SpringBoot —— 简单多模块构建

「爱情、让人受尽委屈。」 2023-10-05 21:53 57阅读 0赞

## 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][springboot]）  
![在这里插入图片描述][watermark_type_ZHJvaWRzYW5zZmFsbGJhY2s_shadow_50_text_Q1NETiBALueMq-eahOagkQ_size_20_color_FFFFFF_t_70_g_se_x_16]

### 3. 新建Module ###

右击项目，选择新建Module  
![在这里插入图片描述][watermark_type_ZHJvaWRzYW5zZmFsbGJhY2s_shadow_50_text_Q1NETiBALueMq-eahOagkQ_size_20_color_FFFFFF_t_70_g_se_x_16 1]  
新建springboot-common、springboot-dao、springboot-service、springboot-api模块(每个子模块的groupId要建议一样)  
![在这里插入图片描述][watermark_type_ZHJvaWRzYW5zZmFsbGJhY2s_shadow_50_text_Q1NETiBALueMq-eahOagkQ_size_20_color_FFFFFF_t_70_g_se_x_16 2]  
全部建好之后，效果如下：  
![在这里插入图片描述][f6a0ee3ab4da49c48c0806a18207638b.png]

### 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/> 
        </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>
    
        
        <packaging>pom</packaging>
    
        
        <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>
    
        
        <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>
    
        
        <parent>
            <groupId>com.local.springboot</groupId>
            <artifactId>springboot-parent</artifactId>
            <version>0.0.1-SNAPSHOT</version>
        </parent>
    
        <dependencies>
            
            <dependency>
                <groupId>com.local.springboot</groupId>
                <artifactId>springboot-service</artifactId>
                <version>0.0.1-SNAPSHOT</version>
            </dependency>
            
            <dependency>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-starter-web</artifactId>
            </dependency>
            
            <dependency>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-starter-test</artifactId>
                <scope>test</scope>
            </dependency>
            
            <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>
            
            <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

### 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();
            }
    
        }
    
    }

### 6. 代码搬家 ###

将以前的代码搬运过来（不完整），大致结构如下：  
![在这里插入图片描述][watermark_type_ZHJvaWRzYW5zZmFsbGJhY2s_shadow_50_text_Q1NETiBALueMq-eahOagkQ_size_17_color_FFFFFF_t_70_g_se_x_16]

## 二、测试 ##

![在这里插入图片描述][watermark_type_ZHJvaWRzYW5zZmFsbGJhY2s_shadow_50_text_Q1NETiBALueMq-eahOagkQ_size_20_color_FFFFFF_t_70_g_se_x_16 3]  
启动程序，浏览器输入`http://localhost:8080/user/list?pageNumber=1&pageSize=10`  
![在这里插入图片描述][34df67aac13940d699d97bd5a22b98f6.png]

SpringBoot-简单多模块构建就到这里，还有很多没完善的地方，以后慢慢完善。

[«][Link 1] 上一章：[SpringBoot —— Filter过滤器的使用][Link 1]  
[»][Link 2] 下一章：[SpringBoot —— 整合RabbitMQ常见问题及解决方案][Link 2]

[springboot]: https://blog.csdn.net/qq_34383510/article/details/120288104
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[f6a0ee3ab4da49c48c0806a18207638b.png]: https://img-blog.csdnimg.cn/f6a0ee3ab4da49c48c0806a18207638b.png
[watermark_type_ZHJvaWRzYW5zZmFsbGJhY2s_shadow_50_text_Q1NETiBALueMq-eahOagkQ_size_17_color_FFFFFF_t_70_g_se_x_16]: https://img-blog.csdnimg.cn/8128874527064c7aa4fa4aba839e45f5.png?x-oss-process=image/watermark,type_ZHJvaWRzYW5zZmFsbGJhY2s,shadow_50,text_Q1NETiBALueMq-eahOagkQ==,size_17,color_FFFFFF,t_70,g_se,x_16
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[34df67aac13940d699d97bd5a22b98f6.png]: https://img-blog.csdnimg.cn/34df67aac13940d699d97bd5a22b98f6.png
[Link 1]: https://blog.csdn.net/qq_34383510/article/details/120652970
[Link 2]: https://blog.csdn.net/qq_34383510/article/details/128197768