Spring集成smart-socket

现今的企业系统开发通常会使用Spring，smart-socket与Spring的集成就是一个基本的通信服务Bean实例托管的过程。

此处以xml配置和注解两种方式为大家介绍smart-socket于spring的集成方案，前期需要做的准备工作就是先搭建一个spring工程，并引入smart-socket依赖，pom.xml配置如下图。

1. xml配置化启动服务

​ 通过2.1章节我们了解到smart-socket启用通信服务依赖两个关键的要素：Protocol、MessageProcessor，在spring的集成应用中我们依旧需要定义它们的实现类。接下来我们会以服务端场景为例给大家演示，如果您是要进行客户端通信服务与Spring的集成，请按同样的操作方式替换一下相应的配置即可。

• 定义协议类

public class StringProtocol implements Protocol<String> {
    @Override
    public String decode(ByteBuffer readBuffer, AioSession<String> session) {
        int remaining = readBuffer.remaining();
        if (remaining < Integer.BYTES) {
            return null;
        }
        readBuffer.mark();
        int length = readBuffer.getInt();
        if (length > readBuffer.remaining()) {
            readBuffer.reset();
            return null;
        }
        byte[] b = new byte[length];
        readBuffer.get(b);
        readBuffer.mark();
        return new String(b);
    }
}

• 定义处理器

public class ServerProcessor implements MessageProcessor<String> {
     @Override
     public void process(AioSession<String> session, String msg) {
         WriteBuffer writeBuffer = session.writeBuffer();
         byte[] bytes = msg.getBytes();
         try {
             writeBuffer.writeInt(bytes.length);
             writeBuffer.write(bytes);
         } catch (IOException e) {
             e.printStackTrace();
         }
     }
     @Override
     public void stateEvent(AioSession<String> session, StateMachineEnum stateMachineEnum, Throwable throwable) {
     }
}

准备工作就绪后，我们需要在application.xml配置它们的实例bean，并将其引用至AioQuickServer的bean配置。因为AioQuickServer的构造方法都是带参数的，所以配置bean的时候需要用到标签constructor-arg。

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xsi:schemaLocation="http://www.springframework.org/schema/beans
        http://www.springframework.org/schema/beans/spring-beans.xsd">
    <bean name="protocol" class="org.smartboot.example.spring.StringProtocol"/>
    <bean name="messageProcessor" class="org.smartboot.example.spring.ServerProcessor"/>
    <bean name="aioQuickServer" class="org.smartboot.socket.transport.AioQuickServer" init-method="start" destroy-method="shutdown">
        <constructor-arg index="0" value="8080"/>
        <constructor-arg index="1" ref="protocol"/>
        <constructor-arg index="2" ref="messageProcessor"/>
    </bean>
</beans>

当启动spring容器时，我们的通信服务便开始运行。接下来我们来验证一下集成后的效果，如果将其配置到真正的web服务中演示过程稍显琐碎，故我们直接通过main函数来调用。

public class SpringDemo {
    public static void main(String[] args) {
        ApplicationContext context = new ClassPathXmlApplicationContext("application.xml");
        AioQuickServer aioQuickServer = context.getBean("aioQuickServer", AioQuickServer.class);
        System.out.println("服务启动成功：" + aioQuickServer);
        ((ClassPathXmlApplicationContext) context).close();
        System.out.println("服务关闭");
    }
}

执行上述代码后控制台会打印服务的启动与关闭日志，如果出现异常，请检查端口号是否被占用。

2. 注解方式启动服务

如果读者习惯用注解的方式使用Spring，那我们需要对原有的代码稍加改动。Protocol和MessageProcessor实现类需要加上注解@Component。

• 定义协议类

@Component("protocol")
public class StringProtocol implements Protocol<String> {
    @Override
    public String decode(ByteBuffer readBuffer, AioSession<String> session) {
        int remaining = readBuffer.remaining();
        if (remaining < Integer.BYTES) {
            return null;
        }
        readBuffer.mark();
        int length = readBuffer.getInt();
        if (length > readBuffer.remaining()) {
            readBuffer.reset();
            return null;
        }
        byte[] b = new byte[length];
        readBuffer.get(b);
        readBuffer.mark();
        return new String(b);
    }
}

• 定义处理器

@Component("messageProcessor")
public class ServerProcessor implements MessageProcessor<String> {
      @Override
      public void process(AioSession<String> session, String msg) {
          WriteBuffer writeBuffer = session.writeBuffer();
          byte[] bytes = msg.getBytes();
          try {
              writeBuffer.writeInt(bytes.length);
              writeBuffer.write(bytes);
          } catch (IOException e) {
              e.printStackTrace();
          }
      }
      @Override
      public void stateEvent(AioSession<String> session, StateMachineEnum stateMachineEnum, Throwable throwable) {
      }
  }

接下来我们修改application.xml配置，default-autowire="byName"表示优先按bean名称注入，而注解的扫描扫描包路径为org.smartboot.example.spring。

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xmlns:context="http://www.springframework.org/schema/context"
       xsi:schemaLocation="http://www.springframework.org/schema/beans
        http://www.springframework.org/schema/beans/spring-beans.xsd
        http://www.springframework.org/schema/context
        http://www.springframework.org/schema/context/spring-context-4.0.xsd"
       default-autowire="byName">
    <context:component-scan base-package="org.smartboot.example.spring"/>
</beans>

最后我们还需要以注解的形式构造AioQuickServer对象并启动服务。

@Component
public class SpringDemo {
    @Autowired
    private MessageProcessor messageProcessor;
    @Autowired
    private Protocol protocol;
    private AioQuickServer aioQuickServer;
    public static void main(String[] args) {
        ApplicationContext context = new ClassPathXmlApplicationContext("application.xml");
        SpringDemo demo = context.getBean("springDemo", SpringDemo.class);
        System.out.println("服务启动成功：" + demo.aioQuickServer);
        ((ClassPathXmlApplicationContext) context).close();
        System.out.println("服务关闭");
    }
    @PostConstruct
    public void init() {
        aioQuickServer = new AioQuickServer(8080, protocol, messageProcessor);
        try {
            aioQuickServer.start();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
    @PreDestroy
    public void destroy() {
        aioQuickServer.shutdown();
    }
}