org.ocap.application.AppFilter Maven / Gradle / Ivy
package org.ocap.application;
import org.dvb.application.AppID;
import org.dvb.application.AppsDatabaseFilter;
import java.util.Enumeration;
/**
* AppFilter provides a means of filtering AppIDs. As a
* subclass of {@link AppsDatabaseFilter}, the method {@link #accept}
* makes a true/false decision based on an AppID.
*
* An AppFilter contains a list of zero or more {@link AppPattern}s. Each
* AppPattern has the attributes: pattern, action, and
* priority. pattern specifies a group of AppIDs with
* a pair of ranges for organization ID and application ID.
* action specifies an action assigned to the AppID group;
* either {@link AppPattern#ALLOW}, {@link AppPattern#DENY}, or {@link
* AppPattern#ASK}. priority specifies this AppPattern's
* position in the search order: the biggest number comes first.
* Applications can insert an AppPattern anywhere in the search
* order by using the priority attribute effectively
* (AppFilter.add). When two or more AppPatterns in an
* AppFilter have the same priority, the search order among them is
* undefined. It is not recommendable to use AppPatterns that have the
* same priority but different actions.
*
*
When accept is called, the given AppID is compared to
* the AppID group of each AppPattern in the search order until a match
* is found. Then, it returns true or false
* if the action of matching AppPattern is ALLOW or
* DENY respectively. If no match is found,
* accept returns true.
*
*
If the action of matching AppPattern is ASK, then
* AppFilter calls AppFilterHandler.accept for the final
* decision; the matching AppPattern is handed over to this method.
* Applications can specify the AppFilterHandler with
* AppFilter.setAskHandler. If no AppFilterHandler is set,
* AppFilter returns true.
*
*
*
AppPatterns can have an expiration time and MSO-private
* information (expirationTime and info).
* accept and getAppPatterns methods ignore
* AppPatterns that have expired. The implementation may delete expired
* AppPatterns from AppFilter.
*
*
Example:
*
*
* import org.ocap.application.*;
* import org.dvb.application.AppID;
*
* AppManagerProxy am = ...;
* AppPattern[] patterns = {
* /* note that search order is dictated by "priority" */
* new AppPattern("10-5f:1-ff", AppPattern.ALLOW, 40), // #3
* new AppPattern("30:2c-34", AppPattern.ALLOW, 100), // #1
* new AppPattern("20-40", AppPattern.DENY, 80), // #2
* };
* AppFilter af = new AppFilter(patterns);
*
* /* false - matches "20-40" */
* boolean badOne = af.accept(new AppID(0x30, 0x10));
*
* /* true - matches "30:2c-34" */
* boolean goodOne = af.accept(new AppID(0x30, 0x30));
*
* /* will be the second entry: priority between 100 and 80 */
* af.add(new AppPattern("40-4f:1000-1fff", DENY, 90));
*
* /* register af with the system */
* am.setAppFilter(af);
*
*
* @see AppPattern
* @see AppFilterHandler
* @see AppManagerProxy
* @see org.dvb.application.AppID
* @see org.dvb.application.AppsDatabaseFilter
*/
public class AppFilter extends AppsDatabaseFilter {
/**
* Constructs an empty AppFilter.
*/
public AppFilter() {
}
/**
* Constructs an AppFilter with initial AppPatterns.
*
* @param patterns AppPatterns to constitute an AppFilter.
*/
public AppFilter(AppPattern[] patterns) {
}
/**
* Returns the AppPatterns in this AppFilter.
*
* @return the enumeration of AppPatterns. When this AppFilter
* has no AppPattern, this method returns an empty Enumeration,
* not null.
*/
public Enumeration getAppPatterns() {
return null;
}
/**
* Returns whether this AppFilter accepts the given AppID.
*
* @param appID an AppID to test.
*
* @return true if appID passes this
* filter.
*/
public boolean accept(AppID appID) {
return true;
}
/**
* Adds an AppPattern to this AppFilter.
*
* @param pattern the AppPattern to add
*/
public void add(AppPattern pattern) {
}
/**
* Removes an AppPattern that equals to pattern in this
* AppFilter. If this AppFilter does not contain
* pattern, it is unchanged.
*
* @param pattern the AppPattern to remove.
*
* @return true if the AppFilter contained the
* specified AppPattern.
*
* @see AppPattern#equals
*/
public boolean remove(AppPattern pattern) {
return false;
}
/**
* Sets the handler to call when accept hits an
* AppPatterns with action {@link AppPattern#ASK}.
*
* If a handler is already registered with this AppFilter, the
* new handler replaces it.
*
* @param handler the handler to set.
*/
public void setAskHandler(AppFilterHandler handler) {
}
}