MyBatis自定义TypeHandler处理枚举类型的字段

首先看一下我们的实体类的sql

SET FOREIGN_KEY_CHECKS=0;

-- ----------------------------
-- Table structure for t_user
-- ----------------------------
DROP TABLE IF EXISTS `t_user`;
CREATE TABLE `t_user` (
  `id` int(12) NOT NULL AUTO_INCREMENT,
  `user_name` varchar(60) NOT NULL,
  `password` varchar(60) NOT NULL,
  `sex` int(10) DEFAULT NULL,
  `mobile` varchar(20) NOT NULL,
  `tel` varchar(20) DEFAULT NULL,
  `email` varchar(60) DEFAULT NULL,
  `note` varchar(512) DEFAULT NULL,
  PRIMARY KEY (`id`)
) ENGINE=InnoDB AUTO_INCREMENT=2 DEFAULT CHARSET=latin1;

实体类

public class User {
	private Long id;
	private String userName;
	private String password;
	private SexEnum sex;
	private String mobile;
	private String tel;
	private String email;
	private String note;
#getter和setter省略
}

性别枚举类

public enum SexEnum {
	MALE(1, "男"),
	FEMALE(0, "女");

	private int id;
	private String name;

	public int getId() {
		return id;
	}

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

	public String getName() {
		return name;
	}

	public void setName(String name) {
		this.name = name;
	}

	SexEnum(int id, String name) {
		this.id = id;
		this.name = name;
	}

	public static SexEnum getSexById(int id) {
		for (SexEnum sex : SexEnum.values()) {
			if (sex.getId() == id) {
				return sex;
			}
		}
		return null;
	}
}

自定义枚举类型typeHandler，需要继承TypeHandler并且标明需要处理的类型，该例子的类型为SexEnum

public class SexEnumTypeHandler implements TypeHandler<SexEnum> {

    Logger logger = Logger.getLogger(SexEnumTypeHandler.class);
    @Override
    public void setParameter(PreparedStatement preparedStatement, int i, SexEnum sexEnum, JdbcType jdbcType) throws SQLException {
        logger.info("设置string参数【" + sexEnum + "】");
        preparedStatement.setInt(i,sexEnum.getId());
    }

    @Override
    public SexEnum getResult(ResultSet resultSet, String s) throws SQLException {
        logger.info("获取string参数1【" + s + "】");
        int i = resultSet.getInt(s);
        return SexEnum.getSexById(i);
    }

    @Override
    public SexEnum getResult(ResultSet resultSet, int i) throws SQLException {
        logger.info("获取string参数2【" + resultSet.getInt(i) + "】");
        return SexEnum.getSexById(resultSet.getInt(i));
    }

    @Override
    public SexEnum getResult(CallableStatement callableStatement, int i) throws SQLException {
        logger.info("获取string参数3【" + callableStatement.getInt(i) + "】");
        return SexEnum.getSexById(callableStatement.getInt(i));
    }
}

mapper映射文件

public interface UserMapper {
	public User getUser(Long id);
}

<?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.framework.modules.mybatis2.mapper.UserMapper">
	<resultMap id="userMapper" type="user">
		<result property="id" column="id" />
		<result property="userName" column="user_name" />
		<result property="password" column="password" />
		<result property="sex" column="sex" 
            typeHandler="com.framework.modules.mybatis2.typehandler.SexEnumTypeHandler"/>
		<result property="mobile" column="mobile" />
		<result property="tel" column="tel" />
		<result property="email" column="email" />
		<result property="note" column="note" />
	</resultMap>
	<select id="getUser" resultMap="userMapper" parameterType="long">
	  select id, user_name, password, sex, mobile, tel, email, note from t_user 
      where id = #{id}
	</select>
</mapper>

测试

        SqlSession sqlSession = null;
		try {
			sqlSession = SqlSessionFactoryUtils.openSqlSession();
			UserMapper userMapper  = sqlSession.getMapper(UserMapper.class);
			User user = userMapper.getUser(1L);
			System.out.println(user.getSex().getName());
		} finally {
			if (sqlSession != null) {
				sqlSession.close();
			}
		}

日志

DEBUG 2019-01-11 11:21:16,459 org.apache.ibatis.logging.commons.JakartaCommonsLoggingImpl: Opening JDBC Connection
DEBUG 2019-01-11 11:21:16,463 org.apache.ibatis.logging.commons.JakartaCommonsLoggingImpl: Setting autocommit to false on JDBC Connection [jdbc:mysql://localhost:3306/ssm, [email protected], MySQL Connector Java]
DEBUG 2019-01-11 11:21:16,468 org.apache.ibatis.logging.commons.JakartaCommonsLoggingImpl: ==>  Preparing: select id, user_name, password, sex, mobile, tel, email, note from t_user where id = ? 
DEBUG 2019-01-11 11:21:16,503 org.apache.ibatis.logging.commons.JakartaCommonsLoggingImpl: ==> Parameters: 1(Long)
 INFO 2019-01-11 11:21:16,572 com.framework.modules.mybatis2.typehandler.SexEnumTypeHandler: 获取string参数1【sex】
DEBUG 2019-01-11 11:21:16,573 org.apache.ibatis.logging.commons.JakartaCommonsLoggingImpl: <==      Total: 1
男