Package com.sun.jini.start

Class NonActivatableServiceDescriptor

java.lang.Object
com.sun.jini.start.NonActivatableServiceDescriptor
All Implemented Interfaces:
ServiceDescriptor, Serializable
public class NonActivatableServiceDescriptor extends Object implements ServiceDescriptor, Serializable
Class used to launch shared, non-activatable, in-process services. Clients construct this object with the details of the service to be launched, then call create(Configuration config) to launch the service in the invoking object's VM.

This class provides separation of the import codebase (where the service implementation classes are loaded from) from the export codebase (where service clients should load classes from, for example stubs). as well as providing an independent security policy file for each service object. This functionality allows multiple service objects to be placed in the same VM, with each object maintaining distinct export codebase and security policy settings.

Services need to implement the following "non-activatable constructor": 

<impl>(String[] args, LifeCycle lc)
where,
  • args - are the service configuration arguments
  • lc - is the hosting environment's LifeCycle reference.
A service implementation can return its service proxy (via the proxy field of the Created object returned by create) in the following order of precedence:
  1. if the service class implements ServiceProxyAccessor then return value of getServiceProxy will be used as the service proxy.
  2. if the service class implements ProxyAccessor then the return value of getProxy will be used as the service proxy.
  3. Otherwise null will be returned as the service proxy.
The following items are discussed below:

Configuring NonActivatableServiceDescriptor

 information for details.

This implementation obtains its configuration entries from the Configuration object passed into the create method. The following configuration entries use the component prefix "com.sun.jini.start":

• servicePreparer
&nbsp Type: ProxyPreparer
&nbsp Default: new BasicProxyPreparer()
&nbsp Description: The default proxy preparer used to prepare the service proxy. This value should not be null. This entry is obtained during the invocation of create and is used to prepare the service proxy returned by the service implementation (see service proxy section for details). This entry is superseded by explicitly passing a ProxyPreparer to one of the constructors that accept a proxy preparer argument.

Loggers and Logging Levels

 This implementation uses the Logger, named com.sun.jini.start.service.starter. The following table describes the type of information logged as well as the levels of information logged.

com.sun.jini.start.service.starter
Level Description
SEVERE for significant service creation problems
FINER for high level service operation tracing
FINEST for low level service operation tracing

Since:
2.0
Author:
Sun Microsystems, Inc.
See Also:

  • Field Details

    • descCreated

      protected transient boolean descCreated
      Flag indicating when create() has been called

    • descCreatedLock

      protected transient Object descCreatedLock
      Lock object for descCreated flag

  • Constructor Details

    • NonActivatableServiceDescriptor

      public NonActivatableServiceDescriptor(String exportCodebase, String policy, String importCodebase, String implClassName, String[] serverConfigArgs, LifeCycle lifeCycle, ProxyPreparer preparer)
      Main constructor. Simply assigns given parameters to their associated, internal fields unless otherwise noted.
      Parameters:
      exportCodebase - location where clients can download required service-related classes (for example, stubs, proxies, etc.). Codebase components must be separated by spaces in which each component is in URL format.
      policy - server policy filename or URL
      importCodebase - location where server implementation classes can be found. This String assumed (in order) to be either 1) a space delimited set of URL(s) representing a codebase or 2) a File.pathSeparator delimited set of class paths.
      implClassName - name of server implementation class
      serverConfigArgs - service configuration arguments. This parameter is passed as the String[] argument to the implementation's constructor.
      lifeCycle - LifeCycle reference for hosting environment. This parameter is passed as the LifeCycle argument to the implementation's constructor. If this argument is null, then a default, no-op LifeCycle object will be assigned.
      preparer - ProxyPreparer reference. This object will be used to prepare the service's proxy object, if any (see service proxy section for details). If this argument is null, then the default service preparer will be used.

    • NonActivatableServiceDescriptor

      public NonActivatableServiceDescriptor(String exportCodebase, String policy, String importCodebase, String implClassName, String[] serverConfigArgs, LifeCycle lifeCycle)
      Convenience constructor. Equivalent to calling this contructor with null for the preparer reference.

    • NonActivatableServiceDescriptor

      public NonActivatableServiceDescriptor(String exportCodebase, String policy, String importCodebase, String implClassName, String[] serverConfigArgs)
      Convenience constructor. Equivalent to calling this contructor with null for the lifeCycle and preparer references.

    • NonActivatableServiceDescriptor

      public NonActivatableServiceDescriptor(String exportCodebase, String policy, String importCodebase, String implClassName, String[] serverConfigArgs, ProxyPreparer preparer)
      Convenience constructor. Equivalent to calling this contructor with null for the lifeCycle reference.

  • Method Details

    • getGlobalPolicy

      public static AggregatePolicyProvider getGlobalPolicy()

    • getExportCodebase

      public final String getExportCodebase()
      Codebase accessor method.
      Returns:
      the export codebase string associated with this service descriptor.

    • getPolicy

      public final String getPolicy()
      Policy accessor method.
      Returns:
      the policy string associated with this service descriptor.

    • getImportCodebase

      public final String getImportCodebase()
      Classpath accessor method.
      Returns:
      the import codebase string associated with this service descriptor.

    • getImplClassName

      public final String getImplClassName()
      Implementation class accessor method.
      Returns:
      the implementation class string associated with this service descriptor.

    • getServerConfigArgs

      public final String[] getServerConfigArgs()
      Service configuration arguments accessor method.
      Returns:
      the service configuration arguments associated with this service descriptor.

    • getLifeCycle

      public final LifeCycle getLifeCycle()
      LifeCycle accessor method.
      Returns:
      the LifeCycle object associated with this service descriptor.

    • setLifeCycle

      public final void setLifeCycle(LifeCycle lc)
      Sets the LifeCycle object for this descriptor. This needs to be called on the service descriptor prior to calling create(). Useful for (re-)setting the the associated LifeCycle upon deserialization of this descriptor.
      Parameters:
      lc - The LifeCycle object to be associated with this service descriptor.
      Throws:
      IllegalStateException - if called after create() is invoked

    • getServicePreparer

      public final ProxyPreparer getServicePreparer()
      ProxyPreparer accessor method.
      Returns:
      the ProxyPreparer object associated with this service descriptor.

    • setServicePreparer

      public final void setServicePreparer(ProxyPreparer serviceProxyPreparer)
      Sets the ProxyPreparer for this descriptor. This needs to be called on the service descriptor prior to calling create(). Useful for (re-)setting the the associated ProxyPreparer upon deserialization of this descriptor.
      Parameters:
      serviceProxyPreparer - The ProxyPreparer object to be associated with this service descriptor.
      Throws:
      IllegalStateException - if called after create() is invoked

    • create

      public Object create(Configuration config) throws Exception
      Attempts to create a service instance based on the service description information provided via constructor parameters.

      This method:

      • installs an RMISecurityManager if no security manager is already in place
      • installs an AggregatePolicyProvider as the VM-global policy object (upon the first invocation of this method)
      • creates an ActivateWrapper.ExportClassLoader with the associated service's import codebase, export codebase and the current thread's context class loader as its arguments
      • associates the newly created ExportClassLoader and the associated service's policy file with the AggregatePolicyProvider
      • sets the newly created ExportClassLoader as the current thread's context class loader
      • loads the service object's class and calls a constructor with the following signature: 
        <impl>(String[], LifeCycle)
      • obtains the service proxy by calling ServiceProxyAccessor.getServiceProxy() or ProxyAccessor.getProxy(), respectively, on the implementation instance. If neither interface is supported, the proxy reference is set to null
      • resets the context class loader to the context classloader in effect when the method was called
      Specified by:
      create in interface ServiceDescriptor
      Parameters:
      config - The Configuration object used to configure the creation of the returned object.
      Returns:
      a Created instance with the service's proxy and implementation references.
      Throws:
      Exception - Thrown if there was any problem creating the object.

    • toString

      public String toString()
      Prints out a field summary
      Overrides:
      toString in class Object