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
引入pom.xml
<?xml version="1.0" encoding="UTF-8"?> <project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd"> <modelVersion>4.0.0</modelVersion> <parent> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-parent</artifactId> <version>2.2.1.RELEASE</version> <relativePath/> <!-- lookup parent from repository --> </parent> <groupId>com.cxy</groupId> <artifactId>netty</artifactId> <version>0.0.1-SNAPSHOT</version> <name>netty</name> <description>Demo project for Spring Boot</description> <properties> <java.version>1.8</java.version> </properties> <dependencies> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-web</artifactId> </dependency> <dependency> <groupId>io.netty</groupId> <artifactId>netty-all</artifactId> <version>4.1.25.Final</version> </dependency> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-test</artifactId> <scope>test</scope> <exclusions> <exclusion> <groupId>org.junit.vintage</groupId> <artifactId>junit-vintage-engine</artifactId> </exclusion> </exclusions> </dependency> </dependencies> <build> <plugins> <plugin> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-maven-plugin</artifactId> </plugin> </plugins> </build> </project>
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;
@Controller
public 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 FilesJavajdk1.8.0_191injava.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 FilesJetBrainsideaIU-2018.1.2.winlibidea_rt.jar=9136:D:Program FilesJetBrainsideaIU-2018.1.2.winin" -Dfile.encoding=UTF-8 -classpath "C:Program FilesJavajdk1.8.0_191jrelibcharsets.jar;C:Program FilesJavajdk1.8.0_191jrelibdeploy.jar;C:Program FilesJavajdk1.8.0_191jrelibextaccess-bridge-64.jar;C:Program FilesJavajdk1.8.0_191jrelibextcldrdata.jar;C:Program FilesJavajdk1.8.0_191jrelibextdnsns.jar;C:Program FilesJavajdk1.8.0_191jrelibextjaccess.jar;C:Program FilesJavajdk1.8.0_191jrelibextjfxrt.jar;C:Program FilesJavajdk1.8.0_191jrelibextlocaledata.jar;C:Program FilesJavajdk1.8.0_191jrelibext ashorn.jar;C:Program FilesJavajdk1.8.0_191jrelibextsunec.jar;C:Program FilesJavajdk1.8.0_191jrelibextsunjce_provider.jar;C:Program FilesJavajdk1.8.0_191jrelibextsunmscapi.jar;C:Program FilesJavajdk1.8.0_191jrelibextsunpkcs11.jar;C:Program FilesJavajdk1.8.0_191jrelibextzipfs.jar;C:Program FilesJavajdk1.8.0_191jrelibjavaws.jar;C:Program FilesJavajdk1.8.0_191jrelibjce.jar;C:Program FilesJavajdk1.8.0_191jrelibjfr.jar;C:Program FilesJavajdk1.8.0_191jrelibjfxswt.jar;C:Program FilesJavajdk1.8.0_191jrelibjsse.jar;C:Program FilesJavajdk1.8.0_191jrelibmanagement-agent.jar;C:Program FilesJavajdk1.8.0_191jrelibplugin.jar;C:Program FilesJavajdk1.8.0_191jrelib esources.jar;C:Program FilesJavajdk1.8.0_191jrelib t.jar;D:工作idea etty argetclasses;D:javamavenorgspringframeworkootspring-boot-starter-web2.2.1.RELEASEspring-boot-starter-web-2.2.1.RELEASE.jar;D:javamavenorgspringframeworkootspring-boot-starter2.2.1.RELEASEspring-boot-starter-2.2.1.RELEASE.jar;D:javamavenorgspringframeworkootspring-boot2.2.1.RELEASEspring-boot-2.2.1.RELEASE.jar;D:javamavenorgspringframeworkootspring-boot-autoconfigure2.2.1.RELEASEspring-boot-autoconfigure-2.2.1.RELEASE.jar;D:javamavenorgspringframeworkootspring-boot-starter-logging2.2.1.RELEASEspring-boot-starter-logging-2.2.1.RELEASE.jar;D:javamavenchqoslogbacklogback-classic1.2.3logback-classic-1.2.3.jar;D:javamavenchqoslogbacklogback-core1.2.3logback-core-1.2.3.jar;D:javamavenorgapachelogginglog4jlog4j-to-slf4j2.12.1log4j-to-slf4j-2.12.1.jar;D:javamavenorgapachelogginglog4jlog4j-api2.12.1log4j-api-2.12.1.jar;D:javamavenorgslf4jjul-to-slf4j1.7.29jul-to-slf4j-1.7.29.jar;D:javamavenjakartaannotationjakarta.annotation-api1.3.5jakarta.annotation-api-1.3.5.jar;D:javamavenorgyamlsnakeyaml1.25snakeyaml-1.25.jar;D:javamavenorgspringframeworkootspring-boot-starter-json2.2.1.RELEASEspring-boot-starter-json-2.2.1.RELEASE.jar;D:javamavencomfasterxmljacksoncorejackson-databind2.10.0jackson-databind-2.10.0.jar;D:javamavencomfasterxmljacksoncorejackson-annotations2.10.0jackson-annotations-2.10.0.jar;D:javamavencomfasterxmljacksoncorejackson-core2.10.0jackson-core-2.10.0.jar;D:javamavencomfasterxmljacksondatatypejackson-datatype-jdk82.10.0jackson-datatype-jdk8-2.10.0.jar;D:javamavencomfasterxmljacksondatatypejackson-datatype-jsr3102.10.0jackson-datatype-jsr310-2.10.0.jar;D:javamavencomfasterxmljacksonmodulejackson-module-parameter-names2.10.0jackson-module-parameter-names-2.10.0.jar;D:javamavenorgspringframeworkootspring-boot-starter-tomcat2.2.1.RELEASEspring-boot-starter-tomcat-2.2.1.RELEASE.jar;D:javamavenorgapache omcatembed omcat-embed-core9.0.27 omcat-embed-core-9.0.27.jar;D:javamavenorgapache omcatembed omcat-embed-el9.0.27 omcat-embed-el-9.0.27.jar;D:javamavenorgapache omcatembed omcat-embed-websocket9.0.27 omcat-embed-websocket-9.0.27.jar;D:javamavenorgspringframeworkootspring-boot-starter-validation2.2.1.RELEASEspring-boot-starter-validation-2.2.1.RELEASE.jar;D:javamavenjakartavalidationjakarta.validation-api2.0.1jakarta.validation-api-2.0.1.jar;D:javamavenorghibernatevalidatorhibernate-validator6.0.18.Finalhibernate-validator-6.0.18.Final.jar;D:javamavenorgjbossloggingjboss-logging3.4.1.Finaljboss-logging-3.4.1.Final.jar;D:javamavencomfasterxmlclassmate1.5.1classmate-1.5.1.jar;D:javamavenorgspringframeworkspring-web5.2.1.RELEASEspring-web-5.2.1.RELEASE.jar;D:javamavenorgspringframeworkspring-beans5.2.1.RELEASEspring-beans-5.2.1.RELEASE.jar;D:javamavenorgspringframeworkspring-webmvc5.2.1.RELEASEspring-webmvc-5.2.1.RELEASE.jar;D:javamavenorgspringframeworkspring-aop5.2.1.RELEASEspring-aop-5.2.1.RELEASE.jar;D:javamavenorgspringframeworkspring-context5.2.1.RELEASEspring-context-5.2.1.RELEASE.jar;D:javamavenorgspringframeworkspring-expression5.2.1.RELEASEspring-expression-5.2.1.RELEASE.jar;D:javamavenio etty etty-all4.1.25.Final etty-all-4.1.25.Final.jar;D:javamavenorgslf4jslf4j-api1.7.29slf4j-api-1.7.29.jar;D:javamavenorgspringframeworkspring-core5.2.1.RELEASEspring-core-5.2.1.RELEASE.jar;D:javamavenorgspringframeworkspring-jcl5.2.1.RELEASEspring-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 etty) 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"); } }
启动类：
package com.cxy.netty; import com.cxy.netty.controller.InitListener; import com.cxy.netty.controller.NettyServer; import org.springframework.boot.CommandLineRunner; import org.springframework.boot.SpringApplication; import org.springframework.boot.autoconfigure.SpringBootApplication; import org.springframework.boot.web.servlet.ServletListenerRegistrationBean; import org.springframework.context.annotation.Bean; @SpringBootApplication public class NettyApplication { public static void main(String[] args) { SpringApplication.run(NettyApplication.class, args); } }
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。
5 利用监听器启动：
package com.cxy.netty.controller; import javax.servlet.ServletContextEvent; import javax.servlet.ServletContextListener; /** * 系统初始化监听器 * @author Administrator * */ public class InitListener implements ServletContextListener { @Override public void contextInitialized(ServletContextEvent sce) { NettyServer nettyServer = new NettyServer(8081); try { nettyServer.start(); } catch (Exception e) { e.printStackTrace(); } } @Override public void contextDestroyed(ServletContextEvent sce) { } }
package com.cxy.netty; import com.cxy.netty.controller.InitListener; import com.cxy.netty.controller.NettyServer; import org.springframework.boot.CommandLineRunner; import org.springframework.boot.SpringApplication; import org.springframework.boot.autoconfigure.SpringBootApplication; import org.springframework.boot.web.servlet.ServletListenerRegistrationBean; import org.springframework.context.annotation.Bean; @SpringBootApplication public class NettyApplication { /** * 注册监听器 * @return */ @SuppressWarnings({ "rawtypes", "unchecked" }) @Bean public ServletListenerRegistrationBean servletListenerRegistrationBean() { ServletListenerRegistrationBean servletListenerRegistrationBean = new ServletListenerRegistrationBean(); servletListenerRegistrationBean.setListener(new InitListener()); return servletListenerRegistrationBean; } public static void main(String[] args) { SpringApplication.run(NettyApplication.class, args); } }
看日志：
