I-第一章：（3）REST 微服务案例

一、准备工作

承接着之前的SpringMVC+Mybatis+MySQL初级高级课程，以Dept部门模块做一个微服务通用案例Consumer消费者（Client）通过REST调用Provider提供者（Server）提供的服务

需要掌握的知识：

  • Spring
  • SpringMVC
  • MyBatis
  • MySQL

项目构建：Maven

Maven的分包分模块架构复习

一个简单的Maven模块结构是这样的：
---- app-parent  一个父项目(app-parent)聚合很多子项目(app-util,app-dao,app-service,app-web)
      |---- pom.xml (pom)
      |
      |-------- app-util
      | |-------- pom.xml (jar)
      |
      |-------- app-dao
      | |-------- pom.xml (jar)
      |
      |-------- app-service
      | |-------- pom.xml (jar)
      |
      |-------- app-web
        |-------- pom.xml (war) 

一个Project带着多个Module子模块

MicroServiceCloud父工程（Project）下初次带着3个子模块（Module）

  • microservicecloud-api：封装的整体entity/接口/公共配置等
  • microservicecloud-provider-dept-8001：微服务落地的服务提供者
  • microservicecloud-consumer-dept-80：微服务调用的客户端使用

Tips： 80端口是为HTTP(HyperText Transport Protocol)即超文本传输协议开放的 此为上网冲浪使用次数最多的协议，主要用于WWW(World Wide Web)即万维网传输信息的协议。

可以通过HTTP地址(即常说的"网址")加":80"来访问网站，

因为浏览网页服务默认的端口号都是80，因此只需输入网址即可，不用输入":80"了。

SpringCloud版本：

<dependencies>
    <dependency>
      <groupId>org.springframework.cloudgroupId>
      <artifactId>spring-cloud-dependenciesartifactId>
      <version>Dalston.SR1version>
      <type>pomtype>
      <scope>importscope>
  dependency>
  <dependency>
      <groupId>org.springframework.bootgroupId>
      <artifactId>spring-boot-dependenciesartifactId>
      <version>1.5.9.RELEASEversion>
      <type>pomtype>
      <scope>importscope>
  dependency>
<dependencies>

二、父工程构建

1、创建Maven Project父工程

（1）新建父工程microservicecloud，切记是Packageing是pom模式

（2）主要是定义POM文件，将后续各个子模块公用的jar包等统一提出来，类似一个抽象父类

（3）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>4.0.0modelVersion>

    <groupId>com.njf.springcloudgroupId>
    <artifactId>microservicecloudartifactId>
    <version>1.0-SNAPSHOTversion>

    <packaging>pompackaging>

    <properties>
        <project.build.sourceEncoding>UTF-8project.build.sourceEncoding>
        <maven.compiler.source>1.8maven.compiler.source>
        <maven.compiler.target>1.8maven.compiler.target>
        <junit.version>4.12junit.version>
        <log4j.version>1.2.17log4j.version>
        <lombok.version>1.16.18lombok.version>
    properties>

    <dependencyManagement>
        <dependencies>
            <dependency>
                <groupId>org.springframework.cloudgroupId>
                <artifactId>spring-cloud-dependenciesartifactId>
                <version>Dalston.SR1version>
                <type>pomtype>
                <scope>importscope>
            dependency>
            <dependency>
                <groupId>org.springframework.bootgroupId>
                <artifactId>spring-boot-dependenciesartifactId>
                <version>1.5.9.RELEASEversion>
                <type>pomtype>
                <scope>importscope>
            dependency>
            <dependency>
                <groupId>mysqlgroupId>
                <artifactId>mysql-connector-javaartifactId>
                <version>5.1.44version>
            dependency>
            <dependency>
                <groupId>com.alibabagroupId>
                <artifactId>druidartifactId>
                <version>1.1.12version>
            dependency>
            <dependency>
                <groupId>org.mybatis.spring.bootgroupId>
                <artifactId>mybatis-spring-boot-starterartifactId>
                <version>1.3.2version>
            dependency>
            <dependency>
                <groupId>ch.qos.logbackgroupId>
                <artifactId>logback-coreartifactId>
                <version>1.2.3version>
            dependency>
            <dependency>
                <groupId>junitgroupId>
                <artifactId>junitartifactId>
                <version>${junit.version}version>
                <scope>testscope>
            dependency>
            <dependency>
                <groupId>log4jgroupId>
                <artifactId>log4jartifactId>
                <version>${log4j.version}version>
            dependency>
        dependencies>
    dependencyManagement>

project>

三、API 公共模块

1、新建microservicecloud-api

eclipse：

IDEA：

2、修改 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">

    
    <parent>
        <artifactId>microservicecloudartifactId>
        <groupId>com.njf.springcloudgroupId>
        <version>1.0-SNAPSHOTversion>
    parent>
    <modelVersion>4.0.0modelVersion>

    
    <artifactId>microservicecloud-apiartifactId>


    
    <dependencies>
        <dependency>
            <groupId>org.projectlombokgroupId>
            <artifactId>lombokartifactId>
        dependency>
    dependencies>

project>


3、新建部门Entity且配合lombok使用

import lombok.AllArgsConstructor;
import lombok.Data;
import lombok.NoArgsConstructor;
import lombok.experimental.Accessors;

import java.io.Serializable;


@SuppressWarnings("serial")
@AllArgsConstructor
@NoArgsConstructor
@Data
@Accessors(chain = true)
public class Dept implements Serializable {
    //主键
    private Long deptno;
    //部门名称
    private String dname;
    //来自那个数据库，因为微服务架构可以一个服务对应一个数据库，同一个信息被存储到不同数据库
    private String db_source;

    public Dept(String dname) {
        this.dname = dname;
    }
}

TIp：IDEA中需要安装 Lombok 插件。

mvn clean install后给其它模块引用，达到通用目的。 也即需要用到部门实体的话，不用每个工程都定义一份，直接引用本模块即可。

四、服务提供者

1、新建microservicecloud-provider-dept-8001 的Maven 模块

2、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">
    <parent>
        <artifactId>microservicecloudartifactId>
        <groupId>com.njf.springcloudgroupId>
        <version>1.0-SNAPSHOTversion>
    parent>
    <modelVersion>4.0.0modelVersion>

    <artifactId>microservicecloud-provider-dept-8001artifactId>

    <dependencies>
        <dependency>
            <groupId>com.njf.springcloudgroupId>
            <artifactId>microservicecloud-apiartifactId>
            <version>1.0-SNAPSHOTversion>
        dependency>
        <dependency>
            <groupId>junitgroupId>
            <artifactId>junitartifactId>
        dependency>
        <dependency>
            <groupId>mysqlgroupId>
            <artifactId>mysql-connector-javaartifactId>
        dependency>
        <dependency>
            <groupId>com.alibabagroupId>
            <artifactId>druidartifactId>
        dependency>
        <dependency>
            <groupId>ch.qos.logbackgroupId>
            <artifactId>logback-coreartifactId>
        dependency>
        <dependency>
            <groupId>org.mybatis.spring.bootgroupId>
            <artifactId>mybatis-spring-boot-starterartifactId>
        dependency>
        <dependency>
            <groupId>org.springframework.bootgroupId>
            <artifactId>spring-boot-starter-jettyartifactId>
        dependency>
        <dependency>
            <groupId>org.springframework.bootgroupId>
            <artifactId>spring-boot-starter-webartifactId>
        dependency>
        <dependency>
            <groupId>org.springframework.bootgroupId>
            <artifactId>spring-boot-starter-testartifactId>
        dependency>
        
        <dependency>
            <groupId>org.springframeworkgroupId>
            <artifactId>springloadedartifactId>
        dependency>
        <dependency>
            <groupId>org.springframework.bootgroupId>
            <artifactId>spring-boot-devtoolsartifactId>
        dependency>
    dependencies>

project>

3、Yml 配置文件

server:
  port: 8001

mybatis:
  config-location: classpath:mybatis/mybatis.cfg.xml        # mybatis配置文件所在路径
  type-aliases-package: com.njf.springcloud.entities        # 所有Entity别名类所在包
  mapper-locations:
    - classpath:mybatis/mapper/**/*.xml                     # mapper映射文件

spring:
  application:
    name: microservicecloud-dept                            #服务名（重要！！！）
  datasource:
    type: com.alibaba.druid.pool.DruidDataSource            # 当前数据源操作类型
    driver-class-name: com.mysql.jdbc.Driver                # mysql驱动包
    url: jdbc:mysql://localhost:3306/cloudDB01?useSSL=false              # 数据库名称
    username: root
    password: root
    dbcp2:
      min-idle: 5                                           # 数据库连接池的最小维持连接数
      initial-size: 5                                       # 初始化连接数
      max-total: 5                                          # 最大连接数
      max-wait-millis: 200                                  # 等待连接获取的最大超时时间

4、MyBatis配置文件

工程src/main/resources目录下新建mybatis文件夹后新建mybatis.cfg.xml文件

<?xml version="1.0" encoding="UTF-8" ?>
configuration
        PUBLIC "-//mybatis.org//DTD Config 3.0//EN"
        "http://mybatis.org/dtd/mybatis-3-config.dtd">

<configuration>

    <settings>
        <setting name="cacheEnabled" value="true"/>
    settings>

configuration>

5、MySQL创建部门数据库脚本

DROP DATABASE IF EXISTS cloudDB01;
CREATE DATABASE cloudDB01 CHARACTER SET UTF8;
USE cloudDB01;
CREATE TABLE dept
(
  deptno BIGINT NOT NULL PRIMARY KEY AUTO_INCREMENT,
  dname VARCHAR(60),
  db_source   VARCHAR(60)
);

INSERT INTO dept(dname,db_source) VALUES('开发部',DATABASE());
INSERT INTO dept(dname,db_source) VALUES('人事部',DATABASE());
INSERT INTO dept(dname,db_source) VALUES('财务部',DATABASE());
INSERT INTO dept(dname,db_source) VALUES('市场部',DATABASE());
INSERT INTO dept(dname,db_source) VALUES('运维部',DATABASE());

SELECT * FROM dept;

6、DeptDao部门接口

@Mapper
public interface DeptDao {
    public boolean addDept(Dept dept);

    public Dept findById(Long id);

    public List findAll();
}

7、创建Mapper文件

工程src/main/resources/mybatis目录下新建mapper文件夹后再建DeptMapper.xml

<?xml version="1.0" encoding="UTF-8" ?>
mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"
        "http://mybatis.org/dtd/mybatis-3-mapper.dtd">

<mapper namespace="com.njf.springcloud.dao.DeptDao">

    <select id="findById" resultType="Dept" parameterType="Long">
        select deptno,dname,db_source from dept where deptno=#{deptno};
    select>

    <select id="findAll" resultType="Dept">
        select deptno,dname,db_source from dept;
    select>

    <insert id="addDept" parameterType="Dept">
        INSERT INTO dept(dname,db_source) VALUES(#{dname},DATABASE());
    insert>

mapper>

8、DeptService部门服务接口

public interface DeptService {
    public boolean add(Dept dept);
    public Dept get(Long id);
    public List list();
}

9、DeptServiceImpl部门服务接口实现类

@Service
public class DeptServiceImpl implements DeptService {
    @Autowired
    private DeptDao dao ;

    @Override
    public boolean add(Dept dept)
    {
        return dao.addDept(dept);
    }

    @Override
    public Dept get(Long id)
    {
        return dao.findById(id);
    }

    @Override
    public List list()
    {
        return dao.findAll();
    }

}

10、DeptController部门微服务提供者REST

@RestController
public class DeptController {
    @Autowired
    private DeptService service;

    @RequestMapping(value="/dept/add", method= RequestMethod.POST)
    public boolean add(@RequestBody Dept dept)
    {
        return service.add(dept);
    }

    @RequestMapping(value="/dept/get/{id}", method=RequestMethod.GET)
    public Dept get(@PathVariable("id") Long id)
    {
        return service.get(id);
    }

    @RequestMapping(value="/dept/list", method=RequestMethod.GET)
    public List list()
    {
        return service.list();
    }

}

11、DeptProvider8001_App主启动类

@SpringBootApplication
public class DeptProvider8001_App {
    public static void main(String[] args) {
        SpringApplication.run(DeptProvider8001_App.class, args);
    }
}

12、通过浏览器测试

13、工程目录

五、服务消费者

1、新建microservicecloud-consumer-dept-80 Maven Model

2、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">
    <parent>
        <artifactId>microservicecloudartifactId>
        <groupId>com.njf.springcloudgroupId>
        <version>1.0-SNAPSHOTversion>
    parent>
    <modelVersion>4.0.0modelVersion>

    <artifactId>microservicecloud-consumer-dept-80artifactId>
    <description>部门微服务消费者description>

    <dependencies>
        <dependency>
            <groupId>com.njf.springcloudgroupId>
            <artifactId>microservicecloud-apiartifactId>
            <version>1.0-SNAPSHOTversion>
        dependency>
        <dependency>
            <groupId>org.springframework.bootgroupId>
            <artifactId>spring-boot-starter-webartifactId>
        dependency>
        
        <dependency>
            <groupId>org.springframeworkgroupId>
            <artifactId>springloadedartifactId>
        dependency>
        <dependency>
            <groupId>org.springframework.bootgroupId>
            <artifactId>spring-boot-devtoolsartifactId>
        dependency>
    dependencies>

project>

3、YML 配置文件

server:
  port: 80

4、编写配置类

com.njf.springcloud.cfgbeans包下ConfigBean的编写（类似spring里面的applicationContext.xml写入的注入Bean）

@Configuration
public class ConfigBean {
    @Bean
    public RestTemplate getRestTemplate() {
        return new RestTemplate();
    }

}

5、创建消费者

com.njf.springcloud.controller包下新建DeptController_Consumer部门微服务消费者REST

6、RestTemplate

（1）RestTemplate 是什么

RestTemplate提供了多种便捷访问远程Http服务的方法， 是一种简单便捷的访问restful服务模板类，是Spring提供的用于访问Rest服务的客户端模板工具集

（2）官网及使用

https://docs.spring.io/spring-framework/docs/4.3.7.RELEASE/javadoc-api/org/springframework/web/client/RestTemplate.html

使用restTemplate访问restful接口非常的简单粗暴无脑。 (url, requestMap, ResponseBean.class)这三个参数分别代表 REST请求地址、请求参数、HTTP响应转换被转换成的对象类型。

7、使用 RESTTemplate 进行服务调用

@RestController
public class DeptController_Consumer {

    @Autowired
    private RestTemplate restTemplate;

    private static final String REST_URL_PREFIX = "http://localhost:8001";

    /**
     * 这三个参数分别代表
     * REST请求地址、请求参数、HTTP响应转换被转换成的对象类型
     * @param dept
     * @return
     */
    @RequestMapping(value = "/consumer/dept/add")
    public boolean add(Dept dept) {
        return restTemplate.postForObject(REST_URL_PREFIX + "/dept/add", dept, Boolean.class);
    }

    @RequestMapping(value = "/consumer/dept/list")
    public List getDept() {
        return restTemplate.getForObject(REST_URL_PREFIX + "/dept/list", List.class);
    }

    @RequestMapping(value = "/consumer/dept/get/{id}")
    public Dept getDeptById(@PathVariable("id") Long id){
        return restTemplate.getForObject(REST_URL_PREFIX + "/dept/get/" + id, Dept.class);
    }

}

8、DeptConsumer80_App主启动类

@SpringBootApplication
public class DeptConsumer80_App {
    public static void main(String[] args) {
        SpringApplication.run(DeptConsumer80_App.class, args);
    }
}

9、测试：

通过消费端进行测试：

http://localhost/consumer/dept/get/2

http://localhost/consumer/dept/list

http://localhost/consumer/dept/add?dname=AI

10、目录结构

SpringCloud

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