io.reactivex.netty.examples.tcp.streaming.StreamingClient Maven / Gradle / Ivy
/*
* Copyright 2016 Netflix, Inc.
*
* 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 io.reactivex.netty.examples.tcp.streaming;
import io.netty.buffer.ByteBuf;
import io.netty.handler.logging.LogLevel;
import io.reactivex.netty.channel.Connection;
import io.reactivex.netty.examples.ExamplesEnvironment;
import io.reactivex.netty.protocol.tcp.client.TcpClient;
import io.reactivex.netty.util.StringLineDecoder;
import org.slf4j.Logger;
import java.net.SocketAddress;
/**
* A TCP streaming example.
*
* This example assumes that the server to which this client connects (using the below mentioned option), sends an
* infinite stream of new line seperated strings. This client only takes 10 items from that infinite stream and then
* terminates the connection.
*
* There are three ways of running this example:
*
* Default
*
* The default way is to just run this class with no arguments, which will start a server ({@link StreamingServer}) on
* an ephemeral port and then send an HTTP request to that server and print the response.
*
* After starting {@link StreamingServer}
*
* If you want to see how {@link StreamingServer} work, you can run {@link StreamingServer} by yourself and then pass
* the port on which the server started to this class as a program argument:
*
java io.reactivex.netty.examples.tcp.streaming.StreamingClient [server port]
*
* Existing TCP server
*
* You can also use this client to connect to an existing TCP server (different than {@link StreamingServer}) by
* passing the port and host of the existing server similar to the case above:
*
java io.reactivex.netty.examples.tcp.streaming.StreamingClient [server port] [server host]
* If the server host is omitted from the above, it defaults to "127.0.0.1"
*
* In all the above usages, this client will print the response received from the server.
*
* @see StreamingServer Default server for this client.
*/
public final class StreamingClient {
public static void main(String[] args) {
ExamplesEnvironment env = ExamplesEnvironment.newEnvironment(StreamingClient.class);
Logger logger = env.getLogger();
/*
* Retrieves the server address, using the following algorithm:
*
- If any arguments are passed, then use the first argument as the server port.
- If available, use the second argument as the server host, else default to localhost
- Otherwise, start the passed server class and use that address.
*/
SocketAddress serverAddress = env.getServerAddress(StreamingServer.class, args);
/*Create a new client for the server address*/
TcpClient.newClient(serverAddress)
.enableWireLogging("streaming-client", LogLevel.DEBUG)
.addChannelHandlerLast("string-decoder", StringLineDecoder::new)
.createConnectionRequest()
.flatMap(Connection::getInput)
.take(10)
.toBlocking()
.forEach(logger::info);
}
}