Nacos在spring boot的使用-Toy模板网

这篇具有很好参考价值的文章主要介绍了Nacos在spring boot的使用。希望对大家有所帮助。如果存在错误或未考虑完全的地方，请大家不吝赐教，您也可以点击"举报违法"按钮提交疑问。

说明：本文章是自己在学习spring boot中使用Nacos服务注册和发现时记录的当做笔记了，有什么不对的欢迎指正。

当你来搜索spring boot中使用nacos的时候就应该知道nacos是什么了，这里就不多废话了，直接看下面的使用吧

1、服务注册：

步骤：

1、去官网安装nacos并且启动nacos service.

成功的页面如下：
nacos springboot,spring boot,spring boot,java,微服务
进入里面的的网页可以看到如下界面：

2、建立spring boot项目引入相关依赖jar包

<!--        spring boot 核心依赖-->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
<!--        spring boot测试依赖-->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
<!--        nacos注册依赖-->
        <dependency>
            <groupId>com.alibaba.boot</groupId>
            <artifactId>nacos-discovery-spring-boot-starter</artifactId>
            <version>0.2.12</version>
        </dependency>
    </dependencies>

3、使项目启动自动注册到服务中心

1、通过配置实现（更推荐，下面的案例也是写yml文件来配置）

server:
  port: 8081
  ip: localhost
spring:
  application:
    name: userserver
nacos:
  discovery:
  	# 设置自动注册，默认是false
    auto-register: true
    # nacos server的ip和端口
    server-addr: localhost:8848

启动项目后可以在nacos server看的如下界面，已经注册到了服务中心
nacos springboot,spring boot,spring boot,java,微服务

2、写配置类（依然需要在配置文件中设置nacos server的ip和端口）

package com.example.config;

import com.alibaba.nacos.api.annotation.NacosInjected;
import com.alibaba.nacos.api.exception.NacosException;
import com.alibaba.nacos.api.naming.NamingService;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.context.annotation.Configuration;

import javax.annotation.PostConstruct;

/**
 * Created by IntelliJ IDEA.
 *
 * @Author : wlh
 * @create 2023/1/18 18:15
 */
@Configuration
public class NacosRegisterConfig {
    // 服务名称
    @Value("${spring.application.name}")
    private String applicationName;
    // 服务的端口号
    @Value("${server.port}")
    private Integer port;
    // 服务ip地址
    @Value("${server.ip}")
    private String ip;
    @NacosInjected
    private NamingService namingService;

    // @PostConstruct 在依赖注入完成时执行注解的方法
    @PostConstruct
    public void register() throws NacosException {
        namingService.registerInstance(applicationName,ip,port);
    }
}

然后在启动类上写上注解@EnableNacosDiscovery。执行后一样的可以在nacos server里面看到注册的服务。
但是需要注意的是：使用配置文件的形式在启动类上是不需要@EnableNacosDiscovery注解的，用了反而注册不上

2、服务发现和调用：

1、获取服务：
使用NamingService对象的selectOneHealthyInstance(“服务名称”);获取一个服务，参数是服务名称。这个方法的作用是根据参数获取对应的服务，如果有多个（集群时）会自己去调用一个（要不是随机的，要不是轮询调度）。
2、远程调用：
RestTemplate对象的方法能够实现远程调用
getForObject — optionsForAllow 分为一组，这类方法是常规的 Rest API（GET、POST、DELETE 等）方法调用；
exchange：接收一个 RequestEntity 参数，可以自己设置 HTTP method，URL，headers 和 body，返回 ResponseEntity；
execute：通过 callback 接口，可以对请求和返回做更加全面的自定义控制。
如下：

    public UserDto queryById(Integer id) throws NacosException {

        User user = userMapper.selectById(id);
        UserDto userDto = new UserDto();
        userDto.setId(user.getId());
        userDto.setName(user.getName());
        userDto.setMoney(user.getMoney());
        // 获取服务
        Instance logserver = namingService.selectOneHealthyInstance("logserver");
        String url = String.format("http://%s:%d/userLog/queryByUserId/"+id,logserver.getIp(),logserver.getPort());
        // 通过restTemplate对象进行跨模块请求数据
        List list = restTemplate.getForObject(url, List.class);
        userDto.setUserLogs(list);
        return userDto;
    }

3、完整案例

需求：写两个服务，一个user服务，一个user_log服务，在user服务获取用户信息时我们需要调用user_log服务来获取对应用户的日志列表。
数据库数据准备
表1：user
nacos springboot,spring boot,spring boot,java,微服务
表2：user_log

user服务：

引入依赖：

<groupId>ikiku.space</groupId>
<artifactId>user-server</artifactId>
<version>0.0.1-SNAPSHOT</version>
<name>user_server</name>
<description>user_server</description>

<?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>2.5.1</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>
    <groupId>ikiku.space</groupId>
    <artifactId>user-server</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>user_server</name>
    <description>user_server</description>
    <properties>
        <java.version>8</java.version>
    </properties>
    <dependencies>
<!--        spring boot 核心依赖-->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
<!--        spring boot测试依赖-->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
<!--        mysql驱动依赖-->
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
        </dependency>
<!--        mybatis-plus依赖-->
        <dependency>
            <groupId>com.baomidou</groupId>
            <artifactId>mybatis-plus-boot-starter</artifactId>
            <version>3.5.2</version>
        </dependency>
<!--        mybatis代码生成器依赖-->
        <dependency>
            <groupId>com.baomidou</groupId>
            <artifactId>mybatis-plus-generator</artifactId>
            <version>3.5.2</version>
        </dependency>
<!--        模板-->
        <!-- https://mvnrepository.com/artifact/org.freemarker/freemarker -->
        <dependency>
            <groupId>org.freemarker</groupId>
            <artifactId>freemarker</artifactId>
            <version>2.3.31</version>
        </dependency>
<!--        lombok-->
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
        </dependency>
<!--        swager注解依赖-->
        <dependency>
            <groupId>io.springfox</groupId>
            <artifactId>springfox-swagger-ui</artifactId>
            <version>2.9.2</version>
        </dependency>
        <dependency>
            <groupId>io.springfox</groupId>
            <artifactId>springfox-swagger2</artifactId>
            <version>2.9.2</version>
        </dependency>
<!--        nacos注册依赖-->
        <dependency>
            <groupId>com.alibaba.boot</groupId>
            <artifactId>nacos-discovery-spring-boot-starter</artifactId>
            <version>0.2.12</version>
        </dependency>
    </dependencies>

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

</project>

yml文件

server:
  # 端口
  port: 8081
  # ip
  ip: localhost
spring:
  application:
    name: userserver #服务的名称
  # 连接数据库的数据源
  datasource:
    driver-class-name: com.mysql.cj.jdbc.Driver
    username: root
    password: 123456
    url: jdbc:mysql://localhost:3306/db2?allowMultiQueries=true&useUnicode=true&characterEncoding=UTF-8&useSSL=false
nacos:
  discovery:
#    自动注册
    auto-register: true
    # nacos服务地址
    server-addr: localhost:8848

controller层：

package com.example.controller;

import com.alibaba.nacos.api.exception.NacosException;
import com.example.dto.UserDto;
import com.example.service.UserLogService;
import com.example.service.UserService;
import jdk.nashorn.internal.ir.ReturnNode;
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;

/**
 * <p>
 *  前端控制器
 * </p>
 *
 * @author wlh
 * @since 2023-01-18
 */
@RestController
@RequestMapping("/user")
public class UserController {

    @Autowired
    private UserService userService;

    @GetMapping("/query/{id}")
    public UserDto queryById(@PathVariable("id") Integer id) throws NacosException {
        return userService.queryById(id);
    }
}

config层

package com.example.config;

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

/**
 * Created by IntelliJ IDEA.
 *
 * @Author : wlh
 * @create 2023/1/18 17:20
 */
@Configuration
public class NacosConfig {

    // 注入RestTemplate对象
    @Bean
    public RestTemplate restTemplate(){
        return new RestTemplate();
    }
}

service层

package com.example.service;

import com.alibaba.nacos.api.exception.NacosException;
import com.example.dto.UserDto;
import com.example.entity.User;
import com.baomidou.mybatisplus.extension.service.IService;

/**
 * <p>
 *  服务类
 * </p>
 *
 * @author wlh
 * @since 2023-01-18
 */
public interface UserService extends IService<User> {
	// 根据id获取用户信息和日志列表
    UserDto queryById(Integer id) throws NacosException;
}

service实现类

package com.example.service.impl;

import com.alibaba.nacos.api.annotation.NacosInjected;
import com.alibaba.nacos.api.exception.NacosException;
import com.alibaba.nacos.api.naming.NamingService;
import com.alibaba.nacos.api.naming.pojo.Instance;
import com.example.dto.UserDto;
import com.example.entity.User;
import com.example.entity.UserLog;
import com.example.mapper.UserMapper;
import com.example.service.UserLogService;
import com.example.service.UserService;
import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
import org.springframework.web.client.RestTemplate;

import javax.annotation.Resource;
import java.util.List;

/**
 * <p>
 *  服务实现类
 * </p>
 *
 * @author wlh
 * @since 2023-01-18
 */
@Service
public class UserServiceImpl extends ServiceImpl<UserMapper, User> implements UserService {

    @Resource
    private UserMapper userMapper;
    @Autowired
    private RestTemplate restTemplate;

    @NacosInjected
    private NamingService namingService;
    @Override
    public UserDto queryById(Integer id) throws NacosException {

        User user = userMapper.selectById(id);
        UserDto userDto = new UserDto();
        userDto.setId(user.getId());
        userDto.setName(user.getName());
        userDto.setMoney(user.getMoney());
        // 获取服务
        Instance logserver = namingService.selectOneHealthyInstance("logserver");
        String url = String.format("http://%s:%d/userLog/queryByUserId/"+id,logserver.getIp(),logserver.getPort());
        // 通过restTemplate对象进行夸模块请求数据
        List list = restTemplate.getForObject(url, List.class);
        userDto.setUserLogs(list);
        return userDto;
    }
}

mapper层

package com.example.mapper;

import com.example.entity.User;
import com.baomidou.mybatisplus.core.mapper.BaseMapper;

/**
 * <p>
 *  Mapper 接口
 * </p>
 *
 * @author wlh
 * @since 2023-01-18
 */
public interface UserMapper extends BaseMapper<User> {

}

实体类

user类

package com.example.entity;

import com.baomidou.mybatisplus.annotation.IdType;
import com.baomidou.mybatisplus.annotation.TableField;
import com.baomidou.mybatisplus.annotation.TableId;
import com.baomidou.mybatisplus.annotation.TableName;
import java.io.Serializable;
import java.math.BigDecimal;
import io.swagger.annotations.ApiModel;
import io.swagger.annotations.ApiModelProperty;
import lombok.Getter;
import lombok.Setter;
import lombok.experimental.Accessors;

/**
 * <p>
 * 
 * </p>
 *
 * @author wlh
 * @since 2023-01-18
 */
@Getter
@Setter
@Accessors(chain = true)
@TableName("user")
@ApiModel(value = "User对象", description = "")
public class User implements Serializable {

    private static final long serialVersionUID = 1L;

    @ApiModelProperty("主键")
    @TableId(value = "id", type = IdType.AUTO)
    private Integer id;

    @ApiModelProperty("姓名")
    @TableField("name")
    private String name;

    @ApiModelProperty("账户余额")
    @TableField("money")
    private BigDecimal money;

}

UserLog类

package com.example.entity;

import com.baomidou.mybatisplus.annotation.IdType;
import com.baomidou.mybatisplus.annotation.TableField;
import com.baomidou.mybatisplus.annotation.TableId;
import com.baomidou.mybatisplus.annotation.TableName;
import java.io.Serializable;
import java.time.LocalDateTime;
import io.swagger.annotations.ApiModel;
import io.swagger.annotations.ApiModelProperty;
import lombok.Getter;
import lombok.Setter;
import lombok.experimental.Accessors;

/**
 * <p>
 * 
 * </p>
 *
 * @author wlh
 * @since 2023-01-18
 */
@Getter
@Setter
@Accessors(chain = true)
@TableName("user_log")
@ApiModel(value = "UserLog对象", description = "")
public class UserLog implements Serializable {

    private static final long serialVersionUID = 1L;

    @TableId(value = "id", type = IdType.AUTO)
    private Integer id;

    @TableField("message")
    private String message;

    @TableField("time")
    private LocalDateTime time;

    @TableField("user_id")
    private Integer userId;

}

dto用于定义数据传输模板

package com.example.dto;

import com.baomidou.mybatisplus.annotation.IdType;
import com.baomidou.mybatisplus.annotation.TableField;
import com.baomidou.mybatisplus.annotation.TableId;
import com.example.entity.UserLog;
import io.swagger.annotations.ApiModelProperty;
import lombok.Data;

import java.io.Serializable;
import java.math.BigDecimal;
import java.util.List;

/**
 * Created by IntelliJ IDEA.
 *
 * @Author : wlh
 * @create 2023/1/18 17:12
 */
@Data
public class UserDto implements Serializable {

    private static final long serialVersionUID = 1L;

    @ApiModelProperty("主键")
    private Integer id;

    @ApiModelProperty("姓名")
    private String name;

    @ApiModelProperty("账户余额")
    private BigDecimal money;

    @ApiModelProperty("日志列表")
    private List<UserLog> userLogs;
}

user_log服务

引入依赖

<?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>2.5.1</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>
    <groupId>ikiku.space</groupId>
    <artifactId>log_server</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>log_server</name>
    <description>log_server</description>
    <properties>
        <java.version>8</java.version>
    </properties>
    <dependencies>
        <!--        spring boot 核心依赖-->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <!--        spring boot测试依赖-->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
        <!--        mysql驱动依赖-->
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
        </dependency>
        <!--        mybatis-plus依赖-->
        <dependency>
            <groupId>com.baomidou</groupId>
            <artifactId>mybatis-plus-boot-starter</artifactId>
            <version>3.5.2</version>
        </dependency>
        <!--        mybatis代码生成器依赖-->
        <dependency>
            <groupId>com.baomidou</groupId>
            <artifactId>mybatis-plus-generator</artifactId>
            <version>3.5.2</version>
        </dependency>
        <!--        freemarker模板-->
        <!-- https://mvnrepository.com/artifact/org.freemarker/freemarker -->
        <dependency>
            <groupId>org.freemarker</groupId>
            <artifactId>freemarker</artifactId>
            <version>2.3.31</version>
        </dependency>
        <!--        lombok-->
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
        </dependency>
<!--        swagger注解依赖-->
        <dependency>
            <groupId>io.springfox</groupId>
            <artifactId>springfox-swagger-ui</artifactId>
            <version>2.9.2</version>
        </dependency>
        <dependency>
            <groupId>io.springfox</groupId>
            <artifactId>springfox-swagger2</artifactId>
            <version>2.9.2</version>
        </dependency>
<!--        nacos注册依赖-->
        <dependency>
            <groupId>com.alibaba.boot</groupId>
            <artifactId>nacos-discovery-spring-boot-starter</artifactId>
            <version>0.2.12</version>
        </dependency>
    </dependencies>

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

</project>

controller层

package com.example.controller;

import com.example.entity.UserLog;
import com.example.service.UserLogService;
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 java.util.List;

/**
 * <p>
 *  前端控制器
 * </p>
 *
 * @author wlh
 * @since 2023-01-18
 */
@RestController
@RequestMapping("/userLog")
public class UserLogController {
    @Autowired
    private UserLogService userLogService;
    @GetMapping("/queryByUserId/{id}")
    public List<UserLog> getLog(@PathVariable("id") Integer id){
        return userLogService.queryById(id);
    }
}

config层暂时不需要，如果需要跨模块访问其他的模块时，在写的和user服务里面的一样即可

yml配置

server:
  port: 8082
  ip: localhost
spring:
  datasource:
    driver-class-name: com.mysql.cj.jdbc.Driver
    username: root
    password: 123456
    url: jdbc:mysql://localhost:3306/db2?allowMultiQueries=true&useUnicode=true&characterEncoding=UTF-8&useSSL=false
  application:
    name: logserver
nacos:
  discovery:
    auto-register: true
    server-addr: localhost:8848

service层

package com.example.service;

import com.example.entity.UserLog;
import com.baomidou.mybatisplus.extension.service.IService;

import java.util.List;

/**
 * <p>
 *  服务类
 * </p>
 *
 * @author wlh
 * @since 2023-01-18
 */
public interface UserLogService extends IService<UserLog> {

    List<UserLog> queryById(Integer id);
}

service实现类层

package com.example.service.impl;

import com.example.entity.UserLog;
import com.example.mapper.UserLogMapper;
import com.example.service.UserLogService;
import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

import javax.annotation.Resource;
import java.util.List;

/**
 * <p>
 *  服务实现类
 * </p>
 *
 * @author wlh
 * @since 2023-01-18
 */
@Service
public class UserLogServiceImpl extends ServiceImpl<UserLogMapper, UserLog> implements UserLogService {

    @Resource
    private UserLogMapper userLogMapper;
    @Override
    public List<UserLog> queryById(Integer id) {
        return userLogMapper.queryByUserId(id);
    }
}

mapper层

package com.example.mapper;

import com.example.entity.UserLog;
import com.baomidou.mybatisplus.core.mapper.BaseMapper;
import org.apache.ibatis.annotations.Param;
import org.apache.ibatis.annotations.Select;

import java.util.List;

/**
 * <p>
 *  Mapper 接口
 * </p>
 *
 * @author wlh
 * @since 2023-01-18
 */
public interface UserLogMapper extends BaseMapper<UserLog> {
    @Select("select  * from user_log where user_id = #{id}")
    List<UserLog> queryByUserId(@Param("id") Integer id);
}

实体类层

package com.example.entity;

import com.baomidou.mybatisplus.annotation.IdType;
import com.baomidou.mybatisplus.annotation.TableField;
import com.baomidou.mybatisplus.annotation.TableId;
import com.baomidou.mybatisplus.annotation.TableName;
import java.io.Serializable;
import java.time.LocalDateTime;
import io.swagger.annotations.ApiModel;
import io.swagger.annotations.ApiModelProperty;
import lombok.Getter;
import lombok.Setter;
import lombok.experimental.Accessors;

/**
 * <p>
 * 
 * </p>
 *
 * @author wlh
 * @since 2023-01-18
 */
@Getter
@Setter
@Accessors(chain = true)
@TableName("user_log")
@ApiModel(value = "UserLog对象", description = "")
public class UserLog implements Serializable {

    private static final long serialVersionUID = 1L;

    @TableId(value = "id", type = IdType.AUTO)
    private Integer id;

    @TableField("message")
    private String message; 

    @TableField("time")
    private LocalDateTime time;

    @TableField("user_id")
    private Integer userId;

}