FilterAttachableImpl.java

/**
 * Logback: the reliable, generic, fast and flexible logging framework.
 * Copyright (C) 1999-2013, QOS.ch. All rights reserved.
 *
 * This program and the accompanying materials are dual-licensed under
 * either the terms of the Eclipse Public License v1.0 as published by
 * the Eclipse Foundation
 *
 *   or (per the licensee's choosing)
 *
 * under the terms of the GNU Lesser General Public License version 2.1
 * as published by the Free Software Foundation.
 */
package ch.qos.logback.core.spi;

import java.util.ArrayList;
import java.util.List;
import java.util.concurrent.CopyOnWriteArrayList;

import ch.qos.logback.core.filter.Filter;

/**
 * Implementation of FilterAttachable.
 * 
 * @author Ceki Gülcü
 */
final public class FilterAttachableImpl<E> implements FilterAttachable<E> {

  CopyOnWriteArrayList<Filter<E>> filterList = new CopyOnWriteArrayList<Filter<E>>();

  /**
   * Add a filter to end of the filter list.
   */
  public void addFilter(Filter<E> newFilter) {
    filterList.add(newFilter);
  }

  /**
   * Clear the filter chain
   */
  public void clearAllFilters() {
    filterList.clear();
  }

  /**
   * Loop through the filters in the list. As soon as a filter decides on
   * ACCEPT or DENY, then that value is returned. If all of the filters return
   * NEUTRAL, then NEUTRAL is returned.
   */
  public FilterReply getFilterChainDecision(E event) {
    for (Filter<E> f : filterList) {
      final FilterReply r = f.decide(event);
      if (r == FilterReply.DENY || r == FilterReply.ACCEPT) {
        return r;
      }
    }
    return FilterReply.NEUTRAL;
  }

  public List<Filter<E>> getCopyOfAttachedFiltersList() {
    return new ArrayList<Filter<E>>(filterList);
  }
}