spring boot mybatis 整合教程

本项目使用的环境：

• 开发工具：Intellij IDEA 2017.1.3
• springboot: 1.5.6
• jdk：1.8.0_161
• maven:3.3.9

额外功能

• PageHelper 分页插件
• mybatis generator 自动生成代码插件

步骤：

1. 创建一个springboot项目：

2. 创建项目的文件结构以及jdk的版本

3. 选择项目所需要的依赖

然后点击finish

4. 看一下文件的结构：

5. 查看一下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>
 
     <groupId>com.winter</groupId>
     <artifactId>springboot-mybatis-demo</artifactId>
     <version>0.0.1-SNAPSHOT</version>
     <packaging>jar</packaging>
 
     <name>springboot-mybatis-demo</name>
     <description>Demo project for Spring Boot</description>
 
     <parent>
         <groupId>org.springframework.boot</groupId>
         <artifactId>spring-boot-starter-parent</artifactId>
         <version>1.5.6.RELEASE</version>
         <relativePath/> <!-- lookup parent from repository -->
     </parent>
 
     <properties>
         <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
         <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
         <java.version>1.7</java.version>
     </properties>
 
     <dependencies>
         <dependency>
             <groupId>org.mybatis.spring.boot</groupId>
             <artifactId>mybatis-spring-boot-starter</artifactId>
             <version>1.3.0</version>
         </dependency>
         <dependency>
             <groupId>org.springframework.boot</groupId>
             <artifactId>spring-boot-starter-thymeleaf</artifactId>
         </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>mysql</groupId>
             <artifactId>mysql-connector-java</artifactId>
             <version>5.1.35</version>
         </dependency>
 
         <dependency>
             <groupId>com.fasterxml.jackson.core</groupId>
             <artifactId>jackson-core</artifactId>
         </dependency>
         <dependency>
             <groupId>com.fasterxml.jackson.core</groupId>
             <artifactId>jackson-databind</artifactId>
         </dependency>
         <dependency>
             <groupId>com.fasterxml.jackson.datatype</groupId>
             <artifactId>jackson-datatype-joda</artifactId>
         </dependency>
         <dependency>
             <groupId>com.fasterxml.jackson.module</groupId>
             <artifactId>jackson-module-parameter-names</artifactId>
         </dependency>
         <!-- 分页插件 -->
         <dependency>
             <groupId>com.github.pagehelper</groupId>
             <artifactId>pagehelper-spring-boot-starter</artifactId>
             <version>1.1.2</version>
         </dependency>
         <!-- alibaba的druid数据库连接池 -->
         <dependency>
             <groupId>com.alibaba</groupId>
             <artifactId>druid-spring-boot-starter</artifactId>
             <version>1.1.0</version>
         </dependency>
     </dependencies>
 
     <build>
         <plugins>
             <plugin>
                 <groupId>org.springframework.boot</groupId>
                 <artifactId>spring-boot-maven-plugin</artifactId>
             </plugin>
             <!-- mybatis generator 自动生成代码插件 -->
             <plugin>
                 <groupId>org.mybatis.generator</groupId>
                 <artifactId>mybatis-generator-maven-plugin</artifactId>
                 <version>1.3.2</version>
                 <configuration>
                     <configurationFile>${basedir}/src/main/resources/generator/generatorConfig.xml</configurationFile>
                     <overwrite>true</overwrite>
                     <verbose>true</verbose>
                 </configuration>
             </plugin>
         </plugins>
     </build>
 
 </project>

6. 项目不使用application.properties文件 而使用更加简洁的application.yml文件：

将原有的resource文件夹下的application.properties文件删除，创建一个新的application.yml配置文件，

文件的内容如下：

 server:
   port: 8080
 
 spring:
     datasource:
         name: test
         url: jdbc:mysql://127.0.0.1:3306/depot
         username: root
         password: root
         # 使用druid数据源
         type: com.alibaba.druid.pool.DruidDataSource
         driver-class-name: com.mysql.jdbc.Driver
         filters: stat
         maxActive: 20
         initialSize: 1
         maxWait: 60000
         minIdle: 1
         timeBetweenEvictionRunsMillis: 60000
         minEvictableIdleTimeMillis: 300000
         validationQuery: select 'x'
         testWhileIdle: true
         testOnBorrow: false
         testOnReturn: false
         poolPreparedStatements: true
         maxOpenPreparedStatements: 20
 
 ## 该配置节点为独立的节点，有很多同学容易将这个配置放在spring的节点下，导致配置无法被识别
 mybatis:
   mapper-locations: classpath:mapping/*.xml  #注意：一定要对应mapper映射xml文件的所在路径
   type-aliases-package: com.winter.model  # 注意：对应实体类的路径
 
 #pagehelper分页插件
 pagehelper:
     helperDialect: mysql
     reasonable: true
     supportMethodsArguments: true
     params: count=countSql

7. 创建数据库：

 CREATE DATABASE mytest;
 
 CREATE TABLE t_user(
   user_id INT NOT NULL PRIMARY KEY AUTO_INCREMENT,
   user_name VARCHAR(255) NOT NULL ,
   password VARCHAR(255) NOT NULL ,
   phone VARCHAR(255) NOT NULL
 ) ENGINE=INNODB AUTO_INCREMENT=1000 DEFAULT CHARSET=utf8;

8. 使用mybatis generator 自动生成代码：

• 配置pom.xml中generator 插件所对应的配置文件 ${basedir}/src/main/resources/generator/generatorConfig.xml

 <?xml version="1.0" encoding="UTF-8"?>
 <!DOCTYPE generatorConfiguration
         PUBLIC "-//mybatis.org//DTD MyBatis Generator Configuration 1.0//EN"
         "http://mybatis.org/dtd/mybatis-generator-config_1_0.dtd">
 <generatorConfiguration>
     <!-- 数据库驱动:选择你的本地硬盘上面的数据库驱动包-->
     <classPathEntry  location="E:\developer\mybatis-generator-core-1.3.2\lib\mysql-connector-java-5.1.25-bin.jar"/>
     <context id="DB2Tables"  targetRuntime="MyBatis3">
         <commentGenerator>
             <property name="suppressDate" value="true"/>
             <!-- 是否去除自动生成的注释 true：是 ： false:否 -->
             <property name="suppressAllComments" value="true"/>
         </commentGenerator>
         <!--数据库链接URL，用户名、密码 -->
         <jdbcConnection driverClass="com.mysql.jdbc.Driver" connectionURL="jdbc:mysql://127.0.0.1/mytest" userId="root" password="root">
         </jdbcConnection>
         <javaTypeResolver>
             <property name="forceBigDecimals" value="false"/>
         </javaTypeResolver>
         <!-- 生成模型的包名和位置-->
         <javaModelGenerator targetPackage="com.winter.model" targetProject="src/main/java">
             <property name="enableSubPackages" value="true"/>
             <property name="trimStrings" value="true"/>
         </javaModelGenerator>
         <!-- 生成映射文件的包名和位置-->
         <sqlMapGenerator targetPackage="mapping" targetProject="src/main/resources">
             <property name="enableSubPackages" value="true"/>
         </sqlMapGenerator>
         <!-- 生成DAO的包名和位置-->
         <javaClientGenerator type="XMLMAPPER" targetPackage="com.winter.mapper" targetProject="src/main/java">
             <property name="enableSubPackages" value="true"/>
         </javaClientGenerator>
         <!-- 要生成的表 tableName是数据库中的表名或视图名 domainObjectName是实体类名-->
         <table tableName="t_user" domainObjectName="User" enableCountByExample="false" enableUpdateByExample="false" enableDeleteByExample="false" enableSelectByExample="false" selectByExampleQueryId="false"></table>
     </context>
 </generatorConfiguration>

• 点击run-Edit Configurations

• 添加配置

• 运行

注意！！！同一张表一定不要运行多次，因为mapper的映射文件中会生成多次的代码，导致报错，切记

最后生成的文件以及结构：

9. 生成的文件

UserMapper.java

 package com.winter.mapper;
 
 import com.winter.model.User;
 
 public interface UserMapper {
     int deleteByPrimaryKey(Integer userId);
 
     int insert(User record);
 
     int insertSelective(User record);
 
     User selectByPrimaryKey(Integer userId);
 
     int updateByPrimaryKeySelective(User record);
 
     int updateByPrimaryKey(User record);
     //这个方式我自己加的
     List<User> selectAllUser();
 }

User.java

 package com.winter.model;
 
 public class User {
     private Integer userId;
 
     private String userName;
 
     private String password;
 
     private String phone;
 
     public Integer getUserId() {
         return userId;
     }
 
     public void setUserId(Integer userId) {
         this.userId = userId;
     }
 
     public String getUserName() {
         return userName;
     }
 
     public void setUserName(String userName) {
         this.userName = userName == null ? null : userName.trim();
     }
 
     public String getPassword() {
         return password;
     }
 
     public void setPassword(String password) {
         this.password = password == null ? null : password.trim();
     }
 
     public String getPhone() {
         return phone;
     }
 
     public void setPhone(String phone) {
         this.phone = phone == null ? null : phone.trim();
     }
 }

对于sql语句这种黄色的背景，真心是看不下去了（解决方案）：

**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.winter.mapper.UserMapper" >
   <resultMap id="BaseResultMap" type="com.winter.model.User" >
     <id column="user_id" property="userId" jdbcType="INTEGER" />
     <result column="user_name" property="userName" jdbcType="VARCHAR" />
     <result column="password" property="password" jdbcType="VARCHAR" />
     <result column="phone" property="phone" jdbcType="VARCHAR" />
   </resultMap>
   <sql id="Base_Column_List" >
     user_id, user_name, password, phone
   </sql>
   <select id="selectByPrimaryKey" resultMap="BaseResultMap" parameterType="java.lang.Integer" >
     select
     <include refid="Base_Column_List" />
     from t_user
     where user_id = #{userId,jdbcType=INTEGER}
   </select>
   <!-- 这个方法是我自己加的 -->
   <select id="selectAllUser" resultMap="BaseResultMap">
     select
     <include refid="Base_Column_List" />
     from t_user
   </select>
   <delete id="deleteByPrimaryKey" parameterType="java.lang.Integer" >
     delete from t_user
     where user_id = #{userId,jdbcType=INTEGER}
   </delete>
   <insert id="insert" parameterType="com.winter.model.User" >
     insert into t_user (user_id, user_name, password,
       phone)
     values (#{userId,jdbcType=INTEGER}, #{userName,jdbcType=VARCHAR}, #{password,jdbcType=VARCHAR},
       #{phone,jdbcType=VARCHAR})
   </insert>
   <insert id="insertSelective" parameterType="com.winter.model.User" >
     insert into t_user
     <trim prefix="(" suffix=")" suffixOverrides="," >
       <if test="userId != null" >
         user_id,
       </if>
       <if test="userName != null" >
         user_name,
       </if>
       <if test="password != null" >
         password,
       </if>
       <if test="phone != null" >
         phone,
       </if>
     </trim>
     <trim prefix="values (" suffix=")" suffixOverrides="," >
       <if test="userId != null" >
         #{userId,jdbcType=INTEGER},
       </if>
       <if test="userName != null" >
         #{userName,jdbcType=VARCHAR},
       </if>
       <if test="password != null" >
         #{password,jdbcType=VARCHAR},
       </if>
       <if test="phone != null" >
         #{phone,jdbcType=VARCHAR},
       </if>
     </trim>
   </insert>
   <update id="updateByPrimaryKeySelective" parameterType="com.winter.model.User" >
     update t_user
     <set >
       <if test="userName != null" >
         user_name = #{userName,jdbcType=VARCHAR},
       </if>
       <if test="password != null" >
         password = #{password,jdbcType=VARCHAR},
       </if>
       <if test="phone != null" >
         phone = #{phone,jdbcType=VARCHAR},
       </if>
     </set>
     where user_id = #{userId,jdbcType=INTEGER}
   </update>
   <update id="updateByPrimaryKey" parameterType="com.winter.model.User" >
     update t_user
     set user_name = #{userName,jdbcType=VARCHAR},
       password = #{password,jdbcType=VARCHAR},
       phone = #{phone,jdbcType=VARCHAR}
     where user_id = #{userId,jdbcType=INTEGER}
   </update>
 </mapper>

10. 打开类SpringbootMybatisDemoApplication.java，这个是springboot的启动类。我们需要添加点东西：

 package com.winter;
 
 import org.mybatis.spring.annotation.MapperScan;
 import org.springframework.boot.SpringApplication;
 import org.springframework.boot.autoconfigure.SpringBootApplication;
 
 @SpringBootApplication
 @MapperScan("com.winter.mapper")//将项目中对应的mapper类的路径加进来就可以了
 public class SpringbootMybatisDemoApplication {
 
     public static void main(String[] args) {
         SpringApplication.run(SpringbootMybatisDemoApplication.class, args);
     }
 }

注意：@MapperScan("com.winter.mapper")这个注解非常的关键，这个对应了项目中mapper（dao）所对应的包路径，很多同学就是这里忘了加导致异常的

11. 到这里所有的搭建工作都完成了，接下来就是测试的工作，没使用junit4进行测试：

首先看一下完成之后的文件的结构：

现在controller，service层的代码都写好：

UserController.java

 package com.winter.Controller;
 
 import com.winter.model.User;
 import com.winter.service.UserService;
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.stereotype.Controller;
 import org.springframework.web.bind.annotation.PathVariable;
 import org.springframework.web.bind.annotation.RequestMapping;
 import org.springframework.web.bind.annotation.ResponseBody;
 
 /**
  * Created by Administrator on 2017/8/16.
  */
 @Controller
 @RequestMapping(value = "/user")
 public class UserController {
 
     @Autowired
     private UserService userService;
 
     @ResponseBody
     @RequestMapping(value = "/add", produces = {"application/json;charset=UTF-8"})
     public int addUser(User user){
         return userService.addUser(user);
     }
 
     @ResponseBody
     @RequestMapping(value = "/all/{pageNum}/{pageSize}", produces = {"application/json;charset=UTF-8"})
     public Object findAllUser(@PathVariable("pageNum") int pageNum, @PathVariable("pageSize") int pageSize){
 
         return userService.findAllUser(pageNum,pageSize);
     }
 }

UserService.java

 package com.winter.service;
 
 import com.winter.model.User;
 
 import java.util.List;
 
 /**
  * Created by Administrator on 2017/8/16.
  */
 public interface UserService {
 
     int addUser(User user);
 
     List<User> findAllUser(int pageNum, int pageSize);
 }

UserServiceImpl.java

 package com.winter.service.impl;
 
 import com.github.pagehelper.PageHelper;
 import com.winter.mapper.UserMapper;
 import com.winter.model.User;
 import com.winter.service.UserService;
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.stereotype.Service;
 
 import java.util.List;
 
 /**
  * Created by Administrator on 2017/8/16.
  */
 @Service(value = "userService")
 public class UserServiceImpl implements UserService {
 
     @Autowired
     private UserMapper userMapper;//这里会报错，但是并不会影响
 
     @Override
     public int addUser(User user) {
 
         return userMapper.insertSelective(user);
     }
 
     /*
     * 这个方法中用到了我们开头配置依赖的分页插件pagehelper
     * 很简单，只需要在service层传入参数，然后将参数传递给一个插件的一个静态方法即可；
     * pageNum 开始页数
     * pageSize 每页显示的数据条数
     * */
     @Override
     public List<User> findAllUser(int pageNum, int pageSize) {
         //将参数传给这个方法就可以实现物理分页了，非常简单。
         PageHelper.startPage(pageNum, pageSize);
         return userMapper.selectAllUser();
     }
 }

如果强迫症看不下去那个报错：（解决方法）

测试我使用了idea一个很用心的功能。

可以发http请求的插件：

点击左侧的运行按钮就可以发送请求了；

如果返回值正确 说明你已经搭建成功了！！

ps：如果出现mapper注入不了的情况，请检查版本，当前博客的搭建方法只适合1.5.*版本的。