ClassUtils


1   /*
2    * Copyright 2003,2004 The Apache Software Foundation.
3    * 
4    * Licensed under the Apache License, Version 2.0 (the "License");
5    * you may not use this file except in compliance with the License.
6    * You may obtain a copy of the License at
7    * 
8    *      http://www.apache.org/licenses/LICENSE-2.0
9    * 
10   * Unless required by applicable law or agreed to in writing, software
11   * distributed under the License is distributed on an "AS IS" BASIS,
12   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13   * See the License for the specific language governing permissions and
14   * limitations under the License.
15   */
16  
17  package org.apache.struts.chain.util;
18  
19  /**
20   * <p>Utility methods to load application classes and create instances.</p>
21   *
22   * @author Craig R. McClanahan
23   * @version $Rev: 54933 $ $Date: 2004-10-16 18:04:52 +0100 (Sat, 16 Oct 2004) $
24   */
25  
26  public final class ClassUtils {
27  
28  
29      // ---------------------------------------------------------- Static Methods
30  
31  
32      /**
33       * <p>Return the <code>Class</code> object for the specified fully
34       * qualified class name, from this web application's class loader.
35       *
36       * @param className Fully qualified class name
37       *
38       * @exception ClassNotFoundException if the specified class cannot
39       *  be loaded
40       */
41      public static Class   getApplicationClass(String   className)
42          throws ClassNotFoundException   {
43  
44          if (className == null) {
45              throw new NullPointerException  ("getApplicationClass called with null className");
46          }
47  
48          ClassLoader   classLoader =
49              Thread.currentThread().getContextClassLoader();
50          if (classLoader == null) {
51              classLoader = ClassUtils.class.getClassLoader();
52          }
53          return (classLoader.loadClass(className));
54  
55      }
56  
57  
58      /**
59       * <p>Return a new instance of the specified fully qualified class name,
60       * after loading the class (if necessary) from this web application's
61       * class loader.</p>
62       *
63       * @param className Fully qualified class name
64       *
65       * @exception ClassNotFoundException if the specified class cannot
66       *  be loaded
67       * @exception IllegalAccessException if this class is not concrete
68       * @exception InstantiationException if this class has no zero-arguments
69       *  constructor
70       */
71      public static Object   getApplicationInstance(String   className)
72          throws ClassNotFoundException  , IllegalAccessException  ,
73                 InstantiationException   {
74  
75          return (getApplicationClass(className).newInstance());
76  
77      }
78  
79  
80  
81  }
82
A to Z: JavaDoc & Examples Daily Java News & Articles Open Source Projects Open Source Codes Free Computer Books Remove Frame
Popular Tags