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This article mainly introduces how to annotate the use of Service or Mapper in Netty, has a certain reference value, interested friends can refer to, I hope you can learn a lot after reading this article, the following let the editor take you to understand it.

Netty annotations using Service or Mapper

SpringBoot is used with Netty, and the use of Service/Mapper is always null in Handler. At first, we use the SpringBoot startup class to inherit ApplicationContextAware, and then write a static method to get Bean to solve the problem.

After running on the server for a few hours, there was a problem, which seemed to be caused by the scheme.

Another way, look at the answer given on the Internet, because Handler is from new and is not managed by Spring, so annotations are of no use at all.

After thinking it over, (with BUG, the following correction is solved: I think we can add @ Component annotation to Handler to be managed by Spring, and then pass Handler to Server through the construction method. Structure code):

Handler@Componentpublic class OBDHandler extends ChannelInboundHandlerAdapter {private final Logger logger = LoggerFactory.getLogger (getClass ()); @ Autowired private OBDMapper mOBDMapper;} Serverpublic class OBDServer {private Logger log = LoggerFactory.getLogger (getClass ()); private OBDHandler obdHandler; private int port; public OBDServer (int port,OBDHandler obdHandler) {this.port = port; this.obdHandler = obdHandler;} private void bind () throws Exception {EventLoopGroup group = new NioEventLoopGroup () ServerBootstrap serverBootstrap = new ServerBootstrap (); serverBootstrap.group (group) / / .channel (NioServerSocketChannel.class) / / .childHandler (new ChannelInitializer () {/ / @ Override public void initChannel (SocketChannel ch) throws Exception {ch.pipeline (). AddLast (new LengthFieldBasedFrameDecoder); ch.pipeline () .childHandler (obdHandler) });}} create Server@Configurationpublic class NettyConfig {@ Autowired private OBDHandler obdHandler; @ Bean public OBDServer obdServer () {OBDServer obdServer = new OBDServer; obdServer.startServer (); return obdServer;}} second revision

Concurrency requires the creation of multiple Handler, and a singleton Handler hosted by Spring will cause the following error:

Is not a @ Sharable handler, so can't be added or removed multiple times.

Finally, by injecting Service/Mapper into the Server and passing it through the Handler construction:

Public class OBDServer {@ Autowired private OBDMapper mOBDMapper; public OBDServer (int port) {this.port = port;} private void bind () throws Exception {EventLoopGroup group = new NioEventLoopGroup (); ServerBootstrap serverBootstrap = new ServerBootstrap () ServerBootstrap.group (group) / / .channel (NioServerSocketChannel.class) / / .childHandler (new ChannelInitializer () {/ / @ Override public void initChannel (SocketChannel ch) throws Exception {ch.pipeline (). AddLast (new LengthFieldBasedFrameDecoder (1024 (1024); ch.pipeline () .addLast (new OBDHandler (mOBDMapper));}}) }} Netty handler injection service is empty injection mode @ Slf4j@Componentpublic class BootNettyChannelInboundHandlerAdapter extends ChannelInboundHandlerAdapter {public static BootNettyChannelInboundHandlerAdapter bootNettyChannelInboundHandlerAdapter; / / 1. Normal injection [remember that the main class also needs to use @ Component annotation] @ Autowired private DeviceUpService deviceUpService; / / 2. The initialization constructor must have public BootNettyChannelInboundHandlerAdapter () {} / / 3. Execute when the container is initialized-here is the focus @ PostConstruct public void init () {bootNettyChannelInboundHandlerAdapter = this; bootNettyChannelInboundHandlerAdapter.deviceUpService = this.deviceUpService;}}

After completing the above steps, pass

BootNettyChannelInboundHandlerAdapter.deviceUpService

Just call the service class

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