Mybatis How to deal with clob type data

Mybatis handles clob type data

When the sql statement is executed and the map type is returned, such as

public List<Map<String, Object>> query(@Param("sql") String sql)

The resulting data is List < Map > Type data, in this case, if there is an clob field returned, the data is oracle. sql. CLOB @ 63636de0. Obviously, this is not what I want, what I need is string data

So how to handle the clob field is very simple

Is to define a type handler that handles the Clob field and converts the Clob data to string data to be returned

@MappedJdbcTypes(JdbcType.CLOB)
public class ClobTypeHandle extends BaseTypeHandler<Object> {
    @Override
    public void setNonNullParameter(PreparedStatement ps, int i, Object parameter, JdbcType jdbcType)
            throws SQLException {
        ps.setObject(i, parameter);
    }
    @Override
    public Object getNullableResult(ResultSet rs, String columnName) throws SQLException {
        return rs.getString(columnName);
    }
    @Override
    public Object getNullableResult(ResultSet rs, int columnIndex) throws SQLException {
        return rs.getString(columnIndex);
    }
    @Override
    public Object getNullableResult(CallableStatement cs, int columnIndex) throws SQLException {
        return cs.getString(columnIndex);
    }
}

Mybatis Large Field clob Processing

1. Entity class View

package com.ttt.sysManager.po;
public class View {
 private String VIEW_NAME;
 private String TEXT_LENGTH;
 private String TEXT;<span style="white-space:pre"> </span>// clob Large field 
 private String EDITIONING_VIEW;
 private String READ_ONLY;
        // ... ( get , set Method) 
}

2. Dao

List<View> getViewByPage(Map<String, Object> map);

3. XML

<resultMap id="viewResultMap" type="com.ttt.sysManager.po.View">     
        <result property="VIEW_NAME" column="VIEW_NAME"/>
        <result property="TEXT_LENGTH" column="TEXT_LENGTH"/>  
        <result property="TEXT" column="TEXT" javaType="String" jdbcType="VARBINARY"/>  
        <result property="EDITIONING_VIEW" column="EDITIONING_VIEW" />  
        <result property="READ_ONLY" column="READ_ONLY" />  
</resultMap>  
 
<select id="getViewByPage" parameterType="map" resultMap="viewResultMap" >
 SELECT VIEW_NAME,TEXT_LENGTH,TEXT,EDITIONING_VIEW,READ_ONLY FROM (
  SELECT A.*,  ROWNUM RN
    FROM (SELECT * FROM user_views) A
    WHERE ROWNUM <![CDATA[<=]]> #{endRow}
  ) WHERE RN <![CDATA[>]]> #{startRow}
</select>

Step 4 Write

Write large fields and ordinary write no difference, but the database field type needs to be clob, such as blob will report an error, temporarily not resolved.