001/**
002 * Licensed to the Apache Software Foundation (ASF) under one or more
003 * contributor license agreements.  See the NOTICE file distributed with
004 * this work for additional information regarding copyright ownership.
005 * The ASF licenses this file to You under the Apache License, Version 2.0
006 * (the "License"); you may not use this file except in compliance with
007 * the License.  You may obtain a copy of the License at
008 *
009 *     http://www.apache.org/licenses/LICENSE-2.0
010 *
011 * Unless required by applicable law or agreed to in writing, software
012 * distributed under the License is distributed on an "AS IS" BASIS,
013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014 * See the License for the specific language governing permissions and
015 * limitations under the License.
016 */
017
018package org.apache.commons.cli;
019
020import java.io.File;
021
022import java.net.MalformedURLException;
023import java.net.URL;
024
025import java.util.Date;
026
027/**
028  * This is a temporary implementation. TypeHandler will handle the
029  * pluggableness of OptionTypes and it will direct all of these types
030  * of conversion functionalities to ConvertUtils component in Commons
031  * already. BeanUtils I think.
032  *
033  * @version $Revision: 741425 $, $Date: 2009-02-05 22:10:54 -0800 (Thu, 05 Feb 2009) $
034  */
035public class TypeHandler
036{
037    /**
038     * Returns the <code>Object</code> of type <code>obj</code>
039     * with the value of <code>str</code>.
040     *
041     * @param str the command line value
042     * @param obj the type of argument
043     * @return The instance of <code>obj</code> initialised with
044     * the value of <code>str</code>.
045     */
046    public static Object createValue(String str, Object obj)
047    throws ParseException
048    {
049        return createValue(str, (Class) obj);
050    }
051
052    /**
053     * Returns the <code>Object</code> of type <code>clazz</code>
054     * with the value of <code>str</code>.
055     *
056     * @param str the command line value
057     * @param clazz the type of argument
058     * @return The instance of <code>clazz</code> initialised with
059     * the value of <code>str</code>.
060     */
061    public static Object createValue(String str, Class clazz)
062    throws ParseException
063    {
064        if (PatternOptionBuilder.STRING_VALUE == clazz)
065        {
066            return str;
067        }
068        else if (PatternOptionBuilder.OBJECT_VALUE == clazz)
069        {
070            return createObject(str);
071        }
072        else if (PatternOptionBuilder.NUMBER_VALUE == clazz)
073        {
074            return createNumber(str);
075        }
076        else if (PatternOptionBuilder.DATE_VALUE == clazz)
077        {
078            return createDate(str);
079        }
080        else if (PatternOptionBuilder.CLASS_VALUE == clazz)
081        {
082            return createClass(str);
083        }
084        else if (PatternOptionBuilder.FILE_VALUE == clazz)
085        {
086            return createFile(str);
087        }
088        else if (PatternOptionBuilder.EXISTING_FILE_VALUE == clazz)
089        {
090            return createFile(str);
091        }
092        else if (PatternOptionBuilder.FILES_VALUE == clazz)
093        {
094            return createFiles(str);
095        }
096        else if (PatternOptionBuilder.URL_VALUE == clazz)
097        {
098            return createURL(str);
099        }
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}