SpringCloud-Nacos-服务注册中心-服务发现HelloWorld(服务之间数据的调用RestTemplate)

SpringCloud-Nacos-服务注册中心-服务发现(服务之间数据的调用)

一、Nacos注册中心的安装

# 一、从Github上克隆项目
git clone https://github.com/nacos-group/nacos-docker.git
# 进入该目录
cd nacos-docker
# 单机模式Mysql启动(带数据库)
docker-compose -f example/standalone-mysql.yaml up -d
# 单机模式Derby启动(不带数据库)
docker-compose -f example/standalone-derby.yaml up -d

访问: http://ip:8848/nacos

账号和密码默认为: nacos
一、利用Spring Initialar(Spring初始化器)创建一个项目，导入SpringCloud相关组件的依赖
项目结构目录,两个子模块都要继承父pom.xml

父pom.xml

    <dependencyManagement>
        <dependencies>
            <dependency>
                <groupId>com.alibaba.cloudgroupId>
                <artifactId>spring-cloud-alibaba-dependenciesartifactId>
                <version>2.1.0.RELEASEversion>
                <type>pomtype>
                <scope>importscope>
            dependency>
        dependencies>
    dependencyManagement>
    <dependencies>
        <dependency>
            <groupId>org.springframework.bootgroupId>
            <artifactId>spring-boot-starter-webartifactId>
        dependency>

        <dependency>
            <groupId>org.springframework.bootgroupId>
            <artifactId>spring-boot-devtoolsartifactId>
            <scope>runtimescope>
            <optional>trueoptional>
        dependency>
        <dependency>
            <groupId>org.springframework.bootgroupId>
            <artifactId>spring-boot-com.springcloudalibaba.springalibabacloudconsumer.configuration-processorartifactId>
            <optional>trueoptional>
        dependency>
        <dependency>
            <groupId>org.projectlombokgroupId>
            <artifactId>lombokartifactId>
            <optional>trueoptional>
        dependency>
        <dependency>
            <groupId>org.springframework.bootgroupId>
            <artifactId>spring-boot-starter-testartifactId>
            <scope>testscope>
            <exclusions>
                <exclusion>
                    <groupId>org.junit.vintagegroupId>
                    <artifactId>junit-vintage-engineartifactId>
                exclusion>
            exclusions>
        dependency>
    dependencies>

服务提供模块poml.xml

        
        
        <dependency>
            <groupId>org.springframework.cloudgroupId>
            <artifactId>spring-cloud-starter-alibaba-nacos-discoveryartifactId>
            <version>0.9.0.RELEASEversion>
        dependency>
        

application.yml

server:
  port: 8090
spring:
  application:
    # ===服务名===
    name: server-provider
  cloud:
    nacos:
      discovery:
        # =====服务的ip地址======
        server-addr: 47.100.57.52:8848

在服务提供模块provider主程序入口添加@EnableDiscoveryCilent注解

编写ProviderController

package com.springcloudalibaba.springcloudprovider.controller;

import lombok.extern.slf4j.Slf4j;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RestController;

@RestController
@Slf4j
public class ProviderController {
    @GetMapping("/provideServer/{id}")
    public String provideServer(@PathVariable Integer id) {
        log.info(id + "");
        return "服务提供者";
    }
}

服务消费模块pom.xml

    <dependencies>
        
        
        <dependency>
            <groupId>org.springframework.cloudgroupId>
            <artifactId>spring-cloud-starter-alibaba-nacos-discoveryartifactId>
            <version>0.9.0.RELEASEversion>
        dependency>
        
        <dependency>
            <groupId>org.springframework.cloudgroupId>
            <artifactId>spring-cloud-starter-openfeignartifactId>
            <version>2.1.3.RELEASEversion>
        dependency>
        
    dependencies>

application.yml

server:
  port: 8091
spring:
  application:
    # ===服务名===
    name: server-consumer
  cloud:
    nacos:
      discovery:
        # =====服务的ip地址======
        server-addr: 47.100.57.52:8848

消费模块主程序入口添加@EnableDiscoveryClient注解

服务消费模块结构

编写RestTemplate配置类，返回RestTemplate对象，用于模块间的调用获取数据

package com.springcloudalibaba.springalibabacloudconsumer.configuration;

import org.springframework.cloud.client.loadbalancer.LoadBalanced;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.web.client.RestTemplate;

//RestTemplate配置类,通过url用于模块之间的调用获取数据的对象
@Configuration
public class RestTemplateConfiguration {

    @Bean
    @LoadBalanced
    public RestTemplate getRestTemplate(){

        return new RestTemplate();
    }
}

编写Service和ServiceImpl

package com.springcloudalibaba.springalibabacloudconsumer.service;


import org.springframework.cloud.openfeign.FeignClient;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PathVariable;

//@FeignClient(value = "server-provider")
public interface UserService {
//    @GetMapping(value = "/provideServer/{uid}")
    String getOrder(Integer uid);
}

package com.springcloudalibaba.springalibabacloudconsumer.service.impl;

import com.springcloudalibaba.springalibabacloudconsumer.service.UserService;
import org.springframework.stereotype.Service;
import org.springframework.web.client.RestTemplate;

import javax.annotation.Resource;

@Service
public class UserServiceImpl implements UserService {
    @Resource
    RestTemplate restTemplate;
    @Override
    public String getOrder(Integer uid) {
        //通过getForObject()方法获取OrderController里的数据
        //第二个参数为获取到的数据的返回类型
        String orderData = restTemplate.getForObject("http://server-provider/provideServer/" + uid, String.class);
        return orderData;
    }
}

编写服务消费模块Controller

package com.springcloudalibaba.springalibabacloudconsumer.controller;

import com.springcloudalibaba.springalibabacloudconsumer.service.UserService;
import lombok.extern.slf4j.Slf4j;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RestController;

import javax.annotation.Resource;

@RestController
@Slf4j
public class UserController {
    @Resource
    UserService userService;

    @GetMapping("/consumeServer/{uid}")
    public String consumeServer(@PathVariable Integer uid) {
        String order = userService.getOrder(uid);
        return order;
    }
}

二、搭建好Demo后准备启动两个服务进行测试

启动后，在Nacos后台可以看到两个服务都已经成功注册进Nacos注册中心了！

先访问服务提供者模块，成功获取到数据！

再访问服务消费者，成功拿到服务提供者模块返回的数据！

RestTemplate在调用数据的时候会有一定的缺陷(参数拼接的问题)，下一篇将附上使用Feign进行服务间的通信。