src/org/jivesoftware/smack/filter/AndFilter.java

/**
 * $RCSfile$
 * $Revision$
 * $Date$
 *
 * Copyright 2003-2007 Jive Software.
 *
 * All rights reserved. Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.jivesoftware.smack.filter;

import org.jivesoftware.smack.packet.Packet;

import java.util.List;
import java.util.ArrayList;

/**
 * Implements the logical AND operation over two or more packet filters.
 * In other words, packets pass this filter if they pass <b>all</b> of the filters.
 *
 * @author Matt Tucker
 */
public class AndFilter implements PacketFilter {

    /**
     * The list of filters.
     */
    private List<PacketFilter> filters = new ArrayList<PacketFilter>();

    /**
     * Creates an empty AND filter. Filters should be added using the
     * {@link #addFilter(PacketFilter)} method.
     */
    public AndFilter() {

    }

    /**
     * Creates an AND filter using the specified filters.
     *
     * @param filters the filters to add.
     */
    public AndFilter(PacketFilter... filters) {
        if (filters == null) {
            throw new IllegalArgumentException("Parameter cannot be null.");
        }
        for(PacketFilter filter : filters) {
            if(filter == null) {
                throw new IllegalArgumentException("Parameter cannot be null.");
            }
            this.filters.add(filter);
        }
    }

    /**
     * Adds a filter to the filter list for the AND operation. A packet
     * will pass the filter if all of the filters in the list accept it.
     *
     * @param filter a filter to add to the filter list.
     */
    public void addFilter(PacketFilter filter) {
        if (filter == null) {
            throw new IllegalArgumentException("Parameter cannot be null.");
        }
        filters.add(filter);
    }

    public boolean accept(Packet packet) {
        for (PacketFilter filter : filters) {
            if (!filter.accept(packet)) {
                return false;
            }
        }
        return true;
    }

    public String toString() {
        return filters.toString();
    }
}