This problem occurs only on linux. When run on 1.5 and winXP, everything works fine.

When application that utilized struts-menu 2.3 is under load that is simulated be openload, struts-menu crashes one thread after another untill the whole app dies.

Here is the exception that is thrown:

java.lang.NullPointerException
at net.sf.navigator.taglib.DisplayMenuTag.setLocation(DisplayMenuTag.java:217)
at net.sf.navigator.taglib.DisplayMenuTag.setPageLocation(DisplayMenuTag.java:173)
at net.sf.navigator.taglib.DisplayMenuTag.setPageLocation(DisplayMenuTag.java:205)
at net.sf.navigator.taglib.DisplayMenuTag.doStartTag(DisplayMenuTag.java:123)

According to the stacktrace the exception is thrown DisplayMenuTag.java:217:
 protected void setLocation(MenuComponent menu) throws MalformedURLException {
211 HttpServletRequest request =
212 (HttpServletRequest) pageContext.getRequest();
213
214 // if the location attribute is null,
215 // then set it with a context relative page
216 // attribute if it exists
217 if (menu.getLocation() == null) { ---> here is the exception.
......................
.....................


. Looking through the code revealed that menus are reinitialized on every request (should it be static and cached??) and it uses ArrayList to hold the submenu elements, see MenuComponent.
Once I substituted ArrayList to Vector, the problem was gone.

29 //~ Instance fields ========================================================
30
31 protected List menuComponents = new ArrayList(); ---> ArrayList for some reason created problems
32 protected MenuComponent parentMenu = null;
33