之前搭建了@Select标签来做SringBoot+Mybatis的集成。这次使用@SelectProvider标签的方式搭建一次。

一、搭建SpringBoot的项目

https://start.spring.io/自己配置SpringBoot的项目，点击“Generate Project”按钮就可以下载下来一个配置好的SpringBoot项目。

二、项目结构

三、项目代码

demo代码实现的是对表数据的一个简单查询。

1、pom中的mave配置

org.springframework.boot

spring-boot-starter-jdbc

org.springframework.boot

spring-boot-starter-web

org.mybatis.spring.boot

mybatis-spring-boot-starter

1.3.2

mysql

mysql-connector-java

runtime

org.springframework.boot

spring-boot-starter-test

test

2、Controller

package com.example.demo.Controller;

import com.example.demo.Service.TeacherService;

import com.example.demo.entity.Teacher;

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

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

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

@RestController

public class TeacherController {

@Autowired(required = false)

TeacherService userService;

@RequestMapping("selectUser")

public Teacher getUserOne(String id){

Teacher tea = new Teacher();

tea.setId(id);

Teacher teacher1 = userService.findTeacherById(tea);

return teacher1;

}

@RequestMapping("selectUserByName")

public Teacher getUserOne(String id,String name){

Teacher tea=new Teacher();

tea.setId(id);

tea.setName(name);

Teacher teacher=userService.findTeacherByName(tea);

return teacher;

}

}

3、Service

一个interface接口，一个Impl实现

package com.example.demo.Service;

import com.example.demo.entity.Teacher;

public interface TeacherService {

Teacher findTeacherById(Teacher user);

Teacher findTeacherByName(Teacher user);

}

接口实现：

package com.example.demo.ServiceImpl;

import com.example.demo.Mapper.TeacherMapper;

import com.example.demo.Service.TeacherService;

import com.example.demo.entity.Teacher;

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

import org.springframework.stereotype.Service;

import java.util.HashMap;

import java.util.Map;

@Service

public class TeacherServiceImpl implements TeacherService {

@Autowired(required = false)

TeacherMapper userMapper;

@Override

public Teacher findTeacherById(Teacher teacher) {

return userMapper.findUserById(teacher);

}

@Override

public Teacher findTeacherByName(Teacher teacher) {

Map maps=new HashMap<>();

maps.put("id",teacher.getId());

maps.put("name",teacher.getName());

return userMapper.findUserByName(maps);

}

}

4、Mapper代码

package com.example.demo.Mapper;

import com.example.demo.entity.Teacher;

import org.apache.ibatis.annotations.Mapper;

import org.apache.ibatis.annotations.SelectProvider;

import org.apache.ibatis.jdbc.SQL;

import java.util.Map;

/**

* The interface Teacher mapper.

*/

@Mapper

public interface TeacherMapper {

/**

* The constant returnSql.

*/

String returnSql="id,name";

/**

* Find user by id teacher.

*

* @param user the user

* @return the teacher

*/

@SelectProvider(type = UserDaoProvider.class, method = "findTeacherById")

Teacher findUserById(Teacher user);

/**

* Find user by name teacher.

*

* @param map the map

* @return the teacher

*/

@SelectProvider(type = UserDaoProvider.class, method = "findTeacherByName")

Teacher findUserByName(Map map);

/**

* The type User dao provider.

*/

class UserDaoProvider {

/**

* Find teacher by id string.

*

* @param teacher the teacher

* @return the string

*/

public String findTeacherById(Teacher teacher) {

String sql = "SELECT "+returnSql+" FROM Teacher";

if(teacher.getId()!=null){

sql += " where id = #{id}";

}

return sql;

}

/**

* Find teacher by name string.

*

* @param map the map

* @return the string

*/

public String findTeacherByName(Map map) {

String name = (String) map.get("name");

return new SQL() {

{

SELECT(returnSql);

FROM("Teacher");

WHERE("name="+ name);

}

}.toString();

}

}

}

在程序启动时，会扫描Mapper文件，所以需要在Mapper文件里添加@Mapper注解。

还可以在main文件中添加@MapperScan()注解：

package com.example.demo;

import org.mybatis.spring.annotation.MapperScan;

import org.springframework.boot.SpringApplication;

import org.springframework.boot.autoconfigure.SpringBootApplication;

@SpringBootApplication

@MapperScan("com.example.demo.Mapper")

public class DemoApplication {

public static void main(String[] args) {

SpringApplication.run(DemoApplication.class, args);

}

}

5、实体类

package com.example.demo.entity;

public class Teacher {

private String id;

private String name;

public String getId() { return id; }

public void setId(String id) { this.id = id; }

public String getName() { return name; }

public void setName(String name) { this.name = name; }

}