springboot Mybatis 整合

转：https://blog.csdn.net/Winter_chen001/article/details/80010967

环境/版本一览：

• 开发工具：Intellij IDEA 2017.1.3
• springboot: 2.0.1.RELEASE
• jdk：1.8.0_40
• maven:3.3.9
• alibaba Druid 数据库连接池：1.1.9

额外功能：

• PageHelper 分页插件
• mybatis generator 自动生成代码插件（本次搭建就不讲解了，请参照Spring boot Mybatis 整合（完整版））

开始搭建：

创建项目：

添加基础的依赖：

依赖文件：

按照pom文件补齐需要的依赖：

<?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.winterchen</groupId>
    <artifactId>springboot2-mybatis-demo</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <packaging>jar</packaging>

    <name>springboot2-mybatis-demo</name>
    <description>Demo project for Spring Boot</description>

    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.0.1.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>1.8</java.version>
    </properties>

    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <dependency>
            <groupId>org.mybatis.spring.boot</groupId>
            <artifactId>mybatis-spring-boot-starter</artifactId>
            <version>1.3.2</version>
        </dependency>
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <scope>runtime</scope>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
        <dependency>
            <groupId>org.apache.commons</groupId>
            <artifactId>commons-lang3</artifactId>
            <version>3.4</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>1.2.5</version>
        </dependency>
        <!-- alibaba的druid数据库连接池 -->
        <dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>druid-spring-boot-starter</artifactId>
            <version>1.1.9</version>
        </dependency>
    </dependencies>

    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
        </plugins>
    </build>


</project>

项目结构：

项目启动类：

package com.winterchen;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;

@SpringBootApplication
@MapperScan("com.winterchen.dao")
public class Springboot2MybatisDemoApplication {

    public static void main(String[] args) {
        SpringApplication.run(Springboot2MybatisDemoApplication.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

配置：

可以根据个人使用习惯选择使用properties或者yml文件，本项目使用的是yml配置文件，所以把原本application.properties删除，创建一个application.yml文件

在resource文件夹下创建application.yml

server:
  port: 8080


spring:
    datasource:
        name: mysql_test
        type: com.alibaba.druid.pool.DruidDataSource
        #druid相关配置
        druid:
          #监控统计拦截的filters
          filters: stat
          driver-class-name: com.mysql.jdbc.Driver
          #基本属性
          url: jdbc:mysql://127.0.0.1:3306/mytest?useUnicode=true&characterEncoding=UTF-8&allowMultiQueries=true
          username: root
          password: root
          #配置初始化大小/最小/最大
          initial-size: 1
          min-idle: 1
          max-active: 20
          #获取连接等待超时时间
          max-wait: 60000
          #间隔多久进行一次检测，检测需要关闭的空闲连接
          time-between-eviction-runs-millis: 60000
          #一个连接在池中最小生存的时间
          min-evictable-idle-time-millis: 300000
          validation-query: SELECT 'x'
          test-while-idle: true
          test-on-borrow: false
          test-on-return: false
          #打开PSCache，并指定每个连接上PSCache的大小。oracle设为true，mysql设为false。分库分表较多推荐设置为false
          pool-prepared-statements: false
          max-pool-prepared-statement-per-connection-size: 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:mapper/*.xml  #注意：一定要对应mapper映射xml文件的所在路径
  type-aliases-package: com.winterchen.model  # 注意：对应实体类的路径

#pagehelper
pagehelper:
    helperDialect: mysql
    reasonable: true
    supportMethodsArguments: true
    params: count=countSql
    returnPageInfo: check

创建包：

model，dao，mapper

创建数据库和数据表

CREATE DATABASE mytest;

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

创建实体类：UserDomain.java

package com.winterchen.model;

public class UserDomain {
    private Integer userId;

    private String userName;

    private String password;

    private String phone;

    // get,set方法略...
}

创建dao：

UserDao.java

package com.winterchen.dao;



import com.winterchen.model.UserDomain;
import org.apache.ibatis.annotations.Mapper;

import java.util.List;

public interface UserDao {


    int insert(UserDomain record);



    List<UserDomain> selectUsers();
}

创建mybatis映射文件： 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.winterchen.dao.UserDao" >
  <sql id="BASE_TABLE">
    t_user
  </sql>

  <sql id="BASE_COLUMN">
    userId,userName,password,phone
  </sql>

  <insert id="insert" parameterType="com.winterchen.model.UserDomain">
    INSERT INTO
      <include refid="BASE_TABLE"/>
    <trim prefix="(" suffix=")" suffixOverrides=",">
      userName,password,
      <if test="phone != null">
        phone,
      </if>
    </trim>
    <trim prefix="VALUES(" suffix=")" suffixOverrides=",">
      #{userName, jdbcType=VARCHAR},#{password, jdbcType=VARCHAR},
      <if test="phone != null">
        #{phone, jdbcType=VARCHAR},
      </if>
    </trim>
  </insert>

  <select id="selectUsers" resultType="com.winterchen.model.UserDomain">
      SELECT
        <include refid="BASE_COLUMN"/>
      FROM
        <include refid="BASE_TABLE"/>
  </select>


</mapper>

注意：<mapper namespace="com.winterchen.dao.UserDao" > 一定要对应自己dao所在的包路径

创建剩余的controller，service包和文件

UserService.java

package com.winterchen.service.user;

import com.github.pagehelper.PageInfo;
import com.winterchen.model.UserDomain;

import java.util.List;

/**
 * Created by Administrator on 2018/4/19.
 */
public interface UserService {

    int addUser(UserDomain user);

    PageInfo<UserDomain> findAllUser(int pageNum, int pageSize);
}

UserServiceImpl

package com.winterchen.service.user.impl;

import com.github.pagehelper.PageHelper;
import com.github.pagehelper.PageInfo;
import com.winterchen.dao.UserDao;
import com.winterchen.model.UserDomain;
import com.winterchen.service.user.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 UserDao userDao;//这里会报错，但是并不会影响

    @Override
    public int addUser(UserDomain user) {

        return userDao.insert(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 PageInfo<UserDomain> 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);
        List<UserDomain> userDomains = userDao.selectUsers();
        PageInfo result = new PageInfo(userDomains);
        return result;
    }
}

UserController.java

package com.winterchen.controller;

import com.github.pagehelper.PageHelper;
import com.winterchen.model.UserDomain;
import com.winterchen.service.user.UserService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.*;

/**
 * Created by Administrator on 2017/8/16.
 */
@Controller
@RequestMapping(value = "/user")
public class UserController {

    @Autowired
    private UserService userService;

    @ResponseBody
    @PostMapping("/add")
    public int addUser(UserDomain user){
        return userService.addUser(user);
    }

    @ResponseBody
    @GetMapping("/all")
    public Object findAllUser(
            @RequestParam(name = "pageNum", required = false, defaultValue = "1")
                    int pageNum,
            @RequestParam(name = "pageSize", required = false, defaultValue = "10")
                    int pageSize){
        return userService.findAllUser(pageNum,pageSize);
    }
}

项目最终的结构

到这里如果项目就成功搭建完成了，如果还是报错的话，请仔细看看配置，后面会给出源码地址，程序员就是要不断和bug进行斗争，加油。

测试

启动项目

这样就表示启动成功了

然后，开始测试吧，博主使用的是postMan，一个进行http请求的测试工具

添加数据

查询数据