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1   package org.apache.turbine.util.parser;
2   
3   /*
4    * Licensed to the Apache Software Foundation (ASF) under one
5    * or more contributor license agreements.  See the NOTICE file
6    * distributed with this work for additional information
7    * regarding copyright ownership.  The ASF licenses this file
8    * to you under the Apache License, Version 2.0 (the
9    * "License"); you may not use this file except in compliance
10   * with the License.  You may obtain a copy of the License at
11   *
12   *   http://www.apache.org/licenses/LICENSE-2.0
13   *
14   * Unless required by applicable law or agreed to in writing,
15   * software distributed under the License is distributed on an
16   * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
17   * KIND, either express or implied.  See the License for the
18   * specific language governing permissions and limitations
19   * under the License.
20   */
21  
22  import java.io.Reader;
23  import java.io.StreamTokenizer;
24  import java.util.List;
25  
26  /***
27   * CSVParser is used to parse a stream with comma-separated values and
28   * generate ParameterParser objects which can be used to
29   * extract the values in the desired type.
30   *
31   * <p>The class extends the abstract class DataStreamParser and implements
32   * initTokenizer with suitable values for CSV files to provide this
33   * functionality.
34   *
35   * <p>The class (indirectly through DataStreamParser) implements the
36   * java.util.Iterator interface for convenience.
37   * This allows simple use in a Velocity template for example:
38   *
39   * <pre>
40   * #foreach ($row in $csvfile)
41   *   Name: $row.Name
42   *   Description: $row.Description
43   * #end
44   * </pre>
45   *
46   * @author <a href="mailto:sean@informage.net">Sean Legassick</a>
47   * @author <a href="mailto:martin@mvdb.net">Martin van den Bemt</a>
48   * @author <a href="mailto:hps@intermeta.de">Henning P. Schmiedehausen</a>
49   * @version $Id: CSVParser.java 534527 2007-05-02 16:10:59Z tv $
50   */
51  public class CSVParser extends DataStreamParser
52  {
53      /***
54       * Create a new CSVParser instance. Requires a Reader to read the
55       * comma-separated values from. The column headers must be set
56       * independently either explicitly, or by reading the first line
57       * of the CSV values.
58       *
59       * @param in the input reader.
60       */
61      public CSVParser(Reader in)
62      {
63          super(in, null, null);
64      }
65  
66      /***
67       * Create a new CSVParser instance. Requires a Reader to read the
68       * comma-separated values from, and a list of column names.
69       *
70       * @param in the input reader.
71       * @param columnNames a list of column names.
72       */
73      public CSVParser(Reader in, List columnNames)
74      {
75          super(in, columnNames, null);
76      }
77  
78      /***
79       * Create a new CSVParser instance. Requires a Reader to read the
80       * comma-separated values from, a list of column names and a
81       * character encoding.
82       *
83       * @param in the input reader.
84       * @param columnNames a list of column names.
85       * @param characterEncoding the character encoding of the input.
86       */
87      public CSVParser(Reader in, List columnNames, String characterEncoding)
88      {
89          super(in, columnNames, characterEncoding);
90      }
91  
92      /***
93       * Initialize the StreamTokenizer instance used to read the lines
94       * from the input reader.
95       * It is now only needed to set the fieldSeparator
96       */
97      protected void initTokenizer(StreamTokenizer tokenizer)
98      {
99          // everything is default so let's call super
100         super.initTokenizer(tokenizer);
101         // set the field separator to comma
102         super.setFieldSeparator(',');
103 
104     }
105 }