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  
18  package org.apache.commons.cli;
19  
20  import java.io.File;
21  
22  import java.net.MalformedURLException;
23  import java.net.URL;
24  
25  import java.util.Date;
26  
27  /**
28    * This is a temporary implementation. TypeHandler will handle the
29    * pluggableness of OptionTypes and it will direct all of these types
30    * of conversion functionalities to ConvertUtils component in Commons
31    * already. BeanUtils I think.
32    *
33    * @version $Revision: 741425 $, $Date: 2009-02-06 06:10:54 +0000 (Fri, 06 Feb 2009) $
34    */
35  public class TypeHandler
36  {
37      /**
38       * Returns the <code>Object</code> of type <code>obj</code>
39       * with the value of <code>str</code>.
40       *
41       * @param str the command line value
42       * @param obj the type of argument
43       * @return The instance of <code>obj</code> initialised with
44       * the value of <code>str</code>.
45       */
46      public static Object createValue(String str, Object obj)
47      throws ParseException
48      {
49          return createValue(str, (Class) obj);
50      }
51  
52      /**
53       * Returns the <code>Object</code> of type <code>clazz</code>
54       * with the value of <code>str</code>.
55       *
56       * @param str the command line value
57       * @param clazz the type of argument
58       * @return The instance of <code>clazz</code> initialised with
59       * the value of <code>str</code>.
60       */
61      public static Object createValue(String str, Class clazz)
62      throws ParseException
63      {
64          if (PatternOptionBuilder.STRING_VALUE == clazz)
65          {
66              return str;
67          }
68          else if (PatternOptionBuilder.OBJECT_VALUE == clazz)
69          {
70              return createObject(str);
71          }
72          else if (PatternOptionBuilder.NUMBER_VALUE == clazz)
73          {
74              return createNumber(str);
75          }
76          else if (PatternOptionBuilder.DATE_VALUE == clazz)
77          {
78              return createDate(str);
79          }
80          else if (PatternOptionBuilder.CLASS_VALUE == clazz)
81          {
82              return createClass(str);
83          }
84          else if (PatternOptionBuilder.FILE_VALUE == clazz)
85          {
86              return createFile(str);
87          }
88          else if (PatternOptionBuilder.EXISTING_FILE_VALUE == clazz)
89          {
90              return createFile(str);
91          }
92          else if (PatternOptionBuilder.FILES_VALUE == clazz)
93          {
94              return createFiles(str);
95          }
96          else if (PatternOptionBuilder.URL_VALUE == clazz)
97          {
98              return createURL(str);
99          }
100         else
101         {
102             return null;
103         }
104     }
105 
106     /**
107       * Create an Object from the classname and empty constructor.
108       *
109       * @param classname the argument value
110       * @return the initialised object, or null if it couldn't create
111       * the Object.
112       */
113     public static Object createObject(String classname)
114     throws ParseException
115     {
116         Class cl = null;
117 
118         try
119         {
120             cl = Class.forName(classname);
121         }
122         catch (ClassNotFoundException cnfe)
123         {
124             throw new ParseException("Unable to find the class: " + classname);
125         }
126 
127         Object instance = null;
128 
129         try
130         {
131             instance = cl.newInstance();
132         }
133         catch (Exception e)
134         {
135             throw new ParseException(e.getClass().getName() + "; Unable to create an instance of: " + classname);
136         }
137 
138         return instance;
139     }
140 
141     /**
142      * Create a number from a String. If a . is present, it creates a
143      * Double, otherwise a Long.
144      *
145      * @param str the value
146      * @return the number represented by <code>str</code>, if <code>str</code>
147      * is not a number, null is returned.
148      */
149     public static Number createNumber(String str)
150     throws ParseException
151     {
152         try
153         {
154             if (str.indexOf('.') != -1)
155             {
156                 return Double.valueOf(str);
157             }
158             else
159             {
160                 return Long.valueOf(str);
161             }
162         }
163         catch (NumberFormatException e)
164         {
165             throw new ParseException(e.getMessage());
166         }
167     }
168 
169     /**
170      * Returns the class whose name is <code>classname</code>.
171      *
172      * @param classname the class name
173      * @return The class if it is found, otherwise return null
174      */
175     public static Class createClass(String classname)
176     throws ParseException
177     {
178         try
179         {
180             return Class.forName(classname);
181         }
182         catch (ClassNotFoundException e)
183         {
184             throw new ParseException("Unable to find the class: " + classname);
185         }
186     }
187 
188     /**
189      * Returns the date represented by <code>str</code>.
190      *
191      * @param str the date string
192      * @return The date if <code>str</code> is a valid date string,
193      * otherwise return null.
194      */
195     public static Date createDate(String str)
196     throws ParseException
197     {
198         throw new UnsupportedOperationException("Not yet implemented");
199     }
200 
201     /**
202      * Returns the URL represented by <code>str</code>.
203      *
204      * @param str the URL string
205      * @return The URL is <code>str</code> is well-formed, otherwise
206      * return null.
207      */
208     public static URL createURL(String str)
209     throws ParseException
210     {
211         try
212         {
213             return new URL(str);
214         }
215         catch (MalformedURLException e)
216         {
217             throw new ParseException("Unable to parse the URL: " + str);
218         }
219     }
220 
221     /**
222      * Returns the File represented by <code>str</code>.
223      *
224      * @param str the File location
225      * @return The file represented by <code>str</code>.
226      */
227     public static File createFile(String str)
228     throws ParseException
229     {
230         return new File(str);
231     }
232 
233     /**
234      * Returns the File[] represented by <code>str</code>.
235      *
236      * @param str the paths to the files
237      * @return The File[] represented by <code>str</code>.
238      */
239     public static File[] createFiles(String str)
240     throws ParseException
241     {
242         // to implement/port:
243         //        return FileW.findFiles(str);
244         throw new UnsupportedOperationException("Not yet implemented");
245     }
246 }