springboot使用maven分模块搭建环境（idea）

短命女 2022-05-19 11:50 343阅读 0赞

# 一、搭建基本架构 #

![70][]

### 创建聚合父工程 ###

删除多余文件，只留一个pom文件

### 在父工程下创建子模块 ###

对着父工程右键 - New - Module - > 输入 web

对着父工程右键 - New - Module - > 输入 service

..等

### 修改pom文件，导入依赖模块jar(不是springboot依赖) ###

repo依赖entity,service依赖dao,controller依赖service

修改各个模块的pom.xml文件，例如repo层：（加入依赖的entity的坐标）

其他模块类似**(注意，依赖version一定要写，否则报错，与父工程version一致)**

### clean install各个模块 ###

**注意修改web模块的打包方式为war**

看是否报错，没有报错才能执行下一步

# 二、加入jar包依赖（springboot依赖）,配置 #

我是为了方便全放在父模块的pom里边了，继承springboot父工程

<?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>com.mlj</groupId>
        <artifactId>vote</artifactId>
        <packaging>pom</packaging>
        <version>1.0-SNAPSHOT</version>
        <modules>
            <module>common</module>
            <module>entity</module>
            <module>service</module>
            <module>web</module>
            <module>repo</module>
        </modules>
    
        <parent>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-parent</artifactId>
            <version>2.0.3.RELEASE</version>
            <relativePath/> 
        </parent>
    
        <properties>
            <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
            <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
            <java.version>1.8</java.version>
        </properties>
    
        <dependencies>
            <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>org.springframework.boot</groupId>
                <artifactId>spring-boot-configuration-processor</artifactId>
                <optional>true</optional>
            </dependency>
    
            
            <dependency>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-starter-data-jpa</artifactId>
            </dependency>
    
            
            <dependency>
                <groupId>mysql</groupId>
                <artifactId>mysql-connector-java</artifactId>
            </dependency>
    
            
            <dependency>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-starter-aop</artifactId>
            </dependency>
        </dependencies>
    
        <build>
            <plugins>
                <plugin>
                    <groupId>org.springframework.boot</groupId>
                    <artifactId>spring-boot-maven-plugin</artifactId>
                    <configuration>
                        <mainClass>com.mlj.vote.controller.GirlController</mainClass>
                    </configuration>
                </plugin>
            </plugins>
        </build>
    
    </project>

web模块下resource下创建 application.yml

spring:
    #开发环境配置
    #  profiles:
    #    active: dev
    #数据库配置
      datasource:
        driver-class-name: com.mysql.jdbc.Driver
        url: jdbc:mysql://localhost:3306/dbgirl
        username: root
        password: root
    #jpa配置
      jpa:
        hibernate:
          ddl-auto: update
        show-sql: true

![70 1][]

创建启动类application

package com.mlj.vote;
    
    import org.springframework.boot.SpringApplication;
    import org.springframework.boot.autoconfigure.SpringBootApplication;
    
    @SpringBootApplication
    public class VoteApplication {
    
    	public static void main(String[] args) {
    		SpringApplication.run(VoteApplication.class, args);
    	}
    }

# 三、测试是否搭建成功 #

新建数据库dbvote

实体类

import javax.persistence.Entity;
    import javax.persistence.GeneratedValue;
    import javax.persistence.Id;
    import javax.validation.constraints.Min;
    
    @Entity
    public class Girl {
    
        @Id
        @GeneratedValue
        private Integer id;
    
        private String cupSize;
    
        @Min(value = 18,message = "禁止未成年入内！")
        private Integer age;
    
        public Girl() {
        }
    //    必须有无参构造
    
        public Integer getId() {
            return id;
        }
    
        public void setId(Integer id) {
            this.id = id;
        }
    
        public String getCupSize() {
            return cupSize;
        }
    
        public void setCupSize(String cupSize) {
            this.cupSize = cupSize;
        }
    
        public Integer getAge() {
            return age;
        }
    
        public void setAge(Integer age) {
            this.age = age;
        }
    }

repo

package com.mlj.vote.repo;
    
    import com.mlj.vote.entity.Girl;
    import org.springframework.data.jpa.repository.JpaRepository;
    
    import java.util.List;
    
    public interface GirlRepository extends JpaRepository<Girl,Integer> {
    
    }

controller

package com.mlj.vote.controller;
    
    
    import com.mlj.vote.entity.Girl;
    import com.mlj.vote.repo.GirlRepository;
    import org.springframework.beans.factory.annotation.Autowired;
    import org.springframework.web.bind.annotation.GetMapping;
    import org.springframework.web.bind.annotation.RestController;
    
    import java.util.List;
    
    
    @RestController
    public class GirlController {
    
        @Autowired
        private GirlRepository girlRepository;
    
        /**
         * 获取列表
         *
         * @return
         */
        @GetMapping(value = "/girls")
        public List<Girl> girlList() {
            return girlRepository.findAll();
        }
    
    }

启动运行:

![70 2][]

![70 3][]

# 四、问题与解决 #

### **[Unable to find main class][]** ###

[Spring Boot Maven Plugin打包异常及三种解决方法：Unable to find main class][Unable to find main class]

### **IDEA\_maven依赖错误 包下面红色波浪线** ###

**开始搭建环境时候先把springboot依赖写上了，有些依赖导入不进去，**修改pom 配置文件，讲标红的依赖先删除，并点击reimport, 之后重新加上出错的依赖，再reimport

推荐先把多模块跑起来再加入依赖和配置

### **Error:java:JDK isn't specified for module** ###

**忘记部署了。。web打包方式应该改为war,部署webwar包**

**参考：**[SpringBoot多模块项目实践（Multi-Module）][SpringBoot_Multi-Module]

[70]: /images/20220519/95dc5694d63e4e18a4aed13f820f3b58.png
[70 1]: /images/20220519/b0dab3dde5fe4219bb348344e5aedd2f.png
[70 2]: /images/20220519/427d9612bc0a4e58a4b9ddfdbb05c6c5.png
[70 3]: /images/20220519/232d08c874184128b14d8c17d31dd6d0.png
[Unable to find main class]: https://www.cnblogs.com/thinking-better/p/7827368.html
[SpringBoot_Multi-Module]: https://segmentfault.com/a/1190000011367492