com.google.gwt.rpc.server
Class RpcServlet

java.lang.Object
  javax.servlet.GenericServlet
      javax.servlet.http.HttpServlet
          com.google.gwt.user.server.rpc.AbstractRemoteServiceServlet
              com.google.gwt.rpc.server.RpcServlet

All Implemented Interfaces:

java.io.Serializable, javax.servlet.Servlet, javax.servlet.ServletConfig

Direct Known Subclasses:

HybridServiceServlet

public class RpcServlet
extends AbstractRemoteServiceServlet

EXPERIMENTAL and subject to change. Do not use this in production code.

The servlet base class for your RPC service implementations that automatically deserializes incoming requests from the client and serializes outgoing responses for client/server RPCs.

See Also:

Serialized Form

CLIENT_ORACLE_EXTENSION

protected static final java.lang.String CLIENT_ORACLE_EXTENSION

See Also:

Constant Field Values

RpcServlet

public RpcServlet()

The default constructor.

getClientOracle

public ClientOracle getClientOracle()
                             throws SerializationException

This method creates the ClientOracle that will provide data about the remote client. It delegates to findClientOracleData(String, String) to obtain access to ClientOracle data emitted by the GWT compiler.

Throws:

SerializationException

processCall

public void processCall(ClientOracle clientOracle,
                        java.lang.String payload,
                        java.io.OutputStream stream)
                 throws SerializationException

Process a call originating from the given request. Uses the RPC.invokeAndStreamResponse(Object, java.lang.reflect.Method, Object[], ClientOracle, OutputStream) method to do the actual work.

Subclasses may optionally override this method to handle the payload in any way they desire (by routing the request to a framework component, for instance). The HttpServletRequest and HttpServletResponse can be accessed via the AbstractRemoteServiceServlet.getThreadLocalRequest() and AbstractRemoteServiceServlet.getThreadLocalResponse() methods.

This is public so that it can be unit tested easily without HTTP.

Parameters:

clientOracle - the ClientOracle that will be used to interpret the request

payload - the UTF-8 request payload

stream - the OutputStream that will receive the encoded response

Throws:

SerializationException - if we cannot serialize the response

processPost

public final void processPost(javax.servlet.http.HttpServletRequest request,
                              javax.servlet.http.HttpServletResponse response)
                       throws javax.servlet.ServletException,
                              java.io.IOException,
                              SerializationException

Standard HttpServlet method: handle the POST. This doPost method swallows ALL exceptions, logs them in the ServletContext, and returns a GENERIC_FAILURE_MSG response with status code 500.

Specified by:

processPost in class AbstractRemoteServiceServlet

Throws:

java.io.IOException

javax.servlet.ServletException

SerializationException

allowHostedModeConnections

protected boolean allowHostedModeConnections()

Indicates whether or not an RPC request from a hosted mode client should be serviced. Requests from hosted mode clients will expose unobfuscated identifiers in the payload. It is intended that developers override this method to restrict access based on installation-specific logic (such as a range of IP addresses, checking for certain cookies, etc.)

The default implementation allows hosted-mode connections from the local host, loopback addresses (127.*), site local (RFC 1918), link local (169.254/16) addresses, and their IPv6 equivalents.

Returns:

true if a hosted mode connection should be allowed

See Also:

AbstractRemoteServiceServlet.getThreadLocalRequest(), InetAddress

findClientOracleData

protected java.io.InputStream findClientOracleData(java.lang.String requestModuleBasePath,
                                                   java.lang.String permutationStrongName)
                                            throws SerializationException

Override this method to control access to permutation-specific data. For instance, the permutation-specific data may be stored in a database in order to support older clients.

The default implementation attempts to load the file from the ServletContext as requestModuleBasePath + permutationStrongName + CLIENT_ORACLE_EXTENSION

Parameters:

requestModuleBasePath - the module's base path, modulo protocol and host, as reported by getRequestModuleBasePath()

permutationStrongName - the module's strong name as reported by AbstractRemoteServiceServlet.getPermutationStrongName()

Throws:

SerializationException

getRequestModuleBasePath

protected final java.lang.String getRequestModuleBasePath()

Extract the module's base path from the current request.

Returns:

the module's base path, modulo protocol and host, as reported by GWT.getModuleBaseURL() or null if the request did not contain the "X-GWT-Module-Base" header

shouldCompressResponse

protected boolean shouldCompressResponse(javax.servlet.http.HttpServletRequest request,
                                         javax.servlet.http.HttpServletResponse response)

Determines whether the response to a given servlet request should or should not be GZIP compressed. This method is only called in cases where the requester accepts GZIP encoding.

This implementation currently returns true if the request originates from a non-local address. Subclasses can override this logic.

Parameters:

request - the request being served

response - the response that will be written into

Returns:

true if responsePayload should be GZIP compressed, otherwise false.