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79ce1a49 | 1 | package be.nikiroo.utils.serial.server; |
ce0974c4 NR |
2 | |
3 | import java.io.BufferedReader; | |
4 | import java.io.IOException; | |
5 | import java.io.InputStreamReader; | |
6 | import java.io.OutputStreamWriter; | |
7 | import java.net.Socket; | |
8 | ||
9 | import be.nikiroo.utils.Version; | |
79ce1a49 NR |
10 | import be.nikiroo.utils.serial.Exporter; |
11 | import be.nikiroo.utils.serial.Importer; | |
ce0974c4 | 12 | |
f157aed8 NR |
13 | /** |
14 | * Base class used for the client/server basic handling. | |
15 | * <p> | |
16 | * It represents a single action: a client is expected to only execute one | |
17 | * action, while a server is expected to execute one action for each client | |
18 | * action. | |
19 | * | |
20 | * @author niki | |
21 | */ | |
ce0974c4 NR |
22 | abstract class ConnectAction { |
23 | private Socket s; | |
24 | private boolean server; | |
25 | private Version version; | |
f157aed8 | 26 | private Version clientVersion; |
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27 | |
28 | private Object lock = new Object(); | |
29 | private BufferedReader in; | |
30 | private OutputStreamWriter out; | |
31 | private boolean contentToSend; | |
32 | ||
f157aed8 NR |
33 | /** |
34 | * Method that will be called when an action is performed on either the | |
35 | * client or server this {@link ConnectAction} represent. | |
36 | * | |
37 | * @param version | |
38 | * the counter part version | |
39 | * | |
40 | * @throws Exception | |
41 | * in case of I/O error | |
42 | */ | |
43 | abstract protected void action(Version version) throws Exception; | |
44 | ||
45 | /** | |
46 | * Method called when we negotiate the version with the client. | |
47 | * <p> | |
48 | * Thus, it is only called on the server. | |
49 | * <p> | |
50 | * Will return the actual server version by default. | |
51 | * | |
52 | * @param clientVersion | |
53 | * the client version | |
54 | * | |
55 | * @return the version to send to the client | |
56 | */ | |
57 | abstract protected Version negotiateVersion(Version clientVersion); | |
58 | ||
59 | /** | |
60 | * Handler called when an unexpected error occurs in the code. | |
61 | * | |
62 | * @param e | |
63 | * the exception that occurred | |
64 | */ | |
65 | abstract protected void onError(Exception e); | |
ce0974c4 | 66 | |
f157aed8 NR |
67 | /** |
68 | * Create a new {@link ConnectAction}. | |
69 | * | |
70 | * @param s | |
71 | * the socket to bind to | |
72 | * @param server | |
73 | * TRUE for a server action, FALSE for a client action (will | |
74 | * impact the process) | |
75 | * @param version | |
76 | * the version of this client-or-server | |
77 | */ | |
ce0974c4 NR |
78 | protected ConnectAction(Socket s, boolean server, Version version) { |
79 | this.s = s; | |
80 | this.server = server; | |
81 | ||
82 | if (version == null) { | |
83 | this.version = new Version(); | |
84 | } else { | |
85 | this.version = version; | |
86 | } | |
f157aed8 NR |
87 | |
88 | clientVersion = new Version(); | |
ce0974c4 NR |
89 | } |
90 | ||
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91 | /** |
92 | * The version of this client-or-server. | |
93 | * | |
94 | * @return the version | |
95 | */ | |
96 | public Version getVersion() { | |
97 | return version; | |
ce0974c4 NR |
98 | } |
99 | ||
f157aed8 NR |
100 | /** |
101 | * Actually start the process (this is synchronous). | |
102 | */ | |
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103 | public void connect() { |
104 | try { | |
105 | in = new BufferedReader(new InputStreamReader(s.getInputStream(), | |
106 | "UTF-8")); | |
107 | try { | |
108 | out = new OutputStreamWriter(s.getOutputStream(), "UTF-8"); | |
109 | try { | |
110 | if (server) { | |
217a3310 NR |
111 | String line = in.readLine(); |
112 | if (line != null && line.startsWith("VERSION ")) { | |
113 | // "VERSION client-version" (VERSION 1.0.0) | |
114 | Version clientVersion = new Version( | |
115 | line.substring("VERSION ".length())); | |
116 | this.clientVersion = clientVersion; | |
117 | Version v = negotiateVersion(clientVersion); | |
118 | if (v == null) { | |
119 | v = new Version(); | |
120 | } | |
121 | ||
122 | sendString("VERSION " + v.toString()); | |
123 | } | |
124 | ||
f157aed8 | 125 | action(clientVersion); |
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126 | } else { |
127 | String v = sendString("VERSION " + version.toString()); | |
128 | if (v != null && v.startsWith("VERSION ")) { | |
129 | v = v.substring("VERSION ".length()); | |
130 | } | |
131 | ||
132 | action(new Version(v)); | |
133 | } | |
134 | } finally { | |
135 | out.close(); | |
0988831f | 136 | out = null; |
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137 | } |
138 | } finally { | |
139 | in.close(); | |
0988831f | 140 | in = null; |
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141 | } |
142 | } catch (Exception e) { | |
143 | onError(e); | |
144 | } finally { | |
145 | try { | |
146 | s.close(); | |
147 | } catch (Exception e) { | |
148 | onError(e); | |
149 | } | |
150 | } | |
151 | } | |
152 | ||
f157aed8 NR |
153 | /** |
154 | * Serialise and send the given object to the counter part (and, only for | |
155 | * client, return the deserialised answer -- the server will always receive | |
156 | * NULL). | |
157 | * | |
158 | * @param data | |
159 | * the data to send | |
160 | * | |
161 | * @return the answer (which can be NULL) if this action is a client, always | |
162 | * NULL if it is a server | |
163 | * | |
164 | * @throws IOException | |
165 | * in case of I/O error | |
166 | * @throws NoSuchFieldException | |
167 | * if the serialised data contains information about a field | |
168 | * which does actually not exist in the class we know of | |
169 | * @throws NoSuchMethodException | |
170 | * if a class described in the serialised data cannot be created | |
171 | * because it is not compatible with this code | |
172 | * @throws ClassNotFoundException | |
173 | * if a class described in the serialised data cannot be found | |
174 | */ | |
79ce1a49 | 175 | protected Object sendObject(Object data) throws IOException, |
f157aed8 | 176 | NoSuchFieldException, NoSuchMethodException, ClassNotFoundException { |
ce0974c4 | 177 | synchronized (lock) { |
a359464f NR |
178 | String rep = sendString(new Exporter().append(data).toString(true, |
179 | true)); | |
08a58812 NR |
180 | if (rep != null) { |
181 | return new Importer().read(rep).getValue(); | |
182 | } | |
183 | ||
184 | return null; | |
ce0974c4 NR |
185 | } |
186 | } | |
187 | ||
f157aed8 NR |
188 | /** |
189 | * Reserved for the server: flush the data to the client and retrieve its | |
190 | * answer. | |
191 | * <p> | |
192 | * Also used internally for the client (only do something if there is | |
193 | * contentToSend). | |
194 | * <p> | |
195 | * Will only flush the data if there is contentToSend. | |
196 | * | |
197 | * @return the deserialised answer (which can actually be NULL) | |
198 | * | |
199 | * @throws IOException | |
200 | * in case of I/O error | |
201 | * @throws NoSuchFieldException | |
202 | * if the serialised data contains information about a field | |
203 | * which does actually not exist in the class we know of | |
204 | * @throws NoSuchMethodException | |
205 | * if a class described in the serialised data cannot be created | |
206 | * because it is not compatible with this code | |
207 | * @throws ClassNotFoundException | |
208 | * if a class described in the serialised data cannot be found | |
209 | * @throws java.lang.NullPointerException | |
210 | * if the counter part has no data to send | |
211 | */ | |
79ce1a49 | 212 | protected Object recObject() throws IOException, NoSuchFieldException, |
f157aed8 NR |
213 | NoSuchMethodException, ClassNotFoundException, |
214 | java.lang.NullPointerException { | |
79ce1a49 | 215 | String str = recString(); |
ce0974c4 | 216 | if (str == null) { |
f157aed8 | 217 | throw new NullPointerException("No more data available"); |
ce0974c4 NR |
218 | } |
219 | ||
220 | return new Importer().read(str).getValue(); | |
221 | } | |
222 | ||
cd0c27d2 | 223 | /** |
f157aed8 NR |
224 | * Send the given string to the counter part (and, only for client, return |
225 | * the answer -- the server will always receive NULL). | |
cd0c27d2 | 226 | * |
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227 | * @param line |
228 | * the data to send (we will add a line feed) | |
cd0c27d2 | 229 | * |
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230 | * @return the answer if this action is a client (without the added line |
231 | * feed), NULL if it is a server | |
232 | * | |
233 | * @throws IOException | |
234 | * in case of I/O error | |
cd0c27d2 | 235 | */ |
f157aed8 | 236 | protected String sendString(String line) throws IOException { |
ce0974c4 NR |
237 | synchronized (lock) { |
238 | out.write(line); | |
239 | out.write("\n"); | |
240 | ||
241 | if (server) { | |
242 | out.flush(); | |
243 | return null; | |
ce0974c4 | 244 | } |
cd0c27d2 NR |
245 | |
246 | contentToSend = true; | |
79ce1a49 | 247 | return recString(); |
ce0974c4 NR |
248 | } |
249 | } | |
250 | ||
f157aed8 NR |
251 | /** |
252 | * Reserved for the server (externally): flush the data to the client and | |
253 | * retrieve its answer. | |
254 | * <p> | |
255 | * Also used internally for the client (only do something if there is | |
256 | * contentToSend). | |
257 | * <p> | |
258 | * Will only flush the data if there is contentToSend. | |
259 | * | |
260 | * @return the answer (which can be NULL) | |
261 | * | |
262 | * @throws IOException | |
263 | * in case of I/O error | |
264 | */ | |
79ce1a49 | 265 | protected String recString() throws IOException { |
ce0974c4 NR |
266 | synchronized (lock) { |
267 | if (server || contentToSend) { | |
268 | if (contentToSend) { | |
269 | out.flush(); | |
270 | contentToSend = false; | |
271 | } | |
272 | ||
217a3310 | 273 | return in.readLine(); |
ce0974c4 | 274 | } |
cd0c27d2 NR |
275 | |
276 | return null; | |
ce0974c4 NR |
277 | } |
278 | } | |
279 | } |