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Java > Open Source Codes > org > apache > juddi > validator > ValidatorFactory


1 /*
2  * Copyright 2001-2004 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 package org.apache.juddi.validator;
17
18 import org.apache.commons.logging.Log;
19 import org.apache.commons.logging.LogFactory;
20 import org.apache.juddi.datatype.CategoryBag;
21 import org.apache.juddi.util.Config;
22 import org.apache.juddi.util.Loader;
23
24 /**
25  * Implementation of Factory pattern used to create an implementation of
26  * the org.apache.juddi.validation.Validation interface.
27  *
28  * The name of the Validation implementation to create is passed to the
29  * getValidation method. If a null value is passed then the default
30  * Validation implementation "org.apache.juddi.validation.DefaultValidation"
31  * is created.
32  *
33  * @author Steve Viens (sviens@apache.org)
34  */
35 public class ValidatorFactory
36 {
37   // private reference to the jUDDI logger
38 private static Log log = LogFactory.getLog(ValidatorFactory.class);
39
40   // Validation property key & default implementation
41 private static final String JavaDoc IMPL_KEY = "juddi.validation";
42   private static final String JavaDoc DEFAULT_IMPL = "org.apache.juddi.validation.DefaultValidation";
43
44   // the shared Validation instance
45 private static Validator validation = null;
46
47   /**
48    * Returns a new instance of a ValidationFactory.
49    *
50    * @return Validation
51    */
52   public static Validator getValidation()
53   {
54     if (validation == null)
55       validation = createValidation();
56     return validation;
57   }
58
59   /**
60    * Returns a new instance of a Validation.
61    *
62    * @return Validation
63    */
64   private static synchronized Validator createValidation()
65   {
66     if (validation != null)
67       return validation;
68
69     // grab class name of the Validation implementation to create
70 String JavaDoc className = Config.getStringProperty(IMPL_KEY,DEFAULT_IMPL);
71
72     // write the Validation implementation name to the log
73 log.debug("Validation Implementation = " + className);
74
75     Class JavaDoc implClass = null;
76     try
77     {
78       // Use Loader to locate & load the Validation implementation
79 implClass = Loader.getClassForName(className);
80     }
81     catch(ClassNotFoundException JavaDoc e)
82     {
83       log.error("The specified Validation class '" + className +
84         "' was not found in classpath.");
85       log.error(e);
86     }
87
88     try
89     {
90       // try to instantiate the Validation implementation
91 validation = (Validator)implClass.newInstance();
92     }
93     catch(Exception JavaDoc e)
94     {
95       log.error("Exception while attempting to instantiate the " +
96         "implementation of Validation: " + implClass.getName() +
97         "\n" + e.getMessage());
98       log.error(e);
99     }
100
101     return validation;
102   }
103
104
105   /***************************************************************************/
106   /***************************** TEST DRIVER *********************************/
107   /***************************************************************************/
108
109
110   public static void main(String JavaDoc[] args)
111     throws Exception JavaDoc
112   {
113       Validator validation = ValidatorFactory.getValidation();
114       if (validation != null)
115       {
116         System.out.println("Got a Validation instance: "+validation.getClass().getName());
117
118         if (validation.validate(new CategoryBag()))
119           System.out.println("The objct was successfully validated.");
120         else
121           System.out.println("Sorry validation failed.");
122       }
123       else
124         System.out.println("Couldn't get a Validation instance.");
125   }
126 }
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