create or replace 
   type TOBJRESULT as 
        object (code varchar2(20)
              , message varchar2(4000)
              , num     integer
              , CONSTRUCTOR FUNCTION TOBJRESULT RETURN SELF AS RESULT              
              )

function getResult return TObjResult
is
o#result TObjResult; -- := TObjResult();
begin 
  o#result                := TObjResult('321', '123456', 344654);
 return o#result;
end;    

import oracle.jdbc.OracleCallableStatement;
import oracle.jdbc.OracleConnection;
import oracle.jdbc.OracleTypes;
import oracle.sql.STRUCT;
import oracle.sql.StructDescriptor;



        OracleConnection conn = null;
        //Connection conn = null;
        
        CallableStatement stmt = null;

        
        
        try {
            
            conn = jdbcUtils.getConnection();
            
            StructDescriptor structDesc = StructDescriptor.createDescriptor("TOBJRESULT", conn);
            
            OracleCallableStatement cst = (OracleCallableStatement) conn.prepareCall(
                "{call ? := result.getResul}"
            );            
            
            //cst.setSTRUCT(1, struct);
            cst.registerOutParameter(1, OracleTypes.STRUCT, "TOBJRESULT");
            
            cst.execute();
            
            STRUCT struct = cst.getSTRUCT(1);
            
            Object[] rec = struct.getAttributes();
            
            
            for (int i = 0 ; i< rec.length; i++){
                logger.debug("i=%s, type=%s, value=%s", i, rec[i].getClass().getName(), rec[i] );
            }
            
            retCode     = (String)rec[0];
            retMessage  = Tools.fromBase((String)rec[1]);




        }catch(SQLException e){    
            retCode = Integer.toString(e.getErrorCode());
            retMessage = e.getMessage();
            throw e;
        } finally {
          if (stmt != null )   stmt.close();
          if (conn != null)    conn.close();
        }

INFO  2019-04-22 08:49:52,946 -  i=0, type=java.lang.String, value=???
INFO  2019-04-22 08:49:52,946 -  i=1, type=java.lang.String, value=???
INFO  2019-04-22 08:49:52,946 -  i=2, type=java.math.BigDecimal, value=9876543210