Add UptimeServer and adjust UptimeClient's code style.

Motivation:

Uptime example is lack of server.
UptimeClient's code style is a little bit different from others, which make reader feel confused.
We don't need to create a new Bootstrap instance each time client reconnect to server.

Modification:

Add UptimeServer and UptimeServerHandler which simply accept all connection and discard all message.
Change UptimeClient's code style.
Share a single Bootstrap instance.

Result:

Uptime server support.
Consistent code style.
Single Bootstrap for all reconnection.
This commit is contained in:
kennylbj 2017-04-07 13:33:49 +08:00 committed by Norman Maurer
parent ea1cb20c90
commit 92efa3c916
5 changed files with 120 additions and 27 deletions

View File

@ -38,34 +38,27 @@ public final class UptimeClient {
// Sleep 5 seconds before a reconnection attempt.
static final int RECONNECT_DELAY = Integer.parseInt(System.getProperty("reconnectDelay", "5"));
// Reconnect when the server sends nothing for 10 seconds.
static final int READ_TIMEOUT = Integer.parseInt(System.getProperty("readTimeout", "10"));
private static final int READ_TIMEOUT = Integer.parseInt(System.getProperty("readTimeout", "10"));
private static final UptimeClientHandler handler = new UptimeClientHandler();
private static final Bootstrap bs = new Bootstrap();
public static void main(String[] args) throws Exception {
configureBootstrap(new Bootstrap()).connect();
}
private static Bootstrap configureBootstrap(Bootstrap b) {
return configureBootstrap(b, new NioEventLoopGroup());
}
static Bootstrap configureBootstrap(Bootstrap b, EventLoopGroup g) {
b.group(g)
EventLoopGroup group = new NioEventLoopGroup();
bs.group(group)
.channel(NioSocketChannel.class)
.remoteAddress(HOST, PORT)
.handler(new ChannelInitializer<SocketChannel>() {
@Override
public void initChannel(SocketChannel ch) throws Exception {
protected void initChannel(SocketChannel ch) throws Exception {
ch.pipeline().addLast(new IdleStateHandler(READ_TIMEOUT, 0, 0), handler);
}
});
return b;
bs.connect();
}
static void connect(Bootstrap b) {
b.connect().addListener(new ChannelFutureListener() {
static void connect() {
bs.connect().addListener(new ChannelFutureListener() {
@Override
public void operationComplete(ChannelFuture future) throws Exception {
if (future.cause() != null) {

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@ -15,10 +15,8 @@
*/
package io.netty.example.uptime;
import io.netty.bootstrap.Bootstrap;
import io.netty.channel.ChannelHandler.Sharable;
import io.netty.channel.ChannelHandlerContext;
import io.netty.channel.EventLoop;
import io.netty.channel.SimpleChannelInboundHandler;
import io.netty.handler.timeout.IdleState;
import io.netty.handler.timeout.IdleStateEvent;
@ -70,12 +68,11 @@ public class UptimeClientHandler extends SimpleChannelInboundHandler<Object> {
public void channelUnregistered(final ChannelHandlerContext ctx) throws Exception {
println("Sleeping for: " + UptimeClient.RECONNECT_DELAY + 's');
final EventLoop loop = ctx.channel().eventLoop();
loop.schedule(new Runnable() {
ctx.channel().eventLoop().schedule(new Runnable() {
@Override
public void run() {
println("Reconnecting to: " + UptimeClient.HOST + ':' + UptimeClient.PORT);
UptimeClient.connect(UptimeClient.configureBootstrap(new Bootstrap(), loop));
UptimeClient.connect();
}
}, UptimeClient.RECONNECT_DELAY, TimeUnit.SECONDS);
}

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@ -0,0 +1,67 @@
/*
* Copyright 2017 The Netty Project
*
* The Netty Project licenses 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 io.netty.example.uptime;
import io.netty.bootstrap.ServerBootstrap;
import io.netty.channel.ChannelFuture;
import io.netty.channel.ChannelInitializer;
import io.netty.channel.EventLoopGroup;
import io.netty.channel.nio.NioEventLoopGroup;
import io.netty.channel.socket.SocketChannel;
import io.netty.channel.socket.nio.NioServerSocketChannel;
import io.netty.handler.logging.LogLevel;
import io.netty.handler.logging.LoggingHandler;
/**
* Uptime server is served as a connection server.
* So it simply discards all message received.
*/
public final class UptimeServer {
private static final int PORT = Integer.parseInt(System.getProperty("port", "8080"));
private static final UptimeServerHandler handler = new UptimeServerHandler();
private UptimeServer() {
}
public static void main(String[] args) throws Exception {
EventLoopGroup bossGroup = new NioEventLoopGroup(1);
EventLoopGroup workerGroup = new NioEventLoopGroup();
try {
ServerBootstrap b = new ServerBootstrap();
b.group(bossGroup, workerGroup)
.channel(NioServerSocketChannel.class)
.handler(new LoggingHandler(LogLevel.INFO))
.childHandler(new ChannelInitializer<SocketChannel>() {
@Override
public void initChannel(SocketChannel ch) {
ch.pipeline().addLast(handler);
}
});
// Bind and start to accept incoming connections.
ChannelFuture f = b.bind(PORT).sync();
// Wait until the server socket is closed.
// In this example, this does not happen, but you can do that to gracefully
// shut down your server.
f.channel().closeFuture().sync();
} finally {
workerGroup.shutdownGracefully();
bossGroup.shutdownGracefully();
}
}
}

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@ -0,0 +1,35 @@
/*
* Copyright 2017 The Netty Project
*
* The Netty Project licenses 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 io.netty.example.uptime;
import io.netty.channel.ChannelHandler.Sharable;
import io.netty.channel.ChannelHandlerContext;
import io.netty.channel.SimpleChannelInboundHandler;
@Sharable
public class UptimeServerHandler extends SimpleChannelInboundHandler<Object> {
@Override
public void channelRead0(ChannelHandlerContext ctx, Object msg) throws Exception {
// discard
}
@Override
public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) {
// Close the connection when an exception is raised.
cause.printStackTrace();
ctx.close();
}
}

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@ -38,6 +38,7 @@ EXAMPLE_MAP=(
'memcache-binary-client:io.netty.example.memcache.binary.MemcacheClient'
'stomp-client:io.netty.example.stomp.StompClient'
'uptime-client:io.netty.example.uptime.UptimeClient'
'uptime-server:io.netty.example.uptime.UptimeServer'
'sctpecho-client:io.netty.example.sctp.SctpEchoClient'
'sctpecho-server:io.netty.example.sctp.SctpEchoServer'
'localecho:io.netty.example.localecho.LocalEcho'