如何使用带有springboot-mybatis-mysql的RESTFUL API对我的MySQL数据库进行基本的SELECT FROM调用？

Question

到目前为止，我成功地使用了字符串语句

@RestController
@RequestMapping("/")
public class ApplicationRestController {

    Actor actor;
    //this works easily because no connections to SQL are being made.
    @GetMapping("/hello")
    public String hello() {
        return "HELO WORLD";        
    }
}

但是，如果我想从数据库中获取数据，该怎么办呢？如何做到这一点？是否需要SQLSession？

有人有有用的链接吗？

java.io.FileNotFoundException：无法打开类路径资源[mybatis-sakila/src/main/resources/mybatis-mapper/actorMapper.xml],因为它不存在

这些是我的相关档案：

actor.java

public class Actor {

    private static final long serialVersionUID = 1L;

    private int actor_id;
    private String first_name;
    private String last_name;
    private Date last_update;

    public int getActor_id() {
        return actor_id;
    }
    public void setActor_id(int actor_id) {
        this.actor_id = actor_id;
    }
    public String getFirst_name() {
        return first_name;
    }
    public void setFirst_name(String first_name) {
        this.first_name = first_name;
    }
    public String getLast_name() {
        return last_name;
    }
    public void setLast_name(String last_name) {
        this.last_name = last_name;
    }
    public Date getLast_update() {
        return last_update;
    }
    public void setLast_update(Date last_update) {
        this.last_update = last_update;
    }
}

import org.apache.ibatis.annotations.Mapper;
import org.springframework.beans.factory.annotation.Autowired;  
import com.helios.mybatissakila.model.Actor;

@Mapper
public interface ActorMapper {

    List <Actor> selectAllActors();
}

ApplicationRestController.java

@RestController
@RequestMapping("/")
public class ApplicationRestController {

    @Autowired
    ActorMapper actorMapper;

    //working as not connected to mysql
    @GetMapping("/hello")
    public String hello() {
        return "MyBatis + SpringBoot + MySQL!";

    }
    //error 
    @GetMapping("/actors")
    public List<Actor> selectAllActors(){
            return actorMapper.selectAllActors();
    }
}

ActorMapper.xml

<resultMap id="ActorResultMap" type="Actor">
    <id column="actor_id" property="actor_id" jdbcType="INTEGER"/>
    <result column="first_name" property="first_name" />
    <result column="last_name" property="last_name" />
    <result column="last_update" property="last_update" />
</resultMap>

<select id="selectAllActors" resultMap="ActorResultMap">
        select * from actor
</select>

server.port = 9090

spring.datasource.url= jdbc:mysql://localhost:3306/sakila
spring.datasource.username = root
spring.datasource.password = password
spring.datasource.dbcp2.test-while-idle= true
spring.datasource.dbcp2.validation-query= select 1

#mybatis entity scan packages
mybatis.type-aliases-package=com.helios.mybatissakila.model
#Mapper.xml location
mybatis.mapper-locations=classpath*:mybatis-sakila/src/main/resources/ActorMapper.xml
mybatis.typeAliasesPackage=com.helios.mybatissakila.model.Actor

logging.level.root=WARN
logging.level.sample.mybatis.mapper=TRACE

mybatis.mapper-locations=classpath*:mybatis-sakila/src/main/resources/ActorMapper.xml

注意：我已经设法使用@Annotation样式执行了REST API调用，但我想使用XML样式。

Answer 1

您不需要SqlSession，MyBatis使用它自己的实现，您唯一需要做的就是创建MyBatis配置并设置它的所有依赖项。

简单地说，您需要做到以下几点：

创建POJO：

public class Dog{
   private Long id;
   private String name;

  //Getters and Setters
}

public interface DogMapper{
   public void insert(Dog dog);
}

@Service
public class DogService{
   @Autowired
   private DogMapper dogMapper;

   public void insert(Dog dog){
       dogMapper.insert(dog);
   }
}