Java tutorial
/* * Copyright 2014 Matthias Einwag * * The jawampa authors license this file to you under the Apache License, * version 2.0 (the "License"); you may not use this file except in compliance * with the License. You may obtain a copy of the License at: * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the * License for the specific language governing permissions and limitations * under the License. */ package ws.wamp.jawampa.client; import java.util.EnumSet; import java.util.Iterator; import java.util.List; import ws.wamp.jawampa.ApplicationError; import ws.wamp.jawampa.WampClient; import ws.wamp.jawampa.WampMessages; import ws.wamp.jawampa.WampRoles; import ws.wamp.jawampa.WampMessages.AbortMessage; import ws.wamp.jawampa.WampMessages.AuthenticateMessage; import ws.wamp.jawampa.WampMessages.ChallengeMessage; import ws.wamp.jawampa.WampMessages.WampMessage; import ws.wamp.jawampa.WampMessages.WelcomeMessage; import ws.wamp.jawampa.auth.client.ClientSideAuthentication; import ws.wamp.jawampa.connection.IConnectionController; import ws.wamp.jawampa.connection.IWampConnectionPromise; import com.fasterxml.jackson.databind.JsonNode; import com.fasterxml.jackson.databind.node.ObjectNode; /** * The state where the WAMP handshake (HELLO, WELCOME, ...) is exchanged. */ public class HandshakingState implements ClientState { private final StateController stateController; /** The currently active connection */ public final IConnectionController connectionController; private int nrReconnectAttempts; private boolean challengeMsgAllowed = true; Throwable disconnectReason; public HandshakingState(StateController stateController, IConnectionController connectionController, int nrReconnectAttempts) { this.stateController = stateController; this.connectionController = connectionController; this.nrReconnectAttempts = nrReconnectAttempts; } @Override public void onEnter(ClientState lastState) { sendHelloMessage(); } @Override public void onLeave(ClientState newState) { } @Override public void initClose() { closeIncompleteSession(null, ApplicationError.SYSTEM_SHUTDOWN, false); } void closeIncompleteSession(Throwable disconnectReason, String optAbortReason, boolean reconnectAllowed) { // Send abort to the remote if (optAbortReason != null) { AbortMessage msg = new AbortMessage(null, optAbortReason); connectionController.sendMessage(msg, IWampConnectionPromise.Empty); } int nrReconnects = reconnectAllowed ? nrReconnectAttempts : 0; if (nrReconnects == 0) { stateController.setExternalState(new WampClient.DisconnectedState(disconnectReason)); } WaitingForDisconnectState newState = new WaitingForDisconnectState(stateController, nrReconnects); connectionController.close(true, newState.closePromise()); stateController.setState(newState); } void handleProtocolError() { handleSessionError(new ApplicationError(ApplicationError.PROTCOL_ERROR), ApplicationError.PROTCOL_ERROR); } void handleSessionError(ApplicationError error, String closeReason) { boolean reconnectAllowed = !stateController.clientConfig().closeClientOnErrors(); if (!reconnectAllowed) { // Record the error that happened during the session stateController.setCloseError(error); } closeIncompleteSession(error, closeReason, reconnectAllowed); } /** * Is called if the underlying connection was closed from the remote side. * Won't be called if the user issues the close, since the client will then move * to the {@link WaitingForDisconnectState} directly. * @param closeReason An optional reason why the connection closed. */ void onConnectionClosed(Throwable closeReason) { if (closeReason == null) closeReason = new ApplicationError(ApplicationError.TRANSPORT_CLOSED); closeIncompleteSession(closeReason, null, true); } /** * Is called after the low-level connection between the client and the server was established */ void sendHelloMessage() { // System.out.println("Session websocket connection established"); // Connection to the remote host was established // However the WAMP session is not established until the handshake was finished connectionController.sendMessage(new WampMessages.HelloMessage(stateController.clientConfig().realm(), stateController.clientConfig().helloDetails()), IWampConnectionPromise.Empty); } void onMessage(WampMessage msg) { // We were not yet welcomed if (msg instanceof WelcomeMessage) { // Receive a welcome. Now the session is established! ObjectNode welcomeDetails = ((WelcomeMessage) msg).details; long sessionId = ((WelcomeMessage) msg).sessionId; // Extract the roles of the remote side JsonNode roleNode = welcomeDetails.get("roles"); if (roleNode == null || !roleNode.isObject()) { handleProtocolError(); return; } EnumSet<WampRoles> routerRoles = EnumSet.noneOf(WampRoles.class); Iterator<String> roleKeys = roleNode.fieldNames(); while (roleKeys.hasNext()) { WampRoles role = WampRoles.fromString(roleKeys.next()); if (role != null) routerRoles.add(role); } SessionEstablishedState newState = new SessionEstablishedState(stateController, connectionController, sessionId, welcomeDetails, routerRoles); stateController.setState(newState); } else if (msg instanceof ChallengeMessage) { if (!challengeMsgAllowed) { // Allow Challenge message only a single time handleProtocolError(); return; } challengeMsgAllowed = false; ChallengeMessage challenge = (ChallengeMessage) msg; String authMethodString = challenge.authMethod; List<ClientSideAuthentication> authMethods = stateController.clientConfig().authMethods(); for (ClientSideAuthentication authMethod : authMethods) { if (authMethod.getAuthMethod().equals(authMethodString)) { AuthenticateMessage reply = authMethod.handleChallenge(challenge, stateController.clientConfig().objectMapper()); if (reply == null) { handleProtocolError(); } else { connectionController.sendMessage(reply, IWampConnectionPromise.Empty); } return; } } handleProtocolError(); } else if (msg instanceof AbortMessage) { // The remote doesn't want us to connect :( AbortMessage abort = (AbortMessage) msg; handleSessionError(new ApplicationError(abort.reason), null); } } }