ratpack.websocket.WebSockets Maven / Gradle / Ivy
/*
* Copyright 2013 the original author or authors.
*
* 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.
*/
package ratpack.websocket;
import io.netty.buffer.ByteBuf;
import io.netty.buffer.ByteBufAllocator;
import io.netty.buffer.ByteBufUtil;
import io.netty.util.CharsetUtil;
import org.reactivestreams.Publisher;
import ratpack.func.Function;
import ratpack.handling.Context;
import ratpack.server.ServerConfig;
import ratpack.stream.Streams;
import ratpack.websocket.internal.DefaultWebSocketConnector;
import ratpack.websocket.internal.WebSocketEngine;
import ratpack.websocket.internal.WebsocketBroadcastSubscriber;
import java.nio.CharBuffer;
/**
* WebSockets support for Ratpack.
*
* An example that broadcasts strings to a websocket every second:
*
{@code
* import org.reactivestreams.Publisher;
* import ratpack.test.embed.EmbeddedApp;
* import ratpack.websocket.WebSockets;
*
* import java.time.Duration;
*
* import static ratpack.stream.Streams.periodically;
*
* chain.get("whatever", context -> {
* Publisher stream = periodically(context, Duration.ofSeconds(1), i ->
* i < 5 ? i.toString() : null
* );
*
* WebSockets.websocketBroadcast(context, stream);
* });
* }
*
* @see Writing WebSocket client applications
*/
public abstract class WebSockets {
public static WebSocketConnector websocket(Context context, Function openAction) {
return new DefaultWebSocketConnector<>(context, openAction);
}
public static void websocket(Context context, WebSocketHandler handler) {
WebSocketEngine.connect(context, "/", context.get(ServerConfig.class).getMaxContentLength(), handler);
}
/**
* Sets up a websocket that sends the published Strings to a client.
*
* This takes the place of a {@link Streams#bindExec(Publisher)} call.
*
* @param context the request handling context
* @param broadcaster a {@link Publisher} of Strings to send to the websocket client
*/
public static void websocketBroadcast(final Context context, final Publisher broadcaster) {
ByteBufAllocator bufferAllocator = context.get(ByteBufAllocator.class);
websocketByteBufBroadcast(context, Streams.map(broadcaster, s ->
ByteBufUtil.encodeString(bufferAllocator, CharBuffer.wrap(s), CharsetUtil.UTF_8)
));
}
/**
* Sets up a websocket that sends the published byte buffers to a client.
*
* This takes the place of a {@link Streams#bindExec(Publisher)} call.
*
* @param context the request handling context
* @param broadcaster a {@link Publisher} of {@link ByteBuf}s to send to the websocket client
*/
public static void websocketByteBufBroadcast(final Context context, final Publisher broadcaster) {
websocket(context, new AutoCloseWebSocketHandler() {
@Override
public AutoCloseable onOpen(final WebSocket webSocket) throws Exception {
WebsocketBroadcastSubscriber subscriber = new WebsocketBroadcastSubscriber(webSocket);
Streams.bindExec(broadcaster, ByteBuf::release).subscribe(subscriber);
return subscriber;
}
});
}
}