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Source code: org/apache/axis/encoding/ser/BaseSerializerFactory.java


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  
17  package org.apache.axis.encoding.ser;
18  
19  import org.apache.axis.Constants;
20  import org.apache.axis.components.logger.LogFactory;
21  import org.apache.axis.encoding.Serializer;
22  import org.apache.axis.encoding.SerializerFactory;
23  import org.apache.axis.utils.Messages;
24  import org.apache.commons.logging.Log;
25  
26  import javax.xml.namespace.QName;
27  import javax.xml.rpc.JAXRPCException;
28  import java.lang.reflect.Constructor;
29  import java.lang.reflect.InvocationTargetException;
30  import java.lang.reflect.Method;
31  import java.util.Iterator;
32  import java.util.Vector;
33  
34  /**
35   * Base class for Axis Serialization Factory classes for code reuse
36   *
37   * @author Rich Scheuerle <scheu@us.ibm.com>
38   */
39  public abstract class BaseSerializerFactory extends BaseFactory
40      implements SerializerFactory {
41  
42      protected static Log log =
43              LogFactory.getLog(BaseSerializerFactory.class.getName());
44      
45      transient static Vector mechanisms = null;
46      
47      protected Class serClass = null;
48      protected QName xmlType = null;
49      protected Class javaType = null;
50  
51      transient protected Serializer ser = null;
52      transient protected Constructor serClassConstructor = null;
53      transient protected Method getSerializer = null;
54  
55      /**
56       * Constructor
57       * @param serClass is the class of the Serializer
58       * Sharing is only valid for xml primitives.
59       */
60      public BaseSerializerFactory(Class serClass) {
61          if (!Serializer.class.isAssignableFrom(serClass)) {
62              throw new ClassCastException(
63                      Messages.getMessage("BadImplementation00",
64                              serClass.getName(),
65                              Serializer.class.getName()));
66          }
67          this.serClass = serClass;
68      }
69  
70      public BaseSerializerFactory(Class serClass,
71                                   QName xmlType, Class javaType) {
72          this(serClass);
73          this.xmlType = xmlType;
74          this.javaType = javaType;
75      }
76  
77      public javax.xml.rpc.encoding.Serializer 
78          getSerializerAs(String mechanismType)
79          throws JAXRPCException {
80          synchronized (this) {
81              if (ser==null) {
82                  ser = getSerializerAsInternal(mechanismType);
83              }
84              return ser;
85          }
86      }
87      
88      protected Serializer getSerializerAsInternal(String mechanismType)
89          throws JAXRPCException {
90          // Try getting a specialized Serializer
91          Serializer serializer = getSpecialized(mechanismType);
92          
93          // Try getting a general purpose Serializer via constructor
94          // invocation
95          if (serializer == null) {
96              serializer = getGeneralPurpose(mechanismType);
97          }
98  
99          try {            
100             // If not successfull, try newInstance
101             if (serializer == null) {
102                 serializer = (Serializer) serClass.newInstance();
103             }
104         } catch (Exception e) {
105             throw new JAXRPCException(
106                 Messages.getMessage("CantGetSerializer", 
107                                     serClass.getName()),
108                 e);
109         }
110         return serializer;
111     }
112     
113     /**
114      * Obtains a serializer by invoking <constructor>(javaType, xmlType) 
115      * on the serClass.
116      */
117     protected Serializer getGeneralPurpose(String mechanismType) {
118         if (javaType != null && xmlType != null) {
119             Constructor serClassConstructor = getSerClassConstructor();
120             if (serClassConstructor != null) {
121                 try {
122                     return (Serializer) 
123                         serClassConstructor.newInstance(
124                             new Object[] {javaType, xmlType});
125                 } catch (InstantiationException e) {
126                     if(log.isDebugEnabled()) {
127                         log.debug(org.apache.axis.utils.Messages.getMessage("exception00"), e);
128                     }
129                 } catch (IllegalAccessException e) {
130                     if(log.isDebugEnabled()) {
131                         log.debug(org.apache.axis.utils.Messages.getMessage("exception00"), e);
132                     }
133                 } catch (InvocationTargetException e) {
134                     if(log.isDebugEnabled()) {
135                         log.debug(org.apache.axis.utils.Messages.getMessage("exception00"), e);
136                     }
137                 }
138             }
139         }
140         return null;
141     }
142 
143 
144     private static final Class[] CLASS_QNAME_CLASS = new Class[] { Class.class, QName.class };
145     
146     /**
147      * return constructor for class if any
148      */ 
149     private Constructor getConstructor(Class clazz) {
150         try {
151             return clazz.getConstructor(CLASS_QNAME_CLASS);
152         } catch (NoSuchMethodException e) {}
153         return null;
154     }
155     
156     /**
157      * Obtains a serializer by invoking getSerializer method in the 
158      * javaType class or its Helper class.
159      */
160     protected Serializer getSpecialized(String mechanismType) {
161         if (javaType != null && xmlType != null) {
162             Method getSerializer = getGetSerializer();
163             if (getSerializer != null) {
164                 try {
165                     return (Serializer) 
166                         getSerializer.invoke(
167                             null,
168                             new Object[] {mechanismType, 
169                                           javaType, 
170                                           xmlType});
171                 } catch (IllegalAccessException e) {
172                     if(log.isDebugEnabled()) {
173                         log.debug(org.apache.axis.utils.Messages.getMessage("exception00"), e);
174                     }
175                 } catch (InvocationTargetException e) {
176                     if(log.isDebugEnabled()) {
177                         log.debug(org.apache.axis.utils.Messages.getMessage("exception00"), e);
178                     }
179                 }
180             }
181         }
182         return null;
183     }
184 
185     /**
186      * Returns a list of all XML processing mechanism types supported
187      * by this SerializerFactory.
188      *
189      * @return List of unique identifiers for the supported XML 
190      * processing mechanism types
191      */
192     public Iterator getSupportedMechanismTypes() {
193         if (mechanisms == null) {
194             mechanisms = new Vector(1);
195             mechanisms.add(Constants.AXIS_SAX);
196         }
197         return mechanisms.iterator();
198     }
199 
200     /**
201      * get xmlType
202      * @return xmlType QName for this factory
203      */
204     public QName getXMLType() {
205         return xmlType;
206     }
207     
208     /**
209      * get javaType
210      * @return javaType Class for this factory
211      */
212     public Class getJavaType() {
213         return javaType;
214     }
215 
216     /**
217      * Utility method that intospects on a factory class to decide how to 
218      * create the factory.  Tries in the following order:
219      * public static create(Class javaType, QName xmlType)
220      * public <constructor>(Class javaType, QName xmlType)
221      * public <constructor>()
222      * @param factory class
223      * @param xmlType
224      * @param javaType
225      */
226     public static SerializerFactory createFactory(Class factory, 
227                                                   Class javaType, 
228                                                   QName xmlType) {
229         if (factory == null) {
230             return null;
231         }
232 
233         try {
234             if (factory == BeanSerializerFactory.class) {
235                 return new BeanSerializerFactory(javaType, xmlType);
236             } else if (factory == SimpleSerializerFactory.class) {
237                 return new SimpleSerializerFactory(javaType, xmlType);
238             } else if (factory == EnumSerializerFactory.class) {
239                 return new EnumSerializerFactory(javaType, xmlType);
240             } else if (factory == ElementSerializerFactory.class) {
241                 return new ElementSerializerFactory();
242             } else if (factory == SimpleListSerializerFactory.class) {
243                 return new SimpleListSerializerFactory(javaType, xmlType);
244             }
245         } catch (Exception e) {
246             if (log.isDebugEnabled()) {
247                 log.debug(org.apache.axis.utils.Messages.getMessage("exception00"), e);
248             }
249             return null;
250         }
251 
252         SerializerFactory sf = null;
253         try {
254             Method method = 
255                 factory.getMethod("create", CLASS_QNAME_CLASS);
256             sf = (SerializerFactory) 
257                 method.invoke(null, 
258                               new Object[] {javaType, xmlType});
259         } catch (NoSuchMethodException e) {
260             if(log.isDebugEnabled()) {
261                 log.debug(org.apache.axis.utils.Messages.getMessage("exception00"), e);
262             }
263         } catch (IllegalAccessException e) {
264             if(log.isDebugEnabled()) {
265                 log.debug(org.apache.axis.utils.Messages.getMessage("exception00"), e);
266             }
267         } catch (InvocationTargetException e) {
268             if(log.isDebugEnabled()) {
269                 log.debug(org.apache.axis.utils.Messages.getMessage("exception00"), e);
270             }
271         }
272 
273         if (sf == null) {
274             try {
275                 Constructor constructor =  
276                     factory.getConstructor(CLASS_QNAME_CLASS);
277                 sf = (SerializerFactory) 
278                     constructor.newInstance(
279                         new Object[] {javaType, xmlType});
280             } catch (NoSuchMethodException e) {
281                 if(log.isDebugEnabled()) {
282                     log.debug(org.apache.axis.utils.Messages.getMessage("exception00"), e);
283                 }
284             } catch (InstantiationException e) {
285                 if(log.isDebugEnabled()) {
286                     log.debug(org.apache.axis.utils.Messages.getMessage("exception00"), e);
287                 }
288             } catch (IllegalAccessException e) {
289                 if(log.isDebugEnabled()) {
290                     log.debug(org.apache.axis.utils.Messages.getMessage("exception00"), e);
291                 }
292             } catch (InvocationTargetException e) {
293                 if(log.isDebugEnabled()) {
294                     log.debug(org.apache.axis.utils.Messages.getMessage("exception00"), e);
295                 }
296             }
297         }
298         
299         if (sf == null) {
300             try {
301                 sf = (SerializerFactory) factory.newInstance();
302             } catch (InstantiationException e) {
303             } catch (IllegalAccessException e) {}
304         }
305         return sf;
306     }
307 
308     /**
309      * Returns the getSerializer.
310      * @return Method
311      */
312     protected Method getGetSerializer() {
313       if (getSerializer == null) {
314             getSerializer = getMethod(javaType, "getSerializer");
315         }
316       return getSerializer;
317     }
318     
319     /**
320      * Returns the serClassConstructor.
321      * @return Constructor
322      */
323     protected Constructor getSerClassConstructor() {
324       if (serClassConstructor == null) {
325             serClassConstructor = getConstructor(serClass);
326         }
327       return serClassConstructor;
328     }
329     
330 }