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.

An operator form without the FINALLY keyword creates an action that executes another action and intercepts errors that are thrown in it. In this case, the error is not passed anywhere.

An operator form with the FINALLY keyword creates an action that executes another action, intercepts errors that occur, then, regardless of whether an error was thrown or not, executes the action specified in the FINALLY block, and then, if an error was thrown and there was no CATCH block, passes this error to the top action in the stack.

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 System.messageCaughtException[], the java error stack will be written to System.javaStackTraceCaughtException[], and the LSF stack will be written to System.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);
    }
}