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| 1 | /* | ||
| 2 | * Copyright (c) 1995, 2006, 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 java.lang; | ||
| 27 | |||
| 28 | import java.io.*; | ||
| 29 | import java.util.StringTokenizer; | ||
| 30 | |||
| 31 | /** | ||
| 32 | * Every Java application has a single instance of class | ||
| 33 | * <code>Runtime</code> that allows the application to interface with | ||
| 34 | * the environment in which the application is running. The current | ||
| 35 | * runtime can be obtained from the <code>getRuntime</code> method. | ||
| 36 | * <p> | ||
| 37 | * An application cannot create its own instance of this class. | ||
| 38 | * | ||
| 39 | * @author unascribed | ||
| 40 | * @see java.lang.Runtime#getRuntime() | ||
| 41 | * @since JDK1.0 | ||
| 42 | */ | ||
| 43 | |||
| 44 | public class Runtime { | ||
| 45 | private static Runtime currentRuntime = new Runtime(); | ||
| 46 | |||
| 47 | /** | ||
| 48 | * Returns the runtime object associated with the current Java application. | ||
| 49 | * Most of the methods of class <code>Runtime</code> are instance | ||
| 50 | * methods and must be invoked with respect to the current runtime object. | ||
| 51 | * | ||
| 52 | * @return the <code>Runtime</code> object associated with the current | ||
| 53 | * Java application. | ||
| 54 | */ | ||
| 55 | public static Runtime getRuntime() { | ||
| 56 | return currentRuntime; | ||
| 57 | } | ||
| 58 | |||
| 59 | /** Don't let anyone else instantiate this class */ | ||
| 60 | private Runtime() {} | ||
| 61 | |||
| 62 | /** | ||
| 63 | * Terminates the currently running Java virtual machine by initiating its | ||
| 64 | * shutdown sequence. This method never returns normally. The argument | ||
| 65 | * serves as a status code; by convention, a nonzero status code indicates | ||
| 66 | * abnormal termination. | ||
| 67 | * | ||
| 68 | * <p> The virtual machine's shutdown sequence consists of two phases. In | ||
| 69 | * the first phase all registered {@link #addShutdownHook shutdown hooks}, | ||
| 70 | * if any, are started in some unspecified order and allowed to run | ||
| 71 | * concurrently until they finish. In the second phase all uninvoked | ||
| 72 | * finalizers are run if {@link #runFinalizersOnExit finalization-on-exit} | ||
| 73 | * has been enabled. Once this is done the virtual machine {@link #halt | ||
| 74 | * halts}. | ||
| 75 | * | ||
| 76 | * <p> If this method is invoked after the virtual machine has begun its | ||
| 77 | * shutdown sequence then if shutdown hooks are being run this method will | ||
| 78 | * block indefinitely. If shutdown hooks have already been run and on-exit | ||
| 79 | * finalization has been enabled then this method halts the virtual machine | ||
| 80 | * with the given status code if the status is nonzero; otherwise, it | ||
| 81 | * blocks indefinitely. | ||
| 82 | * | ||
| 83 | * <p> The <tt>{@link System#exit(int) System.exit}</tt> method is the | ||
| 84 | * conventional and convenient means of invoking this method. <p> | ||
| 85 | * | ||
| 86 | * @param status | ||
| 87 | * Termination status. By convention, a nonzero status code | ||
| 88 | * indicates abnormal termination. | ||
| 89 | * | ||
| 90 | * @throws SecurityException | ||
| 91 | * If a security manager is present and its <tt>{@link | ||
| 92 | * SecurityManager#checkExit checkExit}</tt> method does not permit | ||
| 93 | * exiting with the specified status | ||
| 94 | * | ||
| 95 | * @see java.lang.SecurityException | ||
| 96 | * @see java.lang.SecurityManager#checkExit(int) | ||
| 97 | * @see #addShutdownHook | ||
| 98 | * @see #removeShutdownHook | ||
| 99 | * @see #runFinalizersOnExit | ||
| 100 | * @see #halt(int) | ||
| 101 | */ | ||
| 102 | public void exit(int status) { | ||
| 103 | SecurityManager security = System.getSecurityManager(); | ||
| 104 | if (security != null) { | ||
| 105 | security.checkExit(status); | ||
| 106 | } | ||
| 107 | Shutdown.exit(status); | ||
| 108 | } | ||
| 109 | |||
| 110 | /** | ||
| 111 | * Registers a new virtual-machine shutdown hook. | ||
| 112 | * | ||
| 113 | * <p> The Java virtual machine <i>shuts down</i> in response to two kinds | ||
| 114 | * of events: | ||
| 115 | * | ||
| 116 | * <ul> | ||
| 117 | * | ||
| 118 | * <p> <li> The program <i>exits</i> normally, when the last non-daemon | ||
| 119 | * thread exits or when the <tt>{@link #exit exit}</tt> (equivalently, | ||
| 120 | * <tt>{@link System#exit(int) System.exit}</tt>) method is invoked, or | ||
| 121 | * | ||
| 122 | * <p> <li> The virtual machine is <i>terminated</i> in response to a | ||
| 123 | * user interrupt, such as typing <tt>^C</tt>, or a system-wide event, | ||
| 124 | * such as user logoff or system shutdown. | ||
| 125 | * | ||
| 126 | * </ul> | ||
| 127 | * | ||
| 128 | * <p> A <i>shutdown hook</i> is simply an initialized but unstarted | ||
| 129 | * thread. When the virtual machine begins its shutdown sequence it will | ||
| 130 | * start all registered shutdown hooks in some unspecified order and let | ||
| 131 | * them run concurrently. When all the hooks have finished it will then | ||
| 132 | * run all uninvoked finalizers if finalization-on-exit has been enabled. | ||
| 133 | * Finally, the virtual machine will halt. Note that daemon threads will | ||
| 134 | * continue to run during the shutdown sequence, as will non-daemon threads | ||
| 135 | * if shutdown was initiated by invoking the <tt>{@link #exit exit}</tt> | ||
| 136 | * method. | ||
| 137 | * | ||
| 138 | * <p> Once the shutdown sequence has begun it can be stopped only by | ||
| 139 | * invoking the <tt>{@link #halt halt}</tt> method, which forcibly | ||
| 140 | * terminates the virtual machine. | ||
| 141 | * | ||
| 142 | * <p> Once the shutdown sequence has begun it is impossible to register a | ||
| 143 | * new shutdown hook or de-register a previously-registered hook. | ||
| 144 | * Attempting either of these operations will cause an | ||
| 145 | * <tt>{@link IllegalStateException}</tt> to be thrown. | ||
| 146 | * | ||
| 147 | * <p> Shutdown hooks run at a delicate time in the life cycle of a virtual | ||
| 148 | * machine and should therefore be coded defensively. They should, in | ||
| 149 | * particular, be written to be thread-safe and to avoid deadlocks insofar | ||
| 150 | * as possible. They should also not rely blindly upon services that may | ||
| 151 | * have registered their own shutdown hooks and therefore may themselves in | ||
| 152 | * the process of shutting down. Attempts to use other thread-based | ||
| 153 | * services such as the AWT event-dispatch thread, for example, may lead to | ||
| 154 | * deadlocks. | ||
| 155 | * | ||
| 156 | * <p> Shutdown hooks should also finish their work quickly. When a | ||
| 157 | * program invokes <tt>{@link #exit exit}</tt> the expectation is | ||
| 158 | * that the virtual machine will promptly shut down and exit. When the | ||
| 159 | * virtual machine is terminated due to user logoff or system shutdown the | ||
| 160 | * underlying operating system may only allow a fixed amount of time in | ||
| 161 | * which to shut down and exit. It is therefore inadvisable to attempt any | ||
| 162 | * user interaction or to perform a long-running computation in a shutdown | ||
| 163 | * hook. | ||
| 164 | * | ||
| 165 | * <p> Uncaught exceptions are handled in shutdown hooks just as in any | ||
| 166 | * other thread, by invoking the <tt>{@link ThreadGroup#uncaughtException | ||
| 167 | * uncaughtException}</tt> method of the thread's <tt>{@link | ||
| 168 | * ThreadGroup}</tt> object. The default implementation of this method | ||
| 169 | * prints the exception's stack trace to <tt>{@link System#err}</tt> and | ||
| 170 | * terminates the thread; it does not cause the virtual machine to exit or | ||
| 171 | * halt. | ||
| 172 | * | ||
| 173 | * <p> In rare circumstances the virtual machine may <i>abort</i>, that is, | ||
| 174 | * stop running without shutting down cleanly. This occurs when the | ||
| 175 | * virtual machine is terminated externally, for example with the | ||
| 176 | * <tt>SIGKILL</tt> signal on Unix or the <tt>TerminateProcess</tt> call on | ||
| 177 | * Microsoft Windows. The virtual machine may also abort if a native | ||
| 178 | * method goes awry by, for example, corrupting internal data structures or | ||
| 179 | * attempting to access nonexistent memory. If the virtual machine aborts | ||
| 180 | * then no guarantee can be made about whether or not any shutdown hooks | ||
| 181 | * will be run. <p> | ||
| 182 | * | ||
| 183 | * @param hook | ||
| 184 | * An initialized but unstarted <tt>{@link Thread}</tt> object | ||
| 185 | * | ||
| 186 | * @throws IllegalArgumentException | ||
| 187 | * If the specified hook has already been registered, | ||
| 188 | * or if it can be determined that the hook is already running or | ||
| 189 | * has already been run | ||
| 190 | * | ||
| 191 | * @throws IllegalStateException | ||
| 192 | * If the virtual machine is already in the process | ||
| 193 | * of shutting down | ||
| 194 | * | ||
| 195 | * @throws SecurityException | ||
| 196 | * If a security manager is present and it denies | ||
| 197 | * <tt>{@link RuntimePermission}("shutdownHooks")</tt> | ||
| 198 | * | ||
| 199 | * @see #removeShutdownHook | ||
| 200 | * @see #halt(int) | ||
| 201 | * @see #exit(int) | ||
| 202 | * @since 1.3 | ||
| 203 | */ | ||
| 204 | public void addShutdownHook(Thread hook) { | ||
| 205 | SecurityManager sm = System.getSecurityManager(); | ||
| 206 | if (sm != null) { | ||
| 207 | sm.checkPermission(new RuntimePermission("shutdownHooks")); | ||
| 208 | } | ||
| 209 | ApplicationShutdownHooks.add(hook); | ||
| 210 | } | ||
| 211 | |||
| 212 | /** | ||
| 213 | * De-registers a previously-registered virtual-machine shutdown hook. <p> | ||
| 214 | * | ||
| 215 | * @param hook the hook to remove | ||
| 216 | * @return <tt>true</tt> if the specified hook had previously been | ||
| 217 | * registered and was successfully de-registered, <tt>false</tt> | ||
| 218 | * otherwise. | ||
| 219 | * | ||
| 220 | * @throws IllegalStateException | ||
| 221 | * If the virtual machine is already in the process of shutting | ||
| 222 | * down | ||
| 223 | * | ||
| 224 | * @throws SecurityException | ||
| 225 | * If a security manager is present and it denies | ||
| 226 | * <tt>{@link RuntimePermission}("shutdownHooks")</tt> | ||
| 227 | * | ||
| 228 | * @see #addShutdownHook | ||
| 229 | * @see #exit(int) | ||
| 230 | * @since 1.3 | ||
| 231 | */ | ||
| 232 | public boolean removeShutdownHook(Thread hook) { | ||
| 233 | SecurityManager sm = System.getSecurityManager(); | ||
| 234 | if (sm != null) { | ||
| 235 | sm.checkPermission(new RuntimePermission("shutdownHooks")); | ||
| 236 | } | ||
| 237 | return ApplicationShutdownHooks.remove(hook); | ||
| 238 | } | ||
| 239 | |||
| 240 | /** | ||
| 241 | * Forcibly terminates the currently running Java virtual machine. This | ||
| 242 | * method never returns normally. | ||
| 243 | * | ||
| 244 | * <p> This method should be used with extreme caution. Unlike the | ||
| 245 | * <tt>{@link #exit exit}</tt> method, this method does not cause shutdown | ||
| 246 | * hooks to be started and does not run uninvoked finalizers if | ||
| 247 | * finalization-on-exit has been enabled. If the shutdown sequence has | ||
| 248 | * already been initiated then this method does not wait for any running | ||
| 249 | * shutdown hooks or finalizers to finish their work. <p> | ||
| 250 | * | ||
| 251 | * @param status | ||
| 252 | * Termination status. By convention, a nonzero status code | ||
| 253 | * indicates abnormal termination. If the <tt>{@link Runtime#exit | ||
| 254 | * exit}</tt> (equivalently, <tt>{@link System#exit(int) | ||
| 255 | * System.exit}</tt>) method has already been invoked then this | ||
| 256 | * status code will override the status code passed to that method. | ||
| 257 | * | ||
| 258 | * @throws SecurityException | ||
| 259 | * If a security manager is present and its <tt>{@link | ||
| 260 | * SecurityManager#checkExit checkExit}</tt> method does not permit | ||
| 261 | * an exit with the specified status | ||
| 262 | * | ||
| 263 | * @see #exit | ||
| 264 | * @see #addShutdownHook | ||
| 265 | * @see #removeShutdownHook | ||
| 266 | * @since 1.3 | ||
| 267 | */ | ||
| 268 | public void halt(int status) { | ||
| 269 | SecurityManager sm = System.getSecurityManager(); | ||
| 270 | if (sm != null) { | ||
| 271 | sm.checkExit(status); | ||
| 272 | } | ||
| 273 | Shutdown.halt(status); | ||
| 274 | } | ||
| 275 | |||
| 276 | /** | ||
| 277 | * Enable or disable finalization on exit; doing so specifies that the | ||
| 278 | * finalizers of all objects that have finalizers that have not yet been | ||
| 279 | * automatically invoked are to be run before the Java runtime exits. | ||
| 280 | * By default, finalization on exit is disabled. | ||
| 281 | * | ||
| 282 | * <p>If there is a security manager, | ||
| 283 | * its <code>checkExit</code> method is first called | ||
| 284 | * with 0 as its argument to ensure the exit is allowed. | ||
| 285 | * This could result in a SecurityException. | ||
| 286 | * | ||
| 287 | * @param value true to enable finalization on exit, false to disable | ||
| 288 | * @deprecated This method is inherently unsafe. It may result in | ||
| 289 | * finalizers being called on live objects while other threads are | ||
| 290 | * concurrently manipulating those objects, resulting in erratic | ||
| 291 | * behavior or deadlock. | ||
| 292 | * | ||
| 293 | * @throws SecurityException | ||
| 294 | * if a security manager exists and its <code>checkExit</code> | ||
| 295 | * method doesn't allow the exit. | ||
| 296 | * | ||
| 297 | * @see java.lang.Runtime#exit(int) | ||
| 298 | * @see java.lang.Runtime#gc() | ||
| 299 | * @see java.lang.SecurityManager#checkExit(int) | ||
| 300 | * @since JDK1.1 | ||
| 301 | */ | ||
| 302 | @Deprecated | ||
| 303 | public static void runFinalizersOnExit(boolean value) { | ||
| 304 | SecurityManager security = System.getSecurityManager(); | ||
| 305 | if (security != null) { | ||
| 306 | try { | ||
| 307 | security.checkExit(0); | ||
| 308 | } catch (SecurityException e) { | ||
| 309 | throw new SecurityException("runFinalizersOnExit"); | ||
| 310 | } | ||
| 311 | } | ||
| 312 | Shutdown.setRunFinalizersOnExit(value); | ||
| 313 | } | ||
| 314 | |||
| 315 | /** | ||
| 316 | * Executes the specified string command in a separate process. | ||
| 317 | * | ||
| 318 | * <p>This is a convenience method. An invocation of the form | ||
| 319 | * <tt>exec(command)</tt> | ||
| 320 | * behaves in exactly the same way as the invocation | ||
| 321 | * <tt>{@link #exec(String, String[], File) exec}(command, null, null)</tt>. | ||
| 322 | * | ||
| 323 | * @param command a specified system command. | ||
| 324 | * | ||
| 325 | * @return A new {@link Process} object for managing the subprocess | ||
| 326 | * | ||
| 327 | * @throws SecurityException | ||
| 328 | * If a security manager exists and its | ||
| 329 | * {@link SecurityManager#checkExec checkExec} | ||
| 330 | * method doesn't allow creation of the subprocess | ||
| 331 | * | ||
| 332 | * @throws IOException | ||
| 333 | * If an I/O error occurs | ||
| 334 | * | ||
| 335 | * @throws NullPointerException | ||
| 336 | * If <code>command</code> is <code>null</code> | ||
| 337 | * | ||
| 338 | * @throws IllegalArgumentException | ||
| 339 | * If <code>command</code> is empty | ||
| 340 | * | ||
| 341 | * @see #exec(String[], String[], File) | ||
| 342 | * @see ProcessBuilder | ||
| 343 | */ | ||
| 344 | public Process exec(String command) throws IOException { | ||
| 345 | return exec(command, null, null); | ||
| 346 | } | ||
| 347 | |||
| 348 | /** | ||
| 349 | * Executes the specified string command in a separate process with the | ||
| 350 | * specified environment. | ||
| 351 | * | ||
| 352 | * <p>This is a convenience method. An invocation of the form | ||
| 353 | * <tt>exec(command, envp)</tt> | ||
| 354 | * behaves in exactly the same way as the invocation | ||
| 355 | * <tt>{@link #exec(String, String[], File) exec}(command, envp, null)</tt>. | ||
| 356 | * | ||
| 357 | * @param command a specified system command. | ||
| 358 | * | ||
| 359 | * @param envp array of strings, each element of which | ||
| 360 | * has environment variable settings in the format | ||
| 361 | * <i>name</i>=<i>value</i>, or | ||
| 362 | * <tt>null</tt> if the subprocess should inherit | ||
| 363 | * the environment of the current process. | ||
| 364 | * | ||
| 365 | * @return A new {@link Process} object for managing the subprocess | ||
| 366 | * | ||
| 367 | * @throws SecurityException | ||
| 368 | * If a security manager exists and its | ||
| 369 | * {@link SecurityManager#checkExec checkExec} | ||
| 370 | * method doesn't allow creation of the subprocess | ||
| 371 | * | ||
| 372 | * @throws IOException | ||
| 373 | * If an I/O error occurs | ||
| 374 | * | ||
| 375 | * @throws NullPointerException | ||
| 376 | * If <code>command</code> is <code>null</code>, | ||
| 377 | * or one of the elements of <code>envp</code> is <code>null</code> | ||
| 378 | * | ||
| 379 | * @throws IllegalArgumentException | ||
| 380 | * If <code>command</code> is empty | ||
| 381 | * | ||
| 382 | * @see #exec(String[], String[], File) | ||
| 383 | * @see ProcessBuilder | ||
| 384 | */ | ||
| 385 | public Process exec(String command, String[] envp) throws IOException { | ||
| 386 | return exec(command, envp, null); | ||
| 387 | } | ||
| 388 | |||
| 389 | /** | ||
| 390 | * Executes the specified string command in a separate process with the | ||
| 391 | * specified environment and working directory. | ||
| 392 | * | ||
| 393 | * <p>This is a convenience method. An invocation of the form | ||
| 394 | * <tt>exec(command, envp, dir)</tt> | ||
| 395 | * behaves in exactly the same way as the invocation | ||
| 396 | * <tt>{@link #exec(String[], String[], File) exec}(cmdarray, envp, dir)</tt>, | ||
| 397 | * where <code>cmdarray</code> is an array of all the tokens in | ||
| 398 | * <code>command</code>. | ||
| 399 | * | ||
| 400 | * <p>More precisely, the <code>command</code> string is broken | ||
| 401 | * into tokens using a {@link StringTokenizer} created by the call | ||
| 402 | * <code>new {@link StringTokenizer}(command)</code> with no | ||
| 403 | * further modification of the character categories. The tokens | ||
| 404 | * produced by the tokenizer are then placed in the new string | ||
| 405 | * array <code>cmdarray</code>, in the same order. | ||
| 406 | * | ||
| 407 | * @param command a specified system command. | ||
| 408 | * | ||
| 409 | * @param envp array of strings, each element of which | ||
| 410 | * has environment variable settings in the format | ||
| 411 | * <i>name</i>=<i>value</i>, or | ||
| 412 | * <tt>null</tt> if the subprocess should inherit | ||
| 413 | * the environment of the current process. | ||
| 414 | * | ||
| 415 | * @param dir the working directory of the subprocess, or | ||
| 416 | * <tt>null</tt> if the subprocess should inherit | ||
| 417 | * the working directory of the current process. | ||
| 418 | * | ||
| 419 | * @return A new {@link Process} object for managing the subprocess | ||
| 420 | * | ||
| 421 | * @throws SecurityException | ||
| 422 | * If a security manager exists and its | ||
| 423 | * {@link SecurityManager#checkExec checkExec} | ||
| 424 | * method doesn't allow creation of the subprocess | ||
| 425 | * | ||
| 426 | * @throws IOException | ||
| 427 | * If an I/O error occurs | ||
| 428 | * | ||
| 429 | * @throws NullPointerException | ||
| 430 | * If <code>command</code> is <code>null</code>, | ||
| 431 | * or one of the elements of <code>envp</code> is <code>null</code> | ||
| 432 | * | ||
| 433 | * @throws IllegalArgumentException | ||
| 434 | * If <code>command</code> is empty | ||
| 435 | * | ||
| 436 | * @see ProcessBuilder | ||
| 437 | * @since 1.3 | ||
| 438 | */ | ||
| 439 | public Process exec(String command, String[] envp, File dir) | ||
| 440 | throws IOException { | ||
| 441 | if (command.length() == 0) | ||
| 442 | throw new IllegalArgumentException("Empty command"); | ||
| 443 | |||
| 444 | StringTokenizer st = new StringTokenizer(command); | ||
| 445 | String[] cmdarray = new String[st.countTokens()]; | ||
| 446 | for (int i = 0; st.hasMoreTokens(); i++) | ||
| 447 | cmdarray[i] = st.nextToken(); | ||
| 448 | return exec(cmdarray, envp, dir); | ||
| 449 | } | ||
| 450 | |||
| 451 | /** | ||
| 452 | * Executes the specified command and arguments in a separate process. | ||
| 453 | * | ||
| 454 | * <p>This is a convenience method. An invocation of the form | ||
| 455 | * <tt>exec(cmdarray)</tt> | ||
| 456 | * behaves in exactly the same way as the invocation | ||
| 457 | * <tt>{@link #exec(String[], String[], File) exec}(cmdarray, null, null)</tt>. | ||
| 458 | * | ||
| 459 | * @param cmdarray array containing the command to call and | ||
| 460 | * its arguments. | ||
| 461 | * | ||
| 462 | * @return A new {@link Process} object for managing the subprocess | ||
| 463 | * | ||
| 464 | * @throws SecurityException | ||
| 465 | * If a security manager exists and its | ||
| 466 | * {@link SecurityManager#checkExec checkExec} | ||
| 467 | * method doesn't allow creation of the subprocess | ||
| 468 | * | ||
| 469 | * @throws IOException | ||
| 470 | * If an I/O error occurs | ||
| 471 | * | ||
| 472 | * @throws NullPointerException | ||
| 473 | * If <code>cmdarray</code> is <code>null</code>, | ||
| 474 | * or one of the elements of <code>cmdarray</code> is <code>null</code> | ||
| 475 | * | ||
| 476 | * @throws IndexOutOfBoundsException | ||
| 477 | * If <code>cmdarray</code> is an empty array | ||
| 478 | * (has length <code>0</code>) | ||
| 479 | * | ||
| 480 | * @see ProcessBuilder | ||
| 481 | */ | ||
| 482 | public Process exec(String cmdarray[]) throws IOException { | ||
| 483 | return exec(cmdarray, null, null); | ||
| 484 | } | ||
| 485 | |||
| 486 | /** | ||
| 487 | * Executes the specified command and arguments in a separate process | ||
| 488 | * with the specified environment. | ||
| 489 | * | ||
| 490 | * <p>This is a convenience method. An invocation of the form | ||
| 491 | * <tt>exec(cmdarray, envp)</tt> | ||
| 492 | * behaves in exactly the same way as the invocation | ||
| 493 | * <tt>{@link #exec(String[], String[], File) exec}(cmdarray, envp, null)</tt>. | ||
| 494 | * | ||
| 495 | * @param cmdarray array containing the command to call and | ||
| 496 | * its arguments. | ||
| 497 | * | ||
| 498 | * @param envp array of strings, each element of which | ||
| 499 | * has environment variable settings in the format | ||
| 500 | * <i>name</i>=<i>value</i>, or | ||
| 501 | * <tt>null</tt> if the subprocess should inherit | ||
| 502 | * the environment of the current process. | ||
| 503 | * | ||
| 504 | * @return A new {@link Process} object for managing the subprocess | ||
| 505 | * | ||
| 506 | * @throws SecurityException | ||
| 507 | * If a security manager exists and its | ||
| 508 | * {@link SecurityManager#checkExec checkExec} | ||
| 509 | * method doesn't allow creation of the subprocess | ||
| 510 | * | ||
| 511 | * @throws IOException | ||
| 512 | * If an I/O error occurs | ||
| 513 | * | ||
| 514 | * @throws NullPointerException | ||
| 515 | * If <code>cmdarray</code> is <code>null</code>, | ||
| 516 | * or one of the elements of <code>cmdarray</code> is <code>null</code>, | ||
| 517 | * or one of the elements of <code>envp</code> is <code>null</code> | ||
| 518 | * | ||
| 519 | * @throws IndexOutOfBoundsException | ||
| 520 | * If <code>cmdarray</code> is an empty array | ||
| 521 | * (has length <code>0</code>) | ||
| 522 | * | ||
| 523 | * @see ProcessBuilder | ||
| 524 | */ | ||
| 525 | public Process exec(String[] cmdarray, String[] envp) throws IOException { | ||
| 526 | return exec(cmdarray, envp, null); | ||
| 527 | } | ||
| 528 | |||
| 529 | |||
| 530 | /** | ||
| 531 | * Executes the specified command and arguments in a separate process with | ||
| 532 | * the specified environment and working directory. | ||
| 533 | * | ||
| 534 | * <p>Given an array of strings <code>cmdarray</code>, representing the | ||
| 535 | * tokens of a command line, and an array of strings <code>envp</code>, | ||
| 536 | * representing "environment" variable settings, this method creates | ||
| 537 | * a new process in which to execute the specified command. | ||
| 538 | * | ||
| 539 | * <p>This method checks that <code>cmdarray</code> is a valid operating | ||
| 540 | * system command. Which commands are valid is system-dependent, | ||
| 541 | * but at the very least the command must be a non-empty list of | ||
| 542 | * non-null strings. | ||
| 543 | * | ||
| 544 | * <p>If <tt>envp</tt> is <tt>null</tt>, the subprocess inherits the | ||
| 545 | * environment settings of the current process. | ||
| 546 | * | ||
| 547 | * <p>A minimal set of system dependent environment variables may | ||
| 548 | * be required to start a process on some operating systems. | ||
| 549 | * As a result, the subprocess may inherit additional environment variable | ||
| 550 | * settings beyond those in the specified environment. | ||
| 551 | * | ||
| 552 | * <p>{@link ProcessBuilder#start()} is now the preferred way to | ||
| 553 | * start a process with a modified environment. | ||
| 554 | * | ||
| 555 | * <p>The working directory of the new subprocess is specified by <tt>dir</tt>. | ||
| 556 | * If <tt>dir</tt> is <tt>null</tt>, the subprocess inherits the | ||
| 557 | * current working directory of the current process. | ||
| 558 | * | ||
| 559 | * <p>If a security manager exists, its | ||
| 560 | * {@link SecurityManager#checkExec checkExec} | ||
| 561 | * method is invoked with the first component of the array | ||
| 562 | * <code>cmdarray</code> as its argument. This may result in a | ||
| 563 | * {@link SecurityException} being thrown. | ||
| 564 | * | ||
| 565 | * <p>Starting an operating system process is highly system-dependent. | ||
| 566 | * Among the many things that can go wrong are: | ||
| 567 | * <ul> | ||
| 568 | * <li>The operating system program file was not found. | ||
| 569 | * <li>Access to the program file was denied. | ||
| 570 | * <li>The working directory does not exist. | ||
| 571 | * </ul> | ||
| 572 | * | ||
| 573 | * <p>In such cases an exception will be thrown. The exact nature | ||
| 574 | * of the exception is system-dependent, but it will always be a | ||
| 575 | * subclass of {@link IOException}. | ||
| 576 | * | ||
| 577 | * | ||
| 578 | * @param cmdarray array containing the command to call and | ||
| 579 | * its arguments. | ||
| 580 | * | ||
| 581 | * @param envp array of strings, each element of which | ||
| 582 | * has environment variable settings in the format | ||
| 583 | * <i>name</i>=<i>value</i>, or | ||
| 584 | * <tt>null</tt> if the subprocess should inherit | ||
| 585 | * the environment of the current process. | ||
| 586 | * | ||
| 587 | * @param dir the working directory of the subprocess, or | ||
| 588 | * <tt>null</tt> if the subprocess should inherit | ||
| 589 | * the working directory of the current process. | ||
| 590 | * | ||
| 591 | * @return A new {@link Process} object for managing the subprocess | ||
| 592 | * | ||
| 593 | * @throws SecurityException | ||
| 594 | * If a security manager exists and its | ||
| 595 | * {@link SecurityManager#checkExec checkExec} | ||
| 596 | * method doesn't allow creation of the subprocess | ||
| 597 | * | ||
| 598 | * @throws IOException | ||
| 599 | * If an I/O error occurs | ||
| 600 | * | ||
| 601 | * @throws NullPointerException | ||
| 602 | * If <code>cmdarray</code> is <code>null</code>, | ||
| 603 | * or one of the elements of <code>cmdarray</code> is <code>null</code>, | ||
| 604 | * or one of the elements of <code>envp</code> is <code>null</code> | ||
| 605 | * | ||
| 606 | * @throws IndexOutOfBoundsException | ||
| 607 | * If <code>cmdarray</code> is an empty array | ||
| 608 | * (has length <code>0</code>) | ||
| 609 | * | ||
| 610 | * @see ProcessBuilder | ||
| 611 | * @since 1.3 | ||
| 612 | */ | ||
| 613 | public Process exec(String[] cmdarray, String[] envp, File dir) | ||
| 614 | throws IOException { | ||
| 615 | return new ProcessBuilder(cmdarray) | ||
| 616 | .environment(envp) | ||
| 617 | .directory(dir) | ||
| 618 | .start(); | ||
| 619 | } | ||
| 620 | |||
| 621 | /** | ||
| 622 | * Returns the number of processors available to the Java virtual machine. | ||
| 623 | * | ||
| 624 | * <p> This value may change during a particular invocation of the virtual | ||
| 625 | * machine. Applications that are sensitive to the number of available | ||
| 626 | * processors should therefore occasionally poll this property and adjust | ||
| 627 | * their resource usage appropriately. </p> | ||
| 628 | * | ||
| 629 | * @return the maximum number of processors available to the virtual | ||
| 630 | * machine; never smaller than one | ||
| 631 | * @since 1.4 | ||
| 632 | */ | ||
| 633 | public native int availableProcessors(); | ||
| 634 | |||
| 635 | /** | ||
| 636 | * Returns the amount of free memory in the Java Virtual Machine. | ||
| 637 | * Calling the | ||
| 638 | * <code>gc</code> method may result in increasing the value returned | ||
| 639 | * by <code>freeMemory.</code> | ||
| 640 | * | ||
| 641 | * @return an approximation to the total amount of memory currently | ||
| 642 | * available for future allocated objects, measured in bytes. | ||
| 643 | */ | ||
| 644 | public native long freeMemory(); | ||
| 645 | |||
| 646 | /** | ||
| 647 | * Returns the total amount of memory in the Java virtual machine. | ||
| 648 | * The value returned by this method may vary over time, depending on | ||
| 649 | * the host environment. | ||
| 650 | * <p> | ||
| 651 | * Note that the amount of memory required to hold an object of any | ||
| 652 | * given type may be implementation-dependent. | ||
| 653 | * | ||
| 654 | * @return the total amount of memory currently available for current | ||
| 655 | * and future objects, measured in bytes. | ||
| 656 | */ | ||
| 657 | public native long totalMemory(); | ||
| 658 | |||
| 659 | /** | ||
| 660 | * Returns the maximum amount of memory that the Java virtual machine will | ||
| 661 | * attempt to use. If there is no inherent limit then the value {@link | ||
| 662 | * java.lang.Long#MAX_VALUE} will be returned. </p> | ||
| 663 | * | ||
| 664 | * @return the maximum amount of memory that the virtual machine will | ||
| 665 | * attempt to use, measured in bytes | ||
| 666 | * @since 1.4 | ||
| 667 | */ | ||
| 668 | public native long maxMemory(); | ||
| 669 | |||
| 670 | /** | ||
| 671 | * Runs the garbage collector. | ||
| 672 | * Calling this method suggests that the Java virtual machine expend | ||
| 673 | * effort toward recycling unused objects in order to make the memory | ||
| 674 | * they currently occupy available for quick reuse. When control | ||
| 675 | * returns from the method call, the virtual machine has made | ||
| 676 | * its best effort to recycle all discarded objects. | ||
| 677 | * <p> | ||
| 678 | * The name <code>gc</code> stands for "garbage | ||
| 679 | * collector". The virtual machine performs this recycling | ||
| 680 | * process automatically as needed, in a separate thread, even if the | ||
| 681 | * <code>gc</code> method is not invoked explicitly. | ||
| 682 | * <p> | ||
| 683 | * The method {@link System#gc()} is the conventional and convenient | ||
| 684 | * means of invoking this method. | ||
| 685 | */ | ||
| 686 | public native void gc(); | ||
| 687 | |||
| 688 | /* Wormhole for calling java.lang.ref.Finalizer.runFinalization */ | ||
| 689 | private static native void runFinalization0(); | ||
| 690 | |||
| 691 | /** | ||
| 692 | * Runs the finalization methods of any objects pending finalization. | ||
| 693 | * Calling this method suggests that the Java virtual machine expend | ||
| 694 | * effort toward running the <code>finalize</code> methods of objects | ||
| 695 | * that have been found to be discarded but whose <code>finalize</code> | ||
| 696 | * methods have not yet been run. When control returns from the | ||
| 697 | * method call, the virtual machine has made a best effort to | ||
| 698 | * complete all outstanding finalizations. | ||
| 699 | * <p> | ||
| 700 | * The virtual machine performs the finalization process | ||
| 701 | * automatically as needed, in a separate thread, if the | ||
| 702 | * <code>runFinalization</code> method is not invoked explicitly. | ||
| 703 | * <p> | ||
| 704 | * The method {@link System#runFinalization()} is the conventional | ||
| 705 | * and convenient means of invoking this method. | ||
| 706 | * | ||
| 707 | * @see java.lang.Object#finalize() | ||
| 708 | */ | ||
| 709 | public void runFinalization() { | ||
| 710 | runFinalization0(); | ||
| 711 | } | ||
| 712 | |||
| 713 | /** | ||
| 714 | * Enables/Disables tracing of instructions. | ||
| 715 | * If the <code>boolean</code> argument is <code>true</code>, this | ||
| 716 | * method suggests that the Java virtual machine emit debugging | ||
| 717 | * information for each instruction in the virtual machine as it | ||
| 718 | * is executed. The format of this information, and the file or other | ||
| 719 | * output stream to which it is emitted, depends on the host environment. | ||
| 720 | * The virtual machine may ignore this request if it does not support | ||
| 721 | * this feature. The destination of the trace output is system | ||
| 722 | * dependent. | ||
| 723 | * <p> | ||
| 724 | * If the <code>boolean</code> argument is <code>false</code>, this | ||
| 725 | * method causes the virtual machine to stop performing the | ||
| 726 | * detailed instruction trace it is performing. | ||
| 727 | * | ||
| 728 | * @param on <code>true</code> to enable instruction tracing; | ||
| 729 | * <code>false</code> to disable this feature. | ||
| 730 | */ | ||
| 731 | public native void traceInstructions(boolean on); | ||
| 732 | |||
| 733 | /** | ||
| 734 | * Enables/Disables tracing of method calls. | ||
| 735 | * If the <code>boolean</code> argument is <code>true</code>, this | ||
| 736 | * method suggests that the Java virtual machine emit debugging | ||
| 737 | * information for each method in the virtual machine as it is | ||
| 738 | * called. The format of this information, and the file or other output | ||
| 739 | * stream to which it is emitted, depends on the host environment. The | ||
| 740 | * virtual machine may ignore this request if it does not support | ||
| 741 | * this feature. | ||
| 742 | * <p> | ||
| 743 | * Calling this method with argument false suggests that the | ||
| 744 | * virtual machine cease emitting per-call debugging information. | ||
| 745 | * | ||
| 746 | * @param on <code>true</code> to enable instruction tracing; | ||
| 747 | * <code>false</code> to disable this feature. | ||
| 748 | */ | ||
| 749 | public native void traceMethodCalls(boolean on); | ||
| 750 | |||
| 751 | /** | ||
| 752 | * Loads the specified filename as a dynamic library. The filename | ||
| 753 | * argument must be a complete path name, | ||
| 754 | * (for example | ||
| 755 | * <code>Runtime.getRuntime().load("/home/avh/lib/libX11.so");</code>). | ||
| 756 | * <p> | ||
| 757 | * First, if there is a security manager, its <code>checkLink</code> | ||
| 758 | * method is called with the <code>filename</code> as its argument. | ||
| 759 | * This may result in a security exception. | ||
| 760 | * <p> | ||
| 761 | * This is similar to the method {@link #loadLibrary(String)}, but it | ||
| 762 | * accepts a general file name as an argument rather than just a library | ||
| 763 | * name, allowing any file of native code to be loaded. | ||
| 764 | * <p> | ||
| 765 | * The method {@link System#load(String)} is the conventional and | ||
| 766 | * convenient means of invoking this method. | ||
| 767 | * | ||
| 768 | * @param filename the file to load. | ||
| 769 | * @exception SecurityException if a security manager exists and its | ||
| 770 | * <code>checkLink</code> method doesn't allow | ||
| 771 | * loading of the specified dynamic library | ||
| 772 | * @exception UnsatisfiedLinkError if the file does not exist. | ||
| 773 | * @exception NullPointerException if <code>filename</code> is | ||
| 774 | * <code>null</code> | ||
| 775 | * @see java.lang.Runtime#getRuntime() | ||
| 776 | * @see java.lang.SecurityException | ||
| 777 | * @see java.lang.SecurityManager#checkLink(java.lang.String) | ||
| 778 | */ | ||
| 779 | public void load(String filename) { | ||
| 780 | load0(System.getCallerClass(), filename); | ||
| 781 | } | ||
| 782 | |||
| 783 | synchronized void load0(Class fromClass, String filename) { | ||
| 784 | SecurityManager security = System.getSecurityManager(); | ||
| 785 | if (security != null) { | ||
| 786 | security.checkLink(filename); | ||
| 787 | } | ||
| 788 | if (!(new File(filename).isAbsolute())) { | ||
| 789 | throw new UnsatisfiedLinkError( | ||
| 790 | "Expecting an absolute path of the library: " + filename); | ||
| 791 | } | ||
| 792 | ClassLoader.loadLibrary(fromClass, filename, true); | ||
| 793 | } | ||
| 794 | |||
| 795 | /** | ||
| 796 | * Loads the dynamic library with the specified library name. | ||
| 797 | * A file containing native code is loaded from the local file system | ||
| 798 | * from a place where library files are conventionally obtained. The | ||
| 799 | * details of this process are implementation-dependent. The | ||
| 800 | * mapping from a library name to a specific filename is done in a | ||
| 801 | * system-specific manner. | ||
| 802 | * <p> | ||
| 803 | * First, if there is a security manager, its <code>checkLink</code> | ||
| 804 | * method is called with the <code>libname</code> as its argument. | ||
| 805 | * This may result in a security exception. | ||
| 806 | * <p> | ||
| 807 | * The method {@link System#loadLibrary(String)} is the conventional | ||
| 808 | * and convenient means of invoking this method. If native | ||
| 809 | * methods are to be used in the implementation of a class, a standard | ||
| 810 | * strategy is to put the native code in a library file (call it | ||
| 811 | * <code>LibFile</code>) and then to put a static initializer: | ||
| 812 | * <blockquote><pre> | ||
| 813 | * static { System.loadLibrary("LibFile"); } | ||
| 814 | * </pre></blockquote> | ||
| 815 | * within the class declaration. When the class is loaded and | ||
| 816 | * initialized, the necessary native code implementation for the native | ||
| 817 | * methods will then be loaded as well. | ||
| 818 | * <p> | ||
| 819 | * If this method is called more than once with the same library | ||
| 820 | * name, the second and subsequent calls are ignored. | ||
| 821 | * | ||
| 822 | * @param libname the name of the library. | ||
| 823 | * @exception SecurityException if a security manager exists and its | ||
| 824 | * <code>checkLink</code> method doesn't allow | ||
| 825 | * loading of the specified dynamic library | ||
| 826 | * @exception UnsatisfiedLinkError if the library does not exist. | ||
| 827 | * @exception NullPointerException if <code>libname</code> is | ||
| 828 | * <code>null</code> | ||
| 829 | * @see java.lang.SecurityException | ||
| 830 | * @see java.lang.SecurityManager#checkLink(java.lang.String) | ||
| 831 | */ | ||
| 832 | public void loadLibrary(String libname) { | ||
| 833 | loadLibrary0(System.getCallerClass(), libname); | ||
| 834 | } | ||
| 835 | |||
| 836 | synchronized void loadLibrary0(Class fromClass, String libname) { | ||
| 837 | SecurityManager security = System.getSecurityManager(); | ||
| 838 | if (security != null) { | ||
| 839 | security.checkLink(libname); | ||
| 840 | } | ||
| 841 | if (libname.indexOf((int)File.separatorChar) != -1) { | ||
| 842 | throw new UnsatisfiedLinkError( | ||
| 843 | "Directory separator should not appear in library name: " + libname); | ||
| 844 | } | ||
| 845 | ClassLoader.loadLibrary(fromClass, libname, false); | ||
| 846 | } | ||
| 847 | |||
| 848 | /** | ||
| 849 | * Creates a localized version of an input stream. This method takes | ||
| 850 | * an <code>InputStream</code> and returns an <code>InputStream</code> | ||
| 851 | * equivalent to the argument in all respects except that it is | ||
| 852 | * localized: as characters in the local character set are read from | ||
| 853 | * the stream, they are automatically converted from the local | ||
| 854 | * character set to Unicode. | ||
| 855 | * <p> | ||
| 856 | * If the argument is already a localized stream, it may be returned | ||
| 857 | * as the result. | ||
| 858 | * | ||
| 859 | * @param in InputStream to localize | ||
| 860 | * @return a localized input stream | ||
| 861 | * @see java.io.InputStream | ||
| 862 | * @see java.io.BufferedReader#BufferedReader(java.io.Reader) | ||
| 863 | * @see java.io.InputStreamReader#InputStreamReader(java.io.InputStream) | ||
| 864 | * @deprecated As of JDK 1.1, the preferred way to translate a byte | ||
| 865 | * stream in the local encoding into a character stream in Unicode is via | ||
| 866 | * the <code>InputStreamReader</code> and <code>BufferedReader</code> | ||
| 867 | * classes. | ||
| 868 | */ | ||
| 869 | @Deprecated | ||
| 870 | public InputStream getLocalizedInputStream(InputStream in) { | ||
| 871 | return in; | ||
| 872 | } | ||
| 873 | |||
| 874 | /** | ||
| 875 | * Creates a localized version of an output stream. This method | ||
| 876 | * takes an <code>OutputStream</code> and returns an | ||
| 877 | * <code>OutputStream</code> equivalent to the argument in all respects | ||
| 878 | * except that it is localized: as Unicode characters are written to | ||
| 879 | * the stream, they are automatically converted to the local | ||
| 880 | * character set. | ||
| 881 | * <p> | ||
| 882 | * If the argument is already a localized stream, it may be returned | ||
| 883 | * as the result. | ||
| 884 | * | ||
| 885 | * @deprecated As of JDK 1.1, the preferred way to translate a | ||
| 886 | * Unicode character stream into a byte stream in the local encoding is via | ||
| 887 | * the <code>OutputStreamWriter</code>, <code>BufferedWriter</code>, and | ||
| 888 | * <code>PrintWriter</code> classes. | ||
| 889 | * | ||
| 890 | * @param out OutputStream to localize | ||
| 891 | * @return a localized output stream | ||
| 892 | * @see java.io.OutputStream | ||
| 893 | * @see java.io.BufferedWriter#BufferedWriter(java.io.Writer) | ||
| 894 | * @see java.io.OutputStreamWriter#OutputStreamWriter(java.io.OutputStream) | ||
| 895 | * @see java.io.PrintWriter#PrintWriter(java.io.OutputStream) | ||
| 896 | */ | ||
| 897 | @Deprecated | ||
| 898 | public OutputStream getLocalizedOutputStream(OutputStream out) { | ||
| 899 | return out; | ||
| 900 | } | ||
| 901 | |||
| 902 | } | ||