1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
|
/*
* ============LICENSE_START=======================================================
* ONAP
* ================================================================================
* Copyright (C) 2019-2020 AT&T Intellectual Property. All rights reserved.
* ================================================================================
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
* ============LICENSE_END=========================================================
*/
package org.onap.policy.common.utils.coder;
import com.google.gson.JsonArray;
import com.google.gson.JsonElement;
import java.io.Serializable;
/**
* Object type used by the {@link StandardCoder}. Different serialization tools have
* different "standard objects". For instance, GSON uses {@link JsonElement}. This class
* wraps that object so that it can be used without exposing the object, itself.
*/
public class StandardCoderObject implements Serializable {
private static final long serialVersionUID = 1L;
/**
* Data wrapped by this.
*/
private final JsonElement data;
/**
* Constructs the object.
*/
public StandardCoderObject() {
data = null;
}
/**
* Constructs the object.
*
* @param data data wrapped by this object.
*/
protected StandardCoderObject(JsonElement data) {
this.data = data;
}
/**
* Gets the data wrapped by this.
*
* @return the data wrapped by this
*/
protected JsonElement getData() {
return data;
}
/**
* Gets a field's value from this object, traversing the object hierarchy.
*
* @param fields field hierarchy. These may be strings, identifying fields within the
* object, or Integers, identifying an index within an array
* @return the field value or {@code null} if the field does not exist or is not a
* primitive
*/
public String getString(Object... fields) {
JsonElement jel = data;
for (Object field : fields) {
if (jel == null) {
return null;
}
if (field instanceof String) {
jel = getFieldFromObject(jel, field.toString());
} else if (field instanceof Integer) {
jel = getItemFromArray(jel, (int) field);
} else {
throw new IllegalArgumentException("subscript is not a string or integer: " + field);
}
}
return (jel != null && jel.isJsonPrimitive() ? jel.getAsString() : null);
}
/**
* Gets an item from an object.
*
* @param element object from which to extract the item
* @param field name of the field from which to extract the item
* @return the item, or {@code null} if the element is not an object or if the field
* does not exist
*/
protected JsonElement getFieldFromObject(JsonElement element, String field) {
if (!element.isJsonObject()) {
return null;
}
return element.getAsJsonObject().get(field);
}
/**
* Gets an item from an array.
*
* @param element array from which to extract the item
* @param index index of the item to extract
* @return the item, or {@code null} if the element is not an array or if the index is
* out of bounds
*/
protected JsonElement getItemFromArray(JsonElement element, int index) {
if (index < 0) {
throw new IllegalArgumentException("subscript is invalid: " + index);
}
if (!element.isJsonArray()) {
return null;
}
JsonArray array = element.getAsJsonArray();
if (index >= array.size()) {
return null;
}
return array.get(index);
}
}
|
