java代码 netty整合mobus

下面是使用jamod库在Netty中实现Modbus协议的示例代码：

public class ModbusServerHandler extends SimpleChannelInboundHandler<ModbusMessage> {
    
    private ModbusRequestHandler handler;
    
    public ModbusServerHandler(ModbusRequestHandler handler) {
        this.handler = handler;
    }
    
    @Override
    protected void channelRead0(ChannelHandlerContext ctx, ModbusMessage msg) throws Exception {
        // 处理Modbus请求
        ModbusMessage response = handler.handleRequest(msg);
        // 发送Modbus响应
        ctx.writeAndFlush(response);
    }
    
    @Override
    public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) throws Exception {
        // 处理异常
        cause.printStackTrace();
        ctx.close();
    }
}

上述代码定义了一个ModbusServerHandler类，继承了Netty的SimpleChannelInboundHandler类，用于处理Modbus请求和响应。在channelRead0()方法中，调用ModbusRequestHandler处理Modbus请求，然后发送Modbus响应。在exceptionCaught()方法中，处理异常。

下面是ModbusServer的示例代码：

public class ModbusServer {
    
    private int port;
    private ModbusRequestHandler handler;
    
    public ModbusServer(int port, ModbusRequestHandler handler) {
        this.port = port;
        this.handler = handler;
    }
    
    public void run() {
        // 创建EventLoopGroup
        EventLoopGroup bossGroup = new NioEventLoopGroup(1);
        EventLoopGroup workerGroup = new NioEventLoopGroup();
        try {
            // 创建ServerBootstrap
            ServerBootstrap b = new ServerBootstrap();
            b.group(bossGroup, workerGroup)
             .channel(NioServerSocketChannel.class)
             .childHandler(new ChannelInitializer<SocketChannel>() {
                 @Override
                 public void initChannel(SocketChannel ch) throws Exception {
                     ChannelPipeline pipeline = ch.pipeline();
                     // 添加Modbus编码器和解码器
                     pipeline.addLast(new ModbusEncoder());
                     pipeline.addLast(new ModbusDecoder());
                     // 添加ModbusServerHandler
                     pipeline.addLast(new ModbusServerHandler(handler));
                 }
             });
            // 绑定端口
            ChannelFuture f = b.bind(port).sync();
            // 等待服务器关闭
            f.channel().closeFuture().sync();
        } catch (InterruptedException e) {
            e.printStackTrace();
        } finally {
            // 关闭EventLoopGroup
            bossGroup.shutdownGracefully();
            workerGroup.shutdownGracefully();
        }
    }
}

上述代码定义了一个ModbusServer类，用于启动Modbus服务器。在run()方法中，创建EventLoopGroup和ServerBootstrap，然后绑定端口。在childHandler()方法中，添加Modbus编码器和解码器以及ModbusServerHandler。最后，等待服务器关闭。

在启动ModbusServer之前，需要实现ModbusRequestHandler接口，例如：

public class ModbusRequestHandlerImpl implements ModbusRequestHandler {

    @Override
    public ModbusMessage handleRequest(ModbusMessage request) {
        // 处理Modbus请求
        ModbusMessage response = new ModbusMessage();
        response.setFunctionCode(FunctionCode.READ_COILS);
        response.setData(new byte[] {0x01, 0x02, 0x03});
        return response;
    }
    
}

上述代码实现了ModbusRequestHandler接口，处理Modbus请求，并返回Modbus响应。

最后，启动ModbusServer：

public class Main {
    
    public static void main(String[] args) {
        ModbusRequestHandler handler = new ModbusRequestHandlerImpl();
        ModbusServer server = new ModbusServer(502, handler);
        server.run();
    }
    
}

上述代码创建了一个ModbusRequestHandlerImpl对象和ModbusServer对象，并启动ModbusServer。