創建項目服務提供者

1. 創建SpringBoot的nacos項目服務提供者
   
   
   這里為了使搭建的項目足夠純凈，不選擇相關依賴，稍后手動添加

2. pom.xml中添加依賴并下載依賴包

   <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>2.2.2.RELEASE</version>
   </dependency>
   

version版本號建議使用和spring-boot匹配的最新版本，如版本不匹配可能會出現如下所示的錯誤

 [main] DEBUG org.springframework.boot.context.logging.ClasspathLoggingApplicationListener - Application failed to start with classpath: unknown
 [main] ERROR org.springframework.boot.SpringApplication - Application run failed
java.lang.NoClassDefFoundError: org/springframework/boot/Bootstrapper
	at java.base/java.lang.ClassLoader.defineClass1(Native Method)
	at java.base/java.lang.ClassLoader.defineClass(ClassLoader.java:1017)
	at java.base/java.security.SecureClassLoader.defineClass(SecureClassLoader.java:174)
	at java.base/jdk.internal.loader.BuiltinClassLoader.defineClass(BuiltinClassLoader.java:800)
	at java.base/jdk.internal.loader.BuiltinClassLoader.findClassOnClassPathOrNull(BuiltinClassLoader.java:698)
	at java.base/jdk.internal.loader.BuiltinClassLoader.loadClassOrNull(BuiltinClassLoader.java:621)
	at java.base/jdk.internal.loader.BuiltinClassLoader.loadClass(BuiltinClassLoader.java:579)
	at java.base/jdk.internal.loader.ClassLoaders$AppClassLoader.loadClass(ClassLoaders.java:178)
	at java.base/java.lang.ClassLoader.loadClass(ClassLoader.java:522)
	at org.springframework.cloud.bootstrap.encrypt.DecryptEnvironmentPostProcessor.getTextEncryptor(DecryptEnvironmentPostProcessor.java:82)
	at org.springframework.cloud.bootstrap.encrypt.DecryptEnvironmentPostProcessor.postProcessEnvironment(DecryptEnvironmentPostProcessor.java:68)
	at org.springframework.boot.context.config.ConfigFileApplicationListener.onApplicationEnvironmentPreparedEvent(ConfigFileApplicationListener.java:203)
	at org.springframework.boot.context.config.ConfigFileApplicationListener.onApplicationEvent(ConfigFileApplicationListener.java:191)
	at org.springframework.context.event.SimpleApplicationEventMulticaster.doInvokeListener(SimpleApplicationEventMulticaster.java:172)
	at org.springframework.context.event.SimpleApplicationEventMulticaster.invokeListener(SimpleApplicationEventMulticaster.java:165)
	at org.springframework.context.event.SimpleApplicationEventMulticaster.multicastEvent(SimpleApplicationEventMulticaster.java:139)
	at org.springframework.context.event.SimpleApplicationEventMulticaster.multicastEvent(SimpleApplicationEventMulticaster.java:127)
	at org.springframework.boot.context.event.EventPublishingRunListener.environmentPrepared(EventPublishingRunListener.java:80)
	at org.springframework.boot.SpringApplicationRunListeners.environmentPrepared(SpringApplicationRunListeners.java:53)
	at org.springframework.boot.SpringApplication.prepareEnvironment(SpringApplication.java:345)
	at org.springframework.boot.SpringApplication.run(SpringApplication.java:308)
	at org.springframework.boot.SpringApplication.run(SpringApplication.java:1237)
	at org.springframework.boot.SpringApplication.run(SpringApplication.java:1226)
	at com.example.nacosprovider.NacosProviderApplication.main(NacosProviderApplication.java:16)
Caused by: java.lang.ClassNotFoundException: org.springframework.boot.Bootstrapper
	at java.base/jdk.internal.loader.BuiltinClassLoader.loadClass(BuiltinClassLoader.java:581)
	at java.base/jdk.internal.loader.ClassLoaders$AppClassLoader.loadClass(ClassLoaders.java:178)
	at java.base/java.lang.ClassLoader.loadClass(ClassLoader.java:522)
	... 24 common frames omitted

3. 修改application.properties文件

   spring.application.name=nacos-provider
   server.port=8070
   spring.cloud.nacos.discovery.server-addr=127.0.0.1:8848
   

   • spring.application.name應用名
   • server.port項目啟動使用的端口號
   • spring.cloud.nacos.discovery.server-addrnacos服務的地址

4. 修改NacosProviderApplication.java文件

package com.example.nacosprovider;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.client.discovery.EnableDiscoveryClient;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.RestController;

@SpringBootApplication
@EnableDiscoveryClient
public class NacosProviderApplication {

    public static void main(String[] args) {
        SpringApplication.run(NacosProviderApplication.class, args);
    }
    @RestController
    class EchoController {
        @RequestMapping(value = "/echo/{string}", method = RequestMethod.GET)
        public String echo(@PathVariable String string) {
            return "Hello Nacos Discovery " + string;
        }
    }
}

• @EnableDiscoveryClient 用于開啟服務注冊發現功能

創建nacos項目服務消費者

1. 創建SpringBoot的nacos項目服務提供者
   

這里為了使搭建的項目足夠純凈，不選擇相關依賴，稍后手動添加

2. pom.xml中添加依賴并下載依賴包

   <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>2.2.2.RELEASE</version>
   </dependency>
   

3. 修改application.properties文件

   spring.application.name=nacos-consumer
   server.port=8080
   spring.cloud.nacos.discovery.server-addr=127.0.0.1:8848
   

   • spring.application.name應用名
   • server.port項目啟動使用的端口號
   • spring.cloud.nacos.discovery.server-addrnacos服務的地址

4. 修改NacosConsumerApplication文件

package com.example.nacosconsumer;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.client.discovery.EnableDiscoveryClient;
import org.springframework.cloud.client.loadbalancer.LoadBalanced;
import org.springframework.context.annotation.Bean;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.RestController;
import org.springframework.web.client.RestTemplate;

@SpringBootApplication
@EnableDiscoveryClient
public class NacosConsumerApplication {
    @LoadBalanced
    @Bean
    public RestTemplate restTemplate() {
        return new RestTemplate();
    }
    public static void main(String[] args) {
        SpringApplication.run(NacosConsumerApplication.class, args);
    }

    @RestController
    public class TestController {

        private final RestTemplate restTemplate;

        @Autowired
        public TestController(RestTemplate restTemplate) {this.restTemplate = restTemplate;}

        @RequestMapping(value = "/echo/{str}", method = RequestMethod.GET)
        public String echo(@PathVariable String str) {
            return restTemplate.getForObject("http://nacos-provider/echo/" + str, String.class);
        }
    }
}

5. 訪問 http://localhost:8080/echo/2018輸出Hello Nacos Discovery 2018表示部署成功