springboot 多模块将dao(mybatis)项目拆分出去
前言: 以前我们在建项目的时候,要么将所有的package建在一个项目里面,在处理引用的时候,真的很方便. 不用担心,有些东西配置不到或者读取不到. 或者,将package独立出去,到一个项目中或者子项目中. 这时候,项目中的引用处理,还是有些麻烦的. 不过好处更多,不再表述. 在 idea 里面,推荐使用 多模块 建项目,而不再是 eclipse 里面的那种方式. 那这里,就试着将一个springboot 的项目拆分到子模块中去,看看效果如何. 项目拆分: 1. 目录变化 2. 父项目 父pom.xml理论上来说,应该是对子项目中的引用进行一个约束,主要是版本约束. 所以父 pom.xm 中,应该使用dependencyManagement 来约束 子项目中 jar 包版本. 然后对于一些子项目都用得着的引用,可以提到 父项目中去. <?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> <!--申明依赖关系--> <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. 子项目 - 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实体 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; } } 对于pojo和dao中的内容,可以使用mybatis逆向工程生成,可以省去很多麻烦. 4. 子项目 - 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> <!-- 内部引用 --> <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. 子项目 - 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. 子项目 - 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 @Service public class UserSImpl implements UserService { @Autowired private UserMapper userMapper; @Override public List<User> getAll() { System.out.println("UserSImpl getAll"); return userMapper.getAll(); } } 7. 子项目 - web 关键的地方来了. 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: 8080 mybatis: config-location: /mapper/*.xml spring: 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; } } 到目前为止,没什么特别的,都是正常修改,接下来,会出现与不分模块不同的地方. 7.4 入口处修改 @ComponentScan({"cn.elvinle"}) @SpringBootApplication public class WebApplication { public static void main(String[] args) { SpringApplication.run(WebApplication.class,args); } } 这时候,如果直接运行起程序,是不会成功访问的. 原因在于,mybatis的自动化配置和自动化创建,没有支持到多模块中. 这时候,需要我们手动进行配置和创建. 7.5 Mybatis java 配置 <!-- mybatis 的工厂 --> <bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean"> <property name="dataSource" ref="dataSource" /> <property name="configLocation" value="classpath:mybatis/SqlMapConfig.xml"/> <!-- 自动扫描mapping.xml文件 --> <!--<property name="mapperLocations" value="classpath:mapper/*.xml" />--> </bean> <!-- DAO接口所在包名,Spring会自动查找其下的类 --> <bean id="mapperScannerConfigurer" class="org.mybatis.spring.mapper.MapperScannerConfigurer"> <property name="basePackage" value="cn.elvinle.bookshop.mapper" /> <property name="sqlSessionFactoryBeanName" value="sqlSessionFactory"/> </bean> 可以对照着上面的配置文件,进行java配置 MybatisConfig: @Configuration public 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,到这里,就可以把程序跑起来了,看一下结果: 以上就是本文的全部内容,希望对大家的学习有所帮助,也希望大家多多支持编程小技巧。 您可能感兴趣的文章:
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