SpringBoot —— 简单多模块构建

2021-10-15 本文已影响0人猫的树

前言

SpringBoot系列到现在虽然代码不多，但是感觉结构很乱，随着项目的复杂性提高，代码会越来越臃肿，耦合性高。

所以SpringBoot多模块很有必要，简单来说就是由以前按包分模块变为jar包分模块。在多模块jar模式下可以将某个jar拿出来对外共用，能大大提高代码复用率与开发效率。（后续SpringCloud就是将jar升级成war或者多个集合jar，也就是常说的微服务。）

一、模块划分

1.整体流程

（1）新建springboot项目；
（2）在新建后的springboot项目中新建多个module；
（3）修改pom文件以及删除多余的文件及文件夹；
（4）将原项目的代码放进去；

2. 新建springboot项目

通过Spring Initializr新建一个普通的spring boot项目（快速搭建springboot项目）

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3. 新建Module

右击项目，选择新建Module

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新建springboot-common、springboot-dao、springboot-service、springboot-api模块(每个子模块的groupId要建议一样)

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全部建好之后，效果如下：

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4. 删除多余的文件

1.springboot项目
父模块springboot-parent中将src文件和多余的文件删除；

2.module模块
将springboot-service和springboot-dao下面的application启动类和对应配置文件application.yml，一起删除了，springboot-api模块的不动。

4. 修改pom文件

1.修改父模块pom.xml：将打包方式改为pom、新建modules标签
父模块pom.xm用于加载一些全局的或者公共的jar包，以及配置打包。

<?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 https://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.5.5</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>

    <groupId>com.local.springboot</groupId>
    <artifactId>springboot-parent</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>springboot-parent</name>
    <description>Demo project for Spring Boot</description>

    <!--打包方式改为pom-->
    <packaging>pom</packaging>

    <!--子模块信息-->
    <modules>
        <module>springboot-common</module>
        <module>springboot-dao</module>
        <module>springboot-service</module>
        <module>springboot-api</module>
    </modules>

    <properties>
        <java.version>1.8</java.version>
    </properties>

    <!--子模块继承父模块依赖-->
    <dependencies>
        <dependency>
            <groupId>net.sf.json-lib</groupId>
            <artifactId>json-lib</artifactId>
            <version>2.4</version>
            <classifier>jdk15</classifier>
        </dependency>
        <dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>fastjson</artifactId>
            <version>1.2.70</version>
        </dependency>
        <dependency>
            <groupId>commons-lang</groupId>
            <artifactId>commons-lang</artifactId>
            <version>2.5</version>
        </dependency>
        <dependency>
            <groupId>javax.servlet</groupId>
            <artifactId>javax.servlet-api</artifactId>
            <version>4.0.0</version>
        </dependency>
    </dependencies>

</project>

2.修改api模块中的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 https://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <groupId>com.local.springboot</groupId>
    <artifactId>springboot-api</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>springboot-api</name>
    <description>Demo project for Spring Boot</description>

    <!--继承信息-->
    <parent>
        <groupId>com.local.springboot</groupId>
        <artifactId>springboot-parent</artifactId>
        <version>0.0.1-SNAPSHOT</version>
    </parent>

    <dependencies>
        <!--依赖其他子模块-->
        <dependency>
            <groupId>com.local.springboot</groupId>
            <artifactId>springboot-service</artifactId>
            <version>0.0.1-SNAPSHOT</version>
        </dependency>
        <!--spring boot web-->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <!--spring boot test -->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
        <!-- Swagger UI API接口-->
        <dependency>
            <groupId>io.springfox</groupId>
            <artifactId>springfox-swagger2</artifactId>
            <version>2.9.2</version>
        </dependency>
        <dependency>
            <groupId>io.springfox</groupId>
            <artifactId>springfox-swagger-ui</artifactId>
            <version>2.9.2</version>
        </dependency>
        <!-- swagger-bootstrap-ui-->
        <dependency>
            <groupId>com.github.xiaoymin</groupId>
            <artifactId>swagger-bootstrap-ui</artifactId>
            <version>1.9.6</version>
        </dependency>
        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <scope>test</scope>
        </dependency>
        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <scope>test</scope>
        </dependency>
    </dependencies>

    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
        </plugins>
    </build>

</project>

其他模块都继承父模块，这里需要注意：由于我们把其他模块的启动类删了，父模块的spring-boot-maven-plugin插件也需要删掉，然后添加到需要的模块中去，因为springboot这个插件必须要启动类，否则则会出现错误：

Failed to execute goal org.springframework.boot:
spring-boot-maven-plugin:2.5.5:repackage (repackage) on project springboot-common: 
Execution repackage of goal org.springframework.boot:spring-boot-maven-
plugin:2.5.5:repackage failed: Unable to find main class

3.其他模块修改类似，springboot-dao模块存放数据库相关处理逻辑，需要加入mybatis依赖
springboot-dao模块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 https://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <groupId>com.local.springboot</groupId>
    <artifactId>springboot-dao</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>springboot-dao</name>
    <description>Demo project for Spring Boot</description>

    <!--继承信息-->
    <parent>
        <groupId>com.local.springboot</groupId>
        <artifactId>springboot-parent</artifactId>
        <version>0.0.1-SNAPSHOT</version>
    </parent>

    <dependencies>
        <!--依赖其他子模块-->
        <dependency>
            <groupId>com.local.springboot</groupId>
            <artifactId>springboot-common</artifactId>
            <version>0.0.1-SNAPSHOT</version>
        </dependency>

        <!--添加MyBatis-Plus依赖 -->
        <dependency>
            <groupId>com.baomidou</groupId>
            <artifactId>mybatis-plus-boot-starter</artifactId>
            <version>3.4.0</version>
        </dependency>

        <!--mysql-->
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
        </dependency>
    </dependencies>
</project>

5. 修改application.yml

所有的xml配置和yml配置只能放在最外层的模块，application.yml只能放在springboot-api模块下

将以前的代码修改

#内置Tomcat容器配置
server:
  port: 8080
  servlet:
    #应用路径，配置应用路径，可方便进行反向代理
    context-path:
spring:
  # 数据源
  datasource:
    url: jdbc:mysql://localhost:3306/local_develop?serverTimezone=Asia/Shanghai&useUnicode=true&characterEncoding=utf-8
    username: root
    password: root
    driver-class-name: com.mysql.cj.jdbc.Driver
  #profiles:
    #active: @spring.profiles.active@
  #i18n国际化路径
#  messages:
#    basename: i18n/messages
  # 邮件
  mail:
    default-encoding: utf-8
    # 配置 SMTP 服务器地址
    host: smtp.qq.com
    #发送方邮件名
    username: 158111920@qq.com
    #授权码
    password: btdbkkdkrnxqbijh
    # thymeleaf模板格式
    thymeleaf:
      cache: false
      encoding: UTF-8
      mode: HTML
      servlet:
        content-type: text/html
      prefix: classpath:/templates/
      suffix: .html
  # aop
  aop:
    auto: true
    proxy-target-class: true
#日志
logging:
  config: classpath:logback-spring.xml
#mybatis-plus
mybatis-plus:
  global-config:
    db-config:
      #主键策略
      id-type: auto
      field-strategy: not_empty
      #驼峰下划线转换
      column-underline: true
      #逻辑删除配置
      logic-delete-value: 0
      logic-not-delete-value: 1
      db-type: mysql
      #声明全局默认类名的对应的表的前缀
      table-prefix: t_
    refresh: false
  configuration:
    map-underscore-to-camel-case: true
    cache-enabled: false
    #打印出sql语句
    log-impl: org.apache.ibatis.logging.stdout.StdOutImpl
# # mapper-locations: classpath*:com/local/springboot/springbootdao/mapper/**/*Mapper.xml
#  mapper-locations: classpath*:com/local/springboot/springbootdao/mapper/**/*Mapper.xml

SpringbootApiApplication.java启动类修改

package com.local.springboot.springbootapi;

import org.mapstruct.Mapper;
import org.mybatis.spring.annotation.MapperScan;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.boot.web.servlet.ServletComponentScan;
import springfox.documentation.swagger2.annotations.EnableSwagger2;

//@ServletComponentScan
@EnableSwagger2
@SpringBootApplication(scanBasePackages = "com.local.springboot")
@MapperScan(basePackages = "com.local.springboot.*.mapper")
public class SpringbootApiApplication {

    public static void main(String[] args) {
        try {
            SpringApplication.run(SpringbootApiApplication.class, args);
        }catch (Exception e){
            e.printStackTrace();
        }

    }

}