1 /*
2 * Copyright 2009 the original author or authors.
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16 package org.openehealth.ipf.commons.ihe.xds.core.ebxml;
17
18 import java.util.Collection;
19 import java.util.Collections;
20 import java.util.HashMap;
21 import java.util.Map;
22
23 /**
24 * A container of objects used for resolving object references and their ids.
25 * @author Jens Riemschneider
26 */
27 public class EbXMLObjectLibrary {
28 private final Map<String, Object> objLib = new HashMap<>();
29 private final Map<Object, String> reverseLib = new HashMap<>();
30
31 /**
32 * Puts an object into the library.
33 * <p>
34 * The object will only be added if both parameters are non-<code>null</code>.
35 * @param id
36 * the id of the object. Can be <code>null</code>.
37 * @param obj
38 * the object. Can be <code>null</code>.
39 */
40 public void put(String id, Object obj) {
41 if (id != null && obj != null) {
42 objLib.put(id, obj);
43 reverseLib.put(obj, id);
44 }
45 }
46
47 /**
48 * Looks up an object via its ID.
49 * @param id
50 * the id. Can be <code>null</code>.
51 * @return the object or <code>null</code> if the input was <code>null</code>
52 * of if the library does not contain an object with the given id.
53 */
54 public Object getById(String id) {
55 if (id == null) {
56 return null;
57 }
58 return objLib.get(id);
59 }
60
61 /**
62 * Looks up an ID via its object.
63 * @param obj
64 * the object. Can be <code>null</code>.
65 * @return the ID or <code>null</code> if the input was <code>null</code>
66 * or if the library does not contain the object.
67 */
68 public String getByObj(Object obj) {
69 if (obj == null) {
70 return null;
71 }
72 return reverseLib.get(obj);
73 }
74
75 /**
76 * @return a read-only collection of all objects in the library.
77 */
78 public Collection<Object> getObjects() {
79 return Collections.unmodifiableCollection(objLib.values());
80 }
81 }