/**
* Adds an AU extension and associates it with the specified prefix, even before {@link
* DHtmlUpdateServlet} is started.
*
* <p>Unlike {@link #addAuExtension(String, AuExtension)}, it can be called even if the update
* servlet is not loaded yet ({@link #getUpdateServlet} returns null).
*
* <p>If there was an AU extension associated with the same name, the the old AU extension will be
* replaced.
*
* @since 5.0.0
*/
public static final AuExtension addAuExtension(WebApp wapp, String prefix, AuExtension extension)
throws ServletException {
DHtmlUpdateServlet upsv = DHtmlUpdateServlet.getUpdateServlet(wapp);
if (upsv == null) {
synchronized (DHtmlUpdateServlet.class) {
upsv = DHtmlUpdateServlet.getUpdateServlet(wapp);
if (upsv == null) {
checkAuExtension(prefix, extension);
Map aues = (Map) wapp.getAttribute(ATTR_AU_PROCESSORS);
if (aues == null) wapp.setAttribute(ATTR_AU_PROCESSORS, aues = new HashMap(4));
return (AuExtension) aues.put(prefix, extension);
}
}
}
return upsv.addAuExtension(prefix, extension);
}
/**
* Adds an AU extension and associates it with the specified prefix.
*
* <p>If there was an AU extension associated with the same name, the the old AU extension will be
* replaced.
*
* <p>If you want to add an Au extension, even before DHtmlUpdateServlet is started, use {@link
* #addAuExtension(WebApp, String, AuExtension)} instead.
*
* @param prefix the prefix. It must start with "/", but it cannot be "/" nor "/web" (which are
* reserved).
* @param extension the AU extension (never null).
* @return the previous AU extension associated with the specified prefix, or null if the prefix
* was not associated before.
* @see #addAuExtension(WebApp,String,AuExtension)
* @since 5.0.0
*/
public AuExtension addAuExtension(String prefix, AuExtension extension) throws ServletException {
checkAuExtension(prefix, extension);
if (_aues.get(prefix) == extension) // speed up to avoid sync
return extension; // nothing changed
extension.init(this);
// To avoid using sync in doGet(), we make a copy here
final AuExtension old;
synchronized (this) {
final Map ps = new HashMap(_aues);
old = (AuExtension) ps.put(prefix, extension);
_aues = ps;
}
if (old != null)
try {
old.destroy();
} catch (Throwable ex) {
log.warningBriefly("Unable to stop " + old, ex);
}
return old;
}