首先讲解下，spring中初始化加载问题：
很多时候，我们自己写的线程池，还有bean对象，还有其他的服务类，都可以通过，相关注解进行交给spring去管理，那么我们如何让nettyserver初始化加载呢：
在springBean的生命周期中有
1 InitializingBean 在系统初始化之后加载
package com.cxy.netty.controller;import org.springframework.beans.factory.InitializingBean;import org.springframework.stereotype.Controller;@Controllerpublic class DemoController implements InitializingBean { @Override public void afterPropertiesSet() throws Exception { System.out.println("系统加载"); }}
我们可以看下日志：
"C:\Program Files\Java\jdk1.8.0_191\bin\java.exe" -XX:TieredStopAtLevel=1 -noverify -Dspring.output.ansi.enabled=always -Dcom.sun.management.jmxremote -Dcom.sun.management.jmxremote.port=9135 -Dcom.sun.management.jmxremote.authenticate=false -Dcom.sun.management.jmxremote.ssl=false -Djava.rmi.server.hostname=localhost -Dspring.liveBeansView.mbeanDomain -Dspring.application.admin.enabled=true "-javaagent:D:\Program Files\JetBrains\ideaIU-2018.1.2.win\lib\idea_rt.jar=9136:D:\Program Files\JetBrains\ideaIU-2018.1.2.win\bin" -Dfile.encoding=UTF-8 -classpath "C:\Program Files\Java\jdk1.8.0_191\jre\lib\charsets.jar;C:\Program Files\Java\jdk1.8.0_191\jre\lib\deploy.jar;C:\Program Files\Java\jdk1.8.0_191\jre\lib\ext\access-bridge-64.jar;C:\Program Files\Java\jdk1.8.0_191\jre\lib\ext\cldrdata.jar;C:\Program Files\Java\jdk1.8.0_191\jre\lib\ext\dnsns.jar;C:\Program Files\Java\jdk1.8.0_191\jre\lib\ext\jaccess.jar;C:\Program Files\Java\jdk1.8.0_191\jre\lib\ext\jfxrt.jar;C:\Program Files\Java\jdk1.8.0_191\jre\lib\ext\localedata.jar;C:\Program Files\Java\jdk1.8.0_191\jre\lib\ext\nashorn.jar;C:\Program Files\Java\jdk1.8.0_191\jre\lib\ext\sunec.jar;C:\Program Files\Java\jdk1.8.0_191\jre\lib\ext\sunjce_provider.jar;C:\Program Files\Java\jdk1.8.0_191\jre\lib\ext\sunmscapi.jar;C:\Program Files\Java\jdk1.8.0_191\jre\lib\ext\sunpkcs11.jar;C:\Program Files\Java\jdk1.8.0_191\jre\lib\ext\zipfs.jar;C:\Program Files\Java\jdk1.8.0_191\jre\lib\javaws.jar;C:\Program Files\Java\jdk1.8.0_191\jre\lib\jce.jar;C:\Program Files\Java\jdk1.8.0_191\jre\lib\jfr.jar;C:\Program Files\Java\jdk1.8.0_191\jre\lib\jfxswt.jar;C:\Program Files\Java\jdk1.8.0_191\jre\lib\jsse.jar;C:\Program Files\Java\jdk1.8.0_191\jre\lib\management-agent.jar;C:\Program Files\Java\jdk1.8.0_191\jre\lib\plugin.jar;C:\Program Files\Java\jdk1.8.0_191\jre\lib\resources.jar;C:\Program Files\Java\jdk1.8.0_191\jre\lib\rt.jar;D:\工作\idea\netty\target\classes;D:\java\maven\org\springframework\boot\spring-boot-starter-web\2.2.1.RELEASE\spring-boot-starter-web-2.2.1.RELEASE.jar;D:\java\maven\org\springframework\boot\spring-boot-starter\2.2.1.RELEASE\spring-boot-starter-2.2.1.RELEASE.jar;D:\java\maven\org\springframework\boot\spring-boot\2.2.1.RELEASE\spring-boot-2.2.1.RELEASE.jar;D:\java\maven\org\springframework\boot\spring-boot-autoconfigure\2.2.1.RELEASE\spring-boot-autoconfigure-2.2.1.RELEASE.jar;D:\java\maven\org\springframework\boot\spring-boot-starter-logging\2.2.1.RELEASE\spring-boot-starter-logging-2.2.1.RELEASE.jar;D:\java\maven\ch\qos\logback\logback-classic\1.2.3\logback-classic-1.2.3.jar;D:\java\maven\ch\qos\logback\logback-core\1.2.3\logback-core-1.2.3.jar;D:\java\maven\org\apache\logging\log4j\log4j-to-slf4j\2.12.1\log4j-to-slf4j-2.12.1.jar;D:\java\maven\org\apache\logging\log4j\log4j-api\2.12.1\log4j-api-2.12.1.jar;D:\java\maven\org\slf4j\jul-to-slf4j\1.7.29\jul-to-slf4j-1.7.29.jar;D:\java\maven\jakarta\annotation\jakarta.annotation-api\1.3.5\jakarta.annotation-api-1.3.5.jar;D:\java\maven\org\yaml\snakeyaml\1.25\snakeyaml-1.25.jar;D:\java\maven\org\springframework\boot\spring-boot-starter-json\2.2.1.RELEASE\spring-boot-starter-json-2.2.1.RELEASE.jar;D:\java\maven\com\fasterxml\jackson\core\jackson-databind\2.10.0\jackson-databind-2.10.0.jar;D:\java\maven\com\fasterxml\jackson\core\jackson-annotations\2.10.0\jackson-annotations-2.10.0.jar;D:\java\maven\com\fasterxml\jackson\core\jackson-core\2.10.0\jackson-core-2.10.0.jar;D:\java\maven\com\fasterxml\jackson\datatype\jackson-datatype-jdk8\2.10.0\jackson-datatype-jdk8-2.10.0.jar;D:\java\maven\com\fasterxml\jackson\datatype\jackson-datatype-jsr310\2.10.0\jackson-datatype-jsr310-2.10.0.jar;D:\java\maven\com\fasterxml\jackson\module\jackson-module-parameter-names\2.10.0\jackson-module-parameter-names-2.10.0.jar;D:\java\maven\org\springframework\boot\spring-boot-starter-tomcat\2.2.1.RELEASE\spring-boot-starter-tomcat-2.2.1.RELEASE.jar;D:\java\maven\org\apache\tomcat\embed\tomcat-embed-core\9.0.27\tomcat-embed-core-9.0.27.jar;D:\java\maven\org\apache\tomcat\embed\tomcat-embed-el\9.0.27\tomcat-embed-el-9.0.27.jar;D:\java\maven\org\apache\tomcat\embed\tomcat-embed-websocket\9.0.27\tomcat-embed-websocket-9.0.27.jar;D:\java\maven\org\springframework\boot\spring-boot-starter-validation\2.2.1.RELEASE\spring-boot-starter-validation-2.2.1.RELEASE.jar;D:\java\maven\jakarta\validation\jakarta.validation-api\2.0.1\jakarta.validation-api-2.0.1.jar;D:\java\maven\org\hibernate\validator\hibernate-validator\6.0.18.Final\hibernate-validator-6.0.18.Final.jar;D:\java\maven\org\jboss\logging\jboss-logging\3.4.1.Final\jboss-logging-3.4.1.Final.jar;D:\java\maven\com\fasterxml\classmate\1.5.1\classmate-1.5.1.jar;D:\java\maven\org\springframework\spring-web\5.2.1.RELEASE\spring-web-5.2.1.RELEASE.jar;D:\java\maven\org\springframework\spring-beans\5.2.1.RELEASE\spring-beans-5.2.1.RELEASE.jar;D:\java\maven\org\springframework\spring-webmvc\5.2.1.RELEASE\spring-webmvc-5.2.1.RELEASE.jar;D:\java\maven\org\springframework\spring-aop\5.2.1.RELEASE\spring-aop-5.2.1.RELEASE.jar;D:\java\maven\org\springframework\spring-context\5.2.1.RELEASE\spring-context-5.2.1.RELEASE.jar;D:\java\maven\org\springframework\spring-expression\5.2.1.RELEASE\spring-expression-5.2.1.RELEASE.jar;D:\java\maven\io\netty\netty-all\4.1.25.Final\netty-all-4.1.25.Final.jar;D:\java\maven\org\slf4j\slf4j-api\1.7.29\slf4j-api-1.7.29.jar;D:\java\maven\org\springframework\spring-core\5.2.1.RELEASE\spring-core-5.2.1.RELEASE.jar;D:\java\maven\org\springframework\spring-jcl\5.2.1.RELEASE\spring-jcl-5.2.1.RELEASE.jar" com.cxy.netty.NettyApplication . ____ _ __ _ _ /\\ / ___'_ __ _ _(_)_ __ __ _ \ \ \ \ ( ( )\___ | '_ | '_| | '_ \/ _` | \ \ \ \ \\/ ___)| |_)| | | | | || (_| | ) ) ) ) ' |____| .__|_| |_|_| |_\__, | / / / / =========|_|==============|___/=/_/_/_/ :: Spring Boot :: (v2.2.1.RELEASE) 2019-11-23 18:20:49.749 INFO 38380 --- [ main] com.cxy.netty.NettyApplication : Starting NettyApplication on LAPTOP-MEIVCU3E with PID 38380 (started by cxy in D:\工作\idea\netty) 2019-11-23 18:20:49.752 INFO 38380 --- [ main] com.cxy.netty.NettyApplication : No active profile set, falling back to default profiles: default 2019-11-23 18:20:50.606 INFO 38380 --- [ main] o.s.b.w.embedded.tomcat.TomcatWebServer : Tomcat initialized with port(s): 8080 (http) 2019-11-23 18:20:50.623 INFO 38380 --- [ main] o.apache.catalina.core.StandardService : Starting service [Tomcat] 2019-11-23 18:20:50.623 INFO 38380 --- [ main] org.apache.catalina.core.StandardEngine : Starting Servlet engine: [Apache Tomcat/9.0.27] 2019-11-23 18:20:50.736 INFO 38380 --- [ main] o.a.c.c.C.[Tomcat].[localhost].[/] : Initializing Spring embedded WebApplicationContext 2019-11-23 18:20:50.737 INFO 38380 --- [ main] o.s.web.context.ContextLoader : Root WebApplicationContext: initialization completed in 947 ms 系统加载 2019-11-23 18:20:50.894 INFO 38380 --- [ main] o.s.s.concurrent.ThreadPoolTaskExecutor : Initializing ExecutorService 'applicationTaskExecutor' 2019-11-23 18:20:51.029 INFO 38380 --- [ main] o.s.b.w.embedded.tomcat.TomcatWebServer : Tomcat started on port(s): 8080 (http) with context path '' 2019-11-23 18:20:51.032 INFO 38380 --- [ main] com.cxy.netty.NettyApplication : Started NettyApplication in 1.689 seconds (JVM running for 4.137)
打印出了系统加载，这个适合有时候系统停机导致内存中的数据会有少部分丢失，必须要在重启之后才调用相关服务才可以调用，才可以加载缓存，那么这个方法可以很有效的加载在jvm内存的数据
2 注解@PostConstruct
package com.cxy.netty.controller;
import io.netty.bootstrap.ServerBootstrap;
import io.netty.channel.ChannelFuture;
import io.netty.channel.ChannelInitializer;
import io.netty.channel.EventLoopGroup;
import io.netty.channel.nio.NioEventLoopGroup;
import io.netty.channel.socket.SocketChannel;
import io.netty.channel.socket.nio.NioServerSocketChannel;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.boot.autoconfigure.web.ServerProperties;
import org.springframework.stereotype.Component;
import javax.annotation.PostConstruct;
import javax.annotation.PreDestroy;
import java.net.InetSocketAddress;
@Component
public class NettyServer {
private int port =8082;
EventLoopGroup boss = new NioEventLoopGroup();
EventLoopGroup work = new NioEventLoopGroup();
@PostConstruct
public void start() throws Exception {
System.out.println("启动记载netty");
ServerBootstrap b = new ServerBootstrap();
b.group(boss,work)
.channel(NioServerSocketChannel.class)
.localAddress(new InetSocketAddress(port))
.childHandler(new ChannelInitializer<SocketChannel>() {
@Override
protected void initChannel(SocketChannel ch) throws Exception {
ch.pipeline().addLast(new EchoServerHandler());
}
});
System.out.println("启动加载netty2");
ChannelFuture channelFuturef = b.bind().sync();
if (channelFuturef.isSuccess()){
System.out.println("启动成功");
}
}
@PreDestroy
private void destory() throws Exception{
boss.shutdownGracefully();
work.shutdownGracefully();
System.out.println("关闭server");
}
}
看打印日志：
从这里代码又可以应征笔者之前说的，netty的使用只需要自己写好那个助手类就可以了；
package com.cxy.netty.controller;
import io.netty.buffer.ByteBuf;
import io.netty.channel.ChannelFutureListener;
import io.netty.channel.ChannelHandlerContext;
import io.netty.channel.ChannelInboundHandlerAdapter;
import io.netty.util.CharsetUtil;
public class EchoServerHandler extends ChannelInboundHandlerAdapter {
@Override
public void channelRead(ChannelHandlerContext ctx, Object msg){
ByteBuf in = (ByteBuf) msg;
System.out.println("Server received: " + in.toString(CharsetUtil.UTF_8));
ctx.write(in);
}
@Override
public void channelReadComplete(ChannelHandlerContext ctx){
ctx.writeAndFlush(ChannelFutureListener.CLOSE);
}
@Override
public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause){
cause.printStackTrace();
ctx.close();
}
}
@PostConstruct 这个注解，到底是怎么样著有这么神奇的功效呢：
/** * The PostConstruct annotation is used on a method that needs to be executed * after dependency injection is done to perform any initialization. This * method MUST be invoked before the class is put into service. This * annotation MUST be supported on all classes that support dependency * injection. The method annotated with PostConstruct MUST be invoked even * if the class does not request any resources to be injected. Only one * method can be annotated with this annotation. The method on which the * PostConstruct annotation is applied MUST fulfill all of the following * criteria:
看到，表示，某个方法需要初始化的时候，可以使用这个注解：
是作用到方法上面的，使用这个整合时候，需要注意问题，就是，我们需要将整个类交给spring去管理，这样，才可以进行初始化，这个类是在spring的包中，所以需要整合必须要用这个二注解。
3 基础类实现 CommandLineRunner
package com.cxy.netty;
import com.cxy.netty.controller.NettyServer;
import org.springframework.boot.CommandLineRunner;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
@SpringBootApplication
public class NettyApplication implements CommandLineRunner {
public static void main(String[] args) {
SpringApplication.run(NettyApplication.class, args);
}
@Override
public void run(String... args) throws Exception {
NettyServer echoServer = new NettyServer(8081);
echoServer.start();
}
}
package com.cxy.netty.controller;
import io.netty.bootstrap.ServerBootstrap;
import io.netty.channel.ChannelFuture;
import io.netty.channel.ChannelInitializer;
import io.netty.channel.EventLoopGroup;
import io.netty.channel.nio.NioEventLoopGroup;
import io.netty.channel.socket.SocketChannel;
import io.netty.channel.socket.nio.NioServerSocketChannel;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.boot.autoconfigure.web.ServerProperties;
import org.springframework.stereotype.Component;
import javax.annotation.PostConstruct;
import javax.annotation.PreDestroy;
import java.net.InetSocketAddress;
public class NettyServer {
private int port;
public int getPort() {
return port;
}
public void setPort(int port) {
this.port = port;
}
public NettyServer(int port) {
this.port = port;
}
public void start() throws Exception {
System.out.println("启动记载netty");
EventLoopGroup boss = new NioEventLoopGroup();
EventLoopGroup work = new NioEventLoopGroup();
ServerBootstrap b = new ServerBootstrap();
b.group(boss,work)
.channel(NioServerSocketChannel.class)
.localAddress(new InetSocketAddress(port))
.childHandler(new ChannelInitializer<SocketChannel>() {
@Override
protected void initChannel(SocketChannel ch) throws Exception {
ch.pipeline().addLast(new EchoServerHandler());
}
});
System.out.println("启动加载netty2");
ChannelFuture channelFuturef = b.bind().sync();
if (channelFuturef.isSuccess()){
System.out.println("启动成功");
}
}
}
给他初始化的时候，添加启动方法，
看启动日志：
注意事项,在nettyServer上不要加component注解
4 利用 ApplicationListener 上下文监听器
package com.cxy.netty;
import com.cxy.netty.controller.NettyServer;
import org.springframework.context.ApplicationListener;
import org.springframework.context.event.ContextRefreshedEvent;
import org.springframework.stereotype.Component;
@Component
public class NettyBooter implements ApplicationListener<ContextRefreshedEvent> {
@Override
public void onApplicationEvent(ContextRefreshedEvent event) {
NettyServer nettyServer = new NettyServer(8081);
try {
nettyServer.start();
} catch (Exception e) {
e.printStackTrace();
}
}
}
package com.cxy.netty;
import com.cxy.netty.controller.NettyServer;
import org.springframework.boot.CommandLineRunner;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
@SpringBootApplication
public class NettyApplication {
public static void main(String[] args) {
SpringApplication.run(NettyApplication.class, args);
}
}
看启动日志：
可以看server也启动了。