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<h1>@NonNull</h1>
<div class="byline">or: How I learned to stop worrying and love the NullPointerException.</div>
<div class="overview">
<h3>Overview</h3>
<p>
<em>NEW in Lombok 0.11.10: </em>You can use <code>@NonNull</code> on the parameter of a method or constructor to have lombok generate a null-check statement for you.
</p><p>
Lombok has always treated any annotation named <code>@NonNull</code> on a field as a signal to generate a null-check if lombok generates an entire method or constructor for you, via
for example <a href="Data.html"><code>@Data</code></a>. Now, however, using lombok's own <code>@lombok.NonNull</code> on a parameter results in the insertion of just the null-check
statement inside your own method or constructor.
</p><p>
The null-check looks like <code>if (param == null) throw new NullPointerException("param");</code> and will be inserted at the very top of your method. For constructors, the null-check
will be inserted immediately following any explicit <code>this()</code> or <code>super()</code> calls.
</p><p>
If a null-check is already present at the top, no additional null-check will be generated.
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<h3>With Lombok</h3>
<div class="snippet">@HTML_PRE@</div>
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<h3>Vanilla Java</h3>
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<h3>Small print</h3><div class="smallprint">
<p>
Lombok's detection scheme for already existing null-checks consists of scanning for if statements that look just like lombok's own. Any 'throws' statement as
the 'then' part of the if statement, whether in braces or not, counts. The conditional of the if statement <em>must</em> look exactly like <code>PARAMNAME == null</code>.
The first statement in your method that is not such a null-check stops the process of inspecting for null-checks.
</p><p>
While <code>@Data</code> and other method-generating lombok annotations will trigger on any annotation named <code>@NonNull</code> regardless of casing or package name,
this feature only triggers on lombok's own <code>@NonNull</code> annotation from the <code>lombok</code> package.
</p><p>
A <code>@NonNull</code> on a primitive parameter results in a warning. No null-check will be generated.
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