The problem about java.sql.CallableStatement

Question

we need call oracle store procedure to get a record set.
the code below is the oracle's pl/sql program for test
package test2 as
type sample_record is record(id char(4),
name varchar2(10),
addr varchar2(30));
type sample_cursor is ref cursor return sample_record;
function get_resultset return sample_cursor;
end;
package body test2 as
function get_resultset return sample_cursor is
p_cursor sample_cursor;
begin
open p_cursor for select 'aaaa' id,'John' name,'guangzhou' addr from dual;
return p_cursor;
end get_resultset;
end;
and ,in java,how to use java.sql.CallableStatement to
run the store procedure to get the cursor,a sql type define in our oracle programme

Answer 1

see the code below,
public static sun.jdbc.rowset.WebRowSet testmethod(){
     Connection conn = null ;
          CallableStatement cstmt = null ;
          String str = null ;
          ResultSet result = null ;
          str = "{?=call test2.get_resultset()}" ;                    
          try
               conn = DbPool.getConnection() ;
               cstmt = conn.prepareCall(str) ;
               cstmt.registerOutParameter(1, OracleTypes.CURSOR);
               cstmt.execute();
               result = (java.sql.ResultSet)cstmt.getObject(1) ;                                             
               sun.jdbc.rowset.WebRowSet wrs = new sun.jdbc.rowset.WebRowSet() ;
          wrs.populate(result) ;//in this statement,it will throw a NullPointerException
               return wrs;
          catch (Exception e)
               CommLog.writeLog("pr", "PrLogic test: " + e.toString()) ;
               return null ;
          }finally
               try
                    result.close() ;
               catch (Exception e3)
               try
                    cstmt.close() ;
               catch (Exception e1)
               try
                    conn.close() ;
               catch (Exception e2)
     }