blob: defdc399907321aee503b9e366f44cd251eb80a8 (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
|
/*
* ====================================================================
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you 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.
* ====================================================================
*
* This software consists of voluntary contributions made by many
* individuals on behalf of the Apache Software Foundation. For more
* information on the Apache Software Foundation, please see
* <http://www.apache.org/>.
*
*/
package ch.boye.httpclientandroidlib.impl.client.cache;
import java.net.InetAddress;
import java.net.UnknownHostException;
import java.security.NoSuchAlgorithmException;
import java.security.SecureRandom;
import java.util.Formatter;
import java.util.Locale;
import ch.boye.httpclientandroidlib.annotation.GuardedBy;
import ch.boye.httpclientandroidlib.annotation.ThreadSafe;
/**
* Should produce reasonably unique tokens.
*/
@ThreadSafe
class BasicIdGenerator {
private final String hostname;
private final SecureRandom rnd;
@GuardedBy("this")
private long count;
public BasicIdGenerator() {
super();
String hostname;
try {
hostname = InetAddress.getLocalHost().getHostName();
} catch (final UnknownHostException ex) {
hostname = "localhost";
}
this.hostname = hostname;
try {
this.rnd = SecureRandom.getInstance("SHA1PRNG");
} catch (final NoSuchAlgorithmException ex) {
throw new Error(ex);
}
this.rnd.setSeed(System.currentTimeMillis());
}
public synchronized void generate(final StringBuilder buffer) {
this.count++;
final int rndnum = this.rnd.nextInt();
buffer.append(System.currentTimeMillis());
buffer.append('.');
final Formatter formatter = new Formatter(buffer, Locale.US);
formatter.format("%1$016x-%2$08x", this.count, rndnum);
formatter.close();
buffer.append('.');
buffer.append(this.hostname);
}
public String generate() {
final StringBuilder buffer = new StringBuilder();
generate(buffer);
return buffer.toString();
}
}
|
