【SpringCloud】IDEA如何创建一个SpringCloud项目

提示：本文包括父工程创建和环境配置，3个子Module为一个简单的订单微服务工程。

---

新建一个Maven项目

创建一个普通的maven项目

项目处理

1. 删除src目录
   
2. 设置File Encoding都为UTF-8
   
3. 激活注解
   
4. 设置版本为8
   

导入依赖

1. pom.xml

<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>org.examplegroupId>
    <artifactId>SpringcloudTestartifactId>
    <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>
        <mysql.version>8.0.21mysql.version>
        <druid.version>1.1.16druid.version>
        <mybatis.spring.boot.version>1.3.0mybatis.spring.boot.version>
    properties>

    
    <dependencyManagement>
        <dependencies>
            <dependency>
                <groupId>org.apache.maven.pluginsgroupId>
                <artifactId>maven-project-info-reports-pluginartifactId>
                <version>3.0.0version>
            dependency>

            
            
            <dependency>
                <groupId>org.springframework.bootgroupId>
                <artifactId>spring-boot-dependenciesartifactId>
                <version>2.2.2.RELEASEversion>
                <type>pomtype>
                <scope>importscope>
            dependency>
            
            <dependency>
                <groupId>org.springframework.cloudgroupId>
                <artifactId>spring-cloud-dependenciesartifactId>
                <version>Hoxton.SR1version>
                <type>pomtype>
                <scope>importscope>
            dependency>
            
            <dependency>
                <groupId>com.alibaba.cloudgroupId>
                <artifactId>spring-cloud-alibaba-dependenciesartifactId>
                <version>2.1.0.RELEASEversion>
                <type>pomtype>
                <scope>importscope>
            dependency>

            
            <dependency>
                <groupId>mysqlgroupId>
                <artifactId>mysql-connector-javaartifactId>
                <version>${mysql.version}version>
                <scope>runtimescope>
            dependency>
            
            <dependency>
                <groupId>com.alibabagroupId>
                <artifactId>druidartifactId>
                <version>${druid.version}version>
            dependency>
            <dependency>
                <groupId>org.mybatis.spring.bootgroupId>
                <artifactId>mybatis-spring-boot-starterartifactId>
                <version>${mybatis.spring.boot.version}version>
            dependency>
            
            <dependency>
                <groupId>junitgroupId>
                <artifactId>junitartifactId>
                <version>${junit.version}version>
            dependency>
            
            <dependency>
                <groupId>log4jgroupId>
                <artifactId>log4jartifactId>
                <version>${log4j.version}version>
            dependency>
        dependencies>
    dependencyManagement>

    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.bootgroupId>
                <artifactId>spring-boot-maven-pluginartifactId>
                <configuration>
                    <fork>truefork>
                    <addResources>trueaddResources>
                configuration>
            plugin>
        plugins>
    build>
project>

2. maven中的 dependencyManagement 和 dependencies 的区别？

1.dependencyManagement
一般出现在最顶层父工程的pom文件中，我们会看到dependencyManagement元素。通过它来管理jar包的版本，让子项目中引用一个依赖而不用显示的列出版本号。Maven会沿着父子层次向上走，直到找到一个拥有dependencyManagement元素的项目，然后它就会使用在这个dependencyManagement元素中指定的版本号。【注意】dependencyManagement 声明的依赖并没有被导入项目
2. dependencies
管理项目中所有需要导入的依赖
dependencyManagement里只是声明依赖，并不实现引入，因此子项目需要显示的声明需要用的依赖。如果不在子项目中声明依赖，是不会从父项目中继承下来的；只有在子项目中写了该依赖项，并且没有指定具体版本，才会从父项目中继承该项，并且version和scope都读取自父pom;另外如果子项目中指定了版本号，那么会使用子项目中指定的jar版本。

总结：dependencyManagement里只是声明依赖，并不实现引入，因此子项目需要显示的声明需要用的依赖，如果不在子项目中声明依赖，是不会从父项目中继承下来的；只有在子项目中写了该依赖项，并且没有指定具体版本，才会从父项目中继承该项，并且version和scope都读取自父pom。

关于SpringBoot、SpringCloud、SpringCloudAlibaba版本选择

可以根据网站：https://start.spring.io/actuator/info来选择

{
git: {
branch: "f43bda3cdd3be489aa8ce207fb10c6360aeefdd5",
commit: {
id: "f43bda3",
time: "2021-01-20T10:00:44Z"
}
},
build: {
version: "0.0.1-SNAPSHOT",
artifact: "start-site",
versions: {
spring-boot: "2.4.2",
initializr: "0.10.0-SNAPSHOT"
},
name: "start.spring.io website",
time: "2021-01-20T10:04:03.142Z",
group: "io.spring.start"
},
bom-ranges: {
azure: {
2.2.4: "Spring Boot >=2.2.0.RELEASE and <2.3.0.M1",
3.0.0: "Spring Boot >=2.3.0.M1 and <2.4.0-M1"
},
codecentric-spring-boot-admin: {
2.2.4: "Spring Boot >=2.2.0.RELEASE and <2.3.0.M1",
2.3.1: "Spring Boot >=2.3.0.M1 and <2.5.0-M1"
},
solace-spring-boot: {
1.0.0: "Spring Boot >=2.2.0.RELEASE and <2.3.0.M1",
1.1.0: "Spring Boot >=2.3.0.M1 and <2.5.0-M1"
},
solace-spring-cloud: {
1.0.0: "Spring Boot >=2.2.0.RELEASE and <2.3.0.M1",
1.1.1: "Spring Boot >=2.3.0.M1 and <2.5.0-M1"
},
spring-cloud: {
Hoxton.SR9: "Spring Boot >=2.2.0.RELEASE and <2.3.9.BUILD-SNAPSHOT",
Hoxton.BUILD-SNAPSHOT: "Spring Boot >=2.3.9.BUILD-SNAPSHOT and <2.4.0.M1",
2020.0.0-M3: "Spring Boot >=2.4.0.M1 and <=2.4.0.M1",
2020.0.0-M4: "Spring Boot >=2.4.0.M2 and <=2.4.0-M3",
2020.0.0: "Spring Boot >=2.4.0.M4 and <2.4.3-SNAPSHOT",
2020.0.1-SNAPSHOT: "Spring Boot >=2.4.3-SNAPSHOT"
},
spring-cloud-alibaba: {
2.2.1.RELEASE: "Spring Boot >=2.2.0.RELEASE and <2.3.0.M1"
},
spring-cloud-gcp: {
2.0.0: "Spring Boot >=2.4.0-M1 and <2.5.0-M1"
},
spring-cloud-services: {
2.2.6.RELEASE: "Spring Boot >=2.2.0.RELEASE and <2.3.0.RELEASE",
2.3.0.RELEASE: "Spring Boot >=2.3.0.RELEASE and <2.4.0-M1"
},
spring-geode: {
1.2.12.RELEASE: "Spring Boot >=2.2.0.RELEASE and <2.3.0.M1",
1.3.8.RELEASE: "Spring Boot >=2.3.0.M1 and <2.4.0-M1",
1.4.1: "Spring Boot >=2.4.0-M1 and <2.5.0-M1"
},
vaadin: {
14.4.6: "Spring Boot >=2.1.0.RELEASE and <2.5.0-M1"
},
wavefront: {
2.0.2: "Spring Boot >=2.1.0.RELEASE and <2.4.0-M1",
2.1.0-RC1: "Spring Boot >=2.4.0-M1 and <2.4.3-SNAPSHOT",
2.1.0-SNAPSHOT: "Spring Boot >=2.4.3-SNAPSHOT"
}
},
dependency-ranges: {
okta: {
1.4.0: "Spring Boot >=2.2.0.RELEASE and <2.4.0-M1",
1.5.1: "Spring Boot >=2.4.0-M1 and <2.4.1",
2.0.0: "Spring Boot >=2.4.1 and <2.5.0-M1"
},
mybatis: {
2.1.4: "Spring Boot >=2.1.0.RELEASE and <2.5.0-M1"
},
camel: {
3.3.0: "Spring Boot >=2.2.0.RELEASE and <2.3.0.M1",
3.5.0: "Spring Boot >=2.3.0.M1 and <2.4.0-M1",
3.7.0: "Spring Boot >=2.4.0.M1 and <2.5.0-M1"
},
open-service-broker: {
3.1.1.RELEASE: "Spring Boot >=2.2.0.RELEASE and <2.4.0-M1"
}
}
}

Rest微服务工程构建

前面环境搭建好了，现在正式搭建微服务工程，以订单系统为例：上面配置的为父工程，在父工程下我需要新建3个Module，分别表示：微服务提供者、微服务消费者以及两者相同部分重构。【下GIF图为创建Module的步骤】
项目大致结构图：

数据库创建

暂时只需要创建一张订单表：

CREATE TABLE `payment`(
`id` BIGINT(20) NOT NULL AUTO_INCREMENT COMMENT 'ID',
`serial` VARCHAR(200) DEFAULT '',
PRIMARY KEY(`id`)
)ENGINE=InnoDB AUTO_INCREMENT=1 DEFAULT CHARSET=utf8

公共部分

1. 新建一个Module为普通的Maven项目cloud-api-commons。
2. 依赖pom.xml

<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>SpringcloudTestartifactId>
        <groupId>org.examplegroupId>
        <version>1.0-SNAPSHOTversion>
    parent>
    <modelVersion>4.0.0modelVersion>

    <artifactId>cloud-api-commonsartifactId>
    <dependencies>

        <dependency>
            <groupId>org.projectlombokgroupId>
            <artifactId>lombokartifactId>
            <optional>trueoptional>
        dependency>

        
        <dependency>
            <groupId>cn.hutoolgroupId>
            <artifactId>hutool-allartifactId>
            <version>5.1.0version>
        dependency>
    dependencies>

project>

2. 在src/main/java下新建包名为com.gaolang.entities，然后创建两个实体类Payment和CommonResult

Payment 类与数据库表对应

@Data
@AllArgsConstructor
@NoArgsConstructor
public class Payment implements Serializable {
    private Long id;
    private String serial;

}

CommonResult类为了配合前后端发，响应码和信息

@Data
@AllArgsConstructor
@NoArgsConstructor
public class CommonResult<T> {
    private Integer code;
    private String message;
    private T data;

    public CommonResult(Integer code,String message){
        this(code,message,null);
    }
}

3. 做完上面的我们需要对这个Maven项目执行clean和install命令(先clean后install)

微服务提供者

1. 新建一个Module为普通的Maven项目cloud-provider-payment8001。

2. 导入依赖pom.xml

<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>SpringcloudTestartifactId>
        <groupId>org.examplegroupId>
        <version>1.0-SNAPSHOTversion>
    parent>
    <modelVersion>4.0.0modelVersion>

    <artifactId>cloud-provider-payment8001artifactId>
    <dependencies>
         
        <dependency>
            <groupId>org.examplegroupId>
            <artifactId>cloud-api-commonsartifactId>
            <version>${project.version}version>
        dependency>

        <dependency>
            <groupId>org.springframework.bootgroupId>
            <artifactId>spring-boot-starter-webartifactId>
        dependency>
        <dependency>
            <groupId>org.springframework.bootgroupId>
            <artifactId>spring-boot-starter-actuatorartifactId>
        dependency>
        <dependency>
            <groupId>org.mybatis.spring.bootgroupId>
            <artifactId>mybatis-spring-boot-starterartifactId>
        dependency>
        <dependency>
            <groupId>com.alibabagroupId>
            <artifactId>druid-spring-boot-starterartifactId>
            <version>1.1.10version>
        dependency>
        
        <dependency>
            <groupId>mysqlgroupId>
            <artifactId>mysql-connector-javaartifactId>
        dependency>
        
        <dependency>
            <groupId>org.springframework.bootgroupId>
            <artifactId>spring-boot-starter-jdbcartifactId>
        dependency>
        <dependency>
            <groupId>org.projectlombokgroupId>
            <artifactId>lombokartifactId>
            <optional>trueoptional>
        dependency>
        <dependency>
            <groupId>org.springframework.bootgroupId>
            <artifactId>spring-boot-starter-testartifactId>
            <scope>testscope>
        dependency>
    dependencies>

project>

3. 在resource目录下新建一个application.yml配置文件【设置端口、数据库、mybatis】

server:
  port: 8001

spring:
  application:
    name: cloud-provider-payment8001
  datasource:
    type: com.alibaba.druid.pool.DruidDataSource
    driver-class-name: com.mysql.cj.jdbc.Driver
    url: jdbc:mysql://localhost:3306/test?serverTimezone=UTC&useUnicode=true&characterEncoding=utf8&useSSL=false
    username: root
    password: 123456
mybatis:
  mapper-locations: classpath:mapper/*.xml
  type-aliases-package: com.gaolang.entities  # 所有Entity 别名类所在包

4. SpringBoot的启动类，在在src/main/java下新建包名为com.gaolang，然后创建一个PaymentMain8001类

@SpringBootApplication
public class PaymentMain8001 {
    public static void main(String[] args) {
        SpringApplication.run(PaymentMain8001.class,args);
    }
}

5. dao层：在src/main/java下新建包名为com.gaolang.dao，然后创建一个PaymentDao的接口。

@Repository
@Mapper
public interface PaymentDao {
    /**
     *  增加订单操作
     * @param payment  增加的订单
     * @return int
     */
    public int create(Payment payment);

    /**
     *  根据ID查询订单
     * @param id id号
     * @return 订单
     */
    public Payment getPaymentById(@Param("id") Long id);
}

对应在resource/mapper目录下建一个PaymentMapper.xml

<mapper namespace="com.gaolang.dao.PaymentDao">

    <insert id="create" parameterType="Payment" useGeneratedKeys="true" keyProperty="id">
        insert into payment(serial) values (#{serial});
    insert>
    
    <select id="getPaymentById" parameterType="Long" resultType="Payment">
        select * from payment where id = #{id};
    select>

mapper>

6. service层：调用dao层，在src/main/java下新建包名为com.gaolang.service，然后创建一个PaymentService的接口和实现类PaymentServiceImpl。

PaymentService

public interface PaymentService {
    /**
     *  增加订单操作
     * @param payment  增加的订单
     * @return int
     */
    public int create(Payment payment);

    /**
     *  根据ID查询订单
     * @param id id号
     * @return 订单
     */
    public Payment getPaymentById(@Param("id") Long id);
}

PaymentServiceImpl

@Service
public class PaymentServiceImpl implements PaymentService{

    @Autowired
    private PaymentDao paymentDao;

    @Override
    public int create(Payment payment) {
        return paymentDao.create(payment);
    }

    @Override
    public Payment getPaymentById(Long id) {
        return paymentDao.getPaymentById(id);
    }
}

7. controller层：调用service层，在src/main/java下新建包名为com.gaolang.controller，然后创建一个PaymentController类

@RestController
@Slf4j
public class PaymentController {

    @Autowired
    private PaymentService paymentService;

    @PostMapping(value = "/payment/create")
    public CommonResult create(@RequestBody Payment payment){

        int result = paymentService.create(payment);
        log.info("====插入结果：  "+result);

        if (result > 0){
            return new CommonResult(200,"数据库插入成功",result);
        }else {
            return new CommonResult(444,"数据库插入失败",null);
        }
    }

    @GetMapping(value = "/payment/{id}")
    public CommonResult getPaymentById(@PathVariable("id") Long id){
        Payment result = paymentService.getPaymentById(id);
        log.info("****查询结果：" + result);
        if(result != null){
            return new CommonResult(200, "查询成功", result);
        }
        return new CommonResult(444, "没有对应id的记录", null);
    }
}

8. 运行启动类PaymentMain8001，进行测试，在数据库中插入一条id为1的数据，访问：http://localhost:8001/payment/1

微服务消费者

1. 新建一个Module为普通的Maven项目cloud-customer-order80。

2. 导入依赖pom.xml

<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>SpringcloudTestartifactId>
        <groupId>org.examplegroupId>
        <version>1.0-SNAPSHOTversion>
    parent>
    <modelVersion>4.0.0modelVersion>

    <artifactId>cloud-customer-order80artifactId>

    <dependencies>
        <dependency>
            <groupId>org.examplegroupId>
            <artifactId>cloud-api-commonsartifactId>
            <version>${project.version}version>
        dependency>

        <dependency>
            <groupId>org.springframework.bootgroupId>
            <artifactId>spring-boot-starter-webartifactId>
        dependency>
        <dependency>
            <groupId>org.springframework.bootgroupId>
            <artifactId>spring-boot-starter-actuatorartifactId>
        dependency>

        <dependency>
            <groupId>org.projectlombokgroupId>
            <artifactId>lombokartifactId>
            <optional>trueoptional>
        dependency>
        <dependency>
            <groupId>org.springframework.bootgroupId>
            <artifactId>spring-boot-starter-testartifactId>
            <scope>testscope>
        dependency>
    dependencies>
project>

3. 在resource目录下新建一个application.yml配置文件【设置端口】

server:
  port: 80

4. SpringBoot的启动类，在在src/main/java下新建包名为com.gaolang，然后创建一个OrderMain80类

@SpringBootApplication
public class OrderMain80 {
    public static void main(String[] args) {
        SpringApplication.run(OrderMain80.class,args);
    }
}

5. config层：配置RestTemplate，新建一个ApplicationContextConfig类

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

6. controller层：新建一个OrderController类

@RestController
@Slf4j
public class OrderController {

    public static final String PAYMENT_URL = "http://localhost:8001";

    @Autowired
    private RestTemplate restTemplate;

    @PostMapping("customer/payment/create")
    public CommonResult<Payment> create (Payment payment){
        /**
         param1 请求地址，param2 请求参数， param3 返回类型
         */
        return restTemplate.postForObject(PAYMENT_URL + "/payment/create", payment, CommonResult.class);
    }

    @GetMapping("customer/payment/{id}")
    public CommonResult<Payment> getPaymentById(@PathVariable("id")Long id){
        return restTemplate.getForObject(PAYMENT_URL + "/payment/" + id, CommonResult.class);
    }
}

7. 运行启动进行测试：访问 localhost/customer/payment/create?serial=100001

项目结构图

小结

6个步骤

1. 建Module
2. 改pom
3. 写YML
4. 主启动类
5. 业务类
6. 测试