springboot整合mybatis

一.首先新建工程

二.一定要引入mybatis-spring-boot-starter

<dependency>
			<groupId>org.mybatis.spring.boot</groupId>
			<artifactId>mybatis-spring-boot-starter</artifactId>
			<version>2.0.1</version>
		</dependency>

依赖关系：

引入数据源

<!--引入druid数据源-->
<!-- https://mvnrepository.com/artifact/com.alibaba/druid -->
<dependency>
   <groupId>com.alibaba</groupId>
   <artifactId>druid</artifactId>
   <version>1.1.8</version>
</dependenc>

引入log4j的依赖：

<!-- https://mvnrepository.com/artifact/log4j/log4j -->
   	<dependency>
   		<groupId>log4j</groupId>
   		<artifactId>log4j</artifactId>
   		<version>1.2.17</version>
   	</dependency>

配置文件application.yml:

spring:
  datasource:
#   数据源基本配置
    username: root
    password: 123
    driver-class-name: com.mysql.jdbc.Driver
    url: jdbc:mysql://localhost:3306/mybatis
    type: com.alibaba.druid.pool.DruidDataSource
#   数据源其他配置
    initialSize: 5
    minIdle: 5
    maxActive: 20
    maxWait: 60000
    timeBetweenEvictionRunsMillis: 60000
    minEvictableIdleTimeMillis: 300000
    validationQuery: SELECT 1 FROM DUAL
    testWhileIdle: true
    testOnBorrow: false
    testOnReturn: false
    poolPreparedStatements: true
#   配置监控统计拦截的filters，去掉后监控界面sql无法统计，'wall'用于防火墙
    filters: stat,wall,log4j
    maxPoolPreparedStatementPerConnectionSize: 20
    useGlobalDataSourceStat: true
    connectionProperties: druid.stat.mergeSql=true;druid.stat.slowSqlMillis=500

配置类：

package com.example.springbooy06datamybatis.config;

import com.alibaba.druid.pool.DruidDataSource;
import com.alibaba.druid.support.http.StatViewServlet;
import com.alibaba.druid.support.http.WebStatFilter;
import org.springframework.boot.context.properties.ConfigurationProperties;
import org.springframework.boot.web.servlet.FilterRegistrationBean;
import org.springframework.boot.web.servlet.ServletRegistrationBean;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;

import javax.sql.DataSource;
import java.util.Arrays;
import java.util.HashMap;
import java.util.Map;

@Configuration
public class DruidConfig {

    @ConfigurationProperties(prefix = "spring.datasource")
    @Bean
    public DataSource druid(){
        return  new DruidDataSource();
    }

    //配置Druid的监控
    //1、配置一个管理后台的Servlet
    @Bean
    public ServletRegistrationBean statViewServlet(){
        ServletRegistrationBean bean = new ServletRegistrationBean(new StatViewServlet(), "/druid/*");
        Map<String,String> initParams = new HashMap<>();

        initParams.put("loginUsername","admin");
        initParams.put("loginPassword","123456");
        initParams.put("allow","");//默认就是允许所有访问
        initParams.put("deny","192.168.15.21");

        bean.setInitParameters(initParams);
        return bean;
    }


    //2、配置一个web监控的filter
    @Bean
    public FilterRegistrationBean webStatFilter(){
        FilterRegistrationBean bean = new FilterRegistrationBean();
        bean.setFilter(new WebStatFilter());

        Map<String,String> initParams = new HashMap<>();
        initParams.put("exclusions","*.js,*.css,/druid/*");

        bean.setInitParameters(initParams);

        bean.setUrlPatterns(Arrays.asList("/*"));

        return  bean;
    }
}

启动访问：

3.给数据库建表

将sql文件放在resource下的sql文件夹下：

在配置文件中加入schema:

 schema: 
     - classpath:sql/department.sql
     - classpath:sql/employee.sql

4.加入实体类

省略get set ，构造方法

public class Department {
    private Integer id;
    private String departmentName;
}

public class Employee {
    private Integer id;
    private String lastName;
    private Integer gender;
    private String email;
    private Integer d_id;
    }

5.注解映射

编写mapper文件：

package com.example.springbooy06datamybatis.mapper;

import com.example.springbooy06datamybatis.bean.Department;
import org.apache.ibatis.annotations.*;

/**
 * @author shkstart
 * @date 2019/5/22- 11:49
 */
//指定这是一个操作数据库的mapper
@Mapper
public interface DepartmentMapper {
    @Select("select * from department where id = #{id} ")
    public Department getDeptById(Integer id);

    @Delete("delete from department where id = #{id}")
    public int deleteDeptById(Integer id);
    
	 //插入自动生成的主键
    @Options(useGeneratedKeys =true,keyProperty = "id")
    @Insert("insert into department(departmentName) values (#{departmentName})")
    public int insertDept(Department department);

    @Update("update  department set departmentName = #{departmentName} where id = #{id}")
    public int updateDept(Department department);
}

controller层：

package com.example.springbooy06datamybatis.controller;

import com.example.springbooy06datamybatis.bean.Department;
import com.example.springbooy06datamybatis.mapper.DepartmentMapper;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RestController;

/**
 * @author shkstart
 * @date 2019/5/22- 11:56
 */
@RestController
public class DeptController {
    @Autowired
    DepartmentMapper departMentMapper;


    @GetMapping("/dept/{id}")
    public Department getDeptById(@PathVariable("id") Integer id){
        return departMentMapper.getDeptById(id);
    }

    @GetMapping("/dept")
    public Department insertDept(Department department){
        departMentMapper.insertDept(department);
        return department;
    }


}

测试：http://localhost:8080/dept/1

要实现驼峰命名规则：
需要自定义mybatis配置类：
给容器中添加一个ConfigurationCustomizer

package com.example.springbooy06datamybatis.config;

import org.apache.ibatis.session.Configuration;
import org.mybatis.spring.boot.autoconfigure.ConfigurationCustomizer;
import org.springframework.context.annotation.Bean;

/**
 * MyBatis的配置类,自定义驼峰命名规则
 */
@org.springframework.context.annotation.Configuration
public class MyBatisConfig {
    @Bean
    public ConfigurationCustomizer configurationCustomizer(){
        return new ConfigurationCustomizer() {
            @Override
            public void customize(Configuration configuration) {
                configuration.setMapUnderscoreToCamelCase(true);
            }
        };
    }
}

若是mapper文件很多，可以在Springbooy06DataMybatisApplication中加入注解：

@MapperScan(value = "com.example.springbooy06datamybatis.mapper")