Method: static {...}

1: /**
2: * Copyright (C) 2016 Czech Technical University in Prague
3: *
4: * This program is free software: you can redistribute it and/or modify it under
5: * the terms of the GNU General Public License as published by the Free Software
6: * Foundation, either version 3 of the License, or (at your option) any
7: * later version.
8: *
9: * This program is distributed in the hope that it will be useful, but WITHOUT
10: * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
11: * FOR A PARTICULAR PURPOSE. See the GNU General Public License for more
12: * details. You should have received a copy of the GNU General Public License
13: * along with this program. If not, see <http://www.gnu.org/licenses/>.
14: */
15: package cz.cvut.kbss.jopa.oom;
16:
17: import java.net.URI;
18: import java.util.HashMap;
19: import java.util.Map;
20:
21: class InstanceRegistry {
22:
23: protected Map<URI, Map<URI, Object>> instances = new HashMap<>();
24:
25: <T> void registerInstance(URI primaryKey, T instance, URI context) {
26: assert primaryKey != null;
27:
28: if (!instances.containsKey(context)) {
29: instances.put(context, new HashMap<>());
30: }
31: instances.get(context).put(primaryKey, instance);
32: }
33:
34: boolean containsInstance(URI primaryKey, URI context) {
35: return instances.containsKey(context) && instances.get(context).containsKey(primaryKey);
36: }
37:
38: Object getInstance(URI primaryKey, URI context) {
39: if (instances.containsKey(context) && instances.get(context).containsKey(primaryKey)) {
40: return instances.get(context).get(primaryKey);
41: }
42: return null;
43: }
44:
45: void reset() {
46: this.instances = new HashMap<>();
47: }
48: }