1 package org.esigate.util;
2
3 import java.util.Set;
4 import java.util.TreeSet;
5
6 /**
7 * A list that contains some String tokens and is intended to be used as a black list or white list. Methods "add" and
8 * "remove" support single String tokens, comma-separated lists and "*" wildcard expression. The list is
9 * case-insensitive.
10 *
11 * @author Francois-Xavier Bonnet
12 *
13 */
14 public class FilterList {
15 private Set<String> set = new TreeSet<>(String.CASE_INSENSITIVE_ORDER);
16 private boolean defaultContains = false;
17
18 /**
19 * Add some tokens to the list. By default the list is empty. If the list already contains the added tokens or
20 * everything, this method will have no effect.
21 *
22 * @param toAdd
23 * String token to add to the list. This argument can be:
24 * <ul>
25 * <li>A single String token</li>
26 * <li>* (in this case the list will then act as if it contained any token but you will be able to make
27 * except some tokens using the remove method)</li>
28 * </ul>
29 */
30 public void add(String toAdd) {
31 if (toAdd.contains("*")) {
32 set.clear();
33 defaultContains = true;
34 } else {
35 if (!defaultContains) {
36 set.add(toAdd);
37 } else {
38 set.remove(toAdd);
39 }
40 }
41 }
42
43 /**
44 * Remove some tokens from the list. If the list is already empty or does not contains the tokens, this method will
45 * have no effect.
46 *
47 * @param toRemove
48 * String tokens to add to the list. This argument can be:
49 * <ul>
50 * <li>A single String token</li>
51 * <li>* (in this case the list will then be empty again)</li>
52 * </ul>
53 */
54 public void remove(String toRemove) {
55 if (toRemove.contains("*")) {
56 set.clear();
57 defaultContains = false;
58 } else {
59 if (defaultContains) {
60 set.add(toRemove);
61 } else {
62 set.remove(toRemove);
63 }
64 }
65 }
66
67 /**
68 * @param token
69 * @return true if the list contains the token
70 */
71 public boolean contains(String token) {
72 if (defaultContains) {
73 return !set.contains(token);
74 } else {
75 return set.contains(token);
76 }
77 }
78 }