在springboot环境下tk-mybatis的使用记录

Posted 2021-12-05 windpoplar

1. 新建springboot工程

访问https://start.spring.io/，新建一个springboot工程。

自动生成的工程主要的注意点如下：

1）pom.xml

<parent>

<groupId>org.springframework.boot</groupId>

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

<version>2.1.2.RELEASE</version>

<relativePath /> <!-- lookup parent from repository -->

</parent>

<dependency>

<groupId>org.springframework.boot</groupId>

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

</dependency>

<dependency>

<groupId>org.springframework.boot</groupId>

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

<scope>test</scope>

</dependency>

将Spring Boot应用打包为可执行的jar或war文件:

<build>

<plugins>

<plugin>

<groupId>org.springframework.boot</groupId>

<artifactId>spring-boot-maven-plugin</artifactId>

</plugin>

</plugins>

</build>

 

2. 使用tk-mybatis构建数据库访问示例

1）application.properties

resources目录下的application.properties文件配置如下：

spring.datasource.driver-class-name=com.mysql.jdbc.Driver

spring.datasource.url=jdbc:mysql://127.0.0.1:3306/mytest?useUnicode=true&characterEncoding=utf8&useSSL=false

spring.datasource.username=root

spring.datasource.password=123456

spring.datasource.max-idle=10

spring.datasource.max-wait=10000

spring.datasource.min-idle=5

spring.datasource.initial-size=5

logging.level.com.tkmybatislearning.demo=DEBUG

 

2）entity

新建entity实体类Country.java, 命名与数据库的表名country对应:

package com.tkmybatislearning.demo.entity;

import javax.persistence.Id;

public class Country {

    @Id

    private Integer id;

    private String  countryname;

    private String  countrycode;

public Integer getId() {

return id;

}

public void setId(Integer id) {

this.id = id;

}

public String getCountryname() {

return countryname;

}

public void setCountryname(String countryname) {

this.countryname = countryname;

}

public String getCountrycode() {

return countrycode;

}

public void setCountrycode(String countrycode) {

this.countrycode = countrycode;

}

}

 

3）mapper

新增mapper接口文件CountryMapper.java，继承tk的Mapper，可以自定义方法:

package com.tkmybatislearning.demo.mapper;

import org.apache.ibatis.annotations.Select;

import com.tkmybatislearning.demo.entity.Country;

import tk.mybatis.mapper.common.Mapper;

public interface CountryMapper extends Mapper<Country> {

    @Select("select * from country where countryname = #{countryname}")

    Country selectByCountryName(String countryname);

}

 

4）service

新增service服务文件CountryService.java，自动注入CountryMapper，可以使用tk自带的方法，对数据库表进行CRUD操作：

package com.tkmybatislearning.demo.service;

import java.util.List;

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

import org.springframework.stereotype.Service;

import com.tkmybatislearning.demo.entity.Country;

import com.tkmybatislearning.demo.mapper.CountryMapper;

@Service

public class CountryService {

@Autowired

private CountryMapper countryMapper;

public void testCountry() {

//从 MyBatis 或者 Spring 中获取 countryMapper，然后调用 selectAll 方法

List<Country> countries = countryMapper.selectAll();

//根据主键查询

Country country = countryMapper.selectByPrimaryKey(1);

//或者使用对象传参，适用于1个字段或者多个字段联合主键使用

Country query = new Country();

query.setId(1);

country = countryMapper.selectByPrimaryKey(query);

}

}

 

 

3. 新建应用启动程序

DemoApplication.java:

package com.tkmybatislearning.demo;

import org.springframework.boot.SpringApplication;

import org.springframework.boot.autoconfigure.SpringBootApplication;

import tk.mybatis.spring.annotation.MapperScan;

@SpringBootApplication

@MapperScan("com.tkmybatislearning.demo.mapper")

public class DemoApplication {

public static void main(String[] args) {

SpringApplication.run(DemoApplication.class, args);

}

}

 

4. 使用单元测试验证示例

新建DemoApplicationTests.java:

package com.tkmybatislearning.demo;

import org.junit.Test;

import org.junit.runner.RunWith;

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

import org.springframework.boot.test.context.SpringBootTest;

import org.springframework.test.context.junit4.SpringRunner;

import com.tkmybatislearning.demo.service.CountryService;

@RunWith(SpringRunner.class)

@SpringBootTest(classes = DemoApplication.class)

public class DemoApplicationTests {

@Autowired

private CountryService countryService;

@Test

public void contextLoads() {

countryService.testCountry();

}

}