Mybatis 与 枚举 实现自动转换

1.建表

DROP TABLE IF EXISTS `account`;CREATE TABLE `account` (  `id` int(10) unsigned NOT NULL AUTO_INCREMENT,  `account` varchar(40) NOT NULL,  `pwd` varchar(40) NOT NULL,  `status` tinyint(1) NOT NULL DEFAULT '0' COMMENT '0不可用,1可用',  PRIMARY KEY (`id`)) ENGINE=InnoDB AUTO_INCREMENT=5 DEFAULT CHARSET=utf8;

如图

2.编写对应的枚举类

public enum AccountStatus {    // 账号不可用    DISABLE(1, "账号不可用"),    // 账号可用    AVALIABLE(2, "账号可用");    // 用一个map对象存储所有枚举对象    private static Map<Integer, AccountStatus> map = new HashMap<Integer, AccountStatus>();    static {        for (AccountStatus accountStatus : AccountStatus.values()) {            map.put(accountStatus.getValue(), accountStatus);        }    }    public static AccountStatus getEnumByValue(int value) {        return map.get(value);    }    private int value;    private String description;    private AccountStatus(int value, String description) {        this.value = value;        this.description = description;    }    //省略getter和setter方法}

3.Handler

public class MyEnumHandler extends BaseTypeHandler<AccountStatus> {    /**     * 数据库类型转换为对应的Java类型      */    @Override    public AccountStatus getNullableResult(ResultSet resultSet, String columnName) throws SQLException {        int value = resultSet.getInt(columnName);        AccountStatus accountStatus = null;        if (!resultSet.wasNull()) {            accountStatus = AccountStatus.getEnumByValue(value);        }        return accountStatus;    }    /**     * 数据库类型转换为对应的Java类型      */    @Override    public AccountStatus getNullableResult(ResultSet resultSet, int columnIndex) throws SQLException {        int value = resultSet.getInt(columnIndex);        AccountStatus accountStatus = null;        if (!resultSet.wasNull()) {            accountStatus = AccountStatus.getEnumByValue(value);        }        return accountStatus;    }    /**     * 数据库类型转换为对应的Java类型      */    @Override    public AccountStatus getNullableResult(CallableStatement callableStatement, int columnIndex) throws SQLException {        int value = callableStatement.getInt(columnIndex);        AccountStatus accountStatus = null;        if (!callableStatement.wasNull()) {            accountStatus = AccountStatus.getEnumByValue(value);        }        return accountStatus;    }    /**     * Java类型 转换为对应的数据库类型     */    @Override    public void setNonNullParameter(PreparedStatement preparedStatement, int parameterIndex, AccountStatus accountStatus, JdbcType jdbcType)            throws SQLException {        preparedStatement.setInt(parameterIndex, accountStatus.getValue());    }}

4.实体类

public class Account {    private int id;    private String account;    private String pwd;    private AccountStatus status;    //省略getter和setter方法}

5.映射文件

<?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="mapper.AccountMapper">    <insert id="insert" parameterType="po.Account">        insert into account (account, pwd, status)        values (#{account,jdbcType=VARCHAR}, #{pwd,jdbcType=VARCHAR},         #{status,typeHandler=util.MyEnumHandler})    </insert>    <resultMap type="po.Account" id="accountMap">        <id column="id" property="id"/>        <result column="account" property="account"/>        <result column="pwd" property="pwd"/>        <result column="status" property="status" typeHandler="util.MyEnumHandler"/>    </resultMap>    <select id="selectByPrimaryKey" resultMap="accountMap">        select id, account, pwd, status from account where id=#{id,jdbcType=INTEGER}    </select></mapper>

6.测试

public class Main {    @Test    public void testInsert() {        SqlSession session = MybatisUtil.getSession();        Account account = new Account();        account.setAccount("zidingyi1");        account.setPwd("zidingyi1");        account.setStatus(AccountStatus.AVALIABLE);        session.insert("mapper.AccountMapper.insert", account);        session.commit();    }    @Test    public void testSelect () {        SqlSession session = MybatisUtil.getSession();        Account account = session.selectOne("mapper.AccountMapper.selectByPrimaryKey", 2);        System.out.println(account.getStatus());        if (AccountStatus.AVALIABLE.equals(account.getStatus())) {            System.out.println("账号可用");        } else {            System.out.println("账号不可用");        }        System.out.println(account.getStatus().getDescription());    }}

6.测试结果