MyBatis

新建工程，选好资源

实体类

不需要添加各种注解，直接把对应字段生成get与set方法即可

package com.bruce.SpringBootMVC04Mybatis.entity;

import java.io.Serializable;

public class Account implements Serializable {

private static final long serialVersionUID = -8149090919935604147L;

private Integer id;

private String loginName;

private String password;

private String nickName;

private Integer age;

private String location;

private String role;

public Integer getId() {

return id;

}

public void setId(Integer id) {

this.id = id;

}

public String getLoginName() {

return loginName;

}

public void setLoginName(String loginName) {

this.loginName = loginName;

}

public String getPassword() {

return password;

}

public void setPassword(String password) {

this.password = password;

}

public String getNickName() {

return nickName;

}

public void setNickName(String nickName) {

this.nickName = nickName;

}

public Integer getAge() {

return age;

}

public void setAge(Integer age) {

this.age = age;

}

public String getLocation() {

return location;

}

public void setLocation(String location) {

this.location = location;

}

public String getRole() {

return role;

}

public void setRole(String role) {

this.role = role;

}

public Account() {

super();

}

}

Dao层接口定义

在接口上要加上@Mapper注解

package com.bruce.SpringBootMVC04Mybatis.mapper;

import java.util.List;

import org.apache.ibatis.annotations.Mapper;

import com.bruce.SpringBootMVC04Mybatis.entity.Account;

@Mapper

public interface AccountMapper {

List<Account> findAll();

}

注：如果这里不想每个接口都加注解的话，可以在SpringBoot启动类上面加上注解@MapperScan("com.bruce.SpringBootMVC04Mybatis.mapper")，括号中对应Dao层的路径，这样每个Dao接口上面就不用加@Mapper注解了

Service层实现定义

在类名上加上@Service注解，在注入的Dao接口对象上加上@Autowired注解

package com.bruce.SpringBootMVC04Mybatis.service;

import java.util.List;

import org.springframework.beans.factory.annotation.Autowired;

import org.springframework.stereotype.Service;

import com.bruce.SpringBootMVC04Mybatis.entity.Account;

import com.bruce.SpringBootMVC04Mybatis.mapper.AccountMapper;

@Service

public class AccountService {

@Autowired

AccountMapper accountMapper;

public List<Account> findAll() {

return accountMapper.findAll();

}

}

Controller层定义

在Controller类上加上@RestController注解，在注入的Service对象加上注解@Autowired
对应的Controller方法上加上@RequestMapping注解来配置请求路径

package com.bruce.SpringBootMVC04Mybatis.controller;

import java.util.List;

import org.springframework.beans.factory.annotation.Autowired;

import org.springframework.web.bind.annotation.RequestMapping;

import org.springframework.web.bind.annotation.ResponseBody;

import org.springframework.web.bind.annotation.RestController;

import com.bruce.SpringBootMVC04Mybatis.entity.Account;

import com.bruce.SpringBootMVC04Mybatis.service.AccountService;

@RestController

@RequestMapping("/account")

public class AccountController {

@Autowired

AccountService accountService;

@RequestMapping("/list")

@ResponseBody

public Object list() {

List<Account> accounts = accountService.findAll();

return accounts;

}

}

配置MyBatis的xml配置文件

配置文件中mapper节点的namespace属性对应Dao层接口路径，resultMap节点的type属性对应实体类对象路径

<?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.bruce.SpringBootMVC04Mybatis.mapper.AccountMapper">

<resultMap id="BaseResultMap"

type="com.bruce.SpringBootMVC04Mybatis.entity.Account">

<id column="id" jdbcType="INTEGER" property="id" />

<result column="login_name" jdbcType="VARCHAR"

property="loginName" />

<result column="password" jdbcType="VARCHAR"

property="password" />

<result column="nick_name" jdbcType="VARCHAR"

property="nickName" />

<result column="age" jdbcType="INTEGER" property="age" />

<result column="location" jdbcType="VARCHAR"

property="location" />

<result column="role" jdbcType="VARCHAR" property="role" />

</resultMap>

<select id="findAll" resultMap="BaseResultMap">

select * from account

</select>

</mapper>

在application.properties文件中进行相关配置

spring.datasource.url=jdbc:mysql://localhost:3306/ssm?characterEncoding=utf8&useSSL=false&serverTimezone=UTC

spring.datasource.username=root

spring.datasource.password=root

server.servlet.context-path = /SpringBoot

mybatis.type-aliases-package=com.bruce.SpringBootMVC04Mybatis.mapper (对应dao层接口的路径)

mybatis.mapper-locations=classpath:mybatis/mapper/*.xml （对应MyBatis的xml配置文件的路径）

一些基础代码，可以通过代码生成器来完成，这样基础的代码就不用自己再去手动写了

mybatis-generator-gui 使用说明与下载地址：https://github.com/zouzg/mybatis-generator-gui

生成的代码中Dao层的基类MyBatisBaseDao包含了所有的基本方法

/**

* DAO公共基类，由MybatisGenerator自动生成请勿修改

* @param <Model> The Model Class 这里是泛型不是Model类

* @param <PK> The Primary Key Class 如果是无主键，则可以用Model来跳过，如果是多主键则是Key类

* @param <E> The Example Class

*/

public interface MyBatisBaseDao<Model, PK extends Serializable, E> {

    long countByExample(E example);

    int deleteByExample(E example);

    int deleteByPrimaryKey(PK id);

    int insert(Model record);

    int insertSelective(Model record);

    List<Model> selectByExample(E example);

    Model selectByPrimaryKey(PK id);

    int updateByExampleSelective(@Param("record") Model record, @Param("example") E example);

    int updateByExample(@Param("record") Model record, @Param("example") E example);

    int updateByPrimaryKeySelective(Model record);

    int updateByPrimaryKey(Model record);

}

每个实体类对应Dao层的mapper都有一个对应的实体类的Example，Service层可以调用mapper的基本增删改查方法，当需要查询列表数据的时候，可以调用selectByExample方法

@Service

public class MenuService {

@Autowired

MenuMapper menuMapper;

public List<Menu> findAll(String name) {

MenuExample menuExample = new MenuExample();

menuExample.createCriteria().andNameEqualTo(name);

return menuMapper.selectByExample(menuExample);

}

public Menu findById(Integer id) {

return menuMapper.selectByPrimaryKey(id);

}

}

通过pagehelper进行分页操作

pagehelper 使用说明文档 https://github.com/pagehelper/pagehelper-spring-boot

如果你使用 Maven，你只需要在 pom.xml 中添加下面的依赖：

<!--分页插件 https://mvnrepository.com/artifact/com.github.pagehelper/pagehelper-spring-boot-starter -->

<dependency>

<groupId>com.github.pagehelper</groupId>

<artifactId>pagehelper-spring-boot-starter</artifactId>

<version>1.2.13</version>

</dependency>

需要加入分页的方法，可以如下进行修改

@Service

public class MenuService {

@Autowired

MenuMapper menuMapper;

public List<Menu> findAll(String name) {

MenuExample menuExample = new MenuExample();

menuExample.createCriteria().andNameEqualTo(name);

return menuMapper.selectByExample(menuExample);

}

public Menu findById(Integer id) {

return menuMapper.selectByPrimaryKey(id);

}

public List<Menu> findByPage(Integer pageNum, Integer pageSize) {

     PageHelper.startPage(pageNum, pageSize);

     MenuExample menuExample=new MenuExample();

     return menuMapper.selectByExample(menuExample);

}

}