举个简单的例子,假设我想在 netty 中只使用 2 个工作线程来处理 3 个同时的 TCP 客户端连接,我该怎么做?
问题 A) 使用下面的代码,我的第三个连接没有从服务器获取任何数据 - 连接就在那里。注意 - 我的工作执行程序和工作人员计数如何为 2。所以如果我有 2 个工作线程和 3 个连接,是否所有三个连接都应该由 2 个线程提供服务?
B) 另一个问题是 - netty 是否使用 java.util.concurrent 的 CompletionService?它似乎没有使用它。另外,我没有看到任何执行 executor.submit 或 future.get 的源代码所以所有这些都增加了它如何处理和提供数据到比它的工作线程更多的连接的混乱?
C)我对netty如何处理10000多个同时TCP连接感到迷茫......它会创建10000个线程吗?每个连接的线程不是一个可扩展的解决方案,所以我很困惑,因为我的测试代码没有按预期工作。
import java.net.InetSocketAddress;
import java.nio.channels.ClosedChannelException;
import java.util.Date;
import java.util.concurrent.Executors;
import java.util.logging.Level;
import java.util.logging.Logger;
import org.jboss.netty.bootstrap.ServerBootstrap;
import org.jboss.netty.channel.Channel;
import org.jboss.netty.channel.ChannelFuture;
import org.jboss.netty.channel.ChannelFutureListener;
import org.jboss.netty.channel.ChannelHandlerContext;
import org.jboss.netty.channel.ChannelPipeline;
import org.jboss.netty.channel.ChannelPipelineFactory;
import org.jboss.netty.channel.ChannelStateEvent;
import org.jboss.netty.channel.Channels;
import org.jboss.netty.channel.ExceptionEvent;
import org.jboss.netty.channel.SimpleChannelUpstreamHandler;
import org.jboss.netty.channel.socket.nio.NioServerSocketChannelFactory;
import org.jboss.netty.handler.codec.string.StringEncoder;
public class SRNGServer {
public static void main(String[] args) throws Exception {
// Configure the server.
ServerBootstrap bootstrap = new ServerBootstrap(
new NioServerSocketChannelFactory(
Executors.newCachedThreadPool(),
//Executors.newCachedThreadPool()
Executors.newFixedThreadPool(2),2
));
// Configure the pipeline factory.
bootstrap.setPipelineFactory(new SRNGServerPipelineFactoryP());
// Bind and start to accept incoming connections.
bootstrap.bind(new InetSocketAddress(8080));
}
private static class SRNGServerHandlerP extends SimpleChannelUpstreamHandler {
private static final Logger logger = Logger.getLogger(SRNGServerHandlerP.class.getName());
@Override
public void channelConnected(
ChannelHandlerContext ctx, ChannelStateEvent e) throws Exception {
// Send greeting for a new connection.
Channel ch=e.getChannel();
System.out.printf("channelConnected with channel=[%s]%n", ch);
ChannelFuture writeFuture=e.getChannel().write("It is " + new Date() + " now.\r\n");
SRNGChannelFutureListener srngcfl=new SRNGChannelFutureListener();
System.out.printf("Registered listener=[%s] for future=[%s]%n", srngcfl, writeFuture);
writeFuture.addListener(srngcfl);
}
@Override
public void exceptionCaught(
ChannelHandlerContext ctx, ExceptionEvent e) {
logger.log(
Level.WARNING,
"Unexpected exception from downstream.",
e.getCause());
if(e.getCause() instanceof ClosedChannelException){
logger.log(Level.INFO, "****** Connection closed by client - Closing Channel");
}
e.getChannel().close();
}
}
private static class SRNGServerPipelineFactoryP implements ChannelPipelineFactory {
public ChannelPipeline getPipeline() throws Exception {
// Create a default pipeline implementation.
ChannelPipeline pipeline = Channels.pipeline();
pipeline.addLast("encoder", new StringEncoder());
pipeline.addLast("handler", new SRNGServerHandlerP());
return pipeline;
}
}
private static class SRNGChannelFutureListener implements ChannelFutureListener{
public void operationComplete(ChannelFuture future) throws InterruptedException{
Thread.sleep(1000*5);
Channel ch=future.getChannel();
if(ch!=null && ch.isConnected()){
ChannelFuture writeFuture=ch.write("It is " + new Date() + " now.\r\n");
//-- Add this instance as listener itself.
writeFuture.addListener(this);
}
}
}
}