Spring Clound Nacos服务注册示例程序+部署到Tomcat服务器的处理

一、Nacos服务注册中心

1、下载Nacos服务注册中心，下载地址https://github.com/alibaba/nacos/releases。

2、将下载下来的nacos-server-XXX.zip文件解压，找到bin文件夹下的startup.bat文件，右键选编辑用记事本打开，把里面的set MODE="cluster"改成set MODE="standalone"，即把集群布置改成独立布置。

3、双击启动startup.bat，在浏览器中输入网址http://localhost:8848/nacos，即可打开页面，输入初始用户名nacos和密码nacos，进入界面。

二、创建一个Service Provider，并在Nacos里注册

1、pom.xml文件如下

<?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>2.5.3</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>
    <groupId>com.example</groupId>
    <artifactId>provider</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <packaging>war</packaging>
    <name>provider</name>
    <description>Demo project for Spring Boot</description>
    <properties>
        <java.version>11</java.version>
        <spring-cloud.version>2020.0.3</spring-cloud.version>
    </properties>
    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <dependency>
            <groupId>com.alibaba.cloud</groupId>
            <artifactId>spring-cloud-starter-alibaba-nacos-discovery</artifactId>
            <version>LATEST</version>
        </dependency>
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-bootstrap</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-tomcat</artifactId>
            <scope>provided</scope>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
    </dependencies>
    <dependencyManagement>
        <dependencies>
            <dependency>
                <groupId>org.springframework.cloud</groupId>
                <artifactId>spring-cloud-dependencies</artifactId>
                <version>${spring-cloud.version}</version>
                <type>pom</type>
                <scope>import</scope>
            </dependency>
        </dependencies>
    </dependencyManagement>

    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
        </plugins>
    </build>

</project>

2、application.properties文件里设置服务注册中心地址以及Service Provider的名称和端口

#Service Provider的名称
spring.application.name=myprovider
#Service Provider的端口
server.port=8080
#nacos服务注册中心的地址和端口，注意端口号后面没有/nacos
spring.cloud.nacos.discovery.server-addr=localhost:8848

3、启动程序添加注解@EnableDiscoveryClient，代码如下：

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.client.discovery.EnableDiscoveryClient;

@SpringBootApplication
@EnableDiscoveryClient
public class ProviderApplication {
    public static void main(String[] args) {
        SpringApplication.run(ProviderApplication.class, args);
    }
}

4、设置完成上述三步之后，在IDEA里启动程序，已经可以看到在Nacos注册中心页面上出现了myprovider这个服务。

三、部署到Tomcat

1、创建一个ServletInitializer类，继承SpringBootServletInitializer，代码如下

import org.springframework.boot.builder.SpringApplicationBuilder;
import org.springframework.boot.web.servlet.support.SpringBootServletInitializer;
import org.springframework.stereotype.Component;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RestController;

@RestController
@Component
public class ServletInitializer extends SpringBootServletInitializer {
    @Override
    protected SpringApplicationBuilder configure(SpringApplicationBuilder application) {
        return application.sources(ProviderApplication.class);
    }
    @GetMapping("/")
    public String echo(){
        return  "helloworld";
    }
}

2、创建一个NacosConfig类，继承ApplicationRunner，代码如下

import com.alibaba.cloud.nacos.registry.NacosAutoServiceRegistration;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.boot.ApplicationArguments;
import org.springframework.boot.ApplicationRunner;
import org.springframework.stereotype.Component;

import javax.management.MBeanServer;
import javax.management.ObjectName;
import javax.management.Query;
import java.lang.management.ManagementFactory;
import java.util.Set;

@Component
public class NacosConfig implements ApplicationRunner {

    @Autowired(required = false)
    private NacosAutoServiceRegistration registration;

    @Value("${server.port}")
    Integer port;

    @Override
    public void run(ApplicationArguments args) {

        if (registration != null && port != null) {
            Integer tomcatPort = port;
            try {
                tomcatPort = new Integer(getTomcatPort());
            } catch (Exception e) {
                e.printStackTrace();
            }

            registration.setPort(tomcatPort);

            registration.start();
        }
    }

    /**
     * 获取外部tomcat端口
     */

    public String getTomcatPort() throws Exception {
        MBeanServer beanServer = ManagementFactory.getPlatformMBeanServer();
        Set<ObjectName> objectNames = beanServer.queryNames(new ObjectName("*:type=Connector,*"), Query.match(Query.attr("protocol"), Query.value("HTTP/1.1")));
        String port = objectNames.iterator().next().getKeyProperty("port");
        return port;
    }

}

3、创建一个NacosListener类，继承ApplicationListener<ApplicationReadyEvent>，代码如下

import com.alibaba.cloud.nacos.registry.NacosAutoServiceRegistration;
import com.alibaba.cloud.nacos.registry.NacosRegistration;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.context.event.ApplicationReadyEvent;
import org.springframework.context.ApplicationListener;
import org.springframework.context.event.EventListener;
import org.springframework.stereotype.Component;

@Component
public class NacosListener implements ApplicationListener<ApplicationReadyEvent> {
    @Autowired
    private NacosRegistration registration;

    @Autowired
    private NacosAutoServiceRegistration nacosAutoServiceRegistration;

    @Override
    public void onApplicationEvent(ApplicationReadyEvent event) {
        String property = event.getApplicationContext().getEnvironment().getProperty("server.port");
        registration.setPort(Integer.valueOf(property));
        nacosAutoServiceRegistration.start();
    }
    @EventListener(ApplicationReadyEvent.class)
    public void onWebServerReady(ApplicationReadyEvent event) {
        String property = event.getApplicationContext().getEnvironment().getProperty("server.port");
        registration.setPort(Integer.valueOf(property));
        nacosAutoServiceRegistration.start();
    }
}

完成后，将程序导出成war文件，部署到Tomcat里。