RFR: 8043306 - Provide a replacement for the API that allowed to listen for LogManager configuration changes

[Daniel Fuchs]

On 9/12/14 2:37 PM, Alan Bateman wrote:
> On 12/09/2014 11:45, Daniel Fuchs wrote:
>>
>> I am still unconvinced this is worth the additional
>> complexity it would bring to the implementation.
>> The deprecated methods were using HashMap to store listeners,
>> and therefore the order in which listeners were invoked was also
>> undefined. Nobody has ever complained.
>>
> I'm not convinced either. The previous methods were rarely used (prior
> to their deprecation and eventual removal there was a static analysis
> done on tens of thousands of projects to get some data on actual usage
> and there were only a handful of actual usages). The only reason for
> introducing alternative methods is that there is a solution for the tiny
> number of cases where LogManager can't be sub-classes. So I think it's
> best to keep it as simpler as possible.

Would modifying the specification of addConfigurationListener()
as follows be sufficient to make the workings of the proposed
implementation clearer?

     /**
      * Adds a configuration listener to be invoked each time the logging
      * properties are read and the configuration is changed.
      * If the listener is already registered the method does nothing.
      * <p>
      * The order in which the listeners are invoked is unspecified.
      * <br>
      * If a security manager is on, each listener will be invoked in the
      * {@linkplain AccessControlContext security context} with which it was
      * registered.
      * <p>
      * It is recommended that listeners do not throw errors or exceptions.
      * Exceptions or errors thrown by listeners will
      * be propagated to the caller of {@link #readConfiguration()} (or 
{@link
      * #readConfiguration(java.io.InputStream)}) preventing those listeners
      * that haven't been invoked yet from being fired.
      *
      * @param listener A configuration listener that will be invoked 
after the
      *        configuration changed.
      * @return This LogManager.
      * @throws SecurityException if a security manager exists and if the
      * caller does not have LoggingPermission("control").
      * @throws NullPointerException if the listener is null.
      *
      * @since 1.9
      */
     public LogManager addConfigurationListener(Runnable listener) {

best regards,

-- daniel

>
> -Alan