B.2. Invoking Stored Procedures

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B.2. Invoking Stored Procedures

After your client creates the connection to the database, it is ready to call the stored procedures. You invoke a stored procedure using the callProcedure() method, passing the procedure name and variables as arguments. For example:

VoltTable[] results;
 
try { results = client.callProcedure("LookupFlight",              1
                                     origin,
                                     dest,
                                     departtime).getResults();    2
} catch (Exception e) {                                           3
     e.printStackTrace();
     System.exit(-1);
}

1

The callProcedure() method takes the procedure name and the procedure's variables as arguments. The LookupFlight() stored procedure requires three variables: the originating airport, the destination, and the departure time.

2

Once a synchronous call completes, you can evaluate the results of the stored procedure. The callProcedure() method returns a ClientResponse object, which includes information about the success or failure of the stored procedure. To retrieve the actual return values you use the getResults() method.

3

Note that since callProcedure() can throw an exception (such as VoltAbortException) it is a good practice to perform error handling and catch known exceptions.