Question

如何构建一个基于netty的后端服务器

Answer 1

public class HttpServerPipelineFactory implements ChannelPipelineFactory {
private ChannelUpstreamHandler channelUpstreamHandler;

public ChannelPipeline getPipeline() throws Exception {
// Create a default pipeline implementation.
ChannelPipeline pipeline = pipeline();

// Uncomment the following line if you want HTTPS
//SSLEngine engine = SecureChatSslContextFactory.getServerContext().createSSLEngine();
//engine.setUseClientMode(false);
//pipeline.addLast("ssl", new SslHandler(engine));

pipeline.addLast("decoder", new HttpRequestDecoder());
// Uncomment the following line if you don't want to handle HttpChunks.
pipeline.addLast("aggregator", new HttpChunkAggregator(1048576));
pipeline.addLast("encoder", new HttpResponseEncoder());
// Remove the following line if you don't want automatic content compression.
pipeline.addLast("deflater", new HttpContentCompressor());
//pipeline.addLast("handler", new HttpRequestHandler());
pipeline.addLast("handler", channelUpstreamHandler);
return pipeline;
}

public void setChannelUpstreamHandler(ChannelUpstreamHandler channelUpstreamHandler) {
this.channelUpstreamHandler = channelUpstreamHandler;
}
}

相关spring配置

Java代码
<bean id="httpServerPipelineFactory" class="com.yunchao.cm.network.http.HttpServerPipelineFactory">
<property name="channelUpstreamHandler" ref="httpRequestHandler"/>
</bean>

Java代码
<bean id="httpRequestHandler" class="com.yunchao.cm.network.http.HttpRequestHandler">
<property name="urlMaps">
<map>
<entry key="/payorder">
<ref bean="payOrderCodecFactory"/>
</entry>
<entry key="/question">
<ref bean="questionCodecFactory"/>
</entry>
<entry key="/sms">
<ref bean="smsCodecFactory"/>
</entry>

代码太多，不全部贴出来，后面整理一下放到我的github上去。

基如此，我们还是得定义一个handler，继承simpleChannelUpstreamHander，并重写了messageReceied方法，具体在这里。

Java代码
QueryStringDecoder queryStringDecoder = new QueryStringDecoder(request.getUri());
String url = queryStringDecoder.getPath();

CodecFactory codecFactory = urlMaps.get(url);

if (null == codecFactory) {
logger.error("unsupported url:{} request.", url);
//sendError(ctx, BAD_REQUEST);
e.getChannel().close();
return;
}

//获取cmwap网络中的手机号码
String phone = PhoneUtils.getPhone(request.getHeader("x-up-calling-line-id"));

if (request.getMethod().equals(HttpMethod.POST)) {
ChannelBuffer content = request.getContent();
String postParams = content.toString(CharsetUtil.UTF_8);

logger.debug("request content:{}", postParams);

ClientRequestModel model = (ClientRequestModel) codecFactory.decode(postParams);
model.setProperty(model.MESSAGE_EVENT_KEY, e);
model.setProperty(model.HTTP_REQUEST_KEY, request);
model.setProperty(model.HTTP_PHONE_KEY, phone);

InetSocketAddress remoteAddress = (InetSocketAddress) e.getRemoteAddress();
model.setProperty(model.IP_KEY, remoteAddress.getAddress().getHostAddress());

logger.info("user request model:{}", model);

model.fireSelf();

Java代码
@Override
public DomainMessage fireSelf() {
DomainMessage em = new DomainMessage(this);
EventUtils.fireEvent(em, "alipayNotifyState");
return em;
}

看到这里基本上能够清楚了，是如何把客户端请求包装成ClientRequestModel了，且后面涉及到处理的对象，全部继承它，在整个架构之
中，has a 优于 is
a，对于客户端netty的一些对象，也是存储在ClientRequestModel中，codec无非也是采用了xml/json/kv，如斯，实现
了字节与对象之间的转换。

除
此之外，突然想到刚来杭州工作的第一家公司，基于此，采用的架构师servlet充当服务器，因为这是一个公司内部的server,而不是一个平台，采用
的数据格式也比较单一，就是xml，但是采用的外部类库也是xstream来处理的，但是整个系统维持的日调用量也是在百万级别，运用的client则是
采用httpclient，对于不同请求后面挂的handler，是在容器启动时加载到内存中，其余也没有什么亮点了。