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<title>@Data</title>
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<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, and <code>@Setter</code> on all non-final fields. You even
get a free constructor to initialize your final fields!</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">@EqualsAndHashCode</code></a> and <a href="GetterSetter.html"><code>@Getter</code> / <code>@Setter</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. In addition, <code>@Data</code> generates a constructor that
initialized all final fields.
</p><p>
<code>@Data</code> is like having implicit <code>@ToString</code> and <code>@EqualsAndHashCode</code> annotations on the class.
However, the parameters of <code>@ToString</code> and <code>@EqualsAndHashCode</code> (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 with an explicit <code>@Setter</code> and/or
<code>@Getter</code> annotation.
</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>
Arrays are 'deep' compared/printed/hashCoded, which means that arrays that contain themselves will result in <code>StackOverflowError</code>s. However,
this behaviour is no different from e.g. <code>ArrayList</code>.
</p><p>
For a general idea of how lombok generated the <code>equals</code>, <code>hashCode</code>, and <code>toString</code> methods, check the example after.
</p><p>
For the purposes of equality, 2 <code>NaN</code> (not a number) values for floats and doubles are considered equal, eventhough 'NaN == NaN' would
return false. This is analogous to <code>java.lang.Double</code>'s equals method, and is in fact required to ensure that comparing an object
to an exact copy of itself returns <code>true</code> for equality.
</p>
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