记录一次学习微服务nacos的简单实例，顺带学习学习trae

我爱吃橘子0526

389人浏览 · 2026-03-22 11:51:12

我爱吃橘子0526 · 2026-03-22 11:51:12 发布

前言

学习微服务，简单的尝试一下微服务架构的搭建
使用nacos注册中心

一、下载nacos

https://nacos.io/
直接官网下载即可，也有教程，不是很复杂

二、使用

引依赖、配地址

1、父工程pom

在这里插入图片描述

<?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 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>

    <groupId>cn.clouddemo.demo</groupId>
    <artifactId>cloud-demo</artifactId>
    <version>1.0</version>
    <modules>
        <module>user-service</module>
        <module>order-service</module>
        <module>eureka-server</module>
        <!--<module>feign-api</module>
        <module>gateway</module>-->
    </modules>

    <packaging>pom</packaging>

    <parent>
         <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.3.9.RELEASE</version>
        <relativePath/>
    </parent> 

    <properties>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
        <java.version>1.8</java.version>
        <spring-cloud.version>Hoxton.SR10</spring-cloud.version>
        <mysql.version>5.1.47</mysql.version>
        <mybatis.version>2.1.1</mybatis.version>
    </properties>

    <dependencyManagement>
        <dependencies>
            <!-- springCloud -->
            <dependency>
                <groupId>org.springframework.cloud</groupId>
                <artifactId>spring-cloud-dependencies</artifactId>
                <version>${spring-cloud.version}</version>
                <type>pom</type>
                <scope>import</scope>
            </dependency>
            <!--nacos的管理依赖-->
            <dependency>
                <groupId>com.alibaba.cloud</groupId>
                <artifactId>spring-cloud-alibaba-dependencies</artifactId>
                <version>2.2.5.RELEASE</version>
                <type>pom</type>
                <scope>import</scope>
            </dependency>
            <!-- mysql驱动 -->
            <dependency>
                <groupId>mysql</groupId>
                <artifactId>mysql-connector-java</artifactId>
                <version>${mysql.version}</version>
            </dependency>
            <!--mybatis-->
            <dependency>
                <groupId>org.mybatis.spring.boot</groupId>
                <artifactId>mybatis-spring-boot-starter</artifactId>
                <version>${mybatis.version}</version>
            </dependency>
        </dependencies>
    </dependencyManagement>
    <dependencies>
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
        </dependency>
    </dependencies>
</project>

2.创建order服务（订单服务）

代码如下（示例）：

(1)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 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <parent>
        <artifactId>cloud-demo</artifactId>
        <groupId>cn.clouddemo.demo</groupId>
        <version>1.0</version>
    </parent>
    <modelVersion>4.0.0</modelVersion>

    <artifactId>order-service</artifactId>

    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
        </dependency>
        <!--mybatis-->
        <dependency>
            <groupId>org.mybatis.spring.boot</groupId>
            <artifactId>mybatis-spring-boot-starter</artifactId>
        </dependency>
        <dependency>
            <groupId>cn.clouddemo.demo</groupId>
            <artifactId>user-service</artifactId>
            <version>1.0</version>
            <scope>compile</scope>
        </dependency>
        <!--eureka客户端依赖-->
        <!--<dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-netflix-eureka-client</artifactId>
        </dependency>-->
        <!-- nacos客户端依赖包 -->
        <dependency>
            <groupId>com.alibaba.cloud</groupId>
            <artifactId>spring-cloud-starter-alibaba-nacos-discovery</artifactId>
        </dependency>
        <!-- <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-openfeign</artifactId>
        </dependency>  -->
        <!--引入HttpClient依赖-->
        <!-- <dependency>
            <groupId>io.github.openfeign</groupId>
            <artifactId>feign-httpclient</artifactId>
        </dependency> -->
        <!--引入feign的统一api-->
        <!-- <dependency>
            <groupId>cn.itcast.demo</groupId>
            <artifactId>feign-api</artifactId>
            <version>1.0</version>
        </dependency> -->
    </dependencies>
    <build>
        <finalName>app</finalName>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
        </plugins>
    </build>
</project>

(2)配置文件application.yml

server:
  port: 8088
spring:
  datasource:
    url: jdbc:mysql://localhost:3306/cloud_order?useSSL=false&useUnicode=true&characterEncoding=utf-8
    username: root
    password: root123456
    driver-class-name: com.mysql.jdbc.Driver
  application:
    name: orderservice
  cloud:
    nacos:
      server-addr: localhost:8848 # nacos服务地址
mybatis:
  type-aliases-package: cn.clouddemo.user.pojo
  configuration:
    map-underscore-to-camel-case: true
logging:
  level:
    cn.clouddemo: debug
  pattern:
    dateformat: MM-dd HH:mm:ss:SSS
#eureka:
#  client:
#    service-url:  # eureka的地址信息
#      defaultZone: http://127.0.0.1:10086/eureka
#userservice:
#  ribbon:
#    NFLoadBalancerRuleClassName: com.alibaba.cloud.nacos.ribbon.NacosRule  # 负载均衡规则
#ribbon:
#  eager-load:
#    enabled: true # 开启饥饿加载
#    clients: # 指定饥饿加载的服务名称
 #     - userservice
#feign:
#  httpclient:
 #   enabled: true # 支持HttpClient的开关
#    max-connections: 200 # 最大连接数
#    max-connections-per-route: 50 # 单个路径的最大连接数

(3)启动类OrderApplication

package cn.clouddemo.order;


import org.mybatis.spring.annotation.MapperScan;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.client.loadbalancer.LoadBalanced;
import org.springframework.context.annotation.Bean;
import org.springframework.web.client.RestTemplate;

@MapperScan("cn.clouddemo.order.mapper")
@SpringBootApplication
public class OrderApplication {

    public static void main(String[] args) {
        SpringApplication.run(OrderApplication.class, args);
    }

    /**
     * 创建RestTemplate并注入Spring容器
     */
    @Bean
    @LoadBalanced
    public RestTemplate restTemplate() {
        return new RestTemplate();
    }

   /* @Bean
    public IRule randomRule() {
        return new RandomRule();
    }*/
}

(4)OrderController

package cn.clouddemo.order.web;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

import cn.clouddemo.order.pojo.Order;
import cn.clouddemo.order.service.OrderService;

@RestController
@RequestMapping("order")
public class OrderController {

   @Autowired
   private OrderService orderService;

    @GetMapping("{orderId}")
    public Order queryOrderByUserId(@PathVariable("orderId") Long orderId) {
        // 根据id查询订单并返回
        return orderService.queryOrderById(orderId);
    }
}

(5)OrderService

package cn.clouddemo.order.service;


import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
import org.springframework.web.client.RestTemplate;

import cn.clouddemo.order.mapper.OrderMapper;
import cn.clouddemo.order.pojo.Order;
import cn.clouddemo.user.pojo.User;

@Service
public class OrderService {

    @Autowired
    private OrderMapper orderMapper;

    @Autowired
    private RestTemplate restTemplate;

    public Order queryOrderById(Long orderId) {
        // 1.查询订单
        Order order = orderMapper.findById(orderId);
        // 2.用Feign远程调用
        User user = restTemplate.getForObject("http://userservice/user/" + order.getUserId(), User.class);
        // 3.封装user到Order
        order.setUser(user);
        // 4.返回
        return order;
    }

    /*@Autowired
    private RestTemplate restTemplate;

    public Order queryOrderById(Long orderId) {
        // 1.查询订单
        Order order = orderMapper.findById(orderId);
        // 2.利用RestTemplate发起http请求，查询用户
        // 2.1.url路径
        String url = "http://userservice/user/" + order.getUserId();
        // 2.2.发送http请求，实现远程调用
        User user = restTemplate.getForObject(url, User.class);
        // 3.封装user到Order
        order.setUser(user);
        // 4.返回
        return order;
    }*/
}

(6)OrderMapper

package cn.clouddemo.order.mapper;

import org.apache.ibatis.annotations.Select;

import cn.clouddemo.order.pojo.Order;

public interface OrderMapper {

    @Select("select * from tb_order where id = #{id}")
    Order findById(Long id);
}

(7)实体类Order

package cn.clouddemo.order.pojo;


import cn.clouddemo.user.pojo.User;
import lombok.Data;

@Data
public class Order {
    private Long id;
    private Long price;
    private String name;
    private Integer num;
    private Long userId;
    private User user;
}

3、创建user服务

在这里插入图片描述

(1)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 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <parent>
        <artifactId>cloud-demo</artifactId>
        <groupId>cn.clouddemo.demo</groupId>
        <version>1.0</version>
    </parent>
    <modelVersion>4.0.0</modelVersion>

    <artifactId>user-service</artifactId>

    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
        </dependency>
        <!--mybatis-->
        <dependency>
            <groupId>org.mybatis.spring.boot</groupId>
            <artifactId>mybatis-spring-boot-starter</artifactId>
        </dependency>
        <!--eureka客户端依赖-->
        <!--<dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-netflix-eureka-client</artifactId>
        </dependency>-->
        <!-- nacos客户端依赖包 -->
         <dependency>
            <groupId>com.alibaba.cloud</groupId>
            <artifactId>spring-cloud-starter-alibaba-nacos-discovery</artifactId>
        </dependency> 
        <!--nacos的配置管理依赖-->
         <dependency>
            <groupId>com.alibaba.cloud</groupId>
            <artifactId>spring-cloud-starter-alibaba-nacos-config</artifactId>
        </dependency> 
    </dependencies>
    <build>
        <finalName>app</finalName>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
        </plugins>
    </build>
</project>

(2)启动类UserApplication

package cn.clouddemo.user;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.mybatis.spring.annotation.MapperScan;

@MapperScan("cn.clouddemo.user.mapper")
@SpringBootApplication
public class UserApplication {
    public static void main(String[] args) {
        SpringApplication.run(UserApplication.class, args);
    }
}

(3)UserController

package cn.clouddemo.user.web;


import lombok.extern.slf4j.Slf4j;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.*;

import cn.clouddemo.user.pojo.User;
import cn.clouddemo.user.service.UserService;



@Slf4j
@RestController
@RequestMapping("/user")
// @RefreshScope
public class UserController {

    @Autowired
    private UserService userService;



    /**
     * 路径： /user/110
     *
     * @param id 用户id
     * @return 用户
     */
    @GetMapping("/{id}")
    public User queryById(@PathVariable("id") Long id ) {
        return userService.queryById(id);
    }
}

(4)UserService

package cn.clouddemo.user.service;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

import cn.clouddemo.user.mapper.UserMapper;
import cn.clouddemo.user.pojo.User;

@Service
public class UserService {

    @Autowired
    private UserMapper userMapper;

    public User queryById(Long id) {
        return userMapper.findById(id);
    }
}

(5)UserMapper

package cn.clouddemo.user.mapper;

import org.apache.ibatis.annotations.Param;
import org.apache.ibatis.annotations.Select;

import cn.clouddemo.user.pojo.User;

public interface UserMapper {
    
    @Select("select * from tb_user where id = #{id}")
    User findById(@Param("id") Long id);
}

(6)实体类User

package cn.clouddemo.user.pojo;

import lombok.Data;

@Data
public class User {
    private Long id;
    private String username;
    private String address;
}

(7)配置文件application.yml

server:
  port: 8081
spring:
  datasource:
    url: jdbc:mysql://localhost:3306/cloud_user?useSSL=false&useUnicode=true&characterEncoding=utf-8
    username: root
    password: root123456
    driver-class-name: com.mysql.jdbc.Driver
  cloud:
    nacos:
      server-addr: localhost:8848 # nacos服务地址
  # shardingsphere:
  #   sharding:
  #     default-database-strategy:
  #     tables:
#      discovery:
#        cluster-name: HZ
mybatis:
  type-aliases-package: cn.clouddemo.user.pojo
  configuration:
    map-underscore-to-camel-case: true
logging:
  level:
    cn.clouddemo: debug
  pattern:
    dateformat: MM-dd HH:mm:ss:SSS
#eureka:
#  client:
#    service-url:  # eureka的地址信息
#      defaultZone: http://127.0.0.1:10086/eureka
pattern:
  name: 本地环境local

4、数据库表

在这里插入图片描述

测试就用了两个数据库，表都给一样的,tb_order,tb_user

(1)tb_user结构

在这里插入图片描述

(2)tb_order结构

在这里插入图片描述

5、测试

(1)先启动nacos

在这里插入图片描述

(2)启动order服务

在这里插入图片描述

(3)、启动user服务

user服务比较特殊，现在需要启动两个user服务来做测试，复制两份太麻烦，就采用启动两个实例的方式来使用
trae的配置是在launch.json配置
在这里插入图片描述

(4)启动

在这里插入图片描述
分别启动两个即可

(5)浏览器访问order

在这里插入图片描述

(6)注意

在使用实例的时候，有可能第二个请求会报错，数据库链接多了，修改下oder和user的mysql链接数

### Error querying database.  Cause: org.springframework.jdbc.CannotGetJdbcConnectionException: Failed to obtain JDBC Connection; nested exception is com.mysql.jdbc.exceptions.jdbc4.MySQLNonTransientConnectionException: Data source rejected establishment of connection,  message from server: "Too many connections"
### The error may exist in cn/clouddemo/user/mapper/UserMapper.java (best guess)
### The error may involve cn.clouddemo.user.mapper.UserMapper.findById       
### The error occurred while executing a query
### Cause: org.springframework.jdbc.CannotGetJdbcConnectionException: Failed to obtain JDBC Connection; nested exception is com.mysql.jdbc.exceptions.jdbc4.MySQLNonTransientConnectionException: Data source rejected establishment of connection,  message from server: "Too many connections"] with root cause   

com.mysql.jdbc.exceptions.jdbc4.MySQLNonTransientConnectionException: Data source rejected establishment of connection,  message from server: "Too many connections"
        at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method) ~[na:1.8.0_201]
        at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62) ~[na:1.8.0_201]
        at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45) ~[na:1.8.0_201]
        at java.lang.reflect.Constructor.newInstance(Constructor.java:423) ~[na:1.8.0_201]
        at com.mysql.jdbc.Util.handleNewInstance(Util.java:425) ~[mysql-connector-java-5.1.47.jar:5.1.47]
        at com.mysql.jdbc.Util.getInstance(Util.java:408) ~[mysql-connector-java-5.1.47.jar:5.1.47]
        at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:919) ~[mysql-connector-java-5.1.47.jar:5.1.47]
        at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:898) ~[mysql-connector-java-5.1.47.jar:5.1.47]
        at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:887) ~[mysql-connector-java-5.1.47.jar:5.1.47]
        at com.mysql.jdbc.MysqlIO.doHandshake(MysqlIO.java:1038) ~[mysql-connector-java-5.1.47.jar:5.1.47]
        at com.mysql.jdbc.ConnectionImpl.coreConnect(ConnectionImpl.java:2199) ~[mysql-connector-java-5.1.47.jar:5.1.47]
        at com.mysql.jdbc.ConnectionImpl.connectOneTryOnly(ConnectionImpl.java:2230) ~[mysql-connector-java-5.1.47.jar:5.1.47]
        at com.mysql.jdbc.ConnectionImpl.createNewIO(ConnectionImpl.java:2025) ~[mysql-connector-java-5.1.47.jar:5.1.47]
        at com.mysql.jdbc.ConnectionImpl.<init>(ConnectionImpl.java:778) ~[mysql-connector-java-5.1.47.jar:5.1.47]
        at com.mysql.jdbc.JDBC4Connection.<init>(JDBC4Connection.java:47) ~[mysql-connector-java-5.1.47.jar:5.1.47]
        at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method) ~[na:1.8.0_201]
        at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62) ~[na:1.8.0_201]
        at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45) ~[na:1.8.0_201]
        at java.lang.reflect.Constructor.newInstance(Constructor.java:423) ~[na:1.8.0_201]
        at com.mysql.jdbc.Util.handleNewInstance(Util.java:425) ~[mysql-connector-java-5.1.47.jar:5.1.47]
        at com.mysql.jdbc.ConnectionImpl.getInstance(ConnectionImpl.java:386) ~[mysql-connector-java-5.1.47.jar:5.1.47]
        at com.mysql.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java:330) ~[mysql-connector-java-5.1.47.jar:5.1.47]
        at com.zaxxer.hikari.util.DriverDataSource.getConnection(DriverDataSource.java:138) ~[HikariCP-3.4.5.jar:na]

在这里插入图片描述

三、总结

作为程序员中的混子，要学的东西太多太多，只有一个心态，能学一点是一点

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