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
|
// Copyright 2017 Yahoo Holdings. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
package com.yahoo.text;
import com.fasterxml.jackson.databind.JsonNode;
import com.fasterxml.jackson.databind.ObjectMapper;
import java.util.Map;
import java.util.Objects;
import static com.yahoo.yolean.Exceptions.uncheck;
/**
* Static methods for working with JSON.
*
* @author bratseth
*/
public final class JSON {
private static final ObjectMapper mapper = new ObjectMapper();
/** No instances */
private JSON() {}
/**
* Outputs a map as a JSON 'object' string, provided that the map values
* are either
* <ul>
* <li>String
* <li>Number
* <li>Any object whose toString returns JSON
* </ul>
*/
public static String encode(Map<String, ?> map) {
StringBuilder b = new StringBuilder("{");
for (Map.Entry<String,?> entry : map.entrySet()) {
b.append("\"").append(escape(entry.getKey())).append("\":");
if (entry.getValue() instanceof String)
b.append("\"").append(escape(entry.getValue().toString())).append("\"");
else // Number, or some other object which returns JSON
b.append(entry.getValue());
b.append(",");
}
if (b.length()>1)
b.setLength(b.length()-1); // remove last comma
b.append("}");
return b.toString();
}
/** Returns the given string as a properly json escaped string */
public static String escape(String s) {
StringBuilder b = null; // lazy create to optimize for "nothing to do" case
for (int i=0; i < s.length(); i = s.offsetByCodePoints(i, 1)) {
final int codepoint = s.codePointAt(i);
if (codepoint == '"') {
if (b == null)
b = new StringBuilder(s.substring(0, i));
b.append('\\');
}
if (b != null)
b.appendCodePoint(codepoint);
}
return b != null ? b.toString() : s;
}
/**
* Test whether two JSON strings are equal, e.g. the order of fields in an object is irrelevant.
*
* <p>When comparing two numbers of the two JSON strings, the result is only guaranteed to be
* correct if (a) both are integers (without fraction and exponent) and each fits in a long, or
* (b) both are non-integers, were syntactically identical, and fits in a double.</p>
*/
public static boolean equals(String left, String right) {
JsonNode leftJsonNode = uncheck(() -> mapper.readTree(left));
JsonNode rightJsonNode = uncheck(() -> mapper.readTree(right));
return Objects.equals(leftJsonNode, rightJsonNode);
}
}
|
