springboot + mybatis 自定义枚举类型转换

springboot+mybatis

https://www.cnblogs.com/jackspan/p/10582948.html

根据我的实际项目测试，与链接中的两种方法为有小差异

我的配置为：

第一种方法：

a）在application.properties文件新增配置

mybatis.type-handlers-package=com.xiao.mywebproject.dao.typehandler

这是自己写的handler包

 

b）在自己写的handler类上面加注解

@MappedTypes(OrderStatusEnum.class)

OrderStatusEnum是自己写的枚举类

 

第二种方法：

删除第一种方法的配置

a） mapper的xml文件里，resultMap相应的字段，增加

typeHandler= com.xiao.mywebproject.dao.typehandler. EnumTypeHandler

(这是主要用于select取值转换)

inset和update语句同样增加typehandler，如下

<insert id="insertTest" parameterType="Order" >
    insert into order_info (id, order_status)
    values (#{id, jdbcType=BIGINT}, #{orderStatus, jdbcType=TINYINT,typeHandler=com.xiao.mywebproject.dao.typehandler.EnumTypeHandler})
</insert>

 

代码demo：

1、 handler类，继承了BaseTypeHandler

@MappedTypes(OrderStatusEnum.class)
public class EnumTypeHandler<E extends BaseEnum<E>> extends BaseTypeHandler<E> {

    private final Map<Integer, E> enumMap;
    private Class<E> type;

    public EnumTypeHandler(Class<E> type) {
        if (type == null) {
            throw new IllegalArgumentException("Type argument cannot be null");
        }
        this.type = type;
        this.enumMap = type.getEnumConstants()[0].getEnumMap();
        if (this.enumMap == null) {
            throw new IllegalArgumentException(type.getSimpleName() + " does not represent an enum type.");
        }
    }

    @Override
    public void setNonNullParameter(PreparedStatement ps, int i, E parameter, JdbcType jdbcType) throws SQLException {
        ps.setInt(i, parameter.getCode());
    }

    @Override
    public E getNullableResult(ResultSet rs, String columnName) throws SQLException {
        int i = rs.getInt(columnName);
        if (rs.wasNull()) {
            return null;
        } else {
            return getEnum(i);
        }
    }

    @Override
    public E getNullableResult(ResultSet rs, int columnIndex) throws SQLException {
        int i = rs.getInt(columnIndex);
        if (rs.wasNull()) {
            return null;
        } else {
            return getEnum(i);
        }
    }

    @Override
    public E getNullableResult(CallableStatement cs, int columnIndex) throws SQLException {
        int i = cs.getInt(columnIndex);
        if (cs.wasNull()) {
            return null;
        } else {
            return getEnum(i);
        }
    }

    private E getEnum(int i) {
        if (enumMap.containsKey(i)) {
            return enumMap.get(i);
        } else {
            throw new IllegalArgumentException("Cannot convertor " + i + " to " + type.getSimpleName() + " by value.");
        }
    }

}

 

2、BaseEnum

public interface BaseEnum<E> {
    int getCode();

    Map<Integer, E> getEnumMap()
}

 

3、 OrderStatusEnum

public enum  OrderStatusEnum implements BaseEnum{
    WATI_PAY(1,"待付款"),
    PAYED(2,"付款成功"),
    WAIT_REFUND(3,"等待退款"),
    REFUNDING(4,"退款中"),
    REFUND_SUCCESS(5,"退款成功"),
    REFUND_FAIL(6,"退款失败"),
    COMPLETED(7,"订单完成");

    private int code;
    private String desc;
    public static Map<Integer,OrderStatusEnum> enumMap = new HashMap<>();
    static{
        for(OrderStatusEnum temp : OrderStatusEnum.values()){
            enumMap.put(temp.getCode(),temp); }
    }

    OrderStatusEnum(int code, String desc) {
        this.code = code;
        this.desc = desc;
    }


    @Override
    public int getCode() {
        return code;
    }

    public void setCode(int code) {
        this.code = code;
    }

    public String getDesc() {
        return desc;
    }

    public void setDesc(String desc) {
        this.desc = desc;
    }

    @Override
    public Map getEnumMap() {
        return enumMap;
    }
}

 

配置：在application.properties

#数据库连接
spring.datasource.url=jdbc:mysql://localhost:3306/myweb_project
spring.datasource.username=root
spring.datasource.password=123456
spring.datasource.driver-class-name=com.mysql.jdbc.Driver

#扫描mapper xml
mybatis.mapper-locations=classpath:mapper/*.xml
#简化mapper  xml文件中类的写法，使在xml里不需要全限定名
mybatis.type-aliases-package=com.xiao.mywebproject.dao.domain
#typehandler配置，与实际handler类的@MappedTypes注解联合使用，即指定了数据插入和查询时的typehandler
mybatis.type-handlers-package=com.xiao.mywebproject.dao.typehandler

(这是第二种配置方法)