Java之SpringCloud nocos注册中心讲解_Java教程

一、nacos是什么？

Nacos是用来发现、配置和管理微服务。Nacos提供了一组简单易用的特性集，帮助快速实现动态服务发现、服务配置、服务元数据及流量管理。

二、使用步骤

1.安装nacos 服务器

直接运行 startup.cmd 访问 localhost:8848/nacos
初始密码 nacos nacos

Java之SpringCloud nocos注册中心讲解

2.导入依赖和配置yaml

Java之SpringCloud nocos注册中心讲解

父项目依赖pom文件

<?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>com.csdn</groupId>
    <artifactId>springcloud_nacos</artifactId>
    <packaging>pom</packaging>
    <version>1.0-SNAPSHOT</version>
    <modules>
        <module>springcloud_share_6002</module>
        <module>springcloud_user_6001</module>
        <module>springcloud_common</module>
    </modules>
    <properties>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <maven.compiler.source>1.8</maven.compiler.source>
        <maven.compiler.target>1.8</maven.compiler.target>
        <junit.version>4.12</junit.version>
        <lombok.version>1.18.16</lombok.version>
        <log4j.version>1.2.17</log4j.version>
        <logback-core.version>1.2.3</logback-core.version>
        <mysql-connector-java.version>8.0.21</mysql-connector-java.version>
        <druid.version>1.1.23</druid.version>
        <mybatis-spring-boot-starter.version>2.1.4</mybatis-spring-boot-starter.version>
        <spring-boot-dependencies.version>2.3.8.RELEASE</spring-boot-dependencies.version>
        <spring-cloud-dependencies.version>Hoxton.SR9</spring-cloud-dependencies.version>
        <spring-cloud-alibaba.version>2.2.3.RELEASE</spring-cloud-alibaba.version>
        <swagger.version>2.7.0</swagger.version>
        <pagehelper.version>1.2.3</pagehelper.version>
        <jodatime.version>2.10.1</jodatime.version>
        <jjwt.version>0.10.7</jjwt.version>
    </properties>

    <dependencyManagement>
        <dependencies>
            <!--很重要的包：springcloud的依赖-->
            <!-- <scope>import</scope>解决单继承问题，类似parent标签， -->
            <dependency>
                <groupId>org.springframework.cloud</groupId>
                <artifactId>spring-cloud-dependencies</artifactId>
                <version>${spring-cloud-dependencies.version}</version>
                <type>pom</type>
                <scope>import</scope>
            </dependency>
            <!--spring-cloud-alibaba-->
            <dependency>
                <groupId>com.alibaba.cloud</groupId>
                <artifactId>spring-cloud-alibaba-dependencies</artifactId>
                <version>${spring-cloud-alibaba.version}</version>
                <type>pom</type>
                <scope>import</scope>
            </dependency>
            <!--springboot-->
            <dependency>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-dependencies</artifactId>
                <version>${spring-boot-dependencies.version}</version>
                <type>pom</type>
                <scope>import</scope>
            </dependency>
            <!--数据库-->
            <dependency>
                <groupId>mysql</groupId>
                <artifactId>mysql-connector-java</artifactId>
                <version>${mysql-connector-java.version}</version>
            </dependency>
            <!--数据源-->
            <dependency>
                <groupId>com.alibaba</groupId>
                <artifactId>druid</artifactId>
                <version>${druid.version}</version>
            </dependency>
            <!--mybatis的springboot启动器-->
            <dependency>
                <groupId>org.mybatis.spring.boot</groupId>
                <artifactId>mybatis-spring-boot-starter</artifactId>
                <version>${mybatis-spring-boot-starter.version}</version>
            </dependency>
            <!--日志测试-->
            <!--junit-->
            <dependency>
                <groupId>junit</groupId>
                <artifactId>junit</artifactId>
                <version>${junit.version}</version>
            </dependency>
            <!--lombok-->
            <dependency>
                <groupId>org.projectlombok</groupId>
                <artifactId>lombok</artifactId>
                <version>${lombok.version}</version>
            </dependency>
            <!--log4j-->
            <dependency>
                <groupId>log4j</groupId>
                <artifactId>log4j</artifactId>
                <version>${log4j.version}</version>
            </dependency>
            <dependency>
                <groupId>ch.qos.logback</groupId>
                <artifactId>logback-core</artifactId>
                <version>${logback-core.version}</version>
            </dependency>
            <!--swagger-->
            <dependency>
                <groupId>io.springfox</groupId>
                <artifactId>springfox-swagger2</artifactId>
                <version>${swagger.version}</version>
            </dependency>
            <!--swagger ui-->
            <dependency>
                <groupId>io.springfox</groupId>
                <artifactId>springfox-swagger-ui</artifactId>
                <version>${swagger.version}</version>
            </dependency>
            <!--druid alibaba-->
            <dependency>
                <groupId>com.alibaba</groupId>
                <artifactId>druid-spring-boot-starter</artifactId>
                <version>${druid.version}</version>
            </dependency>
            <dependency>
                <groupId>com.github.pagehelper</groupId>
                <artifactId>pagehelper-spring-boot-starter</artifactId>
                <version>${pagehelper.version}</version>
            </dependency>
            <!--日期时间工具-->
            <dependency>
                <groupId>joda-time</groupId>
                <artifactId>joda-time</artifactId>
                <version>${jodatime.version}</version>
            </dependency>

            <!-- JWT -->
            <dependency>
                <groupId>io.jsonwebtoken</groupId>
                <artifactId>jjwt-api</artifactId>
                <version>${jjwt.version}</version>
            </dependency>
            <dependency>
                <groupId>io.jsonwebtoken</groupId>
                <artifactId>jjwt-impl</artifactId>
                <version>${jjwt.version}</version>
                <scope>runtime</scope>
            </dependency>
            <dependency>
                <groupId>io.jsonwebtoken</groupId>
                <artifactId>jjwt-jackson</artifactId>
                <version>${jjwt.version}</version>
                <scope>runtime</scope>
            </dependency>
        </dependencies>
    </dependencyManagement>
    <build>
        <!--打包插件-->
    </build>
</project>

在需要被nacos发现的微服务个module加上nacos依赖

<!--服务注册-->
        <dependency>
            <groupId>com.alibaba.cloud</groupId>
            <artifactId>spring-cloud-starter-alibaba-nacos-discovery</artifactId>
        </dependency>

springcloud_common的pom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 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <parent>
        <artifactId>springcloud_nacos</artifactId>
        <groupId>com.csdn</groupId>
        <version>1.0-SNAPSHOT</version>
    </parent>
    <modelVersion>4.0.0</modelVersion>

    <artifactId>springcloud_common</artifactId>
    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
        </dependency>
        <!--swagger-->
        <dependency>
            <groupId>io.springfox</groupId>
            <artifactId>springfox-swagger2</artifactId>
        </dependency>
        <dependency>
            <groupId>io.springfox</groupId>
            <artifactId>springfox-swagger-ui</artifactId>
        </dependency>
        <!--spring默认使用yml中的配置，但有时候要用传统的xml或properties配置，就需要使用spring-boot-configuration-processor了-->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-configuration-processor</artifactId>
            <optional>true</optional>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-amqp</artifactId>
        </dependency>
        <!--服务注册-->
        <dependency>
            <groupId>com.alibaba.cloud</groupId>
            <artifactId>spring-cloud-starter-alibaba-nacos-discovery</artifactId>
        </dependency>
        <!--服务容错-->
        <dependency>
            <groupId>com.alibaba.cloud</groupId>
            <artifactId>spring-cloud-starter-alibaba-sentinel</artifactId>
        </dependency>
        <!--feign-->
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-openfeign</artifactId>
        </dependency>
        <!-- JWT -->
        <dependency>
            <groupId>io.jsonwebtoken</groupId>
            <artifactId>jjwt-api</artifactId>
        </dependency>
        <dependency>
            <groupId>io.jsonwebtoken</groupId>
            <artifactId>jjwt-impl</artifactId>
            <scope>runtime</scope>
        </dependency>
        <dependency>
            <groupId>io.jsonwebtoken</groupId>
            <artifactId>jjwt-jackson</artifactId>
            <scope>runtime</scope>
        </dependency>
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-sleuth</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-zipkin</artifactId>
        </dependency>
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
        </dependency>
    </dependencies>
</project>

Java之SpringCloud nocos注册中心讲解

@Configuration
@EnableSwagger2
public class Swagger2Config {

    /**
     * 定义接口的总体信息
     *
     * @return
     */
    private ApiInfo webApiInfo() {

        return new ApiInfoBuilder()
                .title("Swagger API 文档")
                .description("即使再小的帆也能远航")
                .version("1.0")
                .contact(new Contact("liar", "http://www.jsxllht.com", "**********6@qq.com"))
                .build();
    }

    private ApiInfo adminApiInfo() {

        return new ApiInfoBuilder()
                .title("Swagger Admin 文档")
                .description("即使再小的帆也能远航")
                .version("1.0")
                .contact(new Contact("liar", "http://www.jsxllht.com", "**********6@qq.co"))
                .build();
    }

    @Bean
    public Docket webApiConfig() {

        return new Docket(DocumentationType.SWAGGER_2)
                .groupName("webApi") // 用户组
                .apiInfo(webApiInfo()) // 组的信息
                .select()
                //只显示api路径下的页面
                .paths(Predicates.and(PathSelectors.regex("/api/.*")))  // 用户接口的判断
                .build();

    }

    @Bean
    public Docket adminApiConfig() {

        return new Docket(DocumentationType.SWAGGER_2)
                .groupName("adminApi") // 管路⚪组
                .apiInfo(adminApiInfo()) // 组的信息
                .select()
                //只显示admin路径下的页面
                .paths(Predicates.and(PathSelectors.regex("/admin/.*")))
                .build();

    }
}

/**
 *  业务异常类
 */
@Data
@NoArgsConstructor
@AllArgsConstructor
@Builder
public class AppException extends RuntimeException{

    private String code;
    private String message;

    public AppException(ResponseEnum responseEnum){
        this.code = responseEnum.getCode();
        this.message = responseEnum.getMessage();
    }
}

// 这是一个controller 的增强类【专门在controller 抛出异常的时候  增强】
@ControllerAdvice
public class ControllerExceptionAdvice {

    /**
     *  如果抛出的是 AppException 的增强
     *  返回值 就是返回的页面
     *  参数： controller 抛出的异常
     */
    @ExceptionHandler(AppException.class)
    @ResponseBody
    public R appExceptionHandler(AppException ex, HttpServletRequest request){
       return new R(ex.getCode(),ex.getMessage(),null);
    }

    /**
     *  如果抛出的是Exception 的增强
     */
    @ExceptionHandler(Exception.class)
    @ResponseBody
    public R exceptionHandler(Exception ex, HttpServletRequest request){
        ex.printStackTrace();
        return new R(ResponseEnum.SYSTEM_ERROR,null);
    }
}

@Data
@AllArgsConstructor
@NoArgsConstructor
@Builder
// 创建统一的返回格式
public class R<T> {

    private String code;
    private String message;
    private T data;

    public R(ResponseEnum responseEnum, T data) {
        this.code = responseEnum.getCode();
        this.message = responseEnum.getMessage();
        this.data = data;
    }
}

public enum ResponseEnum {
    SUCCESS("200","成功003"),
    USERNAME_NOT_FOUND("300","用户名不存在"),
    USERNAME_OR_PASSWORD_INVALIDATE("301","用户名或者密码错误"),
    ROLE_NO_MENUS("302","此角色没有任何菜单权限，请尽早分配"),
    HAS_NO_TOKEN("303","还没有登录"),
    TOKEN_ERROR("304","别想试图伪造令牌"),
    TOKEN_TIMEOUT("305","对不起登录状态已经失效，请重新登录"),
    HAS_NO_RIGHT("306","权限不足"),
    SYSTEM_ERROR("500","发生未知异常。。。"),
    FEIGN_BSUY("307","系统正忙，稍后再试。。"),
    FLOW_BLOCK("308","流量被限制了，请稍后再使"),
    DEG_BLOCK("309","系统很忙，稍后再试。。。"),
    SMS_ERROR("310","短信发送失败，请稍后再试。。。"),
    SMS_SEND_ERROR_BUSINESS_LIMIT_CONTROL("311","发送短信太频繁，过会再发。。。"),
    CODE_ERROR("312","验证码错误请重试"),
    CODE_EXCPTION("313","验证码超时"),
    ACCOUNT_NO_EXISTS("314","用户不存在"),
    STATUS_BE_MODIFIED("315","用户已被审核")
    ;
    private String code;
    private String message;

    public String getCode() {
        return code;
    }

    public void setCode(String code) {
        this.code = code;
    }

    public String getMessage() {
        return message;
    }

    public void setMessage(String message) {
        this.message = message;
    }

    ResponseEnum(String code, String message) {
        this.code = code;
        this.message = message;
    }
}

springcloud_user_6001的yaml（在注册中心服务的名字不能一样）

server:
  port: 6001
#数据源
spring:
  datasource:
    druid:
      url: jdbc:mysql://localhost:3306/hub_user_center?useUnicode=true&characterEncoding=utf-8&useSSL=false&serverTimezone=GMT
      driver-class-name: com.mysql.cj.jdbc.Driver
      username: root
      password: 123456
      initial-size: 10
      max-active: 50
      min-idle: 10
      max-wait: 60000
      pool-prepared-statements: true
      max-pool-prepared-statement-per-connection-size: 20
      # mysql 数据库的特征  会关闭已经连接了8个小时的连接
      validation-query: SELECT 1 FROM DUAL
  application:
    name: user-6001
  cloud:
    nacos:
      discovery:
        server-addr: 127.0.0.1:8848
# mybatis 配置
mybatis:
  # 扫描映射文件
  mapper-locations: classpath:mapper/*.xml
  configuration:
    # 开启驼峰映射配置
    map-underscore-to-camel-case: true
# log
# 整个工程只答应info 以及以上级别的日志
logging:
  level:
    root: info
    com.csqf.mapper: debug

springcloud_share_6002的yaml（在注册中心服务的名字不能一样）

server:
  port: 6002
#数据源
spring:
  datasource:
    druid:
      url: jdbc:mysql://localhost:3306/hub_share_center?useUnicode=true&characterEncoding=utf-8&useSSL=false&serverTimezone=GMT
      driver-class-name: com.mysql.cj.jdbc.Driver
      username: root
      password: 123456
      initial-size: 10
      max-active: 50
      min-idle: 10
      max-wait: 60000
      pool-prepared-statements: true
      max-pool-prepared-statement-per-connection-size: 20
      # mysql 数据库的特征  会关闭已经连接了8个小时的连接
      validation-query: SELECT 1 FROM DUAL
  application:
    name: share-6002
  cloud:
    nacos:
      discovery:
        server-addr: 127.0.0.1:8848
# mybatis 配置
mybatis:
  # 扫描映射文件
  mapper-locations: classpath:mapper/*.xml
  configuration:
    # 开启驼峰映射配置
    map-underscore-to-camel-case: true
# log
# 整个工程只答应info 以及以上级别的日志
logging:
  level:
    root: info
    com.csqf.mapper: debug

2.RestTemplate

RestTemplate是Spring Resources中一个访问第三方RESTful API接口的网络请求框架。RestTemplate的设计原则和其他Spring Template(例如JdbcTemplate、JmsTemplate)类!，都是为执行复杂任务提供了一个具有默认行为的简单方法。

设置RestTemplate为Bean

Java之SpringCloud nocos注册中心讲解

springcloud_user_6001中写一个查询方法代码如下（示例）：

@Service
public class UserServiceImpl implements UserService {

    @Autowired
    private UserMapper userMapper;

    @Override
    public String getUserById(Integer id) {
        User user = userMapper.selectByPrimaryKey(id);
        if ("".equals(user)){
            return "";
        }
        return user.getUserName();
    }
}

在springcloud_share_6002写一个DTO（示例）：
继承Share实力类，加上user中返回的userName

@Data
public class ShareDto extends Share {
    private String userName;
}

在springcloud_share_6002中使用RestTemplate调用user并得到userName

@RestController
@RequestMapping("/api/share")
public class ShareContoller {
    @Autowired
    private ShareServiceImpl shareService;
    @Autowired
    private RestTemplate restTemplate;

    @GetMapping("/{id}")
    public R getShareById(@PathVariable("id") Integer id){
        Share share = shareService.getShareById(id);
       R r = restTemplate.getForObject("http://localhost:6001/api/user/" + share.getUserId(), R.class);
        String s = r.getData().toString();
        ShareDto shareDto = new ShareDto();
        BeanUtils.copyProperties(share,shareDto);
        shareDto.setUserName(s);
        return new R(ResponseEnum.SUCCESS,shareDto);
    }
}

最后访问swagger（http://localhost:6002/swagger-ui.html）测试得到dto实体类中的对象