Package de.aristaflow.adept2.base.communication.invocation

Class InvocationHandler<T>

java.lang.Object
de.aristaflow.adept2.base.communication.invocation.InvocationHandler<T>
Type Parameters:
T - The type is the interface this invocation handler will handle invocations for, i.e. the type of the service (getComponent()) and the type of the stub representing the service.
All Implemented Interfaces:
InvocationHandler
public class InvocationHandler<T> extends Object implements InvocationHandler
This InvocationHandler handles invocations to a ADEPT2 service through the API-Interface designated by the type parameter T in a distributed environment. It catches the API method calls to the proxy object that represents the service to the caller (i. e. the client) and delegates them to the communication submodule that is responsible for doing the remote calls on the remote service the proxy object is a proxy for.

If a callback object is passed within a parameter to the requested method, then the handler creates a callback URI, associates this URI with the passed callback object and passes this URI to the skeleton responsible for the execution of the requested method on server side instead of the callback object itself.

With this URI the receiver skeleton can create a stub/proxy object intended to do remote callback invocations on the callback object associated with the given callback URI.

The invocation handler only delegates calls to methods of the service interface, which are neither annotated with ProxyIgnore nor with ProxyFollow.

Calls to methods which are annotated with ProxyIgnore, are dismissed.

Calls to methods which are annotated with Replaces will be replaced by the method described in the annotation. All further then applies to the replacing method, i. e. using cached values for an immutable (replacing) method or following the proxy. Replacing methods may switch from virtual to static invocation (i. e. from an instance method to a class method). In this case the parameter values are shifted by one and the first parameter will be the provided object instance. The replacing method has to consider this appropriately, i. e. the first parameter has to be of the appropriate type (of the object instance).
Additionally, replacing may take place locally. In this case the method call on the proxy will not be forwarded but executed locally instead of remote.

The return value of methods annotated with Immutable will cached internally using a WeakReference. Consecutive calls will then use this cached value if it is still present.

Calls to methods which are annotated with ProxyFollow, are replied with another proxy object.

  • Field Details

    • logger

      protected final Logger logger
      My logger.

    • proxyAnnotCache

      protected final Map<Class<?>,Boolean> proxyAnnotCache
      The cache containing whether a class has a proxy annotation (ProxyAllow, ProxyCallback or ServerSideProxyAllow) or implements ServerSideProxy. This is shared across different invocation handlers. null if no caching should be used.
      See Also:
      • checkIface(Class)

    • lazyTime

      protected final long lazyTime
      The time span in milliseconds which a lazy method is considered immutable.

    • remoteIdentifier

      protected final URI remoteIdentifier
      The (physical) service URI of the ADEPT2 component this object is a proxy for.

    • registeredIdentifier

      protected final URI registeredIdentifier
      The original (logical) URI identifying the remote service to call, in case a URI mapping was applied on the remote identifier URI.

    • callback

      protected final boolean callback
      Whether this invocation handler is a callback object, that is, it is a stub that has been created for a callback parameter in an invocation message.

    • iface

      protected final Class<T> iface
      The interface, this is a proxy for.

  • Constructor Details

    • InvocationHandler

      @Deprecated(since="15.0.0", forRemoval=true) public InvocationHandler(InvocationTarget invTarget, AtomicLong invId, long lazyTime, URI remoteIdentifier, URI registeredIdentifier, Class<T> remoteInterface, boolean callback, Map<Class<?>,Boolean> proxyAnnotCache, Logger logger)
      Deprecated, for removal: This API element is subject to removal in a future version.
      Use InvocationHandler(InvocationTarget, AtomicLong, long, URI, URI, Class, boolean, long, long, Map, Logger) instead.
      Create a new invocation handler.
      Parameters:
      invTarget - The invocation target providing the callback export and the invocation delegate to send messages to.
      invId - The count of each invocation to each have its unique ID.
      lazyTime - The time span in milliseconds which a lazy method is considered immutable.
      remoteIdentifier - The (physical) service URI of the ADEPT2 component this object is a proxy for.
      remoteInterface - The interface of the ADEPT2 component, with T defining the generic type of this handler.
      registeredIdentifier - The original (logical) URI identifying the remote service to call, in case a URI mapping was applied on the original URI.
      callback - Whether this invocation handler is a callback object, that is, it is a stub that has been created for a callback parameter in an invocation message.
      proxyAnnotCache - The cache containing whether a class has a proxy annotation (ProxyAllow, ProxyCallback or ServerSideProxyAllow) or implements ServerSideProxy. This is shared across different invocation handlers. null if no caching should be used.
      logger - The class-specific logger for this invocation handler.

    • InvocationHandler

      public InvocationHandler(InvocationTarget invTarget, AtomicLong invId, long lazyTime, URI remoteIdentifier, URI registeredIdentifier, Class<T> remoteInterface, boolean callback, long cachingRemItInitAliveTime, long cachingRemItAliveTimeExt, Map<Class<?>,Boolean> proxyAnnotCache, Logger logger)
      Create a new invocation handler.
      Parameters:
      invTarget - The invocation target providing the callback export and the invocation delegate to send messages to.
      invId - The count of each invocation to each have its unique ID.
      lazyTime - The time span in milliseconds which a lazy method is considered immutable.
      remoteIdentifier - The service URI of the ADEPT2 component this object is a proxy for.
      remoteInterface - The interface of the ADEPT2 component, with T defining the generic type of this handler.
      registeredIdentifier - The original URI identifying the remote service to call, in case a URI mapping was applied on the original URI.
      callback - Whether this invocation handler is a callback object, that is, it is a stub that has been created for a callback parameter in an invocation message.
      cachingRemItInitAliveTime - The time in milliseconds to keep a caching remote iterator created for each received remote iterator alive after creating it and before accessing it.
      cachingRemItAliveTimeExt - The time in milliseconds to extend the alive time of a caching remote iterator created for each received remote iterator.
      proxyAnnotCache - The cache containing whether a class has a proxy annotation (ProxyAllow, ProxyCallback or ServerSideProxyAllow) or implements ServerSideProxy. This is shared across different invocation handlers. null if no caching should be used.
      logger - The class-specific logger for this invocation handler.

    • InvocationHandler

      @Deprecated(since="15.0.0", forRemoval=true) protected InvocationHandler(InvocationTarget invTarget, AtomicLong invId, long lazyTime, URI remoteObjectIdentifier, URI registeredIdentifier, boolean callback, Stack<Method> preceder, Map<Class<?>,Boolean> proxyAnnotCache, Logger logger)
      Deprecated, for removal: This API element is subject to removal in a future version.
      Use InvocationHandler(InvocationTarget, AtomicLong, long, URI, URI, boolean, Stack, long, long, Map, Logger) instead.
      Create an invocation handler for the configured component name, following the provided methods to the interface this is a proxy for.

      Invocation handler for ProxyFollow objects are created automatically within this class.

      Parameters:
      invTarget - The invocation target providing the callback export and the invocation delegate to send messages to.
      invId - The count of each invocation to each have its unique ID.
      lazyTime - The time span in milliseconds which a lazy method is considered immutable.
      remoteObjectIdentifier - The (physical) service URI of the ADEPT2 component this object is a proxy for.
      registeredIdentifier - The original (logical) URI identifying the remote service to call, in case a URI mapping was applied on the remote object identifier.
      callback - Whether this invocation handler is a callback object, that is, it is a stub that has been created for a callback parameter in an invocation message.
      preceder - The stack of methods of the component, to reach the object this is a proxy for.
      proxyAnnotCache - The cache containing whether a class has a proxy annotation (ProxyAllow, ProxyCallback or ServerSideProxyAllow) or implements ServerSideProxy. This is shared across different invocation handlers. null if no caching should be used.
      logger - The class-specific logger for this invocation handler.

    • InvocationHandler

      protected InvocationHandler(InvocationTarget invTarget, AtomicLong invId, long lazyTime, URI remoteObjectIdentifier, URI registeredIdentifier, boolean callback, Stack<Method> preceder, long cachingRemItInitAliveTime, long cachingRemItAliveTimeExt, Map<Class<?>,Boolean> proxyAnnotCache, Logger logger)
      Create an invocation handler for the configured component name, following the provided methods to the interface this is a proxy for.

      Invocation handler for ProxyFollow objects are created automatically within this class.

      Parameters:
      invTarget - The invocation target providing the callback export and the invocation delegate to send messages to.
      invId - The count of each invocation to each have its unique ID.
      lazyTime - The time span in milliseconds which a lazy method is considered immutable.
      remoteObjectIdentifier - The service URI of the ADEPT2 component this object is a proxy for.
      registeredIdentifier - The original URI identifying the remote service to call, in case a URI mapping was applied on the remote object identifier.
      callback - Whether this invocation handler is a callback object, that is, it is a stub that has been created for a callback parameter in an invocation message.
      preceder - The stack of methods of the component, to reach the object this is a proxy for.
      cachingRemItInitAliveTime - The time in milliseconds to keep a caching remote iterator created for each received remote iterator alive after creating it and before accessing it.
      cachingRemItAliveTimeExt - The time in milliseconds to extend the alive time of a caching remote iterator created for each received remote iterator.
      proxyAnnotCache - The cache containing whether a class has a proxy annotation (ProxyAllow, ProxyCallback or ServerSideProxyAllow) or implements ServerSideProxy. This is shared across different invocation handlers. null if no caching should be used.
      logger - The class-specific logger for this invocation handler.

  • Method Details

    • getRemoteIdentifier

      public URI getRemoteIdentifier()
      Gets the (physical) service URI of the ADEPT2 component this object is a proxy for.
      Returns:
      The (physical) service URI of the ADEPT2 component this object is a proxy for.

    • getComponent

      public T getComponent()
      Returns:
      The component (i.e. a Proxy).

    • nextInvocationId

      protected long nextInvocationId()
      Generates unique invocation IDs.
      Returns:
      A new invocation ID.

    • invoke

      public Object invoke(Object proxyPar, Method method, Object[] args) throws Throwable
      Specified by:
      invoke in interface InvocationHandler
      Throws:
      Throwable