TRY operator

The TRY operator creates an action that executes another action with exception handling.

Syntax

TRY action [CATCH catchAction] [FINALLY finallyAction]

Description

The TRY operator creates an action that executes another action and handles exceptions within it. The exception-handling behavior depends on whether the FINALLY keyword is present.

Without the FINALLY keyword, errors raised by the main action are intercepted and not propagated.

With the FINALLY keyword, finallyAction runs after the main action regardless of whether an error was raised. If an error was raised and no CATCH block is present, the error is re-raised to the surrounding action after finallyAction runs.

Parameters

• action

  A context-dependent operator that describes an action to be executed with exception handling.

• catchAction

  A context-dependent operator that describes an action to be executed if an error is thrown while executing the action. Here the error message will be written to the property messageCaughtException[], the java error stack will be written to javaStackTraceCaughtException[], and the LSF stack will be written to lsfStackTraceCaughtException[].

• finallyAction

  A context-dependent operator that describes an action to be executed after the action being executed, regardless of whether or not an error has been thrown.

Examples

tryToImport(FILE f)  {
    TRY {
        LOCAL a = BPSTRING[10] (INTEGER);

        IMPORT XLS FROM f TO a = A;
    }
}

CLASS MyLock {
    lock 'Blocking'
}

singleDo ()  {
    NEWSESSION {
        lock(MyLock.lock);
        IF lockResult() THEN
        TRY {
            MESSAGE 'Lock Obtained';
        } CATCH {
            MESSAGE messageCaughtException();
        } FINALLY unlock(MyLock.lock);
    }
}