##### Coverage Report - org.apache.any23.extractor.csv.CSVReaderBuilder

Classes in this File | Line Coverage | Branch Coverage | Complexity
CSVReaderBuilder |
0% | 0/46
0% | 0/24
| 3.4285714285714284;3.429

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 |  |
18 |  |
     package org.apache.any23.extractor.csv;
19 |  |
20 |  |
     import org.apache.any23.configuration.DefaultConfiguration;
21 |  |
     import org.apache.commons.csv.CSVParser;
22 |  |
     import org.apache.commons.csv.CSVStrategy;
23 |  |
24 |  |
     import java.io.IOException;
25 |  |
     import java.io.InputStream;
26 |  |
     import java.io.InputStreamReader;
27 |  |
28 |  |
     /**
29 |  |
      * This class is responsible to build a reader first guessing the configuration
30 |  |
      * from the file it self and then, if not successful, from the {@link org.apache.any23.configuration.DefaultConfiguration}.
31 |  |
      *
32 |  |
      * @author Davide Palmisano ( dpalmisano@gmail.com )
33 |  |
      * @author Michele Mostarda ( michele.mostarda@gmail.com )
34 |  |
      */
35 | 0 |
     public class CSVReaderBuilder {
36 |  |
37 |  |
         private static final String DEFAULT_FIELD_DELIMITER = ",";
38 |  |
39 |  |
         private static final String DEFAULT_COMMENT_DELIMITER = "#";
40 |  |
41 |  |
         public static final char NULL_CHAR = ' ';
42 |  |
43 | 0 |
         private static final char[] popularDelimiters = {'\t', '|', ',', ';'};
44 |  |
45 | 0 |
         private static DefaultConfiguration defaultConfiguration =
46 |  |
                 DefaultConfiguration.singleton();
47 |  |
48 |  |
         private static final CSVStrategy[] strategies;
49 |  |
50 |  |
         static {
51 | 0 |
             strategies = new CSVStrategy[ popularDelimiters.length + 1 ];
52 | 0 |
             strategies[0] = CSVStrategy.DEFAULT_STRATEGY;
53 | 0 |
             int index = 1;
54 | 0 |
             for(char dlmt : popularDelimiters) {
55 | 0 |
                 strategies[index++] = getCsvStrategy(dlmt, NULL_CHAR);
56 |  |
             }
57 | 0 |
         }
58 |  |
59 |  |
         /**
60 |  |
          * Builds a not <code>null</code> {@link org.apache.commons.csv.CSVParser} guessing
61 |  |
          * from the provided <i>CSV</i> file.
62 |  |
          *
63 |  |
          * @param is {@link InputStream} of the <i>CSV</i> file where guess the configuration.
64 |  |
          * @return a {@link CSVParser}
65 |  |
          * @throws java.io.IOException
66 |  |
          */
67 |  |
         public static CSVParser build(InputStream is) throws IOException {
68 | 0 |
             CSVStrategy bestStrategy = getBestStrategy(is);
69 | 0 |
             if(bestStrategy == null) bestStrategy = getCSVStrategyFromConfiguration();
70 | 0 |
             return new CSVParser( new InputStreamReader(is), bestStrategy );
71 |  |
         }
72 |  |
73 |  |
         /**
74 |  |
          * Checks whether the given input stream is a CSV or not.
75 |  |
          *
76 |  |
          * @param is input stream to be verified.
77 |  |
          * @return
78 |  |
          * @throws IOException
79 |  |
          */
80 |  |
         public static boolean isCSV(InputStream is) throws IOException {
81 | 0 |
             return getBestStrategy(is) != null;
82 |  |
         }
83 |  |
84 |  |
         private static CSVStrategy getBestStrategy(InputStream is) throws IOException {
85 | 0 |
             for( CSVStrategy strategy : strategies ) {
86 | 0 |
                 if( testStrategy(is, strategy) ) {
87 | 0 |
                     return strategy;
88 |  |
                 }
89 |  |
             }
90 | 0 |
             return null;
91 |  |
         }
92 |  |
93 |  |
         private static CSVStrategy getCsvStrategy(char delimiter, char comment) {
94 | 0 |
             return new CSVStrategy(delimiter, '\'', comment);
95 |  |
         }
96 |  |
97 |  |
         private static CSVStrategy getCSVStrategyFromConfiguration() {
98 | 0 |
             char fieldDelimiter = getCharValueFromConfiguration(
99 |  |
                     "any23.extraction.csv.field",
100 |  |
                     DEFAULT_FIELD_DELIMITER
101 |  |
             );
102 | 0 |
             char commentDelimiter = getCharValueFromConfiguration(
103 |  |
                     "any23.extraction.csv.comment",
104 |  |
                     DEFAULT_COMMENT_DELIMITER
105 |  |
             );
106 | 0 |
             return new CSVStrategy(fieldDelimiter, '\'', commentDelimiter);
107 |  |
         }
108 |  |
109 |  |
         private static char getCharValueFromConfiguration(String property, String defaultValue) {
110 | 0 |
             String delimiter = defaultConfiguration.getProperty(
111 |  |
                     property,
112 |  |
                     defaultValue
113 |  |
             );
114 | 0 |
             if (delimiter.length() != 1 || delimiter.equals("")) {
115 | 0 |
                 throw new RuntimeException(property + " value must be a single character");
116 |  |
             }
117 | 0 |
             return delimiter.charAt(0);
118 |  |
         }
119 |  |
120 |  |
         /**
121 |  |
          * make sure the reader has correct delimiter and quotation set.
122 |  |
          * Check first lines and make sure they have the same amount of columns and at least 2
123 |  |
          *
124 |  |
          * @param is input stream to be checked
125 |  |
          * @param strategy strategy to be verified.
126 |  |
          * @return
127 |  |
          * @throws IOException
128 |  |
          * @param is
129 |  |
          */
130 |  |
         private static boolean testStrategy(InputStream is, CSVStrategy strategy) throws IOException {
131 | 0 |
             final int MIN_COLUMNS = 2;
132 |  |
133 | 0 |
             is.mark(Integer.MAX_VALUE);
134 |  |
             try {
135 | 0 |
                 final CSVParser parser = new CSVParser(new InputStreamReader(is), strategy);
136 | 0 |
                 int linesToCheck = 5;
137 | 0 |
                 int headerColumnCount = -1;
138 | 0 |
                 while (linesToCheck > 0) {
139 |  |
                     String[] row;
140 | 0 |
                     row = parser.getLine();
141 | 0 |
                     if (row == null) {
142 | 0 |
                         break;
143 |  |
                     }
144 | 0 |
                     if (row.length < MIN_COLUMNS) {
145 | 0 |
                         return false;
146 |  |
                     }
147 | 0 |
                     if (headerColumnCount == -1) { // first row
148 | 0 |
                         headerColumnCount = row.length;
149 |  |
                     } else { // make sure rows have the same number of columns or one more than the header
150 | 0 |
                         if (row.length < headerColumnCount) {
151 | 0 |
                             return false;
152 | 0 |
                         } else if (row.length - 1 > headerColumnCount) {
153 | 0 |
                             return false;
154 |  |
                         }
155 |  |
                     }
156 | 0 |
                     linesToCheck--;
157 | 0 |
                 }
158 | 0 |
                 return true;
159 |  |
             } finally {
160 | 0 |
                 is.reset();
161 |  |
             }
162 |  |
         }
163 |  |
164 |  |
165 |  |
     }