客户端

Question

我正在寻找一个示例，通过不使用xml(spring-integration)的快速引导连接TCP。

我从How to create a Tcp Connection in spring boot to accept connections? URL中得到了以下片段。

在本例中，仅使用主方法就足以连接tcp。为什么其他豆类和变压器在这里声明？

这样做不对吗？我不使用简单的Java客户端来接受响应，而是与Spring集成。但是没有使用Java的适当示例。

你能帮忙吗？

package com.example;

import java.net.Socket;

import javax.net.SocketFactory;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.context.ConfigurableApplicationContext;
import org.springframework.context.annotation.Bean;
import org.springframework.integration.annotation.ServiceActivator;
import org.springframework.integration.annotation.Transformer;
import org.springframework.integration.channel.DirectChannel;
import org.springframework.integration.ip.tcp.TcpReceivingChannelAdapter;
import org.springframework.integration.ip.tcp.connection.AbstractServerConnectionFactory;
import org.springframework.integration.ip.tcp.connection.TcpNetServerConnectionFactory;
import org.springframework.integration.transformer.ObjectToStringTransformer;
import org.springframework.messaging.MessageChannel;

@SpringBootApplication
public class So39290834Application {

    public static void main(String[] args) throws Exception {
        ConfigurableApplicationContext context = SpringApplication.run(So39290834Application.class, args);
        Socket socket = SocketFactory.getDefault().createSocket("localhost", 9999);
        socket.getOutputStream().write("foo\r\n".getBytes());
        socket.close();
        Thread.sleep(1000);
        context.close();
    }

    @Bean
    public TcpNetServerConnectionFactory cf() {
        return new TcpNetServerConnectionFactory(9999);
    }

    @Bean
    public TcpReceivingChannelAdapter inbound(AbstractServerConnectionFactory cf) {
        TcpReceivingChannelAdapter adapter = new TcpReceivingChannelAdapter();
        adapter.setConnectionFactory(cf);
        adapter.setOutputChannel(tcpIn());
        return adapter;
    }

    @Bean
    public MessageChannel tcpIn() {
        return new DirectChannel();
    }

    @Transformer(inputChannel = "tcpIn", outputChannel = "serviceChannel")
    @Bean
    public ObjectToStringTransformer transformer() {
        return new ObjectToStringTransformer();
    }

    @ServiceActivator(inputChannel = "serviceChannel")
    public void service(String in) {
        System.out.println(in);
    }

}

Answer 1

这个应用程序既是客户端，也是服务器。

这个问题是关于如何使用Spring编写服务器端(接受连接)。

main()方法只是一个连接到服务器端的测试。它使用标准的Java套接字API；它也可以编写成在客户端使用组件。

顺便说一句，您不必使用XML来编写应用程序，您可以用注释来配置它，或者使用Java。读读文件。

编辑

使用Java 的客户机/服务器示例

@SpringBootApplication
public class So54057281Application {

    public static void main(String[] args) {
        SpringApplication.run(So54057281Application.class, args);
    }

    @Bean
    public IntegrationFlow server() {
        return IntegrationFlows.from(Tcp.inboundGateway(
                    Tcp.netServer(1234)
                        .serializer(codec()) // default is CRLF
                        .deserializer(codec()))) // default is CRLF
                .transform(Transformers.objectToString()) // byte[] -> String
                .<String, String>transform(p -> p.toUpperCase())
                .get();
    }

    @Bean
    public IntegrationFlow client() {
        return IntegrationFlows.from(MyGateway.class)
                .handle(Tcp.outboundGateway(
                    Tcp.netClient("localhost", 1234)
                        .serializer(codec()) // default is CRLF
                        .deserializer(codec()))) // default is CRLF
                .transform(Transformers.objectToString()) // byte[] -> String
                .get();
    }

    @Bean
    public AbstractByteArraySerializer codec() {
        return TcpCodecs.lf();
    }

    @Bean
    @DependsOn("client")
    ApplicationRunner runner(MyGateway gateway) {
        return args -> {
            System.out.println(gateway.exchange("foo"));
            System.out.println(gateway.exchange("bar"));
        };
    }

    public interface MyGateway {

        String exchange(String out);

    }

}

结果

FOO
BAR