You are viewing a plain text version of this content. The canonical link for it is here.
Posted to dev@tomcat.apache.org by Romain Manni-Bucau <rm...@gmail.com> on 2014/09/15 21:01:04 UTC
adding an internal filter
Hi guys,
in TomEE I'd like to add a filter but after context filter are started
(means filterStart() from StandardContext is called).
What I do today is:
try {
final Field def =
StandardContext.class.getDeclaredField("filterDefs");
if (!def.isAccessible()) {
def.setAccessible(true);
}
final Field config =
StandardContext.class.getDeclaredField("filterConfigs");
if (!config.isAccessible()) {
config.setAccessible(true);
}
final Object oldDefs = def.get(context);
final Map<String, ApplicationFilterConfig> oldConfig = new
HashMap<>((Map<String, ApplicationFilterConfig>) config.get(context));
try {
final Map<String, FilterDef> tempDef = new HashMap<>();
tempDef.put(filterDef.getFilterName(), filterDef);
def.set(context, tempDef);
StandardContext.class.cast(context).filterStart();
// update configs
oldConfig.putAll((Map<String,
ApplicationFilterConfig>) config.get(context));
} finally {
def.set(context, oldDefs);
def.set(context, oldConfig);
}
} catch (final Exception e) {
throw new IllegalStateException(e);
}
but it is really hacky just to get a ApplicationFilterConfig. Is there
an easier way I miss or is it possible to make it a bit more easy?
Romain Manni-Bucau
Twitter: @rmannibucau
Blog: http://rmannibucau.wordpress.com/
LinkedIn: http://fr.linkedin.com/in/rmannibucau
Github: https://github.com/rmannibucau
---------------------------------------------------------------------
To unsubscribe, e-mail: dev-unsubscribe@tomcat.apache.org
For additional commands, e-mail: dev-help@tomcat.apache.org
Re: adding an internal filter
Posted by Romain Manni-Bucau <rm...@gmail.com>.
changed to:
private void addFilterConfig(final Context context, final FilterDef filterDef) {
// hack to force filter to get a config otherwise it is
ignored in the http routing
try {
final Constructor<ApplicationFilterConfig> cons =
ApplicationFilterConfig.class.getDeclaredConstructor(Context.class,
FilterDef.class);
if (!cons.isAccessible()) {
cons.setAccessible(true);
}
final ApplicationFilterConfig config =
cons.newInstance(context, filterDef);
((Map<String, ApplicationFilterConfig>)
Reflections.get(context,
"filterConfigs")).put(filterDef.getFilterName(), config);
} catch (final Exception e) {
throw new IllegalStateException(e);
}
}
works fine even if not sexy
Thanks Konstantin for the feedback
Romain Manni-Bucau
Twitter: @rmannibucau
Blog: http://rmannibucau.wordpress.com/
LinkedIn: http://fr.linkedin.com/in/rmannibucau
Github: https://github.com/rmannibucau
2014-09-16 15:50 GMT+02:00 Romain Manni-Bucau <rm...@gmail.com>:
> 2014-09-16 15:16 GMT+02:00 Konstantin Kolinko <kn...@gmail.com>:
>> 2014-09-15 23:01 GMT+04:00 Romain Manni-Bucau <rm...@gmail.com>:
>>> Hi guys,
>>>
>>> in TomEE I'd like to add a filter but after context filter are started
>>> (means filterStart() from StandardContext is called).
>>>
>>
>> Why? What is the use case?
>>
>
> we add a filter with a tomee service (passing after tomee started)
>
>> You code adds filter definitions. A filter definitions just associates
>> filter with a name. A filter is unreachable if it has no mappings for
>> it.
>> Where are filter mappings for your filter? How do you add filter mappings?
>>
>
> full code is:
>
> final FilterDef filterDef = new FilterDef();
> filterDef.setAsyncSupported("true");
> filterDef.setDescription(description);
> filterDef.setFilterName(description);
> filterDef.setDisplayName(description);
> filterDef.setFilter(new CXFJAXRSFilter(cxfRsHttpListener,
> context.findWelcomeFiles()));
> filterDef.setFilterClass(CXFJAXRSFilter.class.getName());
> context.addFilterDef(filterDef);
>
> String mapping = completePath;
> if (!completePath.endsWith("/*")) {
> if (completePath.endsWith("*")) {
> mapping = completePath.substring(0, completePath.length() - 1);
> }
> mapping = mapping + "/*";
> }
>
> final String urlPattern = removeWebContext(webContext, mapping);
> cxfRsHttpListener.setUrlPattern(urlPattern.substring(0,
> urlPattern.length() - 1));
>
> final FilterMap filterMap = new FilterMap();
> filterMap.addURLPattern(urlPattern);
> filterMap.setFilterName(filterDef.getFilterName());
> context.addFilterMap(filterMap);
>
> addFilterConfig(context, filterDef); // the hack I sent previously
>
>
>> When do you add your new filter? Is context already started and
>> serving requests, or it has not started yet? Why cannot you add
>> filter definition before a filterStart() call?
>>
>> Do you use "StandardContext" class directly, or you can subclass it?
>>
>
> directly, tomee doesn't change StandardContext (one big goal)
>
>> The proper solutions should be to add new API, but I would like the
>> answers on the above questions first, as
>> a) There shall be some API for filter mappings as well.
>> b) If context has already been started, implementation would be more
>> complicated.
>>
>>> What I do today is:
>>>
>>
>> Where do I start with this?
>>
>> Just several notes on the code.
>>
>> 1. Missing synchronization. filterStart() uses "synchronized
>> (filterConfigs)" Your code does not use synchronization.
>>
>
> Actually we don't care that much here since that's still in the start
> context (app is not yet fully usable) so multithreading shouldnt
> occur, does it in tomcat?
>
>> 2. If you using "setAccessible(true)",
>>
>> A simpler way would be to mark ApplicationFilterConfig constructor as
>> accessible and call it directly instead of playing with filterStart().
>>
>> Playing with filterStart() without accompanying filterStop() call is broken
>>
>> filterStart() does "filterConfigs.clear();" as one of the first steps.
>> A lot of code in your method are a workaround against that clear()
>> call. (You copy the filterConfigs into a temporary map to preserve the
>> map entries from being cleared). Essentially this clear() call throws
>> away filter instances (wrapped in ApplicationFilterConfig classes)
>> without properly destroying them.
>>
>> You code might break if "filterConfigs" field were marked as"final"
>> (as it should be).
>>
>
> we already got this before in webapp classloader and until tomcat
> supports our feature we forced by reflection the field to not be
> final. That said I agree (and why I ask for a simpler API) that it is
> mainly workarounds but I don't see why StandardContext is not exposing
> it (what would be blocking).
>
>>
>>
>>> try {
>>> final Field def =
>>> StandardContext.class.getDeclaredField("filterDefs");
>>> if (!def.isAccessible()) {
>>> def.setAccessible(true);
>>> }
>>> final Field config =
>>> StandardContext.class.getDeclaredField("filterConfigs");
>>> if (!config.isAccessible()) {
>>> config.setAccessible(true);
>>> }
>>> final Object oldDefs = def.get(context);
>>> final Map<String, ApplicationFilterConfig> oldConfig = new
>>> HashMap<>((Map<String, ApplicationFilterConfig>) config.get(context));
>>> try {
>>> final Map<String, FilterDef> tempDef = new HashMap<>();
>>> tempDef.put(filterDef.getFilterName(), filterDef);
>>> def.set(context, tempDef);
>>>
>>> StandardContext.class.cast(context).filterStart();
>>
>> Why such code style? The following is shorter.
>> ((StandardContext)context).filterStart();
>>
>>
>>> // update configs
>>> oldConfig.putAll((Map<String,
>>> ApplicationFilterConfig>) config.get(context));
>>> } finally {
>>> def.set(context, oldDefs);
>>> def.set(context, oldConfig);
>>> }
>>> } catch (final Exception e) {
>>> throw new IllegalStateException(e);
>>> }
>>>
>>> but it is really hacky just to get a ApplicationFilterConfig. Is there
>>> an easier way I miss or is it possible to make it a bit more easy?
>>>
>>>
>>> Romain Manni-Bucau
>>> Twitter: @rmannibucau
>>> Blog: http://rmannibucau.wordpress.com/
>>> LinkedIn: http://fr.linkedin.com/in/rmannibucau
>>> Github: https://github.com/rmannibucau
>>>
>>
>> ---------------------------------------------------------------------
>> To unsubscribe, e-mail: dev-unsubscribe@tomcat.apache.org
>> For additional commands, e-mail: dev-help@tomcat.apache.org
>>
---------------------------------------------------------------------
To unsubscribe, e-mail: dev-unsubscribe@tomcat.apache.org
For additional commands, e-mail: dev-help@tomcat.apache.org
Re: adding an internal filter
Posted by Romain Manni-Bucau <rm...@gmail.com>.
2014-09-16 15:16 GMT+02:00 Konstantin Kolinko <kn...@gmail.com>:
> 2014-09-15 23:01 GMT+04:00 Romain Manni-Bucau <rm...@gmail.com>:
>> Hi guys,
>>
>> in TomEE I'd like to add a filter but after context filter are started
>> (means filterStart() from StandardContext is called).
>>
>
> Why? What is the use case?
>
we add a filter with a tomee service (passing after tomee started)
> You code adds filter definitions. A filter definitions just associates
> filter with a name. A filter is unreachable if it has no mappings for
> it.
> Where are filter mappings for your filter? How do you add filter mappings?
>
full code is:
final FilterDef filterDef = new FilterDef();
filterDef.setAsyncSupported("true");
filterDef.setDescription(description);
filterDef.setFilterName(description);
filterDef.setDisplayName(description);
filterDef.setFilter(new CXFJAXRSFilter(cxfRsHttpListener,
context.findWelcomeFiles()));
filterDef.setFilterClass(CXFJAXRSFilter.class.getName());
context.addFilterDef(filterDef);
String mapping = completePath;
if (!completePath.endsWith("/*")) {
if (completePath.endsWith("*")) {
mapping = completePath.substring(0, completePath.length() - 1);
}
mapping = mapping + "/*";
}
final String urlPattern = removeWebContext(webContext, mapping);
cxfRsHttpListener.setUrlPattern(urlPattern.substring(0,
urlPattern.length() - 1));
final FilterMap filterMap = new FilterMap();
filterMap.addURLPattern(urlPattern);
filterMap.setFilterName(filterDef.getFilterName());
context.addFilterMap(filterMap);
addFilterConfig(context, filterDef); // the hack I sent previously
> When do you add your new filter? Is context already started and
> serving requests, or it has not started yet? Why cannot you add
> filter definition before a filterStart() call?
>
> Do you use "StandardContext" class directly, or you can subclass it?
>
directly, tomee doesn't change StandardContext (one big goal)
> The proper solutions should be to add new API, but I would like the
> answers on the above questions first, as
> a) There shall be some API for filter mappings as well.
> b) If context has already been started, implementation would be more
> complicated.
>
>> What I do today is:
>>
>
> Where do I start with this?
>
> Just several notes on the code.
>
> 1. Missing synchronization. filterStart() uses "synchronized
> (filterConfigs)" Your code does not use synchronization.
>
Actually we don't care that much here since that's still in the start
context (app is not yet fully usable) so multithreading shouldnt
occur, does it in tomcat?
> 2. If you using "setAccessible(true)",
>
> A simpler way would be to mark ApplicationFilterConfig constructor as
> accessible and call it directly instead of playing with filterStart().
>
> Playing with filterStart() without accompanying filterStop() call is broken
>
> filterStart() does "filterConfigs.clear();" as one of the first steps.
> A lot of code in your method are a workaround against that clear()
> call. (You copy the filterConfigs into a temporary map to preserve the
> map entries from being cleared). Essentially this clear() call throws
> away filter instances (wrapped in ApplicationFilterConfig classes)
> without properly destroying them.
>
> You code might break if "filterConfigs" field were marked as"final"
> (as it should be).
>
we already got this before in webapp classloader and until tomcat
supports our feature we forced by reflection the field to not be
final. That said I agree (and why I ask for a simpler API) that it is
mainly workarounds but I don't see why StandardContext is not exposing
it (what would be blocking).
>
>
>> try {
>> final Field def =
>> StandardContext.class.getDeclaredField("filterDefs");
>> if (!def.isAccessible()) {
>> def.setAccessible(true);
>> }
>> final Field config =
>> StandardContext.class.getDeclaredField("filterConfigs");
>> if (!config.isAccessible()) {
>> config.setAccessible(true);
>> }
>> final Object oldDefs = def.get(context);
>> final Map<String, ApplicationFilterConfig> oldConfig = new
>> HashMap<>((Map<String, ApplicationFilterConfig>) config.get(context));
>> try {
>> final Map<String, FilterDef> tempDef = new HashMap<>();
>> tempDef.put(filterDef.getFilterName(), filterDef);
>> def.set(context, tempDef);
>>
>> StandardContext.class.cast(context).filterStart();
>
> Why such code style? The following is shorter.
> ((StandardContext)context).filterStart();
>
>
>> // update configs
>> oldConfig.putAll((Map<String,
>> ApplicationFilterConfig>) config.get(context));
>> } finally {
>> def.set(context, oldDefs);
>> def.set(context, oldConfig);
>> }
>> } catch (final Exception e) {
>> throw new IllegalStateException(e);
>> }
>>
>> but it is really hacky just to get a ApplicationFilterConfig. Is there
>> an easier way I miss or is it possible to make it a bit more easy?
>>
>>
>> Romain Manni-Bucau
>> Twitter: @rmannibucau
>> Blog: http://rmannibucau.wordpress.com/
>> LinkedIn: http://fr.linkedin.com/in/rmannibucau
>> Github: https://github.com/rmannibucau
>>
>
> ---------------------------------------------------------------------
> To unsubscribe, e-mail: dev-unsubscribe@tomcat.apache.org
> For additional commands, e-mail: dev-help@tomcat.apache.org
>
---------------------------------------------------------------------
To unsubscribe, e-mail: dev-unsubscribe@tomcat.apache.org
For additional commands, e-mail: dev-help@tomcat.apache.org
Re: adding an internal filter
Posted by Konstantin Kolinko <kn...@gmail.com>.
2014-09-15 23:01 GMT+04:00 Romain Manni-Bucau <rm...@gmail.com>:
> Hi guys,
>
> in TomEE I'd like to add a filter but after context filter are started
> (means filterStart() from StandardContext is called).
>
Why? What is the use case?
You code adds filter definitions. A filter definitions just associates
filter with a name. A filter is unreachable if it has no mappings for
it.
Where are filter mappings for your filter? How do you add filter mappings?
When do you add your new filter? Is context already started and
serving requests, or it has not started yet? Why cannot you add
filter definition before a filterStart() call?
Do you use "StandardContext" class directly, or you can subclass it?
The proper solutions should be to add new API, but I would like the
answers on the above questions first, as
a) There shall be some API for filter mappings as well.
b) If context has already been started, implementation would be more
complicated.
> What I do today is:
>
Where do I start with this?
Just several notes on the code.
1. Missing synchronization. filterStart() uses "synchronized
(filterConfigs)" Your code does not use synchronization.
2. If you using "setAccessible(true)",
A simpler way would be to mark ApplicationFilterConfig constructor as
accessible and call it directly instead of playing with filterStart().
Playing with filterStart() without accompanying filterStop() call is broken
filterStart() does "filterConfigs.clear();" as one of the first steps.
A lot of code in your method are a workaround against that clear()
call. (You copy the filterConfigs into a temporary map to preserve the
map entries from being cleared). Essentially this clear() call throws
away filter instances (wrapped in ApplicationFilterConfig classes)
without properly destroying them.
You code might break if "filterConfigs" field were marked as"final"
(as it should be).
> try {
> final Field def =
> StandardContext.class.getDeclaredField("filterDefs");
> if (!def.isAccessible()) {
> def.setAccessible(true);
> }
> final Field config =
> StandardContext.class.getDeclaredField("filterConfigs");
> if (!config.isAccessible()) {
> config.setAccessible(true);
> }
> final Object oldDefs = def.get(context);
> final Map<String, ApplicationFilterConfig> oldConfig = new
> HashMap<>((Map<String, ApplicationFilterConfig>) config.get(context));
> try {
> final Map<String, FilterDef> tempDef = new HashMap<>();
> tempDef.put(filterDef.getFilterName(), filterDef);
> def.set(context, tempDef);
>
> StandardContext.class.cast(context).filterStart();
Why such code style? The following is shorter.
((StandardContext)context).filterStart();
> // update configs
> oldConfig.putAll((Map<String,
> ApplicationFilterConfig>) config.get(context));
> } finally {
> def.set(context, oldDefs);
> def.set(context, oldConfig);
> }
> } catch (final Exception e) {
> throw new IllegalStateException(e);
> }
>
> but it is really hacky just to get a ApplicationFilterConfig. Is there
> an easier way I miss or is it possible to make it a bit more easy?
>
>
> Romain Manni-Bucau
> Twitter: @rmannibucau
> Blog: http://rmannibucau.wordpress.com/
> LinkedIn: http://fr.linkedin.com/in/rmannibucau
> Github: https://github.com/rmannibucau
>
---------------------------------------------------------------------
To unsubscribe, e-mail: dev-unsubscribe@tomcat.apache.org
For additional commands, e-mail: dev-help@tomcat.apache.org