View Javadoc

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.BasicRowProcessor;
23  import org.apache.commons.dbutils.ResultSetHandler;
24  import org.apache.commons.dbutils.RowProcessor;
25  
26  /**
27   * <code>ResultSetHandler</code> implementation that converts a 
28   * <code>ResultSet</code> into an <code>Object[]</code>. This class is 
29   * thread safe.
30   * 
31   * @see org.apache.commons.dbutils.ResultSetHandler
32   */
33  public class ArrayHandler implements ResultSetHandler {
34  
35      /**
36       * Singleton processor instance that handlers share to save memory.  Notice
37       * the default scoping to allow only classes in this package to use this
38       * instance.
39       */
40      static final RowProcessor ROW_PROCESSOR = new BasicRowProcessor();
41  
42      /**
43       * The RowProcessor implementation to use when converting rows 
44       * into arrays.
45       */
46      private RowProcessor convert = ROW_PROCESSOR;
47  
48      /** 
49       * Creates a new instance of ArrayHandler using a 
50       * <code>BasicRowProcessor</code> for conversion.
51       */
52      public ArrayHandler() {
53          super();
54      }
55  
56      /** 
57       * Creates a new instance of ArrayHandler.
58       * 
59       * @param convert The <code>RowProcessor</code> implementation 
60       * to use when converting rows into arrays.
61       */
62      public ArrayHandler(RowProcessor convert) {
63          super();
64          this.convert = convert;
65      }
66  
67      /**
68       * Places the column values from the first row in an <code>Object[]</code>.
69       * 
70       * @return An Object[] or <code>null</code> if there are no rows in the
71       * <code>ResultSet</code>.
72       * 
73       * @throws SQLException if a database access error occurs
74       * @see org.apache.commons.dbutils.ResultSetHandler#handle(java.sql.ResultSet)
75       */
76      public Object handle(ResultSet rs) throws SQLException {
77          return rs.next() ? this.convert.toArray(rs) : null;
78      }
79  
80  }