二.微服务AlibabaCloud介绍和架构环境准备

Evergreen 2020年11月10日微服务预计阅读 6 分钟

### 微服务AlibabaCloud介绍

[官网](https://spring.io/projects/spring-cloud-alibaba#overview)

> 为什么要选择AlibabaCloud , 和SpringCloud的区别？

SpringCloud和AlibabaCloud组件存在很大交集，互相配合

- SpringCloud很多组件是基于第三方整合，目前多个已经不更新了，比如`zuul、eureka、hystrix`等
- AlibabaCloud 提供`一站式`微服务解决方法，已经和SpringCloud进行了整合，组件互相支持

AlibabaCloud全家桶介绍

[GITHUB地址](https://github.com/alibaba/spring-cloud-alibaba)

- 服务注册发现：Nacos
- 服务限流降级：Sentinel
- 分布配置中心：Nacos
- 服务网关：SpringCloud Gateway
- 服务之间调用：Feign、Ribbon
- 链路追踪：Sleuth+Zipkin

### 在线教育微服务模块设计和环境准备

模块划分：`视频服务`，`订单服务`，`用户服务`

必备基础环境：JDK8以上版本+`Maven3.5`(采用默认,防止有些包下载不下来)

### 在线教育微服务数据导入

采用3个数据库，每个服务单独一个库

**视频服务数据库 video表**

```sql
CREATE TABLE `video` (
  `id` int(11) unsigned NOT NULL AUTO_INCREMENT,
  `title` varchar(524) DEFAULT NULL COMMENT '视频标题',
  `summary` varchar(1026) DEFAULT NULL COMMENT '概述',
  `cover_img` varchar(524) DEFAULT NULL COMMENT '封面图',
  `price` int(11) DEFAULT NULL COMMENT '价格,分',
  `create_time` datetime DEFAULT NULL COMMENT '创建时间',
  `point` double(11,2) DEFAULT '8.70' COMMENT '默认8.7，最高10分',
  PRIMARY KEY (`id`)
) ENGINE=InnoDB AUTO_INCREMENT=48 DEFAULT CHARSET=utf8;
```

```sql
INSERT INTO `video` (`id`, `title`, `summary`, `cover_img`, `price`, `create_time`, `point`)
VALUES
  (30, '互联网架构之JAVA虚拟机JVM零基础到高级实战', 'https://xdvideo-file.oss-cn-shenzhen.aliyuncs.com/video/2020/maven/%E8%AF%A6%E6%83%85%E5%9B%BE.png', 'https://xdvideo-file.oss-cn-shenzhen.aliyuncs.com/video/2020/maven/%E5%AE%98%E7%BD%91%E4%B8%BB%E5%9B%BE-mawen.png', 3980, '2021-06-24 22:14:00', 9.10),
  (40, '全新微信小程序零基础到项目实战', 'https://xdvideo-file.oss-cn-shenzhen.aliyuncs.com/video/2020/%E5%BE%AE%E4%BF%A1%E5%B0%8F%E7%A8%8B%E5%BA%8F/%E8%AF%A6%E6%83%85%E5%9B%BE.png', 'https://xdvideo-file.oss-cn-shenzhen.aliyuncs.com/video/2020/%E5%BE%AE%E4%BF%A1%E5%B0%8F%E7%A8%8B%E5%BA%8F/%E5%AE%98%E7%BD%91%E4%B8%BB%E5%9B%BE-%E5%B0%8F%E7%A8%8B%E5%BA%8F.png', 5980, '2021-01-18 22:14:00', 9.10),
  (41, '玩转搜索框架ElasticSearch7.x实战', 'https://xd-video-pc-img.oss-cn-beijing.aliyuncs.com/xdclass_pro/video/2019_backend/elasticsearch7_detail.jpeg', 'https://xd-video-pc-img.oss-cn-beijing.aliyuncs.com/xdclass_pro/video/2019_backend/elasticsearch7.png', 4880, '2021-01-10 22:14:00', 8.70),
  (45, 'Docker实战视频教程入门到高级dockerfile/compose-Harbor', 'https://xdvideo-file.oss-cn-shenzhen.aliyuncs.com/video/2020/Docker/%E8%AF%A6%E6%83%85%E5%9B%BE.jpeg', 'https://xdvideo-file.oss-cn-shenzhen.aliyuncs.com/video/2020/Docker/%E5%AE%98%E7%BD%91%E4%B8%BB%E5%9B%BE-docker.png', 5980, '2021-01-10 22:14:00', 9.30),
  (46, '新版javase零基础到高级教程小白自学编程', 'https://xdvideo-file.oss-cn-shenzhen.aliyuncs.com/video/2020/%E6%96%B0%E7%89%88javase/%E8%AF%A6%E6%83%85%E5%9B%BE.png', 'https://file.xdclass.net/video/2020/%E6%96%B0%E7%89%88javase/%E5%AE%98%E7%BD%91%E4%B8%BB%E5%9B%BE-javase.png', 3980, '2021-01-24 22:14:00', 8.80),
  (47, 'Nodejs教程零基础入门到项目实战前端视频教程', 'https://xdvideo-file.oss-cn-shenzhen.aliyuncs.com/video/2020/node/%E5%AE%98%E7%BD%91%E8%AF%A6%E6%83%85%E5%9B%BE-node.png', 'https://xdvideo-file.oss-cn-shenzhen.aliyuncs.com/video/2020/node/%E5%AE%98%E7%BD%91%E4%B8%BB%E5%9B%BE-node.png', 6980, '2021-01-24 22:14:00', 8.90);
```

**用户服务数据库 user表**

```sql
CREATE TABLE `user` (
  `id` int(11) unsigned NOT NULL AUTO_INCREMENT,
  `phone` varchar(32) DEFAULT NULL,
  `pwd` varchar(128) DEFAULT NULL,
  `sex` int(2) DEFAULT NULL,
  `img` varchar(128) DEFAULT NULL,
  `create_time` datetime DEFAULT NULL,
  `role` int(11) DEFAULT NULL COMMENT '1是普通用户，2是管理员',
  `username` varchar(128) DEFAULT NULL,
  `wechat` varchar(128) DEFAULT NULL,
  PRIMARY KEY (`id`)
) ENGINE=InnoDB AUTO_INCREMENT=5 DEFAULT CHARSET=utf8mb4;
```

```sql
INSERT INTO `user` (`id`, `phone`, `pwd`, `sex`, `img`, `create_time`, `role`, `username`, `wechat`)
VALUES
  (1, '123', '666', 1, 'xdclass.net', '2021-09-09 00:00:00', 1, 'jack', 'xdclass6'),
  (2, '2323432', '794666918', 1, 'wwwww', '2020-05-20 04:54:01', 1, '小滴Anna姐姐', 'xdclass-anna'),
  (3, '2323432', 'xdclass-lw', 1, 'wwwww', '2020-05-20 04:54:42', 1, '二当家小D', 'xdclass1'),
  (4, '2323432', '3232323', 1, 'wwwww', '2020-05-20 04:55:07', 1, '老王', 'xdclass-lw');
```

**订单服务数据库video_order表**

```sql
CREATE TABLE `video_order` (
  `id` int(11) unsigned NOT NULL AUTO_INCREMENT,
  `out_trade_no` varchar(64) DEFAULT NULL COMMENT '订单唯一标识',
  `state` int(11) DEFAULT NULL COMMENT '0表示未支付，1表示已支付',
  `create_time` datetime DEFAULT NULL COMMENT '订单生成时间',
  `total_fee` int(11) DEFAULT NULL COMMENT '支付金额，单位分',
  `video_id` int(11) DEFAULT NULL COMMENT '视频主键',
  `video_title` varchar(256) DEFAULT NULL COMMENT '视频标题',
  `video_img` varchar(256) DEFAULT NULL COMMENT '视频图片',
  `user_id` int(12) DEFAULT NULL COMMENT '用户id',
  PRIMARY KEY (`id`)
) ENGINE=InnoDB AUTO_INCREMENT=42 DEFAULT CHARSET=utf8;
```

### Maven聚合工程创建微服务项目实战

使用maven创建工程：`yuan-alibaba-cloud`父级工程·，删除src目录，改为pom工程，引入相应的依赖包：

```xml

<packaging>pom</packaging>
<properties>
    <java.version>1.8</java.version>
</properties>
<dependencyManagement>
    <dependencies>
        
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-dependencies</artifactId>
            <version>2.3.3.RELEASE</version>
            <type>pom</type>
            <scope>import</scope>
        </dependency>
        
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-dependencies</artifactId>
            <version>Hoxton.SR8</version>
            <type>pom</type>
            <scope>import</scope>
        </dependency>
        
        <dependency>
            <groupId>com.alibaba.cloud</groupId>
            <artifactId>spring-cloud-alibaba-dependencies</artifactId>
            <version>2.2.1.RELEASE</version>
            <type>pom</type>
            <scope>import</scope>
        </dependency>
    </dependencies>
</dependencyManagement>
<build>
    <plugins>
        <plugin>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-maven-plugin</artifactId>
            <configuration>
                <fork>true</fork>
                <addResources>true</addResources>
            </configuration>
        </plugin>
    </plugins>
</build>
```

添加4个子项目：`yuan-common，yuan-video-service，yuan-user-service，yuan-order-service`

父级工程聚合这些：

```xml
   <modules>
        <module>yuan-common</module>
        <module>yuan-video-service</module>
        <module>yuan-user-service</module>
        <module>yuan-order-service</module>
    </modules>
```

对其三个应用服务引入web与common包

```xml
 <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>

<dependency>
            <groupId>cn.yuan</groupId>
            <artifactId>yuan-common</artifactId>
            <version>1.0-SNAPSHOT</version>
        </dependency>
    </dependencies>
```

### AlibabaCloud微服务Mybatis连接Mysql数据库

创建common包实体类

```java
public class User {
        private Integer id;
        private String name;
        private String pwd;
        private String headImg;
        private String phone;
        private Date createTime;
        private String wechat;
}

public class Video {
    private Integer id;
    private String title;
    private String summary;
    private String coverImg;
    private Integer  price;
    private Date createTime;
    private Double point;
}

public class VideoOrder {
    private Integer id;
    private String outTradeNo;
    private Integer state;
    private Date createTime;
    private  Integer totalFee;
    private Integer videoId;
    private String videoTitle;
    private String videoImg;
    private Integer userId;
}
```

Mybatis依赖导入+数据库配置：yuan-video-service，yuan-user-service，yuan-order-service

聚合工程pom.xml修改【注意】

```xml
    <properties>
        <java.version>1.8</java.version>
        <maven.compiler.source>1.8</maven.compiler.source>
        <maven.compiler.target>1.8</maven.compiler.target>
    </properties>
  <dependency>
    <groupId>org.mybatis.spring.boot</groupId>
    <artifactId>mybatis-spring-boot-starter</artifactId>
    <version>2.1.2</version>
    <type>pom</type>
    <scope>import</scope>
  </dependency>
```

添加mybatis依赖和数据库驱动

```xml
  <dependency>
        <groupId>org.mybatis.spring.boot</groupId>
        <artifactId>mybatis-spring-boot-starter</artifactId>
        </dependency>
        <dependency>
        <groupId>mysql</groupId>
        <artifactId>mysql-connector-java</artifactId>
      </dependency>
```

3个模块配置数据库连接（记得修改 端口、应用名称、数据库名称）

```yml
server:
  port: 9000
spring:
  application:
    name: yuan-video-service
  datasource:
    driver-class-name: com.mysql.cj.jdbc.Driver
    url: jdbc:mysql://127.0.0.1:3306/cloud_video?useUnicode=true&characterEncoding=utf-8&useSSL=false
    username: root
    password: 
# 控制台输出sql、下划线转驼峰
mybatis:
  configuration:
    log-impl: org.apache.ibatis.logging.stdout.StdOutImpl
    map-underscore-to-camel-case: true
```

- controller->service->mapper 开发

- application配置

```java
  @SpringBootApplication
  @MapperScan("cn.yuan.dao")
  ```

### 微服务之间的调用-下单购买视频

**服务直接怎么调用**:

**`RPC`**:  远程过程调用，像调用本地服务(方法)一样调用服务器的服务；支持同步、异步调用；客户端和服务器之间建立TCP连接，可以一次建立一个，也可以多个调用复用一次链； RPC数据包小；protobuf；thrift
  rpc：编解码，序列化，链接，丢包，协议

**`Rest(Http`**)：http请求，支持多种协议和功能；开发方便成本低； http数据包大；java开发：resttemplate或者httpclient

用户下单

- 订单服务->视频服务(查询价格和冗余信息)

```java
@Bean
public RestTemplate getRestTemplate(){
    return new RestTemplate();
}  
Video video = restTemplate.getForObject("http://localhost:9000/api/v1/video/find_by_id?videoId="+videoId,Video.class);
```

**存在的问题**：1. 服务之间的IP信息写死；2. 服务之间无法提供负载均衡；3. 多个服务直接关系调用维护复杂

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