SpringCloud Nacos服务注册中心和配置中心

本文介绍: （1）什么是配置中心？使用过SpringBoot项目的开发者都知道，SpringBoot有一个application.yml或者application.properties作为配置文件，里面有着各种各样的配置，比如数据库的url、username等。但是这个配置文件在文件打包之后就无法修改了，所以这时就需要一个配置中心来管理这些文件以达到配置动态更新的效果。从微服务的角度来说，微服务意味着要将单体应用中的业务拆分成一个个子服务，每个服务的粒度相对较小，因此系统中会出现大量的服务。

官方介绍是这样的：

官方网址：http://nacos.io

（1）先下载一个Nacos服务中间件，然后解压

最新版可以去官网下载：Releases · alibaba/nacos · GitHub

（2）解压之后再bin目录下点击startup.cmd运行（如果使用的是Linux系统则点击startup.sh）

启动后界面如下：

<dependencies>
    <!--web组件-->
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-web</artifactId>
    </dependency>
    <!--actuator-->
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-actuator</artifactId>
    </dependency>
    <!--SpringCloud-Nacos相关-->
    <dependency>
        <groupId>com.alibaba.cloud</groupId>
        <artifactId>spring-cloud-starter-alibaba-nacos-discovery</artifactId>
    </dependency>
    <dependency>
        <groupId>com.alibaba.boot</groupId>
        <artifactId>nacos-config-spring-boot-starter</artifactId>
    </dependency>
    <dependency>
        <groupId>com.alibaba.boot</groupId>
        <artifactId>nacos-config-spring-boot-actuator</artifactId>
    </dependency>
    <dependency>
        <groupId>com.alibaba.nacos</groupId>
        <artifactId>nacos-spring-context</artifactId>
    </dependency>
    <dependency>
        <groupId>org.mybatis.spring.boot</groupId>
        <artifactId>mybatis-spring-boot-starter</artifactId>
    </dependency>
    <dependency>
        <groupId>org.projectlombok</groupId>
        <artifactId>lombok</artifactId>
    </dependency>
    <!--MySQL-->
    <dependency>
        <groupId>mysql</groupId>
        <artifactId>mysql-connector-java</artifactId>
    </dependency>
</dependencies>

<dependency>
    <groupId>org.springframework.cloud</groupId>
    <artifactId>spring-cloud-dependencies</artifactId>
    <version>Greenwich.SR2</version>
    <type>pom</type>
    <scope>import</scope>
</dependency>
三、在resources目录下新建application.yml与bootstarp.yml配置文件

spring:
  cloud:
    nacos:
      discovery:
        server-addr: 127.0.0.1:8848　　#服务注册地址
#        ip: 127.0.0.1
  application:
    name: nacos_server

server:
  port: 9668
nacos:
 config:
   server-addr: 127.0.0.1:8848
   group: NAOCS-SPRING-CLOUD-SERVICE
   file-extension: properties
   data-id: mysql-config.properties
management:
  endpoints:
    web:
      exposure:
        include: '*'

package com.wzhi.config;

import com.alibaba.nacos.api.config.annotation.NacosValue;
import com.alibaba.nacos.spring.context.annotation.config.NacosPropertySource;
import lombok.Data;
import org.springframework.stereotype.Component;

/**
 * 从nacos配置中心中获取数据库连接配置
 *
 * @author wzhi
 */
@Component
@Data
@NacosPropertySource(dataId = "${nacos.config.data-id}", groupId = "${nacos.config.group}", autoRefreshed = true)
public class DatabaseConfig {

    @NacosValue(value = "${driver_class_name}", autoRefreshed = true)
    private String driverClassName;

    @NacosValue(value = "${url}", autoRefreshed = true)
    private String url;

    @NacosValue(value = "${user_name}", autoRefreshed = true)
    private String username;

    @NacosValue(value = "${password}", autoRefreshed = true)
    private String password;
    
}

package com.wzhi.config;

import com.zaxxer.hikari.HikariDataSource;
import org.apache.ibatis.session.SqlSessionFactory;
import org.mybatis.spring.SqlSessionFactoryBean;
import org.mybatis.spring.annotation.MapperScan;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.core.io.support.PathMatchingResourcePatternResolver;
import org.springframework.core.io.support.ResourcePatternResolver;

import javax.sql.DataSource;

/**
 * 配置Mybatis和连接池
 * @author wzhi
 */
@Configuration
@MapperScan(basePackages={"com.wzhi.dao"})
public class MybatisConfiguration {
    @Autowired
    private DatabaseConfig dataBaseConfig;

    @Bean
    public DataSource dataSource() {
        HikariDataSource dataSource = new HikariDataSource();
        System.out.println("获取到的配置文件内容为："+dataBaseConfig);
        dataSource.setDriverClassName(dataBaseConfig.getDriverClassName());
        dataSource.setJdbcUrl(dataBaseConfig.getUrl());
        dataSource.setUsername(dataBaseConfig.getUsername());
        dataSource.setPassword(dataBaseConfig.getPassword());
        return dataSource;
    }

    @Bean
    public SqlSessionFactory sqlSessionFactoryBean() throws Exception {

        SqlSessionFactoryBean sqlSessionFactoryBean = new SqlSessionFactoryBean();
        sqlSessionFactoryBean.setDataSource(dataSource());
        ResourcePatternResolver resolver = new PathMatchingResourcePatternResolver();
//        sqlSessionFactoryBean.setMapperLocations(resolver.getResources("classpath:mybatis/mapper/*.xml"));
        return sqlSessionFactoryBean.getObject();
    }

}