MyBatis实现数据库类型和Java类型转换的处理方法

public interface TypeHandler<T> {
  void setParameter(PreparedStatement ps, int i, T parameter, JdbcType jdbcType) throws SQLException;
  T getResult(ResultSet rs, String columnName) throws SQLException;
  T getResult(ResultSet rs, int columnIndex) throws SQLException;
  T getResult(CallableStatement cs, int columnIndex) throws SQLException;
}

@MappedTypes(MyEnum.class)
@MappedJdbcTypes(JdbcType.VARCHAR)
public class MyEnumTypeHandler implements TypeHandler<MyEnum> {
    
    @Override
    public void setParameter(PreparedStatement ps, int i, MyEnum parameter, JdbcType jdbcType) throws SQLException {
        ps.setString(i, parameter.name());
    }

    @Override
    public MyEnum getResult(ResultSet rs, String columnName) throws SQLException {
        return MyEnum.valueOf(rs.getString(columnName));
    }
    
    // 其他getResult方法实现...
}

<typeHandlers>
    <typeHandler handler="com.example.MyEnumTypeHandler"/>
</typeHandlers>

@Configuration
public class MyBatisConfig {
    @Bean
    public ConfigurationCustomizer typeHandlerRegistry() {
        return configuration -> {
            configuration.getTypeHandlerRegistry().register(MyEnum.class, new MyEnumTypeHandler());
        };
    }
}

public class GenericTypeHandler<T> extends BaseTypeHandler<T> {
    private final Class<T> type;
    
    public GenericTypeHandler(Class<T> type) {
        this.type = type;
    }
    
    // 实现方法...
}