Package org.pentaho.platform.web.gwt.rpc

Class AbstractGwtRpc

java.lang.Object
org.pentaho.platform.web.gwt.rpc.AbstractGwtRpc
Direct Known Subclasses:
PluginGwtRpc, SystemGwtRpc
public abstract class AbstractGwtRpc extends Object
The AbstractGwtRpc class is the base abstract class of classes that represent a GWT Remote Procedure Call which is made via HTTP.

One instance of this class is initialized with the HttpServletRequest instance which represents a GWT-RPC request.

The class exposes functionality to:

  1. obtain the target object of the GWT-RPC request, via getTarget();
  2. obtain the class loader which should be current when the call is performed, via getTargetClassLoader();
  3. obtain the serialized request payload from the HTTP request, via getRequestPayload(); this is useful for low-level integration with RemoteServiceServlet;
  4. obtain the parsed request, via getRequest();
  5. invoke the target method on the target object within its class loader and to return a serialized response.

Concrete specialized classes exist that can handle GWT-RPC requests for services of:

  • PluginGwtRpc - services of Pentaho Platform plugins, e.g. /gwtrpc/serviceName;
  • SystemGwtRpc - services of the Pentaho Platform itself, e.g. /ws/gwt/serviceName.

  • Field Details

    • HTTP_GWT_RPC_ATTRIBUTE

      protected static final String HTTP_GWT_RPC_ATTRIBUTE

  • Constructor Details

    • AbstractGwtRpc

      protected AbstractGwtRpc(@NonNull javax.servlet.http.HttpServletRequest httpRequest)
      Creates an instance given an HTTP request.
      Parameters:
      httpRequest - An HTTP request.

  • Method Details

    • setSerializationPolicyCache

      public void setSerializationPolicyCache(@Nullable IGwtRpcSerializationPolicyCache serializationPolicyCache)
      Sets the serialization policy cache which will be used to load a serialization policy before creating one, or to store the created one if none exists.

      The serialization policy is used to safely deserialize the GWT-RPC request and serialize the GWT-RPC response of this call.

      Parameters:
      serializationPolicyCache - A serialization policy cache instance, or null.

    • getSerializationPolicyCache

      @Nullable public IGwtRpcSerializationPolicyCache getSerializationPolicyCache()
      Gets the serialization policy cache instance used by this GWT-RPC call.
      Returns:
      The serialization policy cache instance, if any; null, otherwise.

    • getServletRequest

      @NonNull public javax.servlet.http.HttpServletRequest getServletRequest()
      Gets the associated HTTP request.
      Returns:
      An HTTP request.

    • getServletContext

      @NonNull protected javax.servlet.ServletContext getServletContext()
      Gets the associated servlet context.

      Syntax-sugar method equivalent to getServletRequest().getServletContext().

      Returns:
      A servlet context.

    • getAppContextPath

      @NonNull protected String getAppContextPath()
      Gets the associated web app context path.

      Syntax-sugar method equivalent to getServletRequest().getContextPath().

      Example value: /pentaho.

      Returns:
      The servlet context path.

    • getServletContextPath

      @NonNull protected String getServletContextPath()
      Gets the associated servlet context path.

      Example value: /gwt/rpc/serviceName?bar=foo.

      Returns:
      The servlet context path.

    • getTarget

      @NonNull public Object getTarget()
      Gets the target object on which the remote call will be made.
      Returns:
      The target object.
      Throws:
      GwtRpcProxyException - if the target object cannot be resolved.

    • getTargetClassLoader

      @NonNull public ClassLoader getTargetClassLoader()
      Gets the class loader which must be current to deserialize the request, invoke the method and serialize the response.
      Returns:
      The target class laoder.
      Throws:
      GwtRpcProxyException - if the target class loader cannot be resolved.

    • resolveTarget

      @NonNull protected abstract Object resolveTarget()
      Resolves the target object on which the remote call will be made.
      Returns:
      The target object.
      Throws:
      GwtRpcProxyException - if the target object cannot be resolved.

    • getRequestPayload

      @NonNull public String getRequestPayload() throws GwtRpcProxyException
      Gets the serialized request payload which is present in the HTTP request.
      Returns:
      The serialized request payload.
      Throws:
      GwtRpcProxyException - if the request is not valid.
      See Also:
      • RPCServletUtils.readContentAsGwtRpc(HttpServletRequest)

    • getRequest

      @NonNull public com.google.gwt.user.server.rpc.RPCRequest getRequest()
      Gets the processed GWT-RPC request object.
      Returns:
      The processed request.
      Throws:
      GwtRpcProxyException - if the request is invalid.
      See Also:
      • RPC.decodeRequest(String, Class, com.google.gwt.user.server.rpc.SerializationPolicyProvider)

    • getSerializationPolicy

      @NonNull protected com.google.gwt.user.server.rpc.SerializationPolicy getSerializationPolicy(@Nullable String moduleBaseURL, @Nullable String strongName)

    • loadSerializationPolicy

      @Nullable protected abstract com.google.gwt.user.server.rpc.SerializationPolicy loadSerializationPolicy(@NonNull String moduleContextPath, @Nullable String strongName)
      Loads the serialization policy having the given GWT module context path and strong name.

      Typically, this method loads a serialization policy from a persistence medium.

      Parameters:
      moduleContextPath - The GWT module context path (e.g. /content/data-access/resources/gwt/).
      strongName - The serialization policy strong name.
      Returns:
      The associated serialization policy, if one can be loaded; null, otherwise, in which case the default serialization policy is assumed, as returned by getDefaultSerializationPolicy().

    • getDefaultSerializationPolicy

      @NonNull protected static com.google.gwt.user.server.rpc.SerializationPolicy getDefaultSerializationPolicy()
      Gets a serialization policy to use when no specific serialization policy is available.

      the default serialization policy is a legacy, 1.3.3 compatible, serialization policy and may result in SerializationException.

      Returns:
      The default serialization policy.
      See Also:
      • RPC.getDefaultSerializationPolicy()

    • loadSerializationPolicyFromInputStream

      @Nullable protected static com.google.gwt.user.server.rpc.SerializationPolicy loadSerializationPolicyFromInputStream(@NonNull ThrowingSupplier<InputStream,IOException> inputStreamSupplier, @NonNull String serializationPolicyFileName)
      Loads a serialization policy given an input stream whose content is in GWT-RPC serialization policy standard format.

      Helper method for custom implementations.

      Parameters:
      inputStreamSupplier - A supplier of an input stream of the serialization policy.
      serializationPolicyFileName - The serialization policy file name; used for logging purposes, only.
      Returns:
      The loaded serialization policy, if successfully loaded; null, otherwise.

    • invoke

      @NonNull public String invoke()
      Makes the remote call on the target object and returns the serialized response.
      Returns:
      The serialized response.
      Throws:
      GwtRpcProxyException - if the call does not succeed.

    • getInstance

      @NonNull protected static <R extends AbstractGwtRpc> R getInstance(@NonNull javax.servlet.http.HttpServletRequest httpRequest, @NonNull Function<javax.servlet.http.HttpServletRequest,R> factory, @Nullable IGwtRpcSerializationPolicyCache serializationPolicyCache)
      Gets the instance of a sub-class of AbstractGwtRpc, R, which is stored in the given HTTP request, if there is one already, or creates one and stores it if not.

      The GWT-RPC instance is stored in an HTTP request attribute, as per ServletRequest.getAttribute(String) and ServletRequest.setAttribute(String, Object).

      Helper method for custom implementations.

      Parameters:
      httpRequest - The HTTP request.
      factory - A function which creates an instance of class R given an HTTP request.
      serializationPolicyCache - A serialization policy cache instance to initialize a created instance with.
      Returns:
      The associated GWT-RPC instance.
      See Also: