How to call stored procedures from java program?

Question

I have tried to run a program that calls a stored procedure on MySQL
server version 5.0.17 by using connector/j 5.0, but it always fails on the
statement: con.preparecall() ,
have looked on the internet and found out that people can all mysql
stored procedure all right in their programs, really dont know what's
wrong with this small peiece of code:
import java.sql.*;
public class TestDB {
      // procedure being called is:
     CREATE PROCEDURE `dbsaystorm`.`getsite` ()
     BEGIN
        select  name  from tblsite;
     END
     public static void main(String[] args) {
          try  {
              //Class.forName("org.gjt.mm.mysql.Driver");
              Class.forName("com.mysql.jdbc.Driver");
              Connection con = DriverManager.getConnection("jdbc:mysql://localhost/dbname",
                        "user", "pwd");
       * executing SQL statement here gives perfect correct results:
        // PreparedStatement ps = con.prepareStatement("select name from tblsite");      
        // ResultSet rs =ps.executeQuery();
              // but in stored procedure way...
              //it fails here on this prepare call statement:             
              CallableStatement proc = con.prepareCall("call getsite()");
              ResultSet rs =proc.executeQuery();                      
              if (rs == null) return;                                      
              while (rs.next()){                 
                  System.out.println("site name is: "+ rs.getString(1));                                
              rs.close();
          } catch (SQLException e) {e.printStackTrace();}
           catch (Exception e) {e.printStackTrace();}         
}it always gives this exception:
java.lang.NullPointerException
     at com.mysql.jdbc.StringUtils.indexOfIgnoreCaseRespectQuotes(StringUtils.java:959)
     at com.mysql.jdbc.DatabaseMetaData.getCallStmtParameterTypes(DatabaseMetaData.java:1280)
     at com.mysql.jdbc.DatabaseMetaData.getProcedureColumns(DatabaseMetaData.java:3668)
     at com.mysql.jdbc.CallableStatement.determineParameterTypes(CallableStatement.java:638)
     at com.mysql.jdbc.CallableStatement.<init>(CallableStatement.java:453)
     at com.mysql.jdbc.Connection.parseCallableStatement(Connection.java:4365)
     at com.mysql.jdbc.Connection.prepareCall(Connection.java:4439)
     at com.mysql.jdbc.Connection.prepareCall(Connection.java:4413)
     at saystorm.server.data.database.TestDB.main(TestDB.java:29)
where have I gone wrong?
when I commented out the statement that makes the procedure call and call preparedstatement to execute SQL select statement, it gave perfectly correct result.
it looks like there is no problem with java prog accessing MYSQL server database, but the it seems that it's just java can't call stored procedure stored on the mysql server version 5.
can it or can't it? if it can, how is that accomplished?

Answer 1

It is a bug in the driver because it shouldn't be
returning that exception (null pointer) even if you
are doing something wrong.
Are you using the latest version of the driver?
The stored procedure runs when you run it from the
gui/command line using a MySQL tool - correct?
As suggested you should be using the brackets. What
is the data type of the 'name' field?
You could try returning another value like one of the
following
select 1, name from tblsite;
select name, 1 from tblsite;
That might get around the bug
Additionally try just the following...
select 'test' from tblsite;yes, the driver used is in connector/j 5.0--the lastest one, and the
procedure can run correctedly at either command line or GUI mode
with no problem whatsoever, the returned data type is string type,
I have not got the chance to test it again with those values you
suggested, as I have abandoned the laptop I used to write that code
initately. There have been some other really weird cases happened on
that computer. I guess that must be something wrong with the JVM
installed on it, it was upgraded from jre5.0.04 to 06, and to 09.
something within hte JVM must have been messed up(the only reasonable
explanation). Because the same code runs correctly on my new laptop,
using the same environment: jvm 5.0_09, mysql 5.0.18, connector/J 5.0.
that old laptop really was a nightmare.