Springboot Mybatis 整合（完整版）

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正题
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

5.看一下文件的结构：

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: 8080spring:datasource:name: testurl: jdbc:mysql://127.0.0.1:3306/depotusername: rootpassword: root# 使用druid数据源type: com.alibaba.druid.pool.DruidDataSourcedriver-class-name: com.mysql.jdbc.Driverfilters: statmaxActive: 20initialSize: 1maxWait: 60000minIdle: 1timeBetweenEvictionRunsMillis: 60000minEvictableIdleTimeMillis: 300000validationQuery: select 'x'testWhileIdle: truetestOnBorrow: falsetestOnReturn: falsepoolPreparedStatements: truemaxOpenPreparedStatements: 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: mysqlreasonable: truesupportMethodsArguments: trueparams: 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 generatorConfigurationPUBLIC "-//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：

10. 生成的文件

UserMapper.javapackage 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_userwhere 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_userwhere 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_userset 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：

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 {@Autowiredprivate 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 {@Autowiredprivate UserMapper userMapper;//这里会报错，但是并不会影响@Overridepublic 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* */@Overridepublic 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！

如果出现mapper注入不了的情况，请检查版本.

转自：https://blog.csdn.net/winter_chen001/article/details/77249029