聊聊Gateway集成Netty服务

作者：知了一笑 2023-02-28 08:55:33开发 前端 Netty是聊聊一个异步的，事件驱动的服务网络应用框架，用以快速开发高可靠、聊聊高性能的服务网络应用程序。

一、聊聊Netty简介

Netty是服务一个异步的，事件驱动的聊聊网络应用框架，用以快速开发高可靠、服务高性能的聊聊网络应用程序。

传输服务：提供网络传输能力的服务管理；

协议支持：支持常见的数据传输协议；

核心模块：包括可扩展事件模型、通用的聊聊通信API、零拷贝字节缓冲；

二、服务Netty入门案例

1、聊聊服务端启动

配置Netty服务器端程序，服务引导相关核心组件的聊聊加载；

public class NettyServer { 

public static void main(String[] args) { 

// EventLoop组，处理事件和IO
EventLoopGroup parentGroup = new NioEventLoopGroup();
EventLoopGroup childGroup = new NioEventLoopGroup();

try { 

// 服务端启动引导类
ServerBootstrap serverBootstrap = new ServerBootstrap();
serverBootstrap.group(parentGroup, childGroup)
.channel(NioServerSocketChannel.class).childHandler(new ChannelInit());

// 异步IO的结果
ChannelFuture channelFuture = serverBootstrap.bind(8082).sync();
channelFuture.channel().closeFuture().sync();

} catch (Exception e){ 
e.printStackTrace();
} finally { 
parentGroup.shutdownGracefully();
childGroup.shutdownGracefully();
}
}
}

2、通道初始化

ChannelInitializer特殊的通道处理器，提供一种简单的方法，对注册到EventLoop的通道进行初始化；比如此处设置的编码解码器，自定义处理器；

public class ChannelInit extends ChannelInitializer<SocketChannel> { 

@Override
protected void initChannel(SocketChannel socketChannel) { 

// 获取管道
ChannelPipeline pipeline = socketChannel.pipeline();

// Http编码、解码器
pipeline.addLast("DefHttpServerCodec",new HttpServerCodec());

// 添加自定义的handler
pipeline.addLast("DefHttpHandler", new DefHandler());
}
}

3、自定义处理器

处理对服务器端发起的访问，通常包括请求解析，具体的逻辑执行，请求响应等过程；

public class DefHandler extends SimpleChannelInboundHandler<HttpObject> { 

@Override
protected void channelRead0(ChannelHandlerContext ctx, HttpObject message) throws Exception { 

if(message instanceof HttpRequest) { 
// 请求解析
HttpRequest httpRequest = (HttpRequest) message;
String uri = httpRequest.uri();
String method = httpRequest.method().name();
log.info("【HttpRequest-URI:"+uri+"】");
log.info("【HttpRequest-method:"+method+"】");

Iterator<Map.Entry<String,String>> iterator = httpRequest.headers().iteratorAsString();
while (iterator.hasNext()){ 
Map.Entry<String,String> entry = iterator.next();
log.info("【Header-Key:"+entry.getKey()+";Header-Value:"+entry.getValue()+"】");
}

// 响应构建
ByteBuf content = Unpooled.copiedBuffer("Netty服务", CharsetUtil.UTF_8);
FullHttpResponse response = new DefaultFullHttpResponse
(HttpVersion.HTTP_1_1, HttpResponseStatus.OK, content);
response.headers().set(HttpHeaderNames.CONTENT_TYPE, "text/plain;charset=utf-8");
response.headers().set(HttpHeaderNames.CONTENT_LENGTH, content.readableBytes());
ctx.writeAndFlush(response);
}
}
}

4、测试请求

上面入门案例中，简单的配置了一个Netty服务器端，启动之后在浏览器中模拟访问即可；

http://127.0.0.1:8082/?id=1&name=Spring

三、Gateway集成

1、依赖层级

项目中Gateway网关依赖的版本为2.2.5.RELEASE​，发现Netty依赖的版本为4.1.45.Final，是当下比较主流的版本；

<!-- 1、项目工程依赖 -->
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-starter-gateway</artifactId>
<version>2.2.5.RELEASE</version>
</dependency>

<!-- 2、starter-gateway依赖 -->
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-webflux</artifactId>
<version>2.3.2.RELEASE</version>
</dependency>

<!-- 3、starter-webflux依赖 -->
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-reactor-netty</artifactId>
<version>2.3.2.RELEASE</version>
</dependency>

2、自动化配置

在Gateway网关的自动化配置配置类中，提供了Netty配置的管理；

@AutoConfigureBefore({  HttpHandlerAutoConfiguration.class,WebFluxAutoConfiguration.class })
@ConditionalOnClass(DispatcherHandler.class)
public class GatewayAutoConfiguration { 

@Configuration(proxyBeanMethods = false)
@ConditionalOnClass(HttpClient.class)
protected static class NettyConfiguration { 

@Bean
@ConditionalOnProperty(name = "spring.cloud.gateway.httpserver.wiretap")
public NettyWebServerFactoryCustomizer nettyServerWiretapCustomizer(
Environment environment, ServerProperties serverProperties) { 
return new NettyWebServerFactoryCustomizer(environment, serverProperties) { 
@Override
public void customize(NettyReactiveWebServerFactory factory) { 
factory.addServerCustomizers(httpServer -> httpServer.wiretap(true));
super.customize(factory);
}
};
}
}
}

四、配置加载

1、基础配置

在工程的配置文件中，简单做一些基础性的设置；

server:
port: 8081                  # 端口号
netty:                      # Netty组件
connection-timeout: 3000  # 连接超时

2、属性配置类

在ServerProperties类中，并没有提供很多显式的Netty配置参数，更多信息需要参考工厂类；

@ConfigurationProperties(prefix = "server", ignoreUnknownFields = true)
public class ServerProperties { 
private Integer port;
public static class Netty { 
private Duration connectionTimeout;
}
}

3、配置加载分析

• 基于配置的属性，定制化管理Netty服务的信息；

public class NettyWebServerFactoryCustomizer
implements WebServerFactoryCustomizer<NettyReactiveWebServerFactory>{ 
private final Environment environment;
private final ServerProperties serverProperties;
@Override
public void customize(NettyReactiveWebServerFactory factory) { 
PropertyMapper propertyMapper = PropertyMapper.get().alwaysApplyingWhenNonNull();
ServerProperties.Netty nettyProperties = this.serverProperties.getNetty();
propertyMapper.from(nettyProperties::getConnectionTimeout).whenNonNull()
.to((connectionTimeout) -> customizeConnectionTimeout(factory, connectionTimeout));
}
}

• NettyReactiveWeb服务工厂，基于上述入门案例，创建WebServer时，部分参数信息出自LoopResources接口；

public class NettyReactiveWebServerFactory extends AbstractReactiveWebServerFactory { 

private ReactorResourceFactory resourceFactory;

@Override
public WebServer getWebServer(HttpHandler httpHandler) { 
HttpServer httpServer = createHttpServer();
ReactorHttpHandlerAdapter handlerAdapter = new ReactorHttpHandlerAdapter(httpHandler);
NettyWebServer webServer = new NettyWebServer(httpServer, handlerAdapter, this.lifecycleTimeout);
webServer.setRouteProviders(this.routeProviders);
return webServer;
}

private HttpServer createHttpServer() { 
HttpServer server = HttpServer.create();
if (this.resourceFactory != null) { 
LoopResources resources = this.resourceFactory.getLoopResources();
server = server.tcpConfiguration(
(tcpServer) -> tcpServer.runOn(resources).addressSupplier(this::getListenAddress));
}
return applyCustomizers(server);
}

}

五、周期管理方法

1、控制类

Gateway项目中，Netty服务核心控制类，通过NettyReactiveWebServerFactory工厂类创建，对Netty生命周期的管理提供了一层包装；

public class NettyWebServer implements WebServer { 

private final HttpServer httpServer;
private final ReactorHttpHandlerAdapter handlerAdapter;

/**
* 启动方法
*/
@Override
public void start() throws WebServerException { 
if (this.disposableServer == null) { 
this.disposableServer = startHttpServer();
// 控制台日志
logger.info("Netty started on port(s): " + getPort());
startDaemonAwaitThread(this.disposableServer);
}
}
private DisposableServer startHttpServer() { 
HttpServer server = this.httpServer;
if (this.routeProviders.isEmpty()) { 
server = server.handle(this.handlerAdapter);
}
return server.bindNow();
}

/**
* 停止方法
*/
@Override
public void stop() throws WebServerException { 
if (this.disposableServer != null) { 
// 释放资源
if (this.lifecycleTimeout != null) { 
this.disposableServer.disposeNow(this.lifecycleTimeout);
}
else { 
this.disposableServer.disposeNow();
}
// 对象销毁
this.disposableServer = null;
}
}
}

2、管理类

Netty组件中抽象管理类，以安全的方式构建Http服务；

public abstract class HttpServer { 

public static HttpServer create() { 
return HttpServerBind.INSTANCE;
}

public final DisposableServer bindNow() { 
return bindNow(Duration.ofSeconds(45));
}

public final HttpServer handle(BiFunction<? super HttpServerRequest, ? super
HttpServerResponse, ? extends Publisher<Void>> handler) { 
return new HttpServerHandle(this, handler);
}
}

六、参考源码

编程文档：
https://gitee.com/cicadasmile/butte-java-note

应用仓库：
https://gitee.com/cicadasmile/butte-flyer-parent

责任编辑：武晓燕 来源： 知了一笑 GatewayNetty服务

(责任编辑：百科)