1 /**
2 * Licensed to the Apache Software Foundation (ASF) under one or more
3 * contributor license agreements. See the NOTICE file distributed with
4 * this work for additional information regarding copyright ownership.
5 * The ASF licenses this file to You under the Apache License, Version 2.0
6 * (the "License"); you may not use this file except in compliance with
7 * the License. You may obtain a copy of the License at
8 *
9 * http://www.apache.org/licenses/LICENSE-2.0
10 *
11 * Unless required by applicable law or agreed to in writing, software
12 * distributed under the License is distributed on an "AS IS" BASIS,
13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14 * See the License for the specific language governing permissions and
15 * limitations under the License.
16 */
17 package org.apache.tika.mime;
18
19 /**
20 * Defines a clause to be evaluated.
21 *
22 *
23 */
24 interface Clause {
25
26 /** A clause that is always true. */
27 final static Clause TRUE = new True();
28
29 /** A clause that is always false. */
30 final static Clause FALSE = new False();
31
32 /**
33 * Evaluates this clause with the specified chunk of data.
34 */
35 public boolean eval(byte[] data);
36
37 /**
38 * Returns the size of this clause. The size of a clause is the number of
39 * chars it is composed of.
40 */
41 public int size();
42
43 final static class False implements Clause {
44 public boolean eval(byte[] data) {
45 return false;
46 }
47
48 public int size() {
49 return 0;
50 }
51
52 public String toString() {
53 return "FALSE";
54 }
55 }
56
57 final static class True implements Clause {
58 public boolean eval(byte[] data) {
59 return true;
60 }
61
62 public int size() {
63 return 0;
64 }
65
66 public String toString() {
67 return "TRUE";
68 }
69 }
70
71 }