SQL/MX 3.2 Guide to Stored Procedures in Java (H06.25+, J06.14+)

Writing SPJ Methods
HP NonStop SQL/MX Release 3.2 Guide to Stored Procedures in Java—691166-001
3-11
Exception Handling
Exception Handling
For SPJ methods that access an SQL/MP or SQL/MX database, no special code is
necessary for handling exceptions. If an SQL operation fails inside the SPJ, the error
message associated with the failure is returned to the application that issues the CALL
statement.
Handling Java Exceptions
If an SPJ method returns an uncaught Java exception or an uncaught chain of
java.sql.SQLException objects, NonStop SQL/MX converts each Java exception
object into an SQL/MX error condition, and the CALL statement fails. Each SQL/MX
error condition contains the message text associated with one Java exception object.
If an SPJ method catches and handles exceptions itself, those exceptions do not affect
SQL/MX processing.
User-Defined Exceptions
The SQLSTATE values 38001 to 38999 are reserved for you to define your own error
conditions that SPJ methods can return. By coding your SPJ method to throw a
java.sql.SQLException object, you cause the CALL statement to fail with a
specific user-defined SQLSTATE value and your own error message text.
If you define the SQLSTATE to be outside the range of 38001 to 38999, NonStop
SQL/MX raises SQLSTATE 39001, external routine invocation exception.
This example uses the throw statement in the SPJ method named
numMonthlyOrders() to raise a user-defined error condition when an invalid
argument value is entered for the month:
public static void numMonthlyOrders(int month,
int[] numOrders)
throws java.sql.SQLException
{
if ( month < 1 || month > 12 )
{
throw new java.sql.SQLException (
"Invalid value for month. "
+ "Retry the CALL statement using a number "
+ "from 1 to 12 to represent the month.", "38001" );
}
....
}
For more information about the numMonthlyOrders() method, see the Sales Class
on page A-3.
For information about specific SQL/MX errors, see the SQL/MX Messages Manual,
which lists the SQLCODE, SQLSTATE, message text, and cause-effect-recovery
information for all SQL/MX errors.