需要通过以太网连接实现处理以下协议的服务器：
Establishing a connection
The client connects to the configured server via TCP / IP.
After the connection has been established, the client initially sends a heartbeat message to the
Server:
{
"MessageID": "Heartbeat"
}
Response:
{
"ResponseCode": "Ok"
}
Communication process
To maintain the connection, the client sends every 10 seconds when inactive
Heartbeat message.
Server and client must close the connection if they are not receiving a message for longer than 20 seconds.
An answer must be given within 5 seconds to request.
If no response is received, the connection must also be closed.
The protocol does not contain numbering or any other form of identification.
Communication partner when sending the responses makes sure that they are in the same sequence.
Message structure:
The messages are embedded in an STX-ETX frame.
STX (0x02) message ETX (0x03)
An `escaping` of STX and ETX within the message is not necessary since it is in JSON format
Escape sequence are following:
JSON.stringify({"a": "\x02\x03\x10"}) → "{"a": "\u0002\u0003\u0010"}"
不仅应该使用心跳消息。一个典型的消息应该是这样的:
{
"MessageID": "CheckAccess"
"Parameters": {
"MediaType": "type",
"MediaData": "data"
}
}
相应的回应：
{
"ResponseCode": "some-code",
"DisplayMessage": "some-message",
"SessionID": "some-id"
}
服务器应该是多客户端的，协议本身没有任何标识。
然而，我们至少需要识别客户端发送请求的IP地址。
在Spring Boot应用程序中添加这样的服务器并在启动时启用以及处理其输入和输出逻辑，目前还没有找到解决方案。
欢迎提出任何建议。
解决方案
为TCP服务器配置如下：
@Slf4j
@Component
@RequiredArgsConstructor
public class TCPServer {
private final InetSocketAddress hostAddress;
private final ServerBootstrap serverBootstrap;
private Channel serverChannel;
@PostConstruct
public void start() {
try {
ChannelFuture serverChannelFuture = serverBootstrap.bind(hostAddress).sync();
log.info("Server is STARTED : port {}", hostAddress.getPort());
serverChannel = serverChannelFuture.channel().closeFuture().sync().channel();
} catch (InterruptedException e) {
Thread.currentThread().interrupt();
}
}
@PreDestroy
public void stop() {
if (serverChannel != null) {
serverChannel.close();
serverChannel.parent().close();
}
}
}
@PostConstruct会在应用程序启动时启动服务器。
还有它的配置：
@Configuration
@RequiredArgsConstructor
@EnableConfigurationProperties(NettyProperties.class)
public class NettyConfiguration {
private final LoggingHandler loggingHandler = new LoggingHandler(LogLevel.DEBUG);
private final NettyProperties nettyProperties;
@Bean(name = "serverBootstrap")
public ServerBootstrap bootstrap(SimpleChannelInitializer initializer) {
ServerBootstrap bootstrap = new ServerBootstrap();
bootstrap.group(bossGroup(), workerGroup())
.channel(NioServerSocketChannel.class)
.handler(loggingHandler)
.childHandler(initializer);
bootstrap.option(ChannelOption.SO_BACKLOG, nettyProperties.getBacklog());
bootstrap.childOption(ChannelOption.SO_KEEPALIVE, nettyProperties.isKeepAlive());
return bootstrap;
}
@Bean(destroyMethod = "shutdownGracefully")
public NioEventLoopGroup bossGroup() {
return new NioEventLoopGroup(nettyProperties.getBossCount());
}
@Bean(destroyMethod = "shutdownGracefully")
public NioEventLoopGroup workerGroup() {
return new NioEventLoopGroup(nettyProperties.getWorkerCount());
}
@Bean
@SneakyThrows
public InetSocketAddress tcpSocketAddress() {
return new InetSocketAddress(nettyProperties.getTcpPort());
}
}
初始化逻辑：
@Component
@RequiredArgsConstructor
public class SimpleChannelInitializer extends ChannelInitializer<SocketChannel> {
private final StringEncoder stringEncoder = new StringEncoder();
private final StringDecoder stringDecoder = new StringDecoder();
private final QrReaderProcessingHandler readerServerHandler;
private final NettyProperties nettyProperties;
@Override
protected void initChannel(SocketChannel socketChannel) {
ChannelPipeline pipeline = socketChannel.pipeline();
pipeline.addLast(new DelimiterBasedFrameDecoder(1024 * 1024, Delimiters.lineDelimiter()));
pipeline.addLast(new ReadTimeoutHandler(nettyProperties.getClientTimeout()));
pipeline.addLast(stringDecoder);
pipeline.addLast(stringEncoder);
pipeline.addLast(readerServerHandler);
}
}
属性配置:
@Getter
@Setter
@ConfigurationProperties(prefix = "netty")
public class NettyProperties {
@NotNull
@Size(min = 1000, max = 65535)
private int tcpPort;
@Min(1)
@NotNull
private int bossCount;
@Min(2)
@NotNull
private int workerCount;
@NotNull
private boolean keepAlive;
@NotNull
private int backlog;
@NotNull
private int clientTimeout;
}
以下是 application.yml 文件的一部分示例：
netty:
tcp-port: 9090
boss-count: 1
worker-count: 14
keep-alive: true
backlog: 128
client-timeout: 20
处理程序非常简单。
在控制台上运行本地检查:
telnet localhost 9090
在这里可以正常工作。我希望对于客户端的访问也可以正常工作。