org.gwtproject.rpc.servlet.websocket.RpcEndpoint Maven / Gradle / Ivy

Go to download
Show more of this group Show more artifacts with this name
Show all versions of endpoint-server-servlet Show documentation
There is a newer version: 1.0-alpha-8
Show newest version
/*
 * #%L
 * gwt-websockets-jsr356
 * %%
 * Copyright (C) 2011 - 2018 Vertispan LLC
 * %%
 * Licensed 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.
 * #L%
 */
package org.gwtproject.rpc.servlet.websocket;

import org.gwtproject.rpc.serialization.stream.bytebuffer.ByteBufferSerializationStreamReader;
import org.gwtproject.rpc.serialization.stream.bytebuffer.ByteBufferSerializationStreamWriter;
import org.gwtproject.rpc.api.Client;
import org.gwtproject.rpc.api.Server;
import org.gwtproject.rpc.api.Server.Connection;
import org.gwtproject.rpc.api.impl.AbstractEndpointImpl.EndpointImplConstructor;
import org.gwtproject.rpc.api.impl.AbstractWebSocketClientImpl;

import javax.websocket.*;
import java.io.IOException;
import java.io.UncheckedIOException;
import java.nio.ByteBuffer;
import java.util.List;
import java.util.function.Consumer;

public class RpcEndpoint, C extends Client> {
	private final S server;
	private final EndpointImplConstructor clientConstructor;

	private Consumer handleMessage;

	public RpcEndpoint(S server, EndpointImplConstructor clientConstructor) {
		this.server = server;
		this.clientConstructor = clientConstructor;
	}

	RpcEndpoint(EndpointImplConstructor clientConstructor) {
		this.server = (S) this;
		this.clientConstructor = clientConstructor;
	}


	@OnOpen
	public void onOpen(Session session) {
		C instance = clientConstructor.create(
				serializer -> {
					ByteBufferSerializationStreamWriter writer = new ByteBufferSerializationStreamWriter(serializer);
					writer.prepareToWrite();
					return writer;
				},
				writer -> session.getAsyncRemote().sendBinary(writer.getFullPayload()),
				(onMessage, serializer) -> {
					// using this to delegate to OnMessage, not working otherwise
					handleMessage = message -> onMessage.accept(new ByteBufferSerializationStreamReader(serializer, message));
				}
		);
		List hash = session.getRequestParameterMap().get("checksum");
		try {
			if (hash == null || hash.isEmpty()) {
				session.close(new CloseReason(CloseReason.CloseCodes.CANNOT_ACCEPT, "The checksum query parameter was not specified, cannot accept request"));
				return;
			} else if (hash.size() > 1) {
				session.close(new CloseReason(CloseReason.CloseCodes.CANNOT_ACCEPT, "More than one checksum query parameter specified, cannot accept request"));
				return;
			} else {
				String expected = ((AbstractWebSocketClientImpl) instance).getChecksum();
				String actual = hash.iterator().next();
				if (!expected.equals(actual)) {
					session.close(new CloseReason(CloseReason.CloseCodes.CANNOT_ACCEPT, "Expected checksum with value " + expected));
					return;
				}
			}
		} catch (IOException e) {
			onError(new IOException("Error when closing new connection", e));
		}

		server.setClient(instance);
		instance.setServer(server);

		server.onOpen(new Jsr356Connection(session), server.getClient());

		// Configure defaults present in some servlet containers to avoid some confusing limits. Subclasses
		// can override this method to control those defaults on their own.
		session.setMaxIdleTimeout(0);
		session.setMaxBinaryMessageBufferSize(Integer.MAX_VALUE);
	}

	@OnMessage
	public void onMessage(String message, Session session) throws IOException {
		session.getBasicRemote().sendText("Error: This endpoint does not accept string messages, use binary messages instead.");

		session.close();
	}

	@OnMessage
	public void onMessage(ByteBuffer message) {
		handleMessage.accept(message);
	}
	@OnClose
	public void onClose(Session session) {
		assert server.getClient() != null;
		server.onClose(new Jsr356Connection(session), server.getClient());
	}

	@OnError
	public void onError(Throwable thr) {
		if (server != this) {
			server.onError(thr);
		}
	}

	private static class Jsr356Connection implements Connection {
		private final Session session;

		private Jsr356Connection(Session session) {
			this.session = session;
		}

		@Override
		public void data(String key, Object value) {
			session.getUserProperties().put(key, value);
		}

		@Override
		public Object data(String key) {
			return session.getUserProperties().get(key);
		}

		@Override
		public void close() {
			try {
				session.close();
			} catch (IOException e) {
				throw new UncheckedIOException(e);
			}
		}

		@Override
		public void close(int closeCode, String closeReason) {
			try {
				session.close(new CloseReason(CloseReason.CloseCodes.getCloseCode(closeCode), closeReason));
			} catch (IOException e) {
				throw new UncheckedIOException(e);
			}
		}
	}

}