DefaultComponentDescriptor


1   /*
2    * The contents of this file are subject to the terms of the Common Development
3    * and Distribution License (the License). You may not use this file except in
4    * compliance with the License.
5    *
6    * You can obtain a copy of the License at http://www.netbeans.org/cddl.html
7    * or http://www.netbeans.org/cddl.txt.
8    *
9    * When distributing Covered Code, include this CDDL Header Notice in each file
10   * and include the License file at http://www.netbeans.org/cddl.txt.
11   * If applicable, add the following below the CDDL Header, with the fields
12   * enclosed by brackets [] replaced by your own identifying information:
13   * "Portions Copyrighted [year] [name of copyright owner]"
14   *
15   * The Original Software is NetBeans. The Initial Developer of the Original
16   * Software is Sun Microsystems, Inc. Portions Copyright 1997-2006 Sun
17   * Microsystems, Inc. All Rights Reserved.
18   */
19  
20  package org.netbeans.modules.welcome.content;
21  
22  import java.awt.Component  ;
23  import java.lang.reflect.InvocationTargetException  ;
24  import java.lang.reflect.Method  ;
25  import javax.swing.JLabel  ;
26  import org.openide.ErrorManager;
27  import org.openide.util.Lookup;
28  
29  /**
30   *
31   * @author S. Aubrecht
32   */
33  class DefaultComponentDescriptor extends ComponentDescriptor {
34  
35      /** Creates a new instance of DefaultComponentInfo */
36      public DefaultComponentDescriptor( String   id ) {
37          super( id );
38      }
39  
40      public Component   construct() {
41          try {
42              String   clz = getClassName();
43              if (clz != null) {
44                  return (Component  )loadClass(clz).newInstance();
45              }
46              else {
47                  return newFromFactory(getMethod());
48              }
49              
50          } catch( Exception   e ) {
51              ErrorManager.getDefault().notify( ErrorManager.INFORMATIONAL, e );
52          }
53          return new JLabel  ( "<html>Cannot create component from <br>" + getClassName() ); // NOI18N
54      }
55      
56      private Class   loadClass(final String   clz) throws ClassNotFoundException   {
57          ClassLoader   loader = (ClassLoader  )Lookup.getDefault().lookup( ClassLoader  .class );
58          if( null == loader )
59              loader = ClassLoader.getSystemClassLoader();
60          
61          Class   clazz = Class.forName( clz, true, loader );
62          return clazz;
63      }
64      
65      private Component   newFromFactory (String   methodName) 
66              throws ClassNotFoundException  , NoSuchMethodException  , 
67              IllegalAccessException  , InvocationTargetException   {
68          assert methodName != null: "neither class name nor factory method is specified in "+this;
69          int idx = methodName.lastIndexOf('.');
70          Class   clz = loadClass( methodName.substring(0, idx));
71          Method   m = clz.getMethod(methodName.substring(idx+1), new Class  [] {});
72          Object   obj = m.invoke(null, new Object   [] {});
73          return (Component  )obj;
74      }
75  }
76
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