Spring Boot (教程十一： 集成Mybatis)

GitHub 地址：

https://github.com/asd821300801/Spring-Boot.git

---

集成Mybatis的两种方式

前期准备

• SQL语句

sql文件存放在：src\test\resources\user.sql

-- ------------------------------ Table structure for `user`-- ----------------------------DROP TABLE IF EXISTS `user`;CREATE TABLE `user` (  `id` int(11) NOT NULL AUTO_INCREMENT,  `name` varchar(20) DEFAULT NULL,  `account` varchar(20) DEFAULT NULL,  PRIMARY KEY (`id`),  KEY `aaabb` (`id`)) ENGINE=InnoDB AUTO_INCREMENT=73 DEFAULT CHARSET=utf8;-- ------------------------------ Records of user-- ----------------------------INSERT INTO `user` VALUES ('72', '超级管理员', 'admin');

---

• pom.xml文件中添加mybatis相关依赖

<!-- mysql依赖 --><dependency>    <groupId>mysql</groupId>    <artifactId>mysql-connector-java</artifactId></dependency><!-- mybatis --><dependency>    <groupId>org.mybatis.spring.boot</groupId>    <artifactId>mybatis-spring-boot-starter</artifactId>    <version>1.2.0</version></dependency>

---

• 在启动类中添加对mapper包扫描@MapperScan

@MapperScan("com.example.mapper")//启动时默认不连接数据库@SpringBootApplication(exclude={DataSourceAutoConfiguration.class,HibernateJpaAutoConfiguration.class})

---

• 添加数据源

    //DataSource配置    @Bean    @ConfigurationProperties(prefix="spring.datasource")    public DataSource dataSource() {        return new org.apache.tomcat.jdbc.pool.DataSource();    }    //提供SqlSeesion    @Bean    public SqlSessionFactory sqlSessionFactoryBean() throws Exception {        SqlSessionFactoryBean sqlSessionFactoryBean = new SqlSessionFactoryBean();        sqlSessionFactoryBean.setDataSource(dataSource());        PathMatchingResourcePatternResolver resolver = new PathMatchingResourcePatternResolver();        sqlSessionFactoryBean.setMapperLocations(resolver.getResources("classpath:/mybatis/*.xml"));        return sqlSessionFactoryBean.getObject();    }    @Bean    public PlatformTransactionManager transactionManager() {        return new DataSourceTransactionManager(dataSource());    }

---

• SpringbootHelloApplication.java 完整源码

package com;import javax.sql.DataSource;import org.apache.ibatis.session.SqlSessionFactory;import org.mybatis.spring.SqlSessionFactoryBean;import org.mybatis.spring.annotation.MapperScan;import org.springframework.boot.SpringApplication;import org.springframework.boot.autoconfigure.SpringBootApplication;import org.springframework.boot.autoconfigure.jdbc.DataSourceAutoConfiguration;import org.springframework.boot.autoconfigure.orm.jpa.HibernateJpaAutoConfiguration;import org.springframework.boot.context.properties.ConfigurationProperties;import org.springframework.boot.web.servlet.ServletComponentScan;import org.springframework.boot.web.servlet.ServletRegistrationBean;import org.springframework.context.annotation.Bean;import org.springframework.context.annotation.ComponentScan;import org.springframework.core.io.support.PathMatchingResourcePatternResolver;import org.springframework.jdbc.datasource.DataSourceTransactionManager;import org.springframework.transaction.PlatformTransactionManager;import org.springframework.web.servlet.DispatcherServlet;import com.example.servlet.Servlet1;/** * Spring Boot 教程一 * Spring Boot 入门 * @author LingDu *///@SpringBootApplication(exclude={DataSourceAutoConfiguration.class,HibernateJpaAutoConfiguration.class}) 启动时不使用数据库@SpringBootApplication@ServletComponentScan //使用注解的方式注册servlet需要在SpringbootHelloApplication.java中添加@ServletComponentScan注解@ComponentScan@MapperScan("com.example.mapper")//扫描com.example.mapper包下的类public class SpringbootHelloApplication {    /*@Bean    public ServletRegistrationBean servletRegistrationBean() {        return new ServletRegistrationBean(new Servlet1(),"/servlet/*");// ServletName默认值为首字母小写，即servlet    }*/    /**     * 修改DispatcherServlet默认配置     *     * @param dispatcherServlet2     * @author LingDu     */    @Bean    public ServletRegistrationBean dispatcherRegistration(DispatcherServlet dispatcherServlet) {        ServletRegistrationBean registration = new ServletRegistrationBean(dispatcherServlet);        registration.getUrlMappings().clear();        registration.addUrlMappings("*.action"); //只有*.action 的请求能通过        registration.addUrlMappings("*.json");        return registration;    }    //DataSource配置    @Bean    @ConfigurationProperties(prefix="spring.datasource")    public DataSource dataSource() {        return new org.apache.tomcat.jdbc.pool.DataSource();    }    //提供SqlSeesion    @Bean    public SqlSessionFactory sqlSessionFactoryBean() throws Exception {        SqlSessionFactoryBean sqlSessionFactoryBean = new SqlSessionFactoryBean();        sqlSessionFactoryBean.setDataSource(dataSource());        PathMatchingResourcePatternResolver resolver = new PathMatchingResourcePatternResolver();        sqlSessionFactoryBean.setMapperLocations(resolver.getResources("classpath:/mybatis/*.xml"));//映射文件是resource/mybatis/目录下所有.xml文件        return sqlSessionFactoryBean.getObject();    }    @Bean    public PlatformTransactionManager transactionManager() {        return new DataSourceTransactionManager(dataSource());    }    public static void main(String[] args) {        SpringApplication.run(SpringbootHelloApplication.class, args);    }}

---

• 配置文件中添加数据库信息

application.properties 添加相关配置

spring.datasource.url=jdbc:mysql://127.0.0.1:3306/lingdu?useUnicode=true&characterEncoding=UTF-8&zeroDateTimeBehavior=convertToNull&useSSL=falsespring.datasource.username=rootspring.datasource.password=123456spring.datasource.driver-class-name=com.mysql.jdbc.Driver

      springboot会自动加载spring.datasource.*相关配置，数据源就会自动注入到sqlSessionFactory中，sqlSessionFactory会自动注入到Mapper中

---

• 创建domain类User.java

包所在： com.example.domain

package com.example.domain;/** * domain层 * @author LingDu * */public class User {    private int id;    private String name;    private String account;    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;    }    public String getAccount() {        return account;    }    public void setAccount(String account) {        this.account = account;    }    @Override    public String toString() {        return "User [id=" + id + ", name=" + name + ", account=" + account + "]";    }}

---

xml配置文件的方式集成Mybatis

• 创建UserMapper接口

包所在： com.example.mapper

package com.example.mapper;import java.util.List;import org.springframework.context.annotation.Configuration;import com.example.domain.User;/** * dao层 * 对应User表 * @author LingDu */public interface UserMapper {    public List<User> list();    public User get(Integer id);    public void add(User user);    public void update(User user);    public void delete(Integer id);}

---

• 资源目录添加XML映射文件

文件路径：src/main/resources/mybatis/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="com.example.mapper.UserMapper" ><!-- 命名空间必须指定mapper类的全路径 -->    <!-- id必须与mapper接口方法名一致，不能出现重载 -->    <select id="get" parameterType="int" resultType="com.example.domain.User">        select id,name,account from user where id=#{id}    </select>    <select id="list" resultType="com.example.domain.User">         select id,name,account from user    </select>    <insert id="add" parameterType="com.example.domain.User" useGeneratedKeys="true" keyProperty="id">        <!--             useGeneratedKeys="true" keyProperty="id" 添加之后返回自增的ID         -->        insert into user(id,name,account) values(#{id},#{name},#{account})    </insert>    <update id="update" parameterType="com.example.domain.User">        UPDATE user SET name=#{name} WHERE id=#{id}    </update>    <delete id="delete" parameterType="int">        delete from user where id=#{id}    </delete></mapper>

---

• 创建Server层

包所在：com.example.service

UserService 接口

package com.example.service;import java.util.List;import com.example.domain.User;public interface UserService {    public List<User> getAll();    public User getUser(Integer id);    public void insert(User user);    public void update(User user);    public void delete(Integer id);}

---

UserServiceImp 实现类

package com.example.service;import java.util.List;import org.springframework.beans.factory.annotation.Autowired;import org.springframework.stereotype.Service;import com.example.domain.User;import com.example.mapper.UserMapper;@Servicepublic class UserServiceImp implements UserService {    @Autowired    private UserMapper mapper;    @Override    public List<User> getAll() {        return mapper.list();    }    @Override    public User getUser(Integer id) {        return mapper.get(id);    }    @Override    public void insert(User user) {        mapper.add(user);    }    @Override    public void update(User user) {        mapper.update(user);    }    @Override    public void delete(Integer id) {        mapper.delete(id);    }}

---

• 创建Controller类

包所在：com.example.controller

package com.example.controller;import java.util.List;import org.slf4j.Logger;import org.slf4j.LoggerFactory;import org.springframework.beans.factory.annotation.Autowired;import org.springframework.web.bind.annotation.RequestMapping;import org.springframework.web.bind.annotation.RestController;import com.example.domain.User;import com.example.service.UserService;@RestController@RequestMapping("/user")public class UserController {    private Logger logger =  LoggerFactory.getLogger(this.getClass());    @Autowired    private UserService service;    @RequestMapping("/all")    public List<User> getUser(){        List<User> list = service.getAll();        logger.info(list.toString());        return list;    }}

---

• 测试

http://localhost:8080/user/all.action

---

注解的方式集成Mybatis

上面已经介绍了如何使用xml的方式集成Mybatis，下面来试试纯注解的方式集成Mybatis

• 1、pom.xml添加依赖

• 2、在启动类中添加对mapper包扫描@MapperScan

• 3、application.properties 添加相关配置

---

• 创建Mapper接口

为了区分，我将类名命名为：UserAnnotateMapper

包所在： com.example.mapper

package com.example.mapper;import java.util.List;import org.apache.ibatis.annotations.Delete;import org.apache.ibatis.annotations.Insert;import org.apache.ibatis.annotations.Result;import org.apache.ibatis.annotations.Results;import org.apache.ibatis.annotations.Select;import org.apache.ibatis.annotations.Update;import com.example.domain.User;/** * dao层 * 对应User表 * @author LingDu */public interface UserAnnotateMapper {    @Select("SELECT * FROM USER")    @Results({        @Result(property="id",column="id",javaType=Integer.class),        @Result(property="name",column="name"),        @Result(property="account",column="account")    })    public List<User> list();    @Select("SELECT * FROM USER WHERE ID = #{id}")    @Results({        @Result(property="id",column="id",javaType=Integer.class),        @Result(property="name",column="name"),        @Result(property="account",column="account")    })    public User get(Integer id);    @Insert("INSERT INTO USER(NAME,ACCOUNT) VALUES(#{name},#{account})")    public void add(User user);    @Update("UPDATE USER SET NAME=#{name},ACCOUNT=#{account} WHERE id=#{id}")    public void update(User user);    @Delete("DELETE FROM USER WHERE ID = #{id}")    public void delete(Integer id);}

---

• 创建Service层

跟上面的Service一样，这里就不贴代码了。

---

• 创建测试类

完整测试代码

package com.example.test;import org.junit.Test;import org.junit.runner.RunWith;import org.springframework.beans.factory.annotation.Autowired;import org.springframework.boot.test.context.SpringBootTest;import org.springframework.test.context.junit4.SpringRunner;import com.example.domain.User;import com.example.service.UserService;@RunWith(SpringRunner.class)@SpringBootTestpublic class UserAnnotateMapperTest {    @Autowired    private UserService service;    @Test  //在需要运行的方法上添加 @Test 注解即可运行    public void getAll() throws Exception {        System.out.println(service.getAll());    }    //@Test    public void add() throws Exception {        User user = new User();        user.setName("lingdu");        user.setAccount("lingdu");        service.insert(user);    }    //@Test    public void update() throws Exception {        User user = new User();        //更新id=76的用户        user.setId(79);        //更新后的值        user.setName("admin_lingdu");        user.setAccount("admin_lingdu");        service.update(user);    }    //@Test    public void delete() throws Exception {        service.delete(79);    }    //@Test    public void getUser() throws Exception {        System.out.println(service.getUser(79));    }}

---

• 单个方法进行测试的结果如下：

    /@Test    public void add() throws Exception {        User user = new User();        user.setName("lingdu");        user.setAccount("lingdu");        service.insert(user);    }

---

    @Test    public void getUser() throws Exception {        System.out.println(service.getUser(79));    }

---

    @Test    public void update() throws Exception {        User user = new User();        //更新id=76的用户        user.setId(79);        //更新后的值        user.setName("admin_lingdu");        user.setAccount("admin_lingdu");        service.update(user);    }

---

    @Test    public void getAll() throws Exception {        System.out.println(service.getAll());    }

---

    @Test    public void delete() throws Exception {        service.delete(79);    }

---

工程结构图

---

总结

• 两种模式各有特点，注解版适合简单快速的模式，其实像现在流行的这种微服务模式，一个微服务就会对应一个自已
  的数据库，多表连接查询的需求会大大的降低，会越来越适合这种模式。

• 老传统模式比适合大型项目，可以灵活的动态生成SQL，方便调整SQL，也有痛痛快快，洋洋洒洒的写SQL的感觉。

---

参考

springboot(六)-如何优雅的使用mybatis