1 /*
2 * Licensed to the Apache Software Foundation (ASF) under one or more
3 * contributor license agreements. See the NOTICE file distributed with
4 * this work for additional information regarding copyright ownership.
5 * The ASF licenses this file to You under the Apache License, Version 2.0
6 * (the "License"); you may not use this file except in compliance with
7 * the License. You may obtain a copy of the License at
8 *
9 * http://www.apache.org/licenses/LICENSE-2.0
10 *
11 * Unless required by applicable law or agreed to in writing, software
12 * distributed under the License is distributed on an "AS IS" BASIS,
13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14 * See the License for the specific language governing permissions and
15 * limitations under the License.
16 */
17
18 package org.apache.any23.extractor.microdata;
19
20 /**
21 * Base class for <b>Microdata</b> items.
22 *
23 * @author Michele Mostarda (mostarda@fbk.eu)
24 */
25 public abstract class Item {
26
27 /**
28 * Xpath item location in container document.
29 */
30 private final String xpath;
31
32 /**
33 * Constructor.
34 *
35 * @param xpath
36 * xpath to this item in container document.
37 */
38 public Item(String xpath) {
39 if (xpath == null) {
40 throw new NullPointerException("xpath cannot be null.");
41 }
42 this.xpath = xpath;
43 }
44
45 /**
46 * @return the <b>JSON</b> representation for this item.
47 */
48 public abstract String toJSON();
49
50 /**
51 * @return the item location in container document.
52 */
53 public String getXpath() {
54 return xpath;
55 }
56
57 @Override
58 public int hashCode() {
59 return xpath.hashCode();
60 }
61
62 @Override
63 public boolean equals(Object obj) {
64 if (obj == null) {
65 return false;
66 }
67 if (obj == this) {
68 return true;
69 }
70 if (obj instanceof Item) {
71 final Item other = (Item) obj;
72 return xpath.equals(other.xpath);
73 }
74 return false;
75 }
76 }