1 /*
2 * Copyright (c) 2017, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation. Oracle designates this
8 * particular file as subject to the "Classpath" exception as provided
9 * by Oracle in the LICENSE file that accompanied this code.
10 *
11 * This code is distributed in the hope that it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14 * version 2 for more details (a copy is included in the LICENSE file that
15 * accompanied this code).
16 *
17 * You should have received a copy of the GNU General Public License version
18 * 2 along with this work; if not, write to the Free Software Foundation,
19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20 *
21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22 * or visit www.oracle.com if you need additional information or have any
23 * questions.
24 */
25
26 package jdk.packager.services.singleton;
27
28 import java.io.BufferedReader;
29 import java.io.File;
30 import java.io.FileReader;
31 import java.io.IOException;
32 import java.io.InputStreamReader;
33 import java.io.OutputStream;
34 import java.io.PrintStream;
35 import java.net.Socket;
36 import java.nio.charset.Charset;
37
38 /**
39 * The {@code SingleInstanceService} class provides public methods for using
40 * Single Instance functionality for Java Packager. To use these methods,
41 * the option named "-singleton" must be specified on javapackager command line.
42 *
43 * @since 10
44 */
45 public class SingleInstanceService {
46
47 static private boolean DEBUG = false;
48 static private PrintStream DEBUG_STREAM = null;
49
50 static private int currPort;
51 static private String stringId = null;
52 static private String randomNumberString = null;
53
54 static private SingleInstanceImpl instance = null;
55
56 static final int ENCODING_PLATFORM = 1;
57 static final int ENCODING_UNICODE = 2;
58
59 static final String ENCODING_PLATFORM_NAME = "UTF-8";
60 static final String ENCODING_UNICODE_NAME = "UTF-16LE";
61
62 static final String APP_ID_PREFIX = "javapackager.si.";
63
64 private SingleInstanceService() {}
65
66 static void enableDebug(boolean enable, PrintStream stream) {
67 DEBUG = enable;
68 DEBUG_STREAM = stream;
69 }
70
71 static void trace(String message) {
72 if (DEBUG && DEBUG_STREAM != null) {
73 DEBUG_STREAM.println(message);
74 }
75 }
76
77 static void trace(Throwable t) {
78 if (DEBUG && DEBUG_STREAM != null) {
79 t.printStackTrace(DEBUG_STREAM);
80 }
81 }
82
83 /**
84 * Registers {@code SingleInstanceListener} for current process.
85 * If the {@code SingleInstanceListener} object is already registered, or
86 * {@code slistener} is {@code null}, then the registration is skipped.
87 *
88 * @param slistener the listener to handle the single instance behaviour.
89 */
90 public static void registerSingleInstance(SingleInstanceListener slistener) {
91 registerSingleInstance(slistener, false);
92 }
93
94 /**
95 * Registers {@code SingleInstanceListener} for current process.
96 * If the {@code SingleInstanceListener} object is already registered, or
97 * {@code slistener} is {@code null}, then the registration is skipped.
98 *
99 * @param slistener the listener to handle the single instance behaviour.
100 * @param setFileHandler if {@code true}, the listener is notified when the
101 * application is asked to open a list of files. If OS is not MacOS,
102 * the parameter is ignored.
103 */
104 public static void registerSingleInstance(SingleInstanceListener slistener,
105 boolean setFileHandler) {
106 String appId = APP_ID_PREFIX + ProcessHandle.current().pid();
107 registerSingleInstanceForId(slistener, appId, setFileHandler);
108 }
109
110 static void registerSingleInstanceForId(SingleInstanceListener slistener,
111 String stringId, boolean setFileHandler) {
112 // register SingleInstanceListener for given Id
113 instance = new SingleInstanceImpl();
114 instance.addSingleInstanceListener(slistener, stringId);
115 if (setFileHandler) {
116 instance.setOpenFileHandler();
117 }
118 }
119
120 /**
121 * Unregisters {@code SingleInstanceListener} for current process.
122 * If the {@code SingleInstanceListener} object is not registered, or
123 * {@code slistener} is {@code null}, then the unregistration is skipped.
124 *
125 * @param slistener the listener for unregistering.
126 */
127 public static void unregisterSingleInstance(SingleInstanceListener slistener) {
128 instance.removeSingleInstanceListener(slistener);
129 }
130
131 /**
132 * Returns true if single instance server is running for the id
133 */
134 static boolean isServerRunning(String id) {
135 trace("isServerRunning ? : "+ id);
136 File siDir = new File(SingleInstanceImpl.SI_FILEDIR);
137 String[] fList = siDir.list();
138 if (fList != null) {
139 String prefix = SingleInstanceImpl.getSingleInstanceFilePrefix(id +
140 getSessionSpecificString());
141 for (String file : fList) {
142 trace("isServerRunning: " + file);
143 trace("\t sessionString: " + getSessionSpecificString());
144 trace("\t SingleInstanceFilePrefix: " + prefix);
145 // if file with the same prefix already exist, server is running
146 if (file.startsWith(prefix)) {
147 try {
148 currPort = Integer.parseInt(
149 file.substring(file.lastIndexOf('_') + 1));
150 trace("isServerRunning: " + file + ": port: " + currPort);
151 } catch (NumberFormatException nfe) {
152 trace("isServerRunning: " + file + ": port parsing failed");
153 trace(nfe);
154 return false;
155 }
156
157 trace("Server running at port: " + currPort);
158 File siFile = new File(SingleInstanceImpl.SI_FILEDIR, file);
159
160 // get random number from single instance file
161 try (BufferedReader br = new BufferedReader(new FileReader(siFile))) {
162 randomNumberString = br.readLine();
163 trace("isServerRunning: " + file + ": magic: " + randomNumberString);
164 } catch (IOException ioe ) {
165 trace("isServerRunning: " + file + ": reading magic failed");
166 trace(ioe);
167 }
168 trace("isServerRunning: " + file + ": setting id - OK");
169 stringId = id;
170 return true;
171 } else {
172 trace("isServerRunning: " + file + ": prefix NOK");
173 }
174 }
175 } else {
176 trace("isServerRunning: empty file list");
177 }
178 trace("isServerRunning: false");
179 return false;
180 }
181
182 /**
183 * Returns true if we connect successfully to the server for the stringId
184 */
185 static boolean connectToServer(String[] args) {
186 trace("Connect to: " + stringId + " " + currPort);
187
188 if (randomNumberString == null) {
189 // should not happen
190 trace("MAGIC number is null, bail out.");
191 return false;
192 }
193
194 // Now we open the tcpSocket and the stream
195 Socket socket = null;
196 OutputStream os = null;
197 PrintStream out = null;
198 InputStreamReader isr = null;
199 BufferedReader br = null;
200 try {
201 socket = new Socket("127.0.0.1", currPort);
202 os = socket.getOutputStream();
203 byte[] encoding = new byte[1];
204 encoding[0] = ENCODING_PLATFORM;
205 os.write(encoding);
206 String encodingName = Charset.defaultCharset().name();
207
208 out = new PrintStream(os, true, encodingName);
209 isr = new InputStreamReader(socket.getInputStream(), encodingName);
210 br = new BufferedReader(isr);
211
212 // send random number
213 out.println(randomNumberString);
214 // send MAGICWORD
215 out.println(SingleInstanceImpl.SI_MAGICWORD);
216
217 for (String arg : args) {
218 out.println(arg);
219 }
220
221 // indicate end of file transmission
222 out.println(SingleInstanceImpl.SI_EOF);
223 out.flush();
224
225 // wait for ACK (OK) response
226 trace("Waiting for ack");
227 final int tries = 5;
228
229 // try to listen for ACK
230 for (int i=0; i < tries; i++) {
231 String str = br.readLine();
232 if (str != null && str.equals(SingleInstanceImpl.SI_ACK)) {
233 trace("Got ACK");
234 return true;
235 }
236 }
237 } catch (java.net.SocketException se) {
238 // no server is running - continue launch
239 trace("No server is running - continue launch.");
240 trace(se);
241 } catch (Exception ioe) {
242 trace(ioe);
243 }
244 finally {
245 try {
246 if (br != null) {
247 br.close();
248 }
249 if (isr != null) {
250 isr.close();
251 }
252 if (out != null) {
253 out.close();
254 }
255 if (os != null) {
256 os.close();
257 }
258 if (socket != null) {
259 socket.close();
260 }
261 } catch (IOException ioe) {
262 trace(ioe);
263 }
264 }
265 trace("No ACK from server, bail out.");
266 return false;
267 }
268
269 static String getSessionSpecificString() {
270 // TODO: consider providing session ids
271 return "";
272 }
273 }