Question

我有一个使用Spring集成TCP构建的TCP客户端，服务器支持保持活动消息（ping / pong样式）。使用CachingClientConnectionFactory配置连接，我想利用此服务器功能。这是我的bean配置：

private static final int SERIALIZER_HEADER_SIZE = 2;

/**
 * Serializer used by connection factory to send and receive messages
 */
@Bean
public ByteArrayLengthHeaderSerializer byteArrayLengthHeaderSerializer() {
    return new ByteArrayLengthHeaderSerializer(SERIALIZER_HEADER_SIZE);
}

@Bean
public AbstractClientConnectionFactory tcpClientConnectionFactory() {
    TcpNetClientConnectionFactory connFactory =
        new TcpNetClientConnectionFactory(props.getUrl(), props.getPort());
    connFactory.setSerializer(byteArrayLengthHeaderSerializer());
    connFactory.setDeserializer(byteArrayLengthHeaderSerializer());
    connFactory.setSoTimeout(props.getSoTimeout());
    if (props.isUseSSL()) {
        connFactory.setTcpSocketFactorySupport(new DefaultTcpNetSSLSocketFactorySupport(() -> {
            return SSLContext.getDefault();
        }));
    }

    return connFactory;
}

/**
 * Connection factory used to create TCP client socket connections
 */
@Bean
public AbstractClientConnectionFactory tcpCachedClientConnectionFactory() {
    CachingClientConnectionFactory cachingConnFactory =
        new CachingClientConnectionFactory(tcpClientConnectionFactory(), props.getMaxPoolSize());
    cachingConnFactory.setConnectionWaitTimeout(props.getMaxPoolWait());
    return cachingConnFactory;
}

使用此处发布的解决方案Configure keep alive to keep connection alive all the time我可以保持连接打开但我还想利用这些服务器保持活动消息并不时发送这些消息以检查连接是否仍然存在。这可以提高客户端的性能，因为如果套接字关闭，它将不需要重新连接/创建新连接。

基于此，是否有人建议如何使用spring集成实现这一点？

Answer 1

使用简单的客户端连接工厂时，使用@InboundChannelAdapter设置应用程序级心跳消息非常简单。

简单示例：

@SpringBootApplication
public class So46918267Application {

    public static void main(String[] args) throws IOException {
        // Simulated Server
        final ServerSocket server = ServerSocketFactory.getDefault().createServerSocket(1234);
        ExecutorService executor = Executors.newSingleThreadExecutor();
        executor.execute(() -> {
            try {
                Socket socket = server.accept();
                BufferedReader reader = new BufferedReader(new InputStreamReader(socket.getInputStream()));
                String line;
                while ((line = reader.readLine()) != null) {
                    System.out.println(line);
                    if (line.equals("keep_alive")) {
                        socket.getOutputStream().write("OK\r\n".getBytes());
                    }
                }
            }
            catch (IOException e) {
                e.printStackTrace();
            }
        });
        ConfigurableApplicationContext context = SpringApplication.run(So46918267Application.class, args);
        System.out.println("Hit enter to terminate");
        System.in.read();
        executor.shutdownNow();
        context.close();
        server.close();
    }

    @Bean
    public TcpNetClientConnectionFactory client() {
        return new TcpNetClientConnectionFactory("localhost", 1234);
    }

    @ServiceActivator(inputChannel = "toTcp")
    @Bean
    public TcpOutboundGateway gateway() {
        TcpOutboundGateway gateway = new TcpOutboundGateway();
        gateway.setConnectionFactory(client());
        return gateway;
    }

    // HEARTBEATS

    private final Message<?> heartbeatMessage = MessageBuilder.withPayload("keep_alive")
            .setReplyChannelName("heartbeatReplies")
            .build();

    @InboundChannelAdapter(channel = "toTcp", poller = @Poller(fixedDelay = "25000"))
    public Message<?> heartbeat() {
        return this.heartbeatMessage;
    }

    @ServiceActivator(inputChannel = "heartbeatReplies")
    public void reply(byte[] reply) {
        System.out.println(new String(reply));
    }

}

但是，在使用CachingClientConnectionFactory时，不清楚为什么要保持空闲连接池保持打开状态。但是，池的工作方式是将空闲连接保存在队列中，这样每个请求都将转到最旧的连接，并且连接将返回到队列的末尾。

添加maxMessagesPerPoll将在每次投票时发出该数量的消息并且......

@InboundChannelAdapter(channel = "toTcp", 
    poller = @Poller(fixedDelay = "25000", maxMessagesPerPoll = "5"))

最多可以打开5个连接。它不会打开新连接（如果有至少一个），但如果池包含5个或更多连接，则至少5个将保持打开状态。如果没有打开的连接，它将只打开一个。

如何使用spring集成在TCP连接上实现keep alive连接？

1 个答案: