#Java runtime environment code#

This method checks that cmdarray is a valid operating Representing 'environment' variable settings, this method createsĪ new process in which to execute the specified command. Tokens of a command line, and an array of strings envp, Given an array of strings cmdarray, representing the The specified environment and working directory. Or one of the elements of envp is null IllegalArgumentException - If command is empty Since: 1.3 See Also:Įxecutes the specified command and arguments in a separate process with Method doesn't allow creation of the subprocess IOException - If an I/O error occurs NullPointerException - If command is null, Returns: A new Process object for managing the subprocess Throws: SecurityException - If a security manager exists and its The working directory of the current process. dir - the working directory of the subprocess, or Has environment variable settings in the format envp - array of strings, each element of which Parameters: command - a specified system command. Produced by the tokenizer are then placed in the new stringĪrray cmdarray, in the same order. Into tokens using a StringTokenizer created by the callįurther modification of the character categories. More precisely, the command string is broken Where cmdarray is an array of all the tokens in

An invocation of the formīehaves in exactly the same way as the invocation

Specified environment and working directory. RuntimePermission ('shutdownHooks') Since: 1.3 See Also:Įxecutes the specified string command in a separate process with the Of shutting down SecurityException - If a security manager is present and it denies Has already been run IllegalStateException - If the virtual machine is already in the process Or if it can be determined that the hook is already running or Parameters: hook - An initialized but unstarted Thread object Throws: IllegalArgumentException - If the specified hook has already been registered, Then no guarantee can be made about whether or not any shutdown hooks Method goes awry by, for example, corrupting internal data structures orĪttempting to access nonexistent memory. The virtual machine may also abort if a native SIGKILL signal on Unix or the TerminateProcess call on Virtual machine is terminated externally, for example with the Stop running without shutting down cleanly. In rare circumstances the virtual machine may abort, that is, Terminates the thread it does not cause the virtual machine to exit or Method prints the exception's stack trace to System.err and Uncaught exceptions are handled in shutdown hooks just as in any User interaction or to perform a long-running computation in a shutdown It is therefore inadvisable to attempt any Underlying operating system may only allow a fixed amount of time in Virtual machine is terminated due to user logoff or system shutdown the That the virtual machine will promptly shut down and exit. Shutdown hooks should also finish their work quickly. Services such as the AWT event-dispatch thread, for example, may lead to Have registered their own shutdown hooks and therefore may themselves in

They should also not rely blindly upon services that may Particular, be written to be thread-safe and to avoid deadlocks insofarĪs possible.

Machine and should therefore be coded defensively. Shutdown hooks run at a delicate time in the life cycle of a virtual New shutdown hook or de-register a previously-registered hook.Īttempting either of these operations will cause an Once the shutdown sequence has begun it is impossible to register a Once the shutdown sequence has begun it can be stopped only by Sequence, as will non-daemon threads if shutdown was initiated by Note that daemon threads will continue to run during the shutdown When all the hooks have finished it will then Start all registered shutdown hooks in some unspecified order and let When the virtual machine begins its shutdown sequence it will User interrupt, such as typing ^C, or a system-wide event,Ī shutdown hook is simply an initialized but unstarted

The virtual machine is terminated in response to a.

Thread exits or when the exit (equivalently,

The program exits normally, when the last non-daemon.

The Java virtual machine shuts down in response to two kinds Registers a new virtual-machine shutdown hook. Throws: SecurityException - If a security manager is present and itsĮxiting with the specified status See Also: Otherwise, this methodĬonventional and convenient means of invoking this method. Virtual machine with the given status code. If this method is invoked after all shutdown hooks have alreadyīeen run and the status is nonzero then this method halts the

#Java runtime environment code#

Serves as a status code by convention, a nonzero status code indicatesĪre started in some unspecified order and allowed to run concurrently Terminates the currently running Java virtual machine by initiating its