spring boot 整合mybatis

1、添加依赖

<dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-jdbc</artifactId>
        </dependency>
        
        <dependency>
            <groupId>com.oracle</groupId>
            <artifactId>ojdbc6</artifactId>
            <version>11.1.0.6.0</version>            
        </dependency>
        
        <dependency>
            <groupId>org.mybatis.spring.boot</groupId>
            <artifactId>mybatis-spring-boot-starter</artifactId>
            <version>1.3.2</version>
        </dependency> 

2、配置数据库信息

在application.properties中添加如下代码：

spring.datasource.url=jdbc:oracle:thin:@ip:port:SERVICE_NAME
spring.datasource.username=
spring.datasource.password=
spring.datasource.driver-class-name=oracle.jdbc.OracleDriver

3、创建实体类POJO

public class DefaultUdfUser {

    private String id;
    
    private String password_;
    
    private String username_;
    public String getId() {
        return id;
    }

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

    public String getUsername_() {
        return username_;
    }

    public void setUsername_(String username_) {
        this.username_ = username_;
    }

    public String getPassword_() {
        return password_;
    }

    public void setPassword_(String password_) {
        this.password_ = password_;
    }



    
}

4、在src/main/resources下建立mybatis文件夹，并在此文件夹下建立UserMapper.xml，具体代码如下：

<?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.htkeystone.dcg.mapper.UserMapper" >
    <resultMap id="BaseResultMap" type="com.htkeystone.dcg.entity.DefaultUdfUser" >
    <id column="ID" property="id" jdbcType="VARCHAR" />
    <result column="USERNAME_" property="username_" jdbcType="VARCHAR" />
    <result column="PASSWORD_" property="password_" jdbcType="VARCHAR" />
  </resultMap>
  <sql id="Base_Column_List" >
    ID,USERNAME_,PASSWORD_
  </sql>
    <select id="selectByUsername" resultMap="BaseResultMap" parameterType="java.lang.String">
        select
        <include refid="Base_Column_List" /> 
        from UDF_USER 
        where  USERNAME_=#{username_}
    </select>
</mapper>

5、写UserMapper.java接口

import org.apache.ibatis.annotations.Mapper;
import com.htkeystone.dcg.entity.DefaultUdfUser;

@Mapper
public interface UserMapper {
    DefaultUdfUser selectByUsername(String username_);
}

注意要加上@Mapper注解，要不然会报错

6、在Dao层写如下代码

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
import com.htkeystone.dcg.dao.DemoDao;
import com.htkeystone.dcg.mapper.UserMapper;

@Service
public class DemoDaoImpl implements DemoDao{
    
    @Autowired
    private UserMapper userMapper;

    @Override
    public String hello() {        
        return userMapper.selectByUsername("000000266").getPassword_();
    }
    
}

7、启动报错，如下图：

找不到UserMapper的id selectByUsername

原因是没有指定UserMapper.xml的路径

解决方法：在application.properties加入如下代码

mybatis.mapper-locations: classpath:mybatis/*.xml

再启动就好了