java调存储过程

CallableStatement stmt=null;

String id=null;

try{

stmt=connect.prepareCall("{call testpro(?,?,?)}");

    stmt.setString(1,"123");

    stmt.setString(2,"321");

    stmt.registerOutParameter(3,Types.VARCHAR);

    stmt.execute();

    id=stmt.getString(3);

}catch(Exception ex){

...

}finally{

...

}