MyBatis hot reload beta

• If you use MyBatisPlus, please click to view.
• SQL printing can be enabled by Printing SQL execution and time consumption.
• MyBatis currently supports the Spring environment, and other situations are unknown.

Mapper hot reload

Identification method

All files under the package path of the @MapperScan annotation are read.

• It must be an interface and must contain the org.apache.ibatis.annotations.Mapper annotation
• The class or parent class inherits the com.baomidou.mybatisplus.core.mapper.BaseMapper interface.

WARNING

Because the bytecode injection is modified at startup, it currently does not support reading the variable content configured by @MapperScan. Please write the real package path.

The configuration that works is as follows:
@MapperScan("io.github.future0923.test.dao")
@MapperScan("io.github.future0923.test.**.dao")
@MapperScan("io.github.future0923.test.**")
@MapperScan({"io.github.future0923.test.user.**.dao", "io.github.future0923.test.order.**.dao"})

The configuration that does not work is as follows:
@MapperScan("${mybatis-plus.mapperPackage}")

Hot reload function

Adding new changes to the Mapper interface will regenerate the information in the Mapper interface, such as annotation methods, etc. will regenerate the proxy class and inject it into the Spring Bean, which has the same effect as restarting. Of course, it also supports adding new Mapper classes.

Example

Add new example

Add new Entity file.

public class User {
    
    private Long id;
    
    private Long deptId;
    
    private String userName;
    
    private Integer age;
}

Add new Mapper file.

import org.apache.ibatis.annotations.Mapper;

@Mapper
public interface UserMapper {

    @Select("select user_name, count(1) from user group by user_name")
    Map<String, Integer> getUserCountByName();

    List<User> selectByNameAndAge(@Param("name") String name, @Param("age") Integer age);
}

Add new Mapper file.

<?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="UserMapper">
    <select id="selectByNameAndAge" resultType="User">
        select * from dp_user where name = #{name} and age = #{age}
    </select>
</mapper>

Add a new Service file to use the UserMapper interface.

@Service
public class UserService {
    
    private final UserMapper userMapper;
    
    public UserService(UserMapper userMapper) {
        this.userMapper = userMapper;
    }

    public Map<String, Integer> getUserCountByName() {
        return userMapper.getUserCountByName();
    }
    
    public List<User> selectByNameAndAge(String name, Integer age) {
        return userMapper.selectByNameAndAge(name, age);
    }
}

After hot reloading, we can call the new methods of UserMapper and UserService through Call Method Function and they can be executed normally.

Modify example

import org.apache.ibatis.annotations.Mapper;

public class User {
    
    private Long id;
    
    private Long deptId;
    
    private String userName;
    
    private Integer age;
    
}

@Mapper
public interface UserMapper {

    @Select("select id, dept_id, name, sex from user") 
    List<User> getAll(); 
    
    @Select("select user_name, count(1) from user group by user_name") 
    Map<String, Integer> getUserCountByName();  
    @Select("select sex, count(1) from user group by sex") 
    Map<String, Integer> getUserCountBySex();  

    List<User> selectByNameAndAge(@Param("name") String name, @Param("age") Integer age); 

    Integer selectCount(@Param("name") String name); 
    Long selectCount(@Param("name") String name, @Param("age") Integer age); 
}

After hot reloading, we can call the modified method of UserMapper through Call Method Function and it can be executed normally.

Xml hot reload

Identification method

Get xml resource file changes (add/modify)

• Add: xml file verified by MyBatis
• Modify: xml resource existing in loadedResources in Configuration

Hot reload function

Recompile xml file and reload it into Configuration to make xml effective.

Example

Add example

Generally need to be used with mapper, see Add mapper for examples.

Modify example

Generally need to be used with mapper, see Modify mapper for examples, modifying the content in xml alone can be executed normally.