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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   * TSVParser is used to parse a stream with tab-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 TSV 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 $tsvfile)
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   * @version $Id: TSVParser.java 534527 2007-05-02 16:10:59Z tv $
49   */
50  public class TSVParser extends DataStreamParser
51  {
52      /***
53       * Create a new TSVParser instance. Requires a Reader to read the
54       * tab-separated values from. The column headers must be set
55       * independently either explicitly, or by reading the first line
56       * of the TSV values.
57       *
58       * @param in the input reader.
59       */
60      public TSVParser(Reader in)
61      {
62          super(in, null, null);
63      }
64  
65      /***
66       * Create a new TSVParser instance. Requires a Reader to read the
67       * tab-separated values from, and a list of column names.
68       *
69       * @param in the input reader.
70       * @param columnNames a list of column names.
71       */
72      public TSVParser(Reader in, List columnNames)
73      {
74          super(in, columnNames, null);
75      }
76  
77      /***
78       * Create a new TSVParser instance. Requires a Reader to read the
79       * tab-separated values from, a list of column names and a
80       * character encoding.
81       *
82       * @param in the input reader.
83       * @param columnNames a list of column names.
84       * @param characterEncoding the character encoding of the input.
85       */
86      public TSVParser(Reader in, List columnNames, String characterEncoding)
87      {
88          super(in, columnNames, characterEncoding);
89      }
90  
91      /***
92       * Initialize the StreamTokenizer instance used to read the lines
93       * from the input reader.
94       * It is now only needed to set the fieldSeparator
95       */
96      protected void initTokenizer(StreamTokenizer tokenizer)
97      {
98          super.initTokenizer(tokenizer);
99          // set the field separator to tabs.
100         super.setFieldSeparator('\t');
101     }
102 }