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.commons.cli;
19
20 import java.io.File;
21 import java.io.FileInputStream;
22 import java.net.URL;
23 import java.util.Date;
24
25 /**
26 * <p>Allows Options to be created from a single String.
27 * The pattern contains various single character flags and via
28 * an optional punctuation character, their expected type.
29 * </p>
30 *
31 * <table border="1">
32 * <caption>Overview of PatternOptionBuilder patterns</caption>
33 * <tr><td>a</td><td>-a flag</td></tr>
34 * <tr><td>b@</td><td>-b [classname]</td></tr>
35 * <tr><td>c></td><td>-c [filename]</td></tr>
36 * <tr><td>d+</td><td>-d [classname] (creates object via empty constructor)</td></tr>
37 * <tr><td>e%</td><td>-e [number] (creates Double/Long instance depending on existing of a '.')</td></tr>
38 * <tr><td>f/</td><td>-f [url]</td></tr>
39 * <tr><td>g:</td><td>-g [string]</td></tr>
40 * </table>
41 *
42 * <p>
43 * For example, the following allows command line flags of '-v -p string-value -f /dir/file'.
44 * The exclamation mark precede a mandatory option.
45 * </p>
46 *
47 * <pre>
48 * Options options = PatternOptionBuilder.parsePattern("vp:!f/");
49 * </pre>
50 *
51 * <p>
52 * TODO: These need to break out to OptionType and also to be pluggable.
53 * </p>
54 *
55 * @version $Id$
56 */
57 public class PatternOptionBuilder
58 {
59 /** String class */
60 public static final Class<String> STRING_VALUE = String.class;
61
62 /** Object class */
63 public static final Class<Object> OBJECT_VALUE = Object.class;
64
65 /** Number class */
66 public static final Class<Number> NUMBER_VALUE = Number.class;
67
68 /** Date class */
69 public static final Class<Date> DATE_VALUE = Date.class;
70
71 /** Class class */
72 public static final Class<?> CLASS_VALUE = Class.class;
73
74 /// can we do this one??
75 // is meant to check that the file exists, else it errors.
76 // ie) it's for reading not writing.
77
78 /** FileInputStream class */
79 public static final Class<FileInputStream> EXISTING_FILE_VALUE = FileInputStream.class;
80
81 /** File class */
82 public static final Class<File> FILE_VALUE = File.class;
83
84 /** File array class */
85 public static final Class<File[]> FILES_VALUE = File[].class;
86
87 /** URL class */
88 public static final Class<URL> URL_VALUE = URL.class;
89
90 /**
91 * Retrieve the class that <code>ch</code> represents.
92 *
93 * @param ch the specified character
94 * @return The class that <code>ch</code> represents
95 */
96 public static Object getValueClass(final char ch)
97 {
98 switch (ch)
99 {
100 case '@':
101 return PatternOptionBuilder.OBJECT_VALUE;
102 case ':':
103 return PatternOptionBuilder.STRING_VALUE;
104 case '%':
105 return PatternOptionBuilder.NUMBER_VALUE;
106 case '+':
107 return PatternOptionBuilder.CLASS_VALUE;
108 case '#':
109 return PatternOptionBuilder.DATE_VALUE;
110 case '<':
111 return PatternOptionBuilder.EXISTING_FILE_VALUE;
112 case '>':
113 return PatternOptionBuilder.FILE_VALUE;
114 case '*':
115 return PatternOptionBuilder.FILES_VALUE;
116 case '/':
117 return PatternOptionBuilder.URL_VALUE;
118 }
119
120 return null;
121 }
122
123 /**
124 * Returns whether <code>ch</code> is a value code, i.e.
125 * whether it represents a class in a pattern.
126 *
127 * @param ch the specified character
128 * @return true if <code>ch</code> is a value code, otherwise false.
129 */
130 public static boolean isValueCode(final char ch)
131 {
132 return ch == '@'
133 || ch == ':'
134 || ch == '%'
135 || ch == '+'
136 || ch == '#'
137 || ch == '<'
138 || ch == '>'
139 || ch == '*'
140 || ch == '/'
141 || ch == '!';
142 }
143
144 /**
145 * Returns the {@link Options} instance represented by <code>pattern</code>.
146 *
147 * @param pattern the pattern string
148 * @return The {@link Options} instance
149 */
150 public static Options parsePattern(final String pattern)
151 {
152 char opt = ' ';
153 boolean required = false;
154 Class<?> type = null;
155
156 final Options options = new Options();
157
158 for (int i = 0; i < pattern.length(); i++)
159 {
160 final char ch = pattern.charAt(i);
161
162 // a value code comes after an option and specifies
163 // details about it
164 if (!isValueCode(ch))
165 {
166 if (opt != ' ')
167 {
168 final Option option = Option.builder(String.valueOf(opt))
169 .hasArg(type != null)
170 .required(required)
171 .type(type)
172 .build();
173
174 // we have a previous one to deal with
175 options.addOption(option);
176 required = false;
177 type = null;
178 opt = ' ';
179 }
180
181 opt = ch;
182 }
183 else if (ch == '!')
184 {
185 required = true;
186 }
187 else
188 {
189 type = (Class<?>) getValueClass(ch);
190 }
191 }
192
193 if (opt != ' ')
194 {
195 final Option option = Option.builder(String.valueOf(opt))
196 .hasArg(type != null)
197 .required(required)
198 .type(type)
199 .build();
200
201 // we have a final one to deal with
202 options.addOption(option);
203 }
204
205 return options;
206 }
207 }