Spring boot Mybatis 整合 Spring boot Mybatis 整合（完整版）

LuisChen 2021-03-30 我要评论

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：

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2.创建项目的文件结构以及jdk的版本

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3.选择项目所需要的依赖

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然后点击finish

5.看一下文件的结构：

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6.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>

7.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

8.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;

9.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

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添加配置

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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

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最后生成的文件以及结构：

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10. 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）：

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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>

11.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

12.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：

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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）

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