org.apache.commons.dbutils.RowProcessor#toBean(java.sql.ResultSet, java.lang.Class)
108      * @see org.apache.commons.dbutils.BeanProcessor#toBean(java.sql.ResultSet, java.lang.Class) 
109      */
110     public Object toBean(ResultSet rs, Class type) throws SQLException {
111         return this.convert.toBean(rs, type);
112     }
113 
114     /**
115      * Convert a <code>ResultSet</code> into a <code>List</code> of JavaBeans.  
116      * This implementation delegates to a BeanProcessor instance. 
117      * @see org.apache.commons.dbutils.RowProcessor#toBeanList(java.sql.ResultSet, java.lang.Class)
118      * @see org.apache.commons.dbutils.BeanProcessor#toBeanList(java.sql.ResultSet, java.lang.Class)
119      */
120     public List toBeanList(ResultSet rs, Class type) throws SQLException {
121         return this.convert.toBeanList(rs, type);
122     }
123 
124     /**
125      * Convert a <code>ResultSet</code> row into a <code>Map</code>.  This 
126      * implementation returns a <code>Map</code> with case insensitive column
127      * names as keys.  Calls to <code>map.get("COL")</code> and 
128      * <code>map.get("col")</code> return the same value.
129      * @see org.apache.commons.dbutils.RowProcessor#toMap(java.sql.ResultSet)
130      */
131     public Map toMap(ResultSet rs) throws SQLException {
132         Map result = new CaseInsensitiveHashMap();
133         ResultSetMetaData rsmd = rs.getMetaData();
134         int cols = rsmd.getColumnCount();
135 
136         for (int i = 1; i <= cols; i++) {
137             result.put(rsmd.getColumnName(i), rs.getObject(i));
138         }
139 
140         return result;
141     }
142     
143     /**
144      * A Map that converts all keys to lowercase Strings for case insensitive
145      * lookups.  This is needed for the toMap() implementation because 
146      * databases don't consistenly handle the casing of column names. 
147      */
148     private static class CaseInsensitiveHashMap extends HashMap {
149 
150         /**
151          * @see java.util.Map#containsKey(java.lang.Object)
152          */
153         public boolean containsKey(Object key) {
154             return super.containsKey(key.toString().toLowerCase());
155         }
156 
157         /**
158          * @see java.util.Map#get(java.lang.Object)
159          */
160         public Object get(Object key) {
161             return super.get(key.toString().toLowerCase());
162         }
163 
164         /**
165          * @see java.util.Map#put(java.lang.Object, java.lang.Object)
166          */
167         public Object put(Object key, Object value) {
168             return super.put(key.toString().toLowerCase(), value);
169         }
170 
171         /**
172          * @see java.util.Map#putAll(java.util.Map)
173          */
174         public void putAll(Map m) {
175             Iterator iter = m.keySet().iterator();
176             while (iter.hasNext()) {
177                 Object key = iter.next();
178                 Object value = m.get(key);
179                 this.put(key, value);
180             }
181         }
182 
183         /**
184          * @see java.util.Map#remove(java.lang.Object)
185          */
186         public Object remove(Object key) {
187             return super.remove(key.toString().toLowerCase());
188         }
189     }
190     
191 }