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https://github.com/tiennm99/lombok.git
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Roel Spilker
66 lines
3.3 KiB
HTML
66 lines
3.3 KiB
HTML
<!DOCTYPE html>
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<html><head>
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<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
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<link rel="stylesheet" type="text/css" href="../logi/reset.css" />
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<link rel="stylesheet" type="text/css" href="features.css" />
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<link rel="shortcut icon" href="../favicon.ico" type="image/x-icon" />
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<meta name="description" content="Spice up your java" />
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<title>@Getter(lazy=true)</title>
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</head><body><div id="pepper">
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<div class="minimumHeight"></div>
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<div class="meat">
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<div class="header"><a href="../index.html">Project Lombok</a></div>
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<h1>@Getter(lazy=true)</h1>
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<div class="byline">Laziness is a virtue!</div>
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<div class="overview">
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<h3>Overview</h3>
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<p>
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<em>NEW IN Lombok 0.10: </em>You can let lombok generate a getter which will calculate a value once, the first time this getter is called, and cache it from then on. This can be useful
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if calculating the value takes a lot of CPU, or the value takes a lot of memory. To use this feature, create a <code>private final</code> variable,
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initialize it with the expression that's expensive to run, and annotate your field with <code>@Getter(lazy=true)</code>. The field will be hidden from the
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rest of your code, and the expression will be evaluated no more than once, when the getter is first called. There are no magic marker values (i.e. even
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if the result of your expensive calculation is <code>null</code>, the result is cached) and your expensive calculation need not be thread-safe, as lombok
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takes care of locking.
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</p>
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</div>
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<div class="snippets">
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<div class="pre">
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<h3>With Lombok</h3>
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<div class="snippet">@HTML_PRE@</div>
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</div>
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<div class="sep"></div>
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<div class="post">
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<h3>Vanilla Java</h3>
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<div class="snippet">@HTML_POST@</div>
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</div>
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</div>
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<div style="clear: left;"></div>
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<div class="overview">
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<h3>Small print</h3><div class="smallprint">
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<p>
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Lombok actually creates a few fields all prefixed with <code>$lombok$</code> to cache the value. You should not rely on the exact type, name, and structure
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of these fields as future implementations may change them. To access the lazily initialized value, <em>always</em> use the generated getter.
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</p><p>
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Other Lombok annotations such as <code>@ToString</code> always call the getter even if you use <code>doNotUseGetters=true</code>.
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</p>
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</div>
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</div>
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<div class="footer">
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<a href="index.html">Back to features</a> | <a href="GetterSetter.html">Previous feature (@Getter / @Setter)</a> | <a href="ToString.html">Next feature (@ToString)</a><br />
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<a href="../credits.html" class="creditsLink">credits</a> | <span class="copyright">Copyright © 2009-2011 The Project Lombok Authors, licensed under the <a href="http://www.opensource.org/licenses/mit-license.php">MIT license</a>.</span>
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</div>
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<div style="clear: both;"></div>
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</div>
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