SpringCloud--02、SpringCloud入门

喜欢ヅ旅行 2022-04-12 09:56 272阅读 0赞

### 一、SpringCloud简介 ###

微服务是一种架构方式，最终肯定需要技术架构去实施。

微服务的实现方式很多，但是最火的莫过于Spring Cloud、其次是dubbo

SpringCloud是Spring旗下的项目之一 、它只是将一些非常流行的持术整合到一起、如、路由、负载、熔断器。。。

**SpringCloud主要涉及的组件包括：**

Spring Cloud Netflix：核心组件
    - Eureka：注册中心 
    - Zuul：服务网关
    - Ribbon：负载均衡
    - Feign：服务调用
    - Hystix：熔断器
    
    其它组件：
    - SpringCloud config : 配置中心
    - SpringCloud Sleuth : 服务链追踪
    - SpringBoot Admin : 微服务监控
    - SpringBoot Security：安全组件
    - SpringCloud OAuth2/JWT ：保护微服务系统

架构图：

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3Nzd3F6eA_size_16_color_FFFFFF_t_70][]

SpringCloud版本说明：

最早的Release版本：Angel，第二个Release版本：Brixton，然后是Camden、Dalston、Edgware，目前最新的是Finchley版本。

###  二、微服务场景模拟 ###

**1、创建父工程**

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3Nzd3F6eA_size_16_color_FFFFFF_t_70 1][]

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![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3Nzd3F6eA_size_16_color_FFFFFF_t_70 3][]

pom.xml 对大部分要用到的依赖的版本进行了 管理，方便后续使用

<?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.baidus.demo</groupId>
        <artifactId>cloud-demo</artifactId>
        <version>1.0-SNAPSHOT</version>
        <modules>
            <module>user-service</module>
            <module>consumer-demo</module>
            <module>eureka-server</module>
            <module>zuul-demo</module>
        </modules>
        <packaging>pom</packaging>
    
        <parent>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-parent</artifactId>
            <version>2.0.4.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>Finchley.SR1</spring-cloud.version>
            <mybatis.starter.version>1.3.2</mybatis.starter.version>
            <mapper.starter.version>2.0.2</mapper.starter.version>
            <druid.starter.version>1.1.9</druid.starter.version>
            <mysql.version>5.1.32</mysql.version>
            <pageHelper.starter.version>1.2.3</pageHelper.starter.version>
            <leyou.latest.version>1.0.0-SNAPSHOT</leyou.latest.version>
        </properties>
    
        <dependencyManagement>
            <dependencies>
                
                <dependency>
                    <groupId>org.springframework.cloud</groupId>
                    <artifactId>spring-cloud-dependencies</artifactId>
                    <version>${spring-cloud.version}</version>
                    <type>pom</type>
                    <scope>import</scope>
                </dependency>
                
                <dependency>
                    <groupId>org.mybatis.spring.boot</groupId>
                    <artifactId>mybatis-spring-boot-starter</artifactId>
                    <version>${mybatis.starter.version}</version>
                </dependency>
                
                <dependency>
                    <groupId>tk.mybatis</groupId>
                    <artifactId>mapper-spring-boot-starter</artifactId>
                    <version>${mapper.starter.version}</version>
                </dependency>
                
                <dependency>
                    <groupId>com.github.pagehelper</groupId>
                    <artifactId>pagehelper-spring-boot-starter</artifactId>
                    <version>${pageHelper.starter.version}</version>
                </dependency>
                
                <dependency>
                    <groupId>mysql</groupId>
                    <artifactId>mysql-connector-java</artifactId>
                    <version>${mysql.version}</version>
                </dependency>
            </dependencies>
        </dependencyManagement>
    
        <build>
            <plugins>
                <plugin>
                    <groupId>org.springframework.boot</groupId>
                    <artifactId>spring-boot-maven-plugin</artifactId>
                </plugin>
            </plugins>
        </build>
    </project>

**2、服务提供者**

在父工程下创建module

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3Nzd3F6eA_size_16_color_FFFFFF_t_70 4][]

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3Nzd3F6eA_size_16_color_FFFFFF_t_70 5][]

pom.xml依赖

项目结构：

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3Nzd3F6eA_size_16_color_FFFFFF_t_70 6][]

UserController.java

package com.baidus.user.contrlooer;
    
    import com.baidus.user.pojo.User;
    import com.baidus.user.service.UserService;
    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;
    
    /**
     * @ Author     ：ShaoWei Sun.
     * @ Date       ：Created in 15:54 2018/12/1
     */
    @RestController
    @RequestMapping("user")
    public class UserController {
    
        @Autowired
        private UserService userService;
    
        @GetMapping("/{id}")
        public User queryById(@PathVariable("id") Long id){
            return userService.queryById(id);
        }
    }

service:UserService.java

@Service
    public class UserService {
    
        @Autowired
        private UserMapper userMapper;
    
        public User queryById(Long id) {
            return this.userMapper.selectByPrimaryKey(id);
        }
    }

Mapper:UserMapper.java接口

package com.baidus.user.mapper;
    
    import com.baidus.user.pojo.User;
    
    /**
     * @ Author     ：ShaoWei Sun.
     * @ Date       ：Created in 16:01 2018/12/1
     */
    public interface UserMapper extends tk.mybatis.mapper.common.Mapper<User> {
    }

实体类：User.java

package com.baidus.user.pojo;
    
    import javax.persistence.GeneratedValue;
    import javax.persistence.GenerationType;
    import javax.persistence.Id;
    import javax.persistence.Table;
    import java.io.Serializable;
    import java.util.Date;
    
    /**
     * @ Author     ：ShaoWei Sun.
     * @ Date       ：Created in 15:56 2018/12/1
     */
    
    @Table(name = "tb_user")
    public class User implements Serializable {
    
        private static final long serialVersionUID = 1L;
    
        @Id
        @GeneratedValue(strategy = GenerationType.IDENTITY)
        private Long id;
    
        // 用户名
        private String userName;
    
        // 密码
        private String password;
    
        // 姓名
        private String name;
    
        // 年龄
        private Integer age;
    
        // 性别，1男性，2女性
        private Integer sex;
    
        // 出生日期
        private Date birthday;
    
        // 创建时间
        private Date created;
    
        // 更新时间
        private Date updated;
    
        public static long getSerialVersionUID() {
            return serialVersionUID;
        }
    
        public Long getId() {
            return id;
        }
    
        public void setId(Long id) {
            this.id = id;
        }
    
        public String getUserName() {
            return userName;
        }
    
        public void setUserName(String userName) {
            this.userName = userName;
        }
    
        public String getPassword() {
            return password;
        }
    
        public void setPassword(String password) {
            this.password = password;
        }
    
        public String getName() {
            return name;
        }
    
        public void setName(String name) {
            this.name = name;
        }
    
        public Integer getAge() {
            return age;
        }
    
        public void setAge(Integer age) {
            this.age = age;
        }
    
        public Integer getSex() {
            return sex;
        }
    
        public void setSex(Integer sex) {
            this.sex = sex;
        }
    
        public Date getBirthday() {
            return birthday;
        }
    
        public void setBirthday(Date birthday) {
            this.birthday = birthday;
        }
    
        public Date getCreated() {
            return created;
        }
    
        public void setCreated(Date created) {
            this.created = created;
        }
    
        public Date getUpdated() {
            return updated;
        }
    
        public void setUpdated(Date updated) {
            this.updated = updated;
        }
    
        @Override
        public String toString() {
            return "User{" +
                    "id=" + id +
                    ", userName='" + userName + '\'' +
                    ", password='" + password + '\'' +
                    ", name='" + name + '\'' +
                    ", age=" + age +
                    ", sex=" + sex +
                    ", birthday=" + birthday +
                    ", created=" + created +
                    ", updated=" + updated +
                    '}';
        }
    }

在resources目录看中创建application.yml属性文件

server:
      port: 8081
    
    spring:
      datasource:
        url: jdbc:mysql://localhost:3306/mybatis
        username: root
        password: sswqzx
      application:
        name: user-service # 应用名称
    
    mybatis:
      type-aliases-package: com.baidus.user.pojo

启动类：UserApp.java

package com.baidus.user;
    
    import org.springframework.boot.SpringApplication;
    import org.springframework.boot.autoconfigure.SpringBootApplication;
    import org.springframework.cloud.client.discovery.EnableDiscoveryClient;
    import tk.mybatis.spring.annotation.MapperScan;
    
    /**
     * @ Author     ：ShaoWei Sun.
     * @ Date       ：Created in 16:08 2018/12/1
     */
    @SpringBootApplication
    @MapperScan("com.baidus.user.mapper")
    @EnableDiscoveryClient //开启EurekaClient功能
    public class UserApp {
        public static void main(String[] args) {
            SpringApplication.run(UserApp.class,args);
        }
    }

启动项目、访问[http://localhost:8081/user/][http_localhost_8081_user]7

**3、服务调用者**

创建服务调用者module

![20181203083822283.png][]

pom.xml

项目结构：

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3Nzd3F6eA_size_16_color_FFFFFF_t_70 7][]

**ConsumerController.java**

@RestController
    @RequestMapping("consume")
    public class ConsumerController {
    
        @Autowired
        private UserService userService;
    
        @GetMapping
        public List<User> consume(@RequestParam("ids") List<Long> ids) {
            return this.userService.queryUserByIds(ids);
        }
    }

**UserDao.java**

@Component
    public class UserDao {
    
        @Autowired
        private RestTemplate restTemplate;
    
        public User queryUserById(Long id){
            String url = "http://localhost:8081/user/" + id;
            return this.restTemplate.getForObject(url, User.class);
        }
    }

**User.java**

**UserService.java**

@Service
    public class UserService {
    
        @Autowired
        private UserDao userDao;
    
        public List<User> queryUserByIds(List<Long> ids){
            List<User> users = new ArrayList<>();
            for (Long id : ids) {
                User user = this.userDao.queryUserById(id);
                users.add(user);
            }
            return users;
        }
    }

**application.yml 全局配置文件**

server:
      port: 8080
    
    spring:
      application:
        name: consumer # 应用名称

**consumerDemoApp.java 启动类**

@SpringBootApplication
    public class ConsumerDemoApplication {
    
        @Bean
        public RestTemplate restTemplate() {
            // 这次我们使用了OkHttp客户端,只需要注入工厂即可
            return new RestTemplate(new OkHttp3ClientHttpRequestFactory());
        }
    
        public static void main(String[] args) {
            SpringApplication.run(ConsumerDemoApplication.class, args);
        }
    }

启动测试：我们访问：[http://localhost:8080/consume?ids=6,7,8][http_localhost_8080_consume_ids_6_7_8]

分析：

- user-service-demo：一个提供根据id查询用户的微服务
    - consumer-demo：一个服务调用者，通过RestTemplate远程调用user-service-demo

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3Nzd3F6eA_size_16_color_FFFFFF_t_70 8][]

存在的问题 ：

- 服务管理
      - 如何自动注册和发现
      - 如何实现状态监管
      - 如何实现动态路由
    - 服务如何实现负载均衡
    - 服务如何解决容灾问题
    - 服务如何实现统一配置

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[http_localhost_8081_user]: http://localhost:8081/user/7
[20181203083822283.png]: /images/20220412/73baae8357ec42f6968951266ae4d5ad.png
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[http_localhost_8080_consume_ids_6_7_8]: http://localhost:8080/consume?ids=6,7,8
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