SpringCloudAlibaba入门系列(2) - 微服务环境搭建

摘要：通过使用电商项目中的商品、订单、用户为案例进行实例演示。

2.1 案例准备

2.1.1 技术选型

maven：3.3.9
数据库：MySQL 5.7
持久层: SpingData Jpa
其他: SpringCloud Alibaba 技术栈

2.1.2 模块设计

springcloud-alibaba 父工程
shop-common 公共模块【实体类】
shop-user 用户微服务 【端口: 807x】
shop-product 商品微服务 【端口: 808x】
shop-order 订单微服务 【端口: 809x】

2.1.3 微服务调用

在微服务架构中，最常见的场景就是微服务之间的相互调用。我们以电商系统中常见的用户下单为例来演示微服务的调用：客户向订单微服务发起一个下单的请求，在进行保存订单之前需要调用商品微服务查询商品的信息。

我们一般把服务的主动调用方称为服务消费者，把服务的被调用方称为服务提供者。

在这种场景下，订单微服务就是一个服务消费者， 商品微服务就是一个服务提供者。

2.2 创建父工程

创建一个maven工程，然后在pom.xml文件中添加下面内容

<?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>

    <parent>
		<groupId>org.springframework.boot</groupId>
		<artifactId>spring-boot-starter-parent</artifactId>
		<version>2.1.3.RELEASE</version>
	</parent>
    
    <groupId>com.taiji</groupId>
    <artifactId>springcloud-alibaba</artifactId>
    <packaging>pom</packaging>
    <version>1.0-SNAPSHOT</version>

    <properties>
        <java.version>1.8</java.version>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
        <spring-cloud.version>Greenwich.RELEASE</spring-cloud.version>
        <spring-cloud-alibaba.version>2.1.0.RELEASE</spring-cloud-alibaba.version>
    </properties>
    <dependencyManagement>
        <dependencies>
            <dependency>
                <groupId>org.springframework.cloud</groupId>
                <artifactId>spring-cloud-dependencies</artifactId>
                <version>${spring-cloud.version}</version>
                <type>pom</type>
                <scope>import</scope>
            </dependency>
            <dependency>
                <groupId>com.alibaba.cloud</groupId>
                <artifactId>spring-cloud-alibaba-dependencies</artifactId>
                <version>${spring-cloud-alibaba.version}</version>
                <type>pom</type>
                <scope>import</scope>
            </dependency>
        </dependencies>
    </dependencyManagement>
</project>

版本对应：

2.3 创建基础模块

1 创建shop-common 模块，在pom.xml中添加依赖

<?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-alibaba</artifactId>
        <groupId>com.taiji</groupId>
        <version>1.0-SNAPSHOT</version>
    </parent>
    <modelVersion>4.0.0</modelVersion>

    <artifactId>shop-common</artifactId>
    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-data-jpa</artifactId>
            <version>2.3.0.RELEASE</version>
        </dependency>
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <version>1.18.2</version>
        </dependency>
        <dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>fastjson</artifactId>
            <version>1.2.56</version>
        </dependency>
        <dependency>
        <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>5.1.6</version>
        </dependency>
    </dependencies>
</project>

2 创建实体类

//User.java
//用户
@Entity(name = "shop_user")
@Data
public class User {
    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private Integer uid;//主键
    private String username;//用户名
    private String password;//密码
    private String telephone;//手机号
}

//Product.java
//商品
@Entity(name = "shop_product")
@Data
public class Product {
    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY) private Integer pid;//主键
    private String pname;//商品名称
    private Double pprice;//商品价格
    private Integer stock;//库存
}

//Order.java
//订单
@Entity(name = "shop_order")
@Data   //加上Data装饰器，无需指定get和set方法
public class Order {
    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private Long oid;//订单id
    private Integer uid;//用户id
    private String username;//用户名
    private Integer pid;//商品id
    private String pname;//商品名称
    private Double pprice;//商品单价
    private Integer number;//购买数量
}

2.4 创建用户微服务

步骤:

1. 创建模块 导入依赖
2. 创建SpringBoot主类
3. 加入配置文件
4. 创建必要的接口和实现类(controller service dao)

新建一个shop-user 模块，然后进行下面操作

1 创建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>springcloud-alibaba</artifactId>
        <groupId>com.taiji</groupId>
        <version>1.0-SNAPSHOT</version>
    </parent>
    <modelVersion>4.0.0</modelVersion>

    <artifactId>shop-user</artifactId>
    <dependencies>
        <dependency>
            <groupId>com.taiji</groupId>
            <artifactId>shop-common</artifactId>
            <version>1.0-SNAPSHOT</version>
        </dependency>
    </dependencies>
</project>

2 编写主类UserApplication.java

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

3 创建配置文件application.yml

server:
  port: 8071
spring:
  application:
    name: service-user
  datasource:
    driver-class-name: com.mysql.jdbc.Driver
    url: jdbc:mysql:///shop?serverTimezone=UTC&useUnicode=true&characterEncoding=utf-8&useSSL=true
    username: root
    password: root
  jpa:
    properties:
      hibernate:
        hbm2ddl:
          auto: update
        dialect: org.hibernate.dialect.MySQL5InnoDBDialect

2.5 创建商品微服务

1 创建一个名为shop_product 的模块，并添加springboot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-alibaba</artifactId>
        <groupId>com.taiji</groupId>
        <version>1.0-SNAPSHOT</version>
    </parent>
    <modelVersion>4.0.0</modelVersion>

    <artifactId>shop-product</artifactId>
    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <dependency>
            <groupId>com.taiji</groupId>
            <artifactId>shop-common</artifactId>
            <version>1.0-SNAPSHOT</version>
        </dependency>
    </dependencies>
</project>

2 创建工程的主类ProductApplication.java

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

3 创建配置文件application.yml

server:
  port: 8081
spring:
  application:
    name: service-product
  datasource:
    driver-class-name: com.mysql.jdbc.Driver
    url: jdbc:mysql:///shop?serverTimezone=UTC&useUnicode=true&characterEncoding=utf-8&useSSL=true
    username: root
    password: root
  jpa:
    properties:
      hibernate:
        hbm2ddl:
          auto: update
        dialect: org.hibernate.dialect.MySQL5InnoDBDialect

4 创建ProductDao接口

public interface ProductDao extends JpaRepository<Product,Integer> {
}

5 创建ProductService接口和实现类

public interface ProductService {
    Product findByPid(Integer pid);
}

@Service
public class ProductServiceImpl implements ProductService {
    @Autowired
    private ProductDao productDao;

    public Product findByPid(Integer pid) {
        return productDao.findById(pid).get();
    }
}

6 创建Controller

@RestController
@Slf4j
public class ProductController {
    @Autowired
    private ProductService productService;

    @RequestMapping("/product/{pid}")
    public Product product(@PathVariable("pid")Integer pid){
        log.info("接下来要进行{}号商品信息的查询",pid);

        Product product=productService.findByPid(pid);

        log.info("商品信息查询成功，内容为{}", JSON.toJSONString(product));
        
        return product;
    }
}

7 启动工程，等到数据库表创建完毕之后，加入测试数据

INSERT INTO shop_product VALUE(NULL,'小米','1000','5000');
INSERT INTO shop_product VALUE(NULL,'华为','2000','5000');
INSERT INTO shop_product VALUE(NULL,'苹果','3000','5000');
INSERT INTO shop_product VALUE(NULL,'OPPO','4000','5000');

8 通过浏览器访问服务

2.6 创建订单微服务

1 创建一个名为shop-order 的模块,并添加springboot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-alibaba</artifactId>
        <groupId>com.taiji</groupId>
        <version>1.0-SNAPSHOT</version>
    </parent>
    <modelVersion>4.0.0</modelVersion>

    <artifactId>shop-order</artifactId>

    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <dependency>
            <groupId>com.taiji</groupId>
            <artifactId>shop-common</artifactId>
            <version>1.0-SNAPSHOT</version>
        </dependency>
    </dependencies>
</project>

2 创建工程的主类OrderApplication.java

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

3 创建配置文件application.yml

server:
  port: 8091
spring:
  application:
    name: service-order
  datasource:
    driver-class-name: com.mysql.jdbc.Driver
    url: jdbc:mysql:///shop?serverTimezone=UTC&useUnicode=true&characterEncoding=utf-8&useSSL=true
    username: root
    password: root
  jpa:
    properties:
      hibernate:
        hbm2ddl:
          auto: update
        dialect: org.hibernate.dialect.MySQL5InnoDBDialect

4 创建OrderDao接口

public interface OrderDao extends JpaRepository<Order,Integer> {
}

5 创建OrderService接口和实现类

public interface OrderService {
    void createOrder(Order order);
}

@Service
public class OrderServiceImpl implements OrderService {
    @Autowired
    private OrderDao orderDao;

    public void createOrder(Order order) {
        orderDao.save(order);
    }
}

6 创建RestTemplate

@SpringBootApplication
public class OrderApplication {
    public static void main(String[] args) {
        SpringApplication.run(OrderApplication.class, args);
    }
    
    @Bean
    public RestTemplate restTemplate(){
        return new RestTemplate();
    }
}

7 创建Controller

@RestController
@Slf4j
public class OrderController {
    @Autowired
    private RestTemplate restTemplate;
    @Autowired
    private OrderService orderService;

    @RequestMapping("/order/prod/{pid}")
    public Order order(@PathVariable("pid") Integer pid) {
        log.info("接收到{}号商品的下单请求，接下来调用商品微服务查询此商品信息", pid);

        ///1 一旦服务提供者的地址信息变化了，就得修改服务调用者的代码
        ///2 一旦服务提供者做了集群，服务调用者一方无法实现负载均衡的去调用
        ///3 一旦微服务变得越来越多，如何管理这个服务清单就成了问题
        Product product = restTemplate.getForObject("http://localhost:8081/product/" + pid, Product.class);

        log.info("查询到{}号商品的信息，内容是{}", pid, JSON.toJSONString(product));

        Order order = new Order();
        order.setUid(1);
        order.setUsername("测试用户");
        order.setPid(product.getPid());
        order.setPname(product.getPname());
        order.setPprice(product.getPprice());
        order.setNumber(1);

        orderService.createOrder(order);
        log.info("创建订单成功，订单信息为{}", JSON.toJSONString(order));

        return order;
    }
}

8 启动工程,通过浏览器访问服务进行测试