Classes in this File | Line Coverage | Branch Coverage | Complexity | ||||
SourceFilterFactory |
|
| 1.25;1.25 |
1 | /** | |
2 | * Distribution License: | |
3 | * JSword is free software; you can redistribute it and/or modify it under | |
4 | * the terms of the GNU Lesser General Public License, version 2.1 or later | |
5 | * as published by the Free Software Foundation. This program is distributed | |
6 | * in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even | |
7 | * the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. | |
8 | * See the GNU Lesser General Public License for more details. | |
9 | * | |
10 | * The License is available on the internet at: | |
11 | * http://www.gnu.org/copyleft/lgpl.html | |
12 | * or by writing to: | |
13 | * Free Software Foundation, Inc. | |
14 | * 59 Temple Place - Suite 330 | |
15 | * Boston, MA 02111-1307, USA | |
16 | * | |
17 | * © CrossWire Bible Society, 2005 - 2016 | |
18 | * | |
19 | */ | |
20 | package org.crosswire.jsword.book.filter; | |
21 | ||
22 | import java.util.HashMap; | |
23 | import java.util.Locale; | |
24 | import java.util.Map; | |
25 | ||
26 | import org.crosswire.common.util.PluginUtil; | |
27 | import org.slf4j.Logger; | |
28 | import org.slf4j.LoggerFactory; | |
29 | ||
30 | /** | |
31 | * A simple container for all the known SourceFilters. | |
32 | * | |
33 | * @see gnu.lgpl.License The GNU Lesser General Public License for details. | |
34 | * @author Joe Walker | |
35 | */ | |
36 | public final class SourceFilterFactory { | |
37 | /** | |
38 | * Prevent instantiation | |
39 | */ | |
40 | 0 | private SourceFilterFactory() { |
41 | 0 | } |
42 | ||
43 | /** | |
44 | * Find a filter given a lookup string. If lookup is null or the filter is | |
45 | * not found then the default filter will be used. | |
46 | * | |
47 | * @param lookup the lookup string for the filter | |
48 | * @return the matching filter | |
49 | */ | |
50 | public static SourceFilter getFilter(String lookup) { | |
51 | 0 | SourceFilter reply = filters.get(lookup.toLowerCase(Locale.ENGLISH)); |
52 | ||
53 | 0 | if (reply == null) { |
54 | 0 | reply = deft; |
55 | } | |
56 | ||
57 | 0 | return reply.clone(); |
58 | } | |
59 | ||
60 | /** | |
61 | * Find a filter given a lookup string | |
62 | * | |
63 | * @return the default filter | |
64 | */ | |
65 | public static SourceFilter getDefaultFilter() { | |
66 | 0 | return deft.clone(); |
67 | } | |
68 | ||
69 | /** | |
70 | * Add to our list of known filters | |
71 | * | |
72 | * @param name | |
73 | * @param instance | |
74 | */ | |
75 | public static void addFilter(String name, SourceFilter instance) { | |
76 | 0 | filters.put(name.toLowerCase(Locale.ENGLISH), instance); |
77 | 0 | } |
78 | ||
79 | /** | |
80 | * The lookup table of filters | |
81 | */ | |
82 | 0 | private static Map<String, SourceFilter> filters = new HashMap<String, SourceFilter>(); |
83 | ||
84 | /** | |
85 | * The log stream | |
86 | */ | |
87 | 0 | private static final Logger log = LoggerFactory.getLogger(SourceFilterFactory.class); |
88 | ||
89 | /** | |
90 | * The lookup table of filters | |
91 | */ | |
92 | private static volatile SourceFilter deft; | |
93 | ||
94 | /** | |
95 | * Populate the lookup table of filters and the default from the properties | |
96 | * file. | |
97 | */ | |
98 | static { | |
99 | 0 | Map<String, Class<SourceFilter>> map = PluginUtil.getImplementorsMap(SourceFilter.class); |
100 | ||
101 | // the default value | |
102 | try { | |
103 | 0 | Class<SourceFilter> cdeft = map.remove("default"); |
104 | 0 | deft = cdeft.newInstance(); |
105 | 0 | } catch (InstantiationException e) { |
106 | 0 | log.error("Failed to get default filter, will attempt to use first", e); |
107 | 0 | } catch (IllegalAccessException e) { |
108 | 0 | log.error("Failed to get default filter, will attempt to use first", e); |
109 | 0 | } |
110 | ||
111 | // the lookup table | |
112 | 0 | SourceFilter instance = null; |
113 | 0 | for (Map.Entry<String, Class<SourceFilter>> entry : map.entrySet()) { |
114 | try { | |
115 | 0 | Class<SourceFilter> clazz = entry.getValue(); |
116 | 0 | instance = clazz.newInstance(); |
117 | 0 | addFilter(entry.getKey(), instance); |
118 | 0 | } catch (InstantiationException ex) { |
119 | 0 | log.error("Failed to add filter", ex); |
120 | 0 | } catch (IllegalAccessException ex) { |
121 | 0 | log.error("Failed to add filter", ex); |
122 | 0 | } |
123 | } | |
124 | ||
125 | // if the default didn't work then make a stab at an answer | |
126 | 0 | if (deft == null) { |
127 | 0 | deft = instance; |
128 | } | |
129 | 0 | } |
130 | } |