springboot 多模塊將dao(mybatis)項目拆分出去

前言:

以前我們在建項目的時候, 要么將所有的package建在一個項目裡面, 在處理引用的時候, 真的很方便. 不用擔心, 有些東西配置不到或者讀取不到.

或者, 將package獨立出去, 到一個項目中或者子項目中. 這時候, 項目中的引用處理, 還是有些麻煩的. 不過好處更多, 不再表述.

在idea 裡面, 推薦使用多模塊建項目, 而不再是eclipse 裡面的那種方式. 那這裡, 就試著將一個springboot 的項目拆分到子模塊中去, 看看效果如何.

項目拆分:

1. 目錄變化

2. 父項目

父pom.xml理論上來說, 應該是對子項目中的引用進行一個約束, 主要是版本約束.

所以父pom.xm 中, 應該使用dependencyManagement 來約束子項目中jar 包版本.

然後對於一些子項目都用得著的引用, 可以提到父項目中去.

 <?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>cn.elvinle</groupId> <artifactId>parent</artifactId> <version>0.0.1-SNAPSHOT</version> <packaging>pom</packaging> <name>parent</name> <description>Demo project for Spring Boot</description> <parent> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-parent</artifactId> <version>1.5.9.RELEASE</version> <relativePath/> <!-- lookup parent from repository --> </parent> <modules> <module>pojo</module> <module>web</module> <module>dao</module> <module>service</module> <module>simpl</module> </modules> <properties> <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding> <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding> <java.version>1.8</java.version> <druid.version>1.1.3</druid.version> <mybatis.boot.starter.version>1.3.1</mybatis.boot.starter.version> <mysql.connector.java.version>5.1.44</mysql.connector.java.version> </properties> <dependencyManagement> <dependencies> <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.boot.starter.version}</version> </dependency> <dependency> <groupId>mysql</groupId> <artifactId>mysql-connector-java</artifactId> <version>${mysql.connector.java.version}</version> </dependency> </dependencies> </dependencyManagement> <!--申明依賴關係--> <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> </dependency> </dependencies> <build> <plugins> <plugin> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-maven-plugin</artifactId> </plugin> </plugins> </build></project>

3. 子項目- pojo

3.1 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> <parent> <groupId>cn.elvinle</groupId> <artifactId>parent</artifactId> <version>0.0.1-SNAPSHOT</version> </parent> <groupId>cn.elvinle</groupId> <artifactId>pojo</artifactId> <version>0.0.1-SNAPSHOT</version> <packaging>jar</packaging> <name>pojo</name> <description>Demo project for Spring Boot</description> <properties> <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding> <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding> <java.version>1.8</java.version> </properties> <build> <plugins> <plugin> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-maven-plugin</artifactId> </plugin> </plugins> </build></project>

3.2 db實體

package cn.elvinle.pojo;/** * @author: elvin */public class User { private int id; private String name; public int getId() { return id; } public void setId(int id) { this.id = id; } public String getName() { return name; } public void setName(String name) { this.name = name; }}

對於pojo和dao中的內容, 可以使用mybatis逆向工程生成, 可以省去很多麻煩.

4. 子項目- dao

4.1 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> <parent> <groupId>cn.elvinle</groupId> <artifactId>parent</artifactId> <version>0.0.1-SNAPSHOT</version> </parent> <groupId>cn.elvinle</groupId> <artifactId>dao</artifactId> <version>0.0.1-SNAPSHOT</version> <packaging>jar</packaging> <name>dao</name> <description>Demo project for Spring Boot</description> <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> <!-- 內部引用--> <dependency> <groupId>cn.elvinle</groupId> <artifactId>pojo</artifactId> <version>0.0.1-SNAPSHOT</version> </dependency> <!-- 外部引用--> <!-- https://mvnrepository.com/artifact/com.alibaba/druid --> <dependency> <groupId>com.alibaba</groupId> <artifactId>druid</artifactId> </dependency> <dependency> <groupId>mysql</groupId> <artifactId>mysql-connector-java</artifactId> </dependency> <dependency> <groupId>org.mybatis.spring.boot</groupId> <artifactId>mybatis-spring-boot-starter</artifactId> </dependency> </dependencies> <build> <plugins> <plugin> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-maven-plugin</artifactId> </plugin> </plugins> </build></project>

4.2 mapper

UserMapper.java:

 public interface UserMapper { public List<User> getAll();}

UserMapper.xml:

 <?xml version="1.0" encoding="UTF-8" ?><!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN" "http://mybatis.org/dtd/mybatis-3-mapper.dtd" ><mapper namespace="cn.elvinle.dao.mapper.UserMapper" > <select id="getAll" resultType="cn.elvinle.pojo.User"> select * from user </select></mapper>

5. 子項目- service

5.1 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> <parent> <groupId>cn.elvinle</groupId> <artifactId>parent</artifactId> <version>0.0.1-SNAPSHOT</version> </parent> <groupId>cn.elvinle</groupId> <artifactId>service</artifactId> <version>0.0.1-SNAPSHOT</version> <packaging>jar</packaging> <name>service</name> <description>Demo project for Spring Boot</description> <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>cn.elvinle</groupId> <artifactId>pojo</artifactId> <version>0.0.1-SNAPSHOT</version> </dependency> </dependencies> <build> <plugins> <plugin> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-maven-plugin</artifactId> </plugin> </plugins> </build></project>

5.2 UserService.java

 public interface UserService { public List<User> getAll();}

6. 子項目- simpl

6.1 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> <parent> <groupId>cn.elvinle</groupId> <artifactId>parent</artifactId> <version>0.0.1-SNAPSHOT</version> </parent> <groupId>cn.elvinle</groupId> <artifactId>simpl</artifactId> <version>0.0.1-SNAPSHOT</version> <packaging>jar</packaging> <name>simpl</name> <description>Demo project for Spring Boot</description> <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>cn.elvinle</groupId> <artifactId>pojo</artifactId> <version>0.0.1-SNAPSHOT</version> </dependency> <dependency> <groupId>cn.elvinle</groupId> <artifactId>service</artifactId> <version>0.0.1-SNAPSHOT</version> </dependency> <dependency> <groupId>cn.elvinle</groupId> <artifactId>dao</artifactId> <version>0.0.1-SNAPSHOT</version> </dependency> </dependencies> <build> <plugins> <plugin> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-maven-plugin</artifactId> </plugin> </plugins> </build></project>

6.2 UserSImpl

 @Servicepublic class UserSImpl implements UserService { @Autowired private UserMapper userMapper; @Override public List<User> getAll() { System.out.println("UserSImpl getAll"); return userMapper.getAll(); }}

7. 子項目- web

關鍵的地方來了.

7.1 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> <parent> <groupId>cn.elvinle</groupId> <artifactId>parent</artifactId> <version>0.0.1-SNAPSHOT</version> </parent> <groupId>cn.elvinle</groupId> <artifactId>web</artifactId> <version>0.0.1-SNAPSHOT</version> <packaging>jar</packaging> <name>web</name> <description>Demo project for Spring Boot</description> <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>cn.elvinle</groupId> <artifactId>simpl</artifactId> <version>0.0.1-SNAPSHOT</version> </dependency> </dependencies> <build> <plugins> <plugin> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-maven-plugin</artifactId> </plugin> </plugins> </build></project>

7.2 application.yml

 server: context-path: /parent port: 8080mybatis: config-location: /mapper/*.xmlspring: datasource: username: root password: root url: jdbc:mysql://localhost:3306/shop?useUnicode=true&characterEncoding=utf-8 driver-class-name: com.mysql.jdbc.Driver

7.3 控制器

@RestController@RequestMapping("api")public class ApiController { @Autowired private UserService userService; @RequestMapping("index") public List<User> index(){ List<User> all = userService.getAll(); return all; }}

到目前為止, 沒什麼特別的, 都是正常修改, 接下來, 會出現與不分模塊不同的地方.

7.4 入口處修改

@ComponentScan({"cn.elvinle"})@SpringBootApplicationpublic class WebApplication { public static void main(String[] args) { SpringApplication.run(WebApplication.class, args); }}

這時候, 如果直接運行起程序, 是不會成功訪問的. 原因在於, mybatis的自動化配置和自動化創建, 沒有支持到多模塊中.

這時候, 需要我們手動進行配置和創建.

7.5 Mybatis java 配置

<!-- mybatis 的工廠--> <bean id="sqlSessionFactory"> <property name="dataSource" ref="dataSource" /> <property name="configLocation" value="classpath:mybatis/SqlMapConfig.xml"/> <!-- 自動掃描mapping.xml文件--> <!--<property name="mapperLocations" value="classpath:mapper/*.xml" />--> </bean> <!-- DAO接口所在包名，Spring會自動查找其下的類--> <bean id="mapperScannerConfigurer"> <property name="basePackage" value="cn.elvinle.bookshop.mapper" /> <property name="sqlSessionFactoryBeanName" value="sqlSessionFactory"/> </bean>

可以對照著上面的配置文件, 進行java配置

MybatisConfig:

 @Configurationpublic class MybatisConfig { @Value("${mybatis.config-location}") private String mapperLocationPattern; @Bean @ConfigurationProperties(prefix = "spring.datasource") public DataSource dataSource(){return new com.alibaba.druid.pool.DruidDataSource(); } @Bean(name="sqlSessionFactory") public SqlSessionFactory sqlSessionFactory() throws Exception{ SqlSessionFactoryBean sqlSessionFactoryBean = new SqlSessionFactoryBean(); sqlSessionFactoryBean.setDataSource(dataSource()); PathMatchingResourcePatternResolver resolver = new PathMatchingResourcePatternResolver(); sqlSessionFactoryBean.setMapperLocations(resolver.getResources(mapperLocationPattern)); return sqlSessionFactoryBean.getObject(); }}

MybatisMapperScannerConfig:

 @Configuration@AutoConfigureAfter(MybatisConfig.class)@MapperScan("cn.elvinle.dao.mapper")public class MybatisMapperScannerConfig { public MapperScannerConfigurer mapperScannerConfigurer(){ MapperScannerConfigurer mapperScannerConfigurer = new MapperScannerConfigurer(); mapperScannerConfigurer.setSqlSessionFactoryBeanName("sqlSessionFactory"); mapperScannerConfigurer.setBasePackage("cn.elvinle.dao.mapper"); return mapperScannerConfigurer; }}

OK, 到這裡, 就可以把程序跑起來了, 看一下結果:

以上就是本文的全部內容，希望對大家的學習有所幫助，也希望大家多多支持武林網。