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
|
<!DOCTYPE html>
<html><head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<link rel="stylesheet" type="text/css" href="../logi/reset.css" />
<link rel="stylesheet" type="text/css" href="features.css" />
<link rel="shortcut icon" href="../favicon.ico" type="image/x-icon" />
<meta name="description" content="Spice up your java" />
<title>@Data</title>
</head><body><div id="pepper">
<div class="minimumHeight"></div>
<div class="meat">
<div class="header"><a href="../index.html">Project Lombok</a></div>
<h1>@Data</h1>
<div class="byline">All together now: A shortcut for <code>@ToString</code>, <code>@EqualsAndHashCode</code>,
<code>@Getter</code> on all fields, <code>@Setter</code> on all non-final fields, and <code>@RequiredArgsConstructor</code>!</div>
<div class="overview">
<h3>Overview</h3>
<p>
<code>@Data</code> is a convenient shortcut annotation that bundles the features of <a href="ToString.html"><code>@ToString</code></a>,
<a href="EqualsAndHashCode.html"><code>@EqualsAndHashCode</code></a>, <a href="GetterSetter.html"><code>@Getter</code> / <code>@Setter</code></a>
and <a href="Constructor.html"><code>@RequiredArgsConstructor</code></a> together: In other words, <code>@Data</code> generates <em>all</em> the
boilerplate that is normally associated with simple POJOs (Plain Old Java Objects) and beans: getters for all fields, setters for all non-final fields,
and appropriate <code>toString</code>, <code>equals</code> and <code>hashCode</code> implementations that involve the fields of the class, and a constructor that
initializes all final fields, as well as all non-final fields with no initializer that have been marked with <code>@NonNull</code>,
in order to ensure the field is never null.
</p><p>
<code>@Data</code> is like having implicit <code>@Getter</code>, <code>@Setter</code>, <code>@ToString</code>, <code>@EqualsAndHashCode</code> and <code>@RequiredArgsConstructor</code>
annotations on the class. However, the parameters of these annotations (such as <code>callSuper</code>, <code>includeFieldNames</code> and
<code>exclude</code>) cannot be set with <code>@Data</code>. If you need to set non-default values for any of these parameters, just add those annotations
explicitly; <code>@Data</code> is smart enough to defer to those annotations.
</p><p>
All generated getters and setters will be <code>public</code>. To override the access level, annotate the field or class with an explicit <code>@Setter</code> and/or
<code>@Getter</code> annotation. You can also use this annotation (by combining it with <code>AccessLevel.NONE</code>) to suppress generating a getter and/or setter
altogether.
</p><p>
All fields marked as <code>transient</code> will not be considered for <code>hashCode</code> and <code>equals</code>. All static fields will be
skipped entirely (not considered for any of the generated methods, and no setter/getter will be made for them).
</p><p>
If the class already contains a method with the same name as any method that would normally be generated, that method is not generated, and no warning or
error is emitted. For example, if you already have a method with signature <code>void hashCode(int a, int b, int c)</code>, no <code>int hashCode()</code>
method will be generated, even though technically <code>int hashCode()</code> is an entirely different method. The same rule applies to the constructor,
<code>toString</code>, <code>equals</code>, and all getters and setters.
</p><p>
<code>@Data</code> can handle generics parameters for fields just fine. In order to reduce the boilerplate when constructing objects for classes with
generics, you can use the <code>staticConstructor</code> parameter to generate a private constructor, as well as a static method that returns a new
instance. This way, javac will infer the variable name. Thus, by declaring like so: <code>@Data(staticConstructor="of") class Foo<T> { private T x;}</code>
you can create new instances of <code>Foo</code> by writing: <code>Foo.of(5);</code> instead of having to write: <code>new Foo<Integer>(5);</code>.
</p>
</div>
<div class="snippets">
<div class="pre">
<h3>With Lombok</h3>
<div class="snippet">@HTML_PRE@</div>
</div>
<div class="sep"></div>
<div class="post">
<h3>Vanilla Java</h3>
<div class="snippet">@HTML_POST@</div>
</div>
</div>
<div style="clear: left;"></div>
<div class="overview">
<h3>Small print</h3><div class="smallprint">
<p>See the small print of <a href="ToString.html"><code>@ToString</code></a>, <a href="EqualsAndHashCode.html"><code>@EqualsAndHashCode</code></a>,
<a href="GetterSetter.html"><code>@Getter / @Setter</code></a> and <a href="Constructor.html">@RequiredArgsConstructor</a>.
</p><p>
Any annotations named <code>@NonNull</code> (case insensitive) on a field are interpreted as: This field must not ever hold
<em>null</em>. Therefore, these annotations result in an explicit null check in the generated constructor for the provided field. Also, these
annotations (as well as any annotation named <code>@Nullable</code>) are copied to the constructor parameter, in both the true constructor and
any static constructor. The same principle applies to generated getters and setters (see the documentation for <a href="GetterSetter.html">@Getter / @Setter</a>)
</p><p>
By default, any variables that start with a $ symbol are excluded automatically.
You can include them by specifying an explicit annotation (<code>@Getter</code> or <code>@ToString</code>, for example) and using the 'of' parameter.
</p>
</div>
</div>
<div class="footer">
<a href="index.html">Back to features</a> | <a href="Constructor.html">Previous feature (@<em>X</em>Constructor)</a> | <a href="Cleanup.html">Next feature (@Cleanup)</a><br />
<a href="../credits.html" class="creditsLink">credits</a> | <span class="copyright">Copyright © 2009-2013 The Project Lombok Authors, licensed under the <a href="http://www.opensource.org/licenses/mit-license.php">MIT license</a>.</span>
</div>
<div style="clear: both;"></div>
</div>
</div>
<script type="text/javascript">
var gaJsHost = (("https:" == document.location.protocol) ? "https://ssl." : "http://www.");
document.write(unescape("%3Cscript src='" + gaJsHost + "google-analytics.com/ga.js' type='text/javascript'%3E%3C/script%3E"));
</script>
<script type="text/javascript">
try {
var pageTracker = _gat._getTracker("UA-9884254-1");
pageTracker._trackPageview();
} catch(err) {}
</script>
</body></html>
|
