liqiancao 2016-06-01
一、首先定义接口,提供获取数据库存取的值得方法,如下:
public interface BaseEnum { int getCode(); }二、定义mybatis的typeHandler扩展类,如下:
package com.camelot.assetcenter.sdk.orm.mybatis; import com.camelot.assetcenter.sdk.common.BaseEnum; import com.camelot.openplatform.common.log.Log; import org.apache.ibatis.type.BaseTypeHandler; import org.apache.ibatis.type.JdbcType; import org.slf4j.Logger; import java.sql.CallableStatement; import java.sql.PreparedStatement; import java.sql.ResultSet; import java.sql.SQLException; public class EnumTypeHandler extends BaseTypeHandler<BaseEnum> { private final static Logger logger = Log.get(EnumTypeHandler.class); private Class<BaseEnum> type; private final BaseEnum[] enums; /** * 设置配置文件设置的转换类以及枚举类内容,供其他方法更便捷高效的实现 * @param type 配置文件中设置的转换类 */ public EnumTypeHandler(Class<BaseEnum> type) { if (type == null) throw new IllegalArgumentException("Type argument cannot be null"); this.type = type; this.enums = type.getEnumConstants(); if (this.enums == null) throw new IllegalArgumentException(type.getSimpleName() + " does not represent an enum type."); } @Override public BaseEnum getNullableResult(ResultSet rs, String columnName) throws SQLException { // 根据数据库存储类型决定获取类型,本例子中数据库中存放INT类型 logger.debug(columnName); int i = rs.getInt(columnName); if (rs.wasNull()) { return null; } else { // 根据数据库中的code值,定位EnumStatus子类 return locateEnumStatus(i); } } @Override public BaseEnum getNullableResult(ResultSet rs, int columnIndex) throws SQLException { // 根据数据库存储类型决定获取类型,本例子中数据库中存放INT类型 logger.debug(columnIndex+""); int i = rs.getInt(columnIndex); if (rs.wasNull()) { return null; } else { // 根据数据库中的code值,定位EnumStatus子类 return locateEnumStatus(i); } } @Override public BaseEnum getNullableResult(CallableStatement cs, int columnIndex) throws SQLException { // 根据数据库存储类型决定获取类型,本例子中数据库中存放INT类型 logger.debug(columnIndex+""); int i = cs.getInt(columnIndex); if (cs.wasNull()) { return null; } else { // 根据数据库中的code值,定位EnumStatus子类 return locateEnumStatus(i); } } @Override public void setNonNullParameter(PreparedStatement ps, int i, BaseEnum parameter, JdbcType jdbcType) throws SQLException { // baseTypeHandler已经帮我们做了parameter的null判断 logger.debug(parameter.getCode()+"================================="); ps.setInt(i, parameter.getCode()); } /** * 枚举类型转换,由于构造函数获取了枚举的子类enums,让遍历更加高效快捷 * @param code 数据库中存储的自定义code属性 * @return code对应的枚举类 */ private BaseEnum locateEnumStatus(int code) { for(BaseEnum status : enums) { if(status.getCode() ==code ) { return status; } } throw new IllegalArgumentException("未知的枚举类型:" + code + ",请核对" + type.getSimpleName()); } }三、在mapper文件中的使用:
<select id="queryOverdueDetail" resultMap="assetUserIntegralDetailMap"> <include refid="selectAllColumns" /> where 1=1 <if test="entity!=null"> <if test="entity.type != null and entity.type !=''"> <![CDATA[ and asset_user_integral_detail_.type = #{entity.type,typeHandler=com.camelot.assetcenter.sdk.orm.mybatis.EnumTypeHandler} ]]> </if> <if test="entity.status != null and entity.status !=''"> <![CDATA[ and asset_user_integral_detail_.status = #{entity.status,typeHandler=com.camelot.assetcenter.sdk.orm.mybatis.EnumTypeHandler} ]]> </if> <if test="entity.createTime != null "> <![CDATA[ and asset_user_integral_detail_.create_time < #{overdueTime} ]]> </if> </if> <if test="limitCount !=null and limitCount != '' "> limit #{limitCount} </if> </select>
<resultMap id="assetUserIntegralDetailMap" type="assetUserIntegralDetail"> <result property="userIntegralDetailId" column="user_integral_detail_id" /> <result property="userIntegralId" column="user_integral_id" /> <result property="integral" column="integral" /> <result property="balanceIntegral" column="balance_integral" /> <result property="type" column="type" typeHandler="com.camelot.assetcenter.sdk.orm.mybatis.EnumTypeHandler"/> <result property="businessType" column="business_type" typeHandler="com.camelot.assetcenter.sdk.orm.mybatis.EnumTypeHandler"/> <result property="businessId" column="business_id" /> <result property="source" column="source" typeHandler="com.camelot.assetcenter.sdk.orm.mybatis.EnumTypeHandler"/> <result property="shopId" column="shop_id" /> <result property="status" column="status" typeHandler="com.camelot.assetcenter.sdk.orm.mybatis.EnumTypeHandler"/> <result property="createTime" column="create_time" /> <result property="description" column="description" /> </resultMap>
<if test="entity.type != null and entity.type !=''"> <![CDATA[ and asset_user_integral_detail_.type = #{entity.type,typeHandler=com.camelot.assetcenter.sdk.orm.mybatis.EnumTypeHandler} ]]> </if> <if test="entity.businessType != null and entity.businessType !=''"> <![CDATA[ and asset_user_integral_detail_.business_type = #{entity.businessType,typeHandler=com.camelot.assetcenter.sdk.orm.mybatis.EnumTypeHandler} ]]> </if>按照以上方式既可以实现枚举类型和mybatis映射