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Java > Open Source Codes > org > jivesoftware > smack > filter > AndFilter


1 /**
2  * $RCSfile$
3  * $Revision: 2408 $
4  * $Date: 2004-11-02 20:53:30 -0300 (Tue, 02 Nov 2004) $
5  *
6  * Copyright 2003-2004 Jive Software.
7  *
8  * All rights reserved. Licensed under the Apache License, Version 2.0 (the "License");
9  * you may not use this file except in compliance with the License.
10  * You may obtain a copy of the License at
11  *
12  * http://www.apache.org/licenses/LICENSE-2.0
13  *
14  * Unless required by applicable law or agreed to in writing, software
15  * distributed under the License is distributed on an "AS IS" BASIS,
16  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
17  * See the License for the specific language governing permissions and
18  * limitations under the License.
19  */
20
21 package org.jivesoftware.smack.filter;
22
23 import org.jivesoftware.smack.packet.Packet;
24
25 /**
26  * Implements the logical AND operation over two or more packet filters.
27  * In other words, packets pass this filter if they pass <b>all</b> of the filters.
28  *
29  * @author Matt Tucker
30  */
31 public class AndFilter implements PacketFilter {
32
33     /**
34      * The current number of elements in the filter.
35      */
36     private int size;
37
38     /**
39      * The list of filters.
40      */
41     private PacketFilter [] filters;
42
43     /**
44      * Creates an empty AND filter. Filters should be added using the
45      * {@link #addFilter(PacketFilter)} method.
46      */
47     public AndFilter() {
48         size = 0;
49         filters = new PacketFilter[3];
50     }
51
52     /**
53      * Creates an AND filter using the two specified filters.
54      *
55      * @param filter1 the first packet filter.
56      * @param filter2 the second packet filter.
57      */
58     public AndFilter(PacketFilter filter1, PacketFilter filter2) {
59         if (filter1 == null || filter2 == null) {
60             throw new IllegalArgumentException JavaDoc("Parameters cannot be null.");
61         }
62         size = 2;
63         filters = new PacketFilter[2];
64         filters[0] = filter1;
65         filters[1] = filter2;
66     }
67
68     /**
69      * Adds a filter to the filter list for the AND operation. A packet
70      * will pass the filter if all of the filters in the list accept it.
71      *
72      * @param filter a filter to add to the filter list.
73      */
74     public void addFilter(PacketFilter filter) {
75         if (filter == null) {
76             throw new IllegalArgumentException JavaDoc("Parameter cannot be null.");
77         }
78         // If there is no more room left in the filters array, expand it.
79 if (size == filters.length) {
80             PacketFilter [] newFilters = new PacketFilter[filters.length+2];
81             for (int i=0; i<filters.length; i++) {
82                 newFilters[i] = filters[i];
83             }
84             filters = newFilters;
85         }
86         // Add the new filter to the array.
87 filters[size] = filter;
88         size++;
89     }
90
91     public boolean accept(Packet packet) {
92         for (int i=0; i<size; i++) {
93             if (!filters[i].accept(packet)) {
94                 return false;
95             }
96         }
97         return true;
98     }
99
100     public String JavaDoc toString() {
101         return filters.toString();
102     }
103 }
104
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