前言:在上一章节中我们创建了两个个SpringCloud工程,但在两个工程中分别存在着一些重复的部分,例如重复的实体类(如图所示),这样会造成系统的冗余,所以我们需要把公共的类提取到一个工程里,让另外两个工程可以公用。(除了用于放置重复的代码。也可以用于放置服务接口、工具类、第三方接口等有需要公用的代码)
1、在父工程下新建模块

2、选择模块的项目类型为Maven并选择模块要使用的JDK版本
 
 
3、填写子模块的名称,然后点完成即可完成创建

效果图:
 
4、修改api-commons子模块的pom.xml文件,然后reolad一下,下载依赖
例:
<?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>springcloud01</artifactId>
        <groupId>com.ken.springcloud</groupId>
        <version>1.0-SNAPSHOT</version>
    </parent>
    <modelVersion>4.0.0</modelVersion>
    <artifactId>api-commons</artifactId>
    <dependencies>
        <!--热部署-->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-devtools</artifactId>
            <scope>runtime</scope>
            <optional>true</optional>
        </dependency>
        <!--lombok插件-->
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <optional>true</optional>
        </dependency>
        <!--hutool工具包-->
        <dependency>
            <groupId>cn.hutool</groupId>
            <artifactId>hutool-all</artifactId>
            <version>5.1.0</version>
        </dependency>
    </dependencies>
</project>5、新建实体类包com.ken.springcloud.entities
 
效果图:
 
6、复制公共的实体类,然后粘贴到api-commons的子模块下的实体类包entities包下
(1)复制实体类

(2)把实体类粘贴到api-commons子模块里的entities包里
 
效果图:
 
7、把项目打包发布上传到本地Maven仓库里,供其他两个项目公用实体类
(1)打开Maven窗口,执行clean命令,测试Maven环境配置及清理target包

效果图:

(2)执行install命令,下载安装到我们的本地Maven仓库里

效果图:

8、分别删除其他两个子模块里的entities包
(1)删除consumer-order80模块下的entities包

(2)删除provider-payment8001模块下的entities包
效果图:

9、从Maven仓库引入install后打包成的jar包
(1)修改consumer-order80模块的pom.xml文件内容,从而引入jar包
例:
<?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>springcloud01</artifactId>
        <groupId>com.ken.springcloud</groupId>
        <version>1.0-SNAPSHOT</version>
    </parent>
    <modelVersion>4.0.0</modelVersion>
    <artifactId>provider-payment8001</artifactId>
    <dependencies>
        <!--以下依赖都没写版本号,没写版本号的情况下会引用父项目的版本-->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <!--监控-->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-actuator</artifactId>
        </dependency>
        <!--Mybatis和SpringBoot的整合-->
        <dependency>
            <groupId>org.mybatis.spring.boot</groupId>
            <artifactId>mybatis-spring-boot-starter</artifactId>
        </dependency>
        <dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>druid</artifactId>
        </dependency>
        <!--mysql-connector-java-->
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
        </dependency>
        <!--jdbc-->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-jdbc</artifactId>
        </dependency>
        <!--热部署-->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-devtools</artifactId>
            <scope>runtime</scope>
            <optional>true</optional>
        </dependency>
        <!--lombok插件-->
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <optional>true</optional>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
        <!--引入自己定义的api调用包,可以使用Payment模块的entity-->
        <dependency>
            <groupId>com.ken.springcloud</groupId>
            <artifactId>api-commons</artifactId>
            <version>${project.version}</version>
        </dependency>
    </dependencies>
</project>效果图:

(2)修改provider-payment8001模块的pom.xml文件内容,从而引入jar包
例:
<?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>springcloud01</artifactId>
        <groupId>com.ken.springcloud</groupId>
        <version>1.0-SNAPSHOT</version>
    </parent>
    <modelVersion>4.0.0</modelVersion>
    <artifactId>provider-payment8001</artifactId>
    <dependencies>
        <!--以下依赖都没写版本号,没写版本号的情况下会引用父项目的版本-->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <!--监控-->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-actuator</artifactId>
        </dependency>
        <!--Mybatis和SpringBoot的整合-->
        <dependency>
            <groupId>org.mybatis.spring.boot</groupId>
            <artifactId>mybatis-spring-boot-starter</artifactId>
        </dependency>
        <dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>druid</artifactId>
        </dependency>
        <!--mysql-connector-java-->
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
        </dependency>
        <!--jdbc-->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-jdbc</artifactId>
        </dependency>
        <!--热部署-->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-devtools</artifactId>
            <scope>runtime</scope>
            <optional>true</optional>
        </dependency>
        <!--lombok插件-->
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <optional>true</optional>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
        <!--引入自己定义的api调用包,可以使用Payment模块的entity-->
        <dependency>
            <groupId>com.ken.springcloud</groupId>
            <artifactId>api-commons</artifactId>
            <version>${project.version}</version>
        </dependency>
    </dependencies>
</project>效果图:

ps:引入后需要重新加载Maven项目从而引入jar包,否则idea会因为检测不了jar包从而报错

或者

10、分别运行consumer_order80模块和provider-payment8001模块
consumer_order80模块运行效果图

provider-payment8001模块运行效果图

11、用工具测试接口看模块是否正常运行(我这里测试接口用的工具的postman)
(1)测试新增
在地址栏输入http://localhost/consumer/insert?serial=ken3并点击send调用接口,可以看到数据插入成功
效果图:
 
  
(2)测试查询
在地址栏输入http://localhost/consumer/get/3并点击send调用接口,可以看到数据返回成功
效果图:
 
结语:
至此,我们完成了微服务工程公共部分的提取



















