Package com.zeroc.Ice

Class Application

java.lang.Object
com.zeroc.Ice.Application
Direct Known Subclasses:
Application
public abstract class Application extends Object
Utility base class that makes it easy to correctly initialize and finalize the Ice run time, as well as handle signals. Unless the application specifies a logger, Application installs a per-process logger that logs to the standard error output.

Applications must create a derived class that implements the run(java.lang.String[]) method.

A program can contain only one instance of this class.

See Also:

  • Constructor Details

    • Application

      public Application()
      Initializes an instance that calls Communicator.destroy() if a signal is received.

    • Application

      public Application(SignalPolicy signalPolicy)
      Initializes an instance that handles signals according to the signal policy.
      Parameters:
      signalPolicy - Determines how to respond to signals.
      See Also:

  • Method Details

    • main

      public final int main(String appName, String[] args)
      The application must call main after it has instantiated the derived class. main creates a communicator, establishes the specified signal policy, and, once run returns, destroys the communicator.

      The method prints an error message for any exception that propagates out of run and ensures that the communicator is destroyed correctly even if run completes abnormally.

      Parameters:
      appName - The name of the application. This parameter is used to initialize the value of the Ice.ProgramName property.
      args - The arguments for the application (as passed to Main(String[]) by the operating system.
      Returns:
      The value returned by run. If run terminates with an exception, the return value is non-zero.

    • main

      public final int main(String appName, String[] args, String configFile)
      The application must call main after it has instantiated the derived class. main creates a communicator, establishes the specified signal policy, and, once run returns, destroys the communicator.

      The method prints an error message for any exception that propagates out of run and ensures that the communicator is destroyed correctly even if run completes abnormally.

      Parameters:
      appName - The name of the application. This parameter is used to initialize the value of the Ice.ProgramName property.
      args - Command-line arguments
      configFile - The configuration file with which to initialize Ice properties.
      Returns:
      The value returned by run. If run terminates with an exception, the return value is non-zero.

    • main

      public final int main(String appName, String[] args, InitializationData initializationData)
      The application must call main after it has instantiated the derived class. main creates a communicator, establishes the specified signal policy, and, once run returns, destroys the communicator.

      The method prints an error message for any exception that propagates out of run and ensures that the communicator is destroyed correctly even if run completes abnormally.

      Parameters:
      appName - The name of the application. This parameter is used to initialize the value of the Ice.ProgramName property.
      args - The arguments for the application (as passed to Main(String[]).
      initializationData - Additional data used to initialize the communicator.
      Returns:
      The value returned by run. If run terminates with an exception, the return value is non-zero.
      See Also:

    • doMain

      protected int doMain(String[] args, InitializationData initData)

    • run

      public abstract int run(String[] args)
      Called once the communicator has been initialized. The derived class must implement run, which is the application's starting method.
      Parameters:
      args - The argument vector for the application. Application scans the argument vector passed to main for options that are specific to the Ice run time and removes them; therefore, the vector passed to run is free from Ice-related options and contains only options and arguments that are application-specific.
      Returns:
      The run method should return zero for successful termination, and non-zero otherwise. Application.main returns the value returned by run.

    • appName

      public static String appName()
      Returns the value of appName that is passed to main (which is also the the value of Ice.ProgramName). This method is useful mainly for error messages that include the application name. Because appName is a static method, it is available from anywhere in the program.
      Returns:
      The name of the application.

    • communicator

      public static Communicator communicator()
      Returns the communicator for the application. Because communicator is a static method, it permits access to the communicator from anywhere in the program. Note that, as a consequence, you cannot have more than one instance of Application in a program.
      Returns:
      The communicator for the application.

    • destroyOnInterrupt

      public static void destroyOnInterrupt()
      Instructs Application to call Communicator.destroy() on receipt of a signal. This is default signal handling policy established by the default constructor.
      See Also:

    • shutdownOnInterrupt

      public static void shutdownOnInterrupt()
      Instructs Application to call Communicator.shutdown() on receipt of a signal.
      See Also:

    • setInterruptHook

      public static void setInterruptHook(Runnable newHook)
      Installs a custom shutdown hook. The implementation of the shutdown hook can do whatever cleanup is necessary to shut down the application. The hook is unregistered once run returns. Note that the hook must obey the rules for shutdown hooks; specifically, it must not call exit.
      Parameters:
      newHook - The Runnable to run on shutdown.
      See Also:

    • defaultInterrupt

      public static void defaultInterrupt()
      Clears any shutdown hooks, including any hook established with destroyOnInterrupt() or shutdownOnInterrupt().

    • interrupted

      public static boolean interrupted()
      Determines whether the application shut down intentionally or was forced to shut down by the JVM. This is useful for logging purposes.
      Returns:
      true if a shutdown hook caused the communicator to shut down; false otherwise.