1 /*
2 * Copyright (c) 2004-2009 QOS.ch
3 * All rights reserved.
4 *
5 * Permission is hereby granted, free of charge, to any person obtaining
6 * a copy of this software and associated documentation files (the
7 * "Software"), to deal in the Software without restriction, including
8 * without limitation the rights to use, copy, modify, merge, publish,
9 * distribute, sublicense, and/or sell copies of the Software, and to
10 * permit persons to whom the Software is furnished to do so, subject to
11 * the following conditions:
12 *
13 * The above copyright notice and this permission notice shall be
14 * included in all copies or substantial portions of the Software.
15 *
16 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
17 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
18 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
19 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
20 * LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
21 * OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
22 * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
23 */
24 package org.slf4j;
25
26 import org.slf4j.MDC;
27
28 public class NDC {
29 public final static String PREFIX = "NDC";
30
31 private static int size() {
32 int i = 0;
33 while (true) {
34 String val = MDC.get(PREFIX + i);
35 if (val != null) {
36 i++;
37 } else {
38 break;
39 }
40 }
41 return i;
42 }
43
44 public static void push(String val) {
45 int next = size();
46 MDC.put(PREFIX + next, val);
47 }
48
49 public static String pop() {
50 int next = size();
51 if(next == 0) {
52 return "";
53 }
54 int last = next-1;
55 String key = PREFIX+last;
56 String val = MDC.get(key);
57 MDC.remove(key);
58 return val;
59 }
60
61 }