netty5/src/main/java/org/jboss/netty/example/telnet/TelnetServerHandler.java
Trustin Lee ba28679775 Clean up the examples
Motivation:

The examples have not been updated since long time ago, showing various
issues fixed in this commit.

Modifications:

- Overall simplification to reduce LoC
  - Use system properties to get options instead of parsing args.
  - Minimize option validation
  - Just use System.out/err instead of Logger
  - Do not pass config as parameters - just access it directly
  - Move the main logic to main(String[]) instead of creating a new
    instance meaninglessly
    - Update netty-build-21 to make checkstyle not complain
  - Remove 'throws Exception' clause if possible
- Line wrap at 120 (previously at 80)
- Add an option to enable SSL for most examples
- Use ChannelFuture.sync() instead of await()
- Use System.out for the actual result. Use System.err otherwise.
- Delete examples that are not very useful:
  - websocket/html5
  - websocketx/sslserver
  - localecho/multithreaded
- Add run-example.sh which simplifies launching an example from command
  line

Result:

Shorter and simpler examples.  A user can focus more on what it actually
does than miscellaneous stuff.  A user can launch an example very
easily.
2014-05-22 17:52:23 +09:00

86 lines
3.0 KiB
Java

/*
* Copyright 2012 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 org.jboss.netty.example.telnet;
import org.jboss.netty.channel.ChannelEvent;
import org.jboss.netty.channel.ChannelFuture;
import org.jboss.netty.channel.ChannelFutureListener;
import org.jboss.netty.channel.ChannelHandlerContext;
import org.jboss.netty.channel.ChannelStateEvent;
import org.jboss.netty.channel.ExceptionEvent;
import org.jboss.netty.channel.MessageEvent;
import org.jboss.netty.channel.SimpleChannelUpstreamHandler;
import java.net.InetAddress;
import java.util.Date;
/**
* Handles a server-side channel.
*/
public class TelnetServerHandler extends SimpleChannelUpstreamHandler {
@Override
public void handleUpstream(ChannelHandlerContext ctx, ChannelEvent e) throws Exception {
if (e instanceof ChannelStateEvent) {
System.err.println(e);
}
super.handleUpstream(ctx, e);
}
@Override
public void channelConnected(ChannelHandlerContext ctx, ChannelStateEvent e) throws Exception {
// Send greeting for a new connection.
e.getChannel().write("Welcome to " + InetAddress.getLocalHost().getHostName() + "!\r\n");
e.getChannel().write("It is " + new Date() + " now.\r\n");
}
@Override
public void messageReceived(ChannelHandlerContext ctx, MessageEvent e) {
// Cast to a String first.
// We know it is a String because we put some codec in TelnetPipelineFactory.
String request = (String) e.getMessage();
// Generate and write a response.
String response;
boolean close = false;
if (request.length() == 0) {
response = "Please type something.\r\n";
} else if ("bye".equals(request.toLowerCase())) {
response = "Have a good day!\r\n";
close = true;
} else {
response = "Did you say '" + request + "'?\r\n";
}
// We do not need to write a ChannelBuffer here.
// We know the encoder inserted at TelnetPipelineFactory will do the conversion.
ChannelFuture future = e.getChannel().write(response);
// Close the connection after sending 'Have a good day!'
// if the client has sent 'bye'.
if (close) {
future.addListener(ChannelFutureListener.CLOSE);
}
}
@Override
public void exceptionCaught(ChannelHandlerContext ctx, ExceptionEvent e) {
e.getCause().printStackTrace();
e.getChannel().close();
}
}