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.commons.vfs2.util;
18
19 /**
20 * Creates an instance of {@link Cryptor}.
21 *
22 * @since 2.0
23 */
24 public final class CryptorFactory {
25
26 /**
27 * The System property name to identify the Cryptor class to be used.
28 */
29 public static final String CRYPTOR_CLASS = "org.apache.commons.vfs2.cryptor";
30
31 private static Cryptor instance;
32
33 /**
34 * Gets the Cryptor. If one has not been previously set, create it. The Cryptor class can be set by setting the
35 * "org.apache.commons.vfs2.cryptor" System property to the name of the Cryptor class.
36 *
37 * @return The Cryptor.
38 */
39 public static synchronized Cryptor getCryptor() {
40 if (instance != null) {
41 return instance;
42 }
43
44 final String cryptorClass = System.getProperty(CRYPTOR_CLASS);
45 if (cryptorClass != null) {
46 try {
47 final Class<?> clazz = Class.forName(cryptorClass);
48 instance = (Cryptor) clazz.getConstructor().newInstance();
49 return instance;
50 } catch (final Exception ex) {
51 throw new IllegalStateException("Unable to create Cryptor " + cryptorClass, ex);
52 }
53 }
54 instance = new DefaultCryptor();
55 return instance;
56 }
57
58 /**
59 * Allows the Cryptor class to be set programmatically.
60 *
61 * @param cryptor The Cryptor.
62 */
63 public static synchronized void setCryptor(final Cryptor cryptor) {
64 instance = cryptor;
65 }
66
67 /**
68 * Prevent instantiation of the class.
69 */
70 private CryptorFactory() {
71
72 }
73 }