Showing the changes to java/pkg/java/lang/Runtime.java (1 of 18352 files). Show all
Unified · Split
| @@ -0,0 +1,902 @@ | ||
| 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 | +} | |