SpringBoot集成Netty，Handler中@Autowired注解为空

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最近建了个技术交流群，然后好多小伙伴都问关于Netty的问题，尤其今天的问题最特殊，功能大概是要在Netty接收消息时把数据写入数据库，那个小伙伴用的是 Spring Boot + MyBatis + Netty，所以就碰到了Handler中@Autowired注解为空的问题

参考了一些大神的博文，Spring Boot非controller使用@Autowired注解注入为null的问题，得到结论:

三个要素

• 1、用@Component注解把类设置为组件

@Component
public ClassName class; 

• 2、在方法上面加@PostConstruct注解

	@PostConstructpublic void init() {mclass = this;}

然后就可以用ServerImpl的接口了

 @AutowiredServerImpl serviceImplmclass.serviceImpl.add(Pojo pojo);

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但是，在这个case里面，这一套不好用了！！！就这么神奇…
那最后还是要自己去Spring容器获取Bean
首先改造一下Application，实现ApplicationContextAware接口，这里这样写是考虑到使用完还要释放，所以写的比较复杂

import org.springframework.beans.BeansException;
import org.springframework.beans.factory.support.BeanDefinitionBuilder;
import org.springframework.beans.factory.support.DefaultListableBeanFactory;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.context.ApplicationContext;
import org.springframework.context.ApplicationContextAware;@SpringBootApplication
public class SpbNettyApplication implements ApplicationContextAware {private static ApplicationContext applicationContext;private static DefaultListableBeanFactory defaultListableBeanFactory;public static void main(String[] args) {SpringApplication.run(SpbNettyApplication.class, args);new EchoServer().start(1234);}@Overridepublic void setApplicationContext(ApplicationContext applicationContext) throws BeansException {this.applicationContext = applicationContext;defaultListableBeanFactory = (DefaultListableBeanFactory)applicationContext.getAutowireCapableBeanFactory();}public static <T> T getBean(Class<T> clazz) {BeanDefinitionBuilder beanDefinitionBuilder = BeanDefinitionBuilder.genericBeanDefinition(clazz);String className = clazz.getName();defaultListableBeanFactory.registerBeanDefinition(className, beanDefinitionBuilder.getBeanDefinition());return (T) applicationContext.getBean(className);}public static void destroy(String className){defaultListableBeanFactory.removeBeanDefinition(className);System.out.println("destroy " + className);}}

这时候就可以在Netty的Handler中为所欲为啦！

import com.avanty.spbnetty.pojo.Car;
import com.avanty.spbnetty.service.CarServiceImpl;
import io.netty.channel.ChannelHandlerContext;
import io.netty.channel.ChannelInboundHandlerAdapter;public class EchoHandler extends ChannelInboundHandlerAdapter {@Overridepublic void channelActive(ChannelHandlerContext ctx) {}@Overridepublic void channelRead(ChannelHandlerContext ctx, Object msg){System.out.println(ctx.channel().remoteAddress() + "  " + msg.toString());ctx.channel().write("recv : " + msg.toString());ctx.channel().flush();Car car = new Car();car.setCarBrand("Mustang");car.setCarNum("789632");CarServiceImpl carServiceImpl = SpbNettyApplication.getBean(CarServiceImpl.class);carServiceImpl.addCar(car);SpbNettyApplication.destroy(CarServiceImpl.class.getName());}@Overridepublic void channelReadComplete(ChannelHandlerContext ctx) {}@Overridepublic void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) {}@Overridepublic void handlerRemoved(ChannelHandlerContext ctx) {System.out.println("offline " + ctx.channel().remoteAddress());}}

搞定！

Demo【SpbNetty】地址 https://gitee.com/ichampion/Public-Project-Demo.git

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