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1   /*
2    * Copyright 2007 the original author or authors.
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.springframework.ws.transport;
18  
19  import java.io.IOException;
20  
21  import org.springframework.ws.WebServiceMessage;
22  import org.springframework.ws.WebServiceMessageFactory;
23  
24  /**
25   * Abstract base class for {@link WebServiceConnection} implementations.
26   *
27   * @author Arjen Poutsma
28   * @since 1.0.0
29   */
30  public abstract class AbstractWebServiceConnection implements WebServiceConnection {
31  
32      private TransportInputStream tis;
33  
34      private TransportOutputStream tos;
35  
36      private boolean closed = false;
37  
38      public final void send(WebServiceMessage message) throws IOException {
39          checkClosed();
40          onSendBeforeWrite(message);
41          tos = createTransportOutputStream();
42          if (tos == null) {
43              return;
44          }
45          message.writeTo(tos);
46          tos.flush();
47          onSendAfterWrite(message);
48      }
49  
50      /**
51       * Called before the given message has been written to the <code>TransportOutputStream</code>. Called from {@link
52       * #send(WebServiceMessage)}.
53       * <p/>
54       * Default implementation does nothing.
55       *
56       * @param message the message
57       * @throws IOException when an I/O exception occurs
58       */
59      protected void onSendBeforeWrite(WebServiceMessage message) throws IOException {
60      }
61  
62      /**
63       * Returns a <code>TransportOutputStream</code> for the given message. Called from {@link
64       * #send(WebServiceMessage)}.
65       *
66       * @return the output stream
67       * @throws IOException when an I/O exception occurs
68       */
69      protected abstract TransportOutputStream createTransportOutputStream() throws IOException;
70  
71      /**
72       * Called after the given message has been written to the <code>TransportOutputStream</code>. Called from {@link
73       * #send(WebServiceMessage)}.
74       * <p/>
75       * Default implementation does nothing.
76       *
77       * @param message the message
78       * @throws IOException when an I/O exception occurs
79       */
80      protected void onSendAfterWrite(WebServiceMessage message) throws IOException {
81      }
82  
83      public final WebServiceMessage receive(WebServiceMessageFactory messageFactory) throws IOException {
84          checkClosed();
85          onReceiveBeforeRead();
86          tis = createTransportInputStream();
87          if (tis == null) {
88              return null;
89          }
90          WebServiceMessage message = messageFactory.createWebServiceMessage(tis);
91          onReceiveAfterRead(message);
92          return message;
93      }
94  
95      /**
96       * Called before a message has been read from the <code>TransportInputStream</code>. Called from {@link
97       * #receive(WebServiceMessageFactory)}.
98       * <p/>
99       * Default implementation does nothing.
100      *
101      * @throws IOException when an I/O exception occurs
102      */
103     protected void onReceiveBeforeRead() throws IOException {
104     }
105 
106     /**
107      * Returns a <code>TransportInputStream</code>. Called from {@link #receive(WebServiceMessageFactory)}.
108      *
109      * @return the input stream, or <code>null</code> if no response can be read
110      * @throws IOException when an I/O exception occurs
111      */
112     protected abstract TransportInputStream createTransportInputStream() throws IOException;
113 
114     /**
115      * Called when the given message has been read from the <code>TransportInputStream</code>. Called from {@link
116      * #receive(WebServiceMessageFactory)}.
117      * <p/>
118      * Default implementation does nothing.
119      *
120      * @param message the message
121      * @throws IOException when an I/O exception occurs
122      */
123     protected void onReceiveAfterRead(WebServiceMessage message) throws IOException {
124     }
125 
126     public final void close() throws IOException {
127         IOException ioex = null;
128         if (tis != null) {
129             try {
130                 tis.close();
131             }
132             catch (IOException ex) {
133                 ioex = ex;
134             }
135         }
136         if (tos != null) {
137             try {
138                 tos.close();
139             }
140             catch (IOException ex) {
141                 ioex = ex;
142             }
143         }
144         onClose();
145         closed = true;
146         if (ioex != null) {
147             throw ioex;
148         }
149     }
150 
151     private void checkClosed() {
152         if (closed) {
153             throw new IllegalStateException("Connection has been closed and cannot be reused.");
154         }
155     }
156 
157     /**
158      * Template method invoked from {@link #close()}. Default implementation is empty.
159      *
160      * @throws IOException if an I/O error occurs when closing this connection
161      */
162     protected void onClose() throws IOException {
163     }
164 
165 }