Package javax.rmi

Class PortableRemoteObject

  • Direct Known Subclasses:
    InitialGroupInfoService.InitialGISImpl

    public class PortableRemoteObject
    extends java.lang.Object
    Server implementation objects may either inherit from javax.rmi.PortableRemoteObject or they may implement a remote interface and then use the exportObject method to register themselves as a server object. The toStub method takes a server implementation and returns a stub that can be used to access that server object. The connect method makes a Remote object ready for remote communication. The unexportObject method is used to deregister a server object, allowing it to become available for garbage collection. The narrow method takes an object reference or abstract interface type and attempts to narrow it to conform to the given interface. If the operation is successful the result will be an object of the specified type, otherwise an exception will be thrown.
    • Constructor Summary

      Constructors 
      Modifier Constructor Description
      protected PortableRemoteObject()
      Initializes the object by calling exportObject(this).
    • Method Summary

      All Methods Static Methods Concrete Methods 
      Modifier and Type Method Description
      static void connect​(java.rmi.Remote target, java.rmi.Remote source)
      Makes a Remote object ready for remote communication.
      private static java.lang.Object createDelegateIfSpecified​(java.lang.String classKey)  
      static void exportObject​(java.rmi.Remote obj)
      Makes a server object ready to receive remote calls.
      private static java.util.Properties getORBPropertiesFile()
      Load the orb.properties file.
      private static java.lang.Class loadDelegateClass​(java.lang.String className)  
      static java.lang.Object narrow​(java.lang.Object narrowFrom, java.lang.Class narrowTo)
      Checks to ensure that an object of a remote or abstract interface type can be cast to a desired type.
      static java.rmi.Remote toStub​(java.rmi.Remote obj)
      Returns a stub for the given server object.
      static void unexportObject​(java.rmi.Remote obj)
      Deregisters a server object from the runtime, allowing the object to become available for garbage collection.
      • Methods inherited from class java.lang.Object

        clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
    • Constructor Detail

      • PortableRemoteObject

        protected PortableRemoteObject()
                                throws java.rmi.RemoteException
        Initializes the object by calling exportObject(this).
        Throws:
        java.rmi.RemoteException - if export fails.
    • Method Detail

      • exportObject

        public static void exportObject​(java.rmi.Remote obj)
                                 throws java.rmi.RemoteException
        Makes a server object ready to receive remote calls. Note that subclasses of PortableRemoteObject do not need to call this method, as it is called by the constructor.
        Parameters:
        obj - the server object to export.
        Throws:
        java.rmi.RemoteException - if export fails.
      • toStub

        public static java.rmi.Remote toStub​(java.rmi.Remote obj)
                                      throws java.rmi.NoSuchObjectException
        Returns a stub for the given server object.
        Parameters:
        obj - the server object for which a stub is required. Must either be a subclass of PortableRemoteObject or have been previously the target of a call to exportObject(java.rmi.Remote).
        Returns:
        the most derived stub for the object.
        Throws:
        java.rmi.NoSuchObjectException - if a stub cannot be located for the given server object.
      • unexportObject

        public static void unexportObject​(java.rmi.Remote obj)
                                   throws java.rmi.NoSuchObjectException
        Deregisters a server object from the runtime, allowing the object to become available for garbage collection.
        Parameters:
        obj - the object to unexport.
        Throws:
        java.rmi.NoSuchObjectException - if the remote object is not currently exported.
      • narrow

        public static java.lang.Object narrow​(java.lang.Object narrowFrom,
                                              java.lang.Class narrowTo)
                                       throws java.lang.ClassCastException
        Checks to ensure that an object of a remote or abstract interface type can be cast to a desired type.
        Parameters:
        narrowFrom - the object to check.
        narrowTo - the desired type.
        Returns:
        an object which can be cast to the desired type.
        Throws:
        java.lang.ClassCastException - if narrowFrom cannot be cast to narrowTo.
      • connect

        public static void connect​(java.rmi.Remote target,
                                   java.rmi.Remote source)
                            throws java.rmi.RemoteException
        Makes a Remote object ready for remote communication. This normally happens implicitly when the object is sent or received as an argument on a remote method call, but in some circumstances it is useful to perform this action by making an explicit call. See the Stub.connect(org.omg.CORBA.ORB) method for more information.
        Parameters:
        target - the object to connect.
        source - a previously connected object.
        Throws:
        java.rmi.RemoteException - if source is not connected or if target is already connected to a different ORB than source.
      • createDelegateIfSpecified

        private static java.lang.Object createDelegateIfSpecified​(java.lang.String classKey)
      • loadDelegateClass

        private static java.lang.Class loadDelegateClass​(java.lang.String className)
                                                  throws java.lang.ClassNotFoundException
        Throws:
        java.lang.ClassNotFoundException
      • getORBPropertiesFile

        private static java.util.Properties getORBPropertiesFile()
        Load the orb.properties file.