1. 创建父级项目

1.1 按下图所示创建项目

1.1.1 创建项目

1.1.2 配置jdk 版本

1.1.3 配置文件编码

1.1.4 开启注解处理

1.1.5 删除 src 目录

1.2 编辑 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">
    <modelVersion>4.0.0</modelVersion>

    <groupId>org.example</groupId>
    <artifactId>springcloudalibaba</artifactId>
    <packaging>pom</packaging>
    <version>1.0.0</version>
    <modules>
        <module>shop-common</module>
        <module>user</module>
        <module>product</module>
        <module>order</module>
    </modules>

    <properties>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <maven.compiler.source>1.8</maven.compiler.source>
        <maven.compiler.target>1.8</maven.compiler.target>
        <junit.version>4.12</junit.version>
        <log4j.version>1.2.17</log4j.version>
        <lombok.version>1.16.18</lombok.version>
        <mysql.version>5.7.0</mysql.version>
        <druid.version>1.1.16</druid.version>
        <mybatis.spring.boot.version>1.3.0</mybatis.spring.boot.version>
        <org.spring.boot.starter.web.version>2.6.4</org.spring.boot.starter.web.version>
        <com.mysql.version>8.0.33</com.mysql.version>
    </properties>

    <!--    父工程 -->
    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.2.2.RELEASE</version>
    </parent>

    <!--    依赖版本    -->



    <!-- 子块基础之后，提供作用：锁定版本 + 子module不用写 groupId 和 version -->
    <dependencyManagement>
        <dependencies>
            <dependency>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-project-info-reports-plugin</artifactId>
                <version>3.0.0</version>
            </dependency>

            <!-- 下面三个基本是微服务架构的标配 -->
            <!--spring boot 2.2.2-->
            <dependency>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-dependencies</artifactId>
                <version>2.2.2.RELEASE</version>
                <type>pom</type>
                <scope>import</scope>
            </dependency>
            <!--spring cloud Hoxton.SR1-->
            <dependency>
                <groupId>org.springframework.cloud</groupId>
                <artifactId>spring-cloud-dependencies</artifactId>
                <version>Hoxton.SR1</version>
                <type>pom</type>
                <scope>import</scope>
            </dependency>
            <!--spring cloud 阿里巴巴-->
            <dependency>
                <groupId>com.alibaba.cloud</groupId>
                <artifactId>spring-cloud-alibaba-dependencies</artifactId>
                <version>2.1.0.RELEASE</version>
                <type>pom</type>
                <scope>import</scope>
            </dependency>

            <!--mysql-->
            <dependency>
                <groupId>mysql</groupId>
                <artifactId>mysql-connector-java</artifactId>
                <version>${mysql.version}</version>
                <scope>runtime</scope>
            </dependency>
            <!-- druid-->
            <dependency>
                <groupId>com.alibaba</groupId>
                <artifactId>druid</artifactId>
                <version>${druid.version}</version>
            </dependency>
            <dependency>
                <groupId>org.mybatis.spring.boot</groupId>
                <artifactId>mybatis-spring-boot-starter</artifactId>
                <version>${mybatis.spring.boot.version}</version>
            </dependency>
            <dependency>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-starter-web</artifactId>
                <version>${org.spring.boot.starter.web.version}</version>
            </dependency>
            <!--junit-->
            <dependency>
                <groupId>junit</groupId>
                <artifactId>junit</artifactId>
                <version>${junit.version}</version>
            </dependency>
            <!--log4j-->
            <dependency>
                <groupId>log4j</groupId>
                <artifactId>log4j</artifactId>
                <version>${log4j.version}</version>
            </dependency>

            <dependency>
                <groupId>com.mysql</groupId>
                <artifactId>mysql-connector-j</artifactId>
                <version>${com.mysql.version}</version>
            </dependency>

            <dependency>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-starter-data-jpa</artifactId>
                <version>2.2.0.RELEASE</version>
            </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>

</project>

2. 创建通用子模块 shop-common

2.1 创建 pom.xml，修改依赖

<?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>springcloudalibaba</artifactId>
        <groupId>org.example</groupId>
        <version>1.0.0</version>
    </parent>
    <modelVersion>4.0.0</modelVersion>

    <artifactId>shop-common</artifactId>

    <properties>
        <maven.compiler.source>8</maven.compiler.source>
        <maven.compiler.target>8</maven.compiler.target>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
    </properties>

    <dependencies>

        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <optional>true</optional>
        </dependency>

        <!-- https://mvnrepository.com/artifact/cn.hutool/hutool-all -->
        <dependency>
            <groupId>cn.hutool</groupId>
            <artifactId>hutool-all</artifactId>
            <version>5.8.23</version>
        </dependency>

        <!-- https://mvnrepository.com/artifact/javax.persistence/persistence-api -->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-data-jpa</artifactId>
        </dependency>

    </dependencies>


</project>

2.2 创建 Order 实体

package org.example.entities;

import lombok.Data;

import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;
import java.math.BigDecimal;

@Data
@Entity(name="t_order")
public class Order {
    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private Integer id;
    private String username;
    private Integer product_id;
    private BigDecimal product_price;
    private Integer number;
}

2.3 创建 Product 实体

package org.example.entities;

import lombok.Data;

import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;
import java.math.BigDecimal;

@Data
@Entity(name="t_product")
public class Product {
    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private Integer id;
    private String product_name;
    private BigDecimal product_price;
    private Integer stock;
}

2.4 创建 User 实体

package org.example.entities;

import lombok.Data;
import lombok.Generated;

import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;

@Data
@Entity(name="t_user")
public class User {
    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private Integer id;
    private String username;
    private String password;
    private String telephone;
}

2.5 创建 CommonResult 实体

package org.example.entities;

import lombok.AllArgsConstructor;
import lombok.Data;
import lombok.NoArgsConstructor;

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

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

2.6 创建 main 启动类

public class CommonMain {
    public static void main(String[] args) {
        System.out.println("------打包---------");
    }
}

3. 创建子模块 user

3.1 创建pom.xml，定义依赖

<?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>springcloudalibaba</artifactId>
        <groupId>org.example</groupId>
        <version>1.0.0</version>
    </parent>
    <modelVersion>4.0.0</modelVersion>

    <artifactId>user</artifactId>

    <properties>
        <maven.compiler.source>8</maven.compiler.source>
        <maven.compiler.target>8</maven.compiler.target>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
    </properties>

    <dependencies>
        <!--导入公共部分实体类cloud-api-commons-->
        <dependency>
            <groupId>org.example</groupId>
            <artifactId>shop-common</artifactId>
            <version>1.0.0</version>
        </dependency>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
            <version>2.2.2.RELEASE</version>
        </dependency>


        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-autoconfigure</artifactId>
            <version>2.2.2.RELEASE</version>
            <scope>compile</scope>
        </dependency>

        <!-- https://mvnrepository.com/artifact/cn.hutool/hutool-all -->
        <dependency>
            <groupId>cn.hutool</groupId>
            <artifactId>hutool-all</artifactId>
            <version>5.8.23</version>
        </dependency>

        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <optional>true</optional>
        </dependency>

        <!-- https://mvnrepository.com/artifact/org.springframework.boot/spring-boot-starter-data-jpa -->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-data-jpa</artifactId>
        </dependency>

        <dependency>
            <groupId>com.mysql</groupId>
            <artifactId>mysql-connector-j</artifactId>
        </dependency>
    </dependencies>

</project>

3.2 创建 user/src/main/resources/applications.yml

server:
  port: 8002
spring:
  application:
    name: service-user
  datasource:
    driver-class-name: com.mysql.cj.jdbc.Driver
    url: jdbc:mysql://192.168.88.151:3306/springcloud-alibaba-user?serverTimezone=UTC&useUnicode=true&characterEncoding=utf8&useSSL=false
    username: root
    password: root
  jpa:
    properties:
      hibernate:
        hbm2ddl:
          auto: update
        dialect: org.hibernate.dialect.MySQL57InnoDBDialect

3.3 创建 dao：

/user/src/main/java/org/example/dao/UserDao.java

package org.example.dao;

import org.example.entities.User;
import org.springframework.data.jpa.repository.JpaRepository;

public interface UserDao extends JpaRepository<User, Integer> {
}

3.4 创建 service

3.4.1 创建接口:

/user/src/main/java/org/example/service/UserService.java

package org.example.service;

public interface UserService {
}

3.4.2 创建实现:

/user/src/main/java/org/example/service/impl/UserServiceImpl.java

package org.example.service.impl;

import org.example.service.UserService;

public class UserServiceImpl implements UserService {
}

3.5 创建 controller:

/user/src/main/java/org/example/controller/UserController.java

package org.example.controller;

import org.springframework.web.bind.annotation.RestController;

@RestController
public class UserController {
}

3.6 创建启动类

/user/src/main/java/org/example/UserApplication.java

package org.example;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;

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

3.7 启动 user 服务

启动成功后的效果图：

4. 创建子模块 product

参考步骤 3

5. 创建子模块 order

参考步骤 3

6. 常见问题

6.1 ClassNotFoundException

Spring Boot ClassNotFoundException org.springframework.core.metrics.ApplicationStartup

这个报错大部分属于父子级依赖版本不一致导致的。 SpringBoot项目运行的时候，如果报这个错，一般是依赖版本问题，去查看一下，父项目的springboot版本是否高于或等于子项目的Springboot版本号，如果子项目的版本高于父项目就会导致此报错。

解决办法：

替换掉父项目或子项目的版本号，进行升级或降级，根据自己需求操作即可

6.2 无法启动：run NotFound

由于 SpringBootApplication 类里面没有run 方法，run 方法属于 SpringApplication。
如下图所示：

package org.example;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;

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

6.3 无法创建 order 实体 mysql？

由于order 是mysql的保留关键字，所以不能使用 order 作为表名。

6.4 Invalid syntax error "type= MyISAM" in DDL generated by Hibernate

application.yml 中使用的mysql 配置不对，应该修改为 :
org.hibernate.dialect.MySQL57InnoDBDialect

jpa:
  properties:
    hibernate:
      hbm2ddl:
        auto: update
      dialect: org.hibernate.dialect.MySQL57InnoDBDialect

6.5 pom.xml 中的 dependencyManagement 和 dependencies 的区别？

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。

6.6 javax.persistence.spi.PersistenceUnitInfo.getValidationMode()

这种情况一般是 jpa 和 mybatis 冲突，剔除掉 mybatis 或者 jpa 即可。如果剔除掉mybatis，那么pom.xml 添加如下内容

<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-data-jpa</artifactId>
</dependency>

<dependency>
    <groupId>com.mysql</groupId>
    <artifactId>mysql-connector-j</artifactId>
</dependency>

springcloud微服务创建