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| author | Reinier Zwitserloot <reinier@zwitserloot.com> | 2012-08-13 00:11:02 +0200 |
|---|---|---|
| committer | Reinier Zwitserloot <reinier@zwitserloot.com> | 2012-08-13 00:11:02 +0200 |
| commit | 8850798a04e7f44925ed16b3450623b02f5b6295 (patch) | |
| tree | 7e40b1f95e1ad082ee135bf3ae9b1de4e946d2d4 /website/features/experimental/Value.html | |
| parent | 42f5a55d69850603d951a65929f48a3b462b54ea (diff) | |
| download | lombok-8850798a04e7f44925ed16b3450623b02f5b6295.tar.gz lombok-8850798a04e7f44925ed16b3450623b02f5b6295.tar.bz2 lombok-8850798a04e7f44925ed16b3450623b02f5b6295.zip | |
Documentation for @Value, @FieldDefaults, @Wither
Diffstat (limited to 'website/features/experimental/Value.html')
| -rw-r--r-- | website/features/experimental/Value.html | 87 |
1 files changed, 87 insertions, 0 deletions
diff --git a/website/features/experimental/Value.html b/website/features/experimental/Value.html new file mode 100644 index 00000000..464f0966 --- /dev/null +++ b/website/features/experimental/Value.html @@ -0,0 +1,87 @@ +<!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>EXPERIMENTAL - @ExtensionMethod</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>@Value</h1> + <div class="byline">Immutable classes made very easy.</div> + <div class="since"> + <h3>Since</h3> + <p> + @Value was introduced as experimental feature in lombok v0.11.4. + </p> + </div> + <div class="experimental"> + <h3>Experimental</h3> + <p> + Experimental because: + <ul> + <li>Various choices still have to be vetted as being the correct 'least surprise' choice: Should the class be made final by default, etc.</li> + <li>Dependent on @Wither which is experimental.</li> + </ul> + Current status: <em>positive</em> - Currently we feel this feature may move out of experimental status with no or minor changes soon. + </div> + <div class="overview"> + <h3>Overview</h3> + <p> + <code>@Value</code> is the immutable variant of <a href="../Data.html"><code>@Data</code></a>; all fields are made <code>private</code> and <code>final</code> by default, and instead of setters, each field gets a so-called 'wither', + which is a method that produces a clone with each field having the same value, except for the field you want a new value for. The class itself is also made <code>final</code> by default, because immutability is not something that can + be forced onto a subclass. Like <code>@Data</code>, useful <code>toString()</code>, <code>equals()</code> and <code>hashCode()</code> methods are also generated, each field gets a getter method, and a constructor that covers every + argument (except <code>final</code> fields that are initialized in the field declaration) is also generated. + </p><p> + In practice, <code>@Value</code> is shorthand for: <code>final @ToString @EqualsAndHashCode @AllArgsConstructor @FieldDefaults(makeFinal = true, level = AccessLevel.PRIVATE) @Getter @Wither</code>. + </p><p> + It is possible to override the final-by-default and private-by-default behaviour using either an explicit access level on a field, or by using the <code>@NonFinal</code> or <code>@PackagePrivate</code> annotations.<br /> + It is possible to override any default behaviour for any of the 'parts' that make up <code>@Value</code> by explicitly using that annotation. + </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> + Look for the documentation on the 'parts' of <code>@Value</code>: <a href="../ToString.html"><code>@ToString</code></a>, <a href="../EqualsAndHashCode.html"><code>@EqualsAndHashCode</code></a>, + <a href="../Constructor.html"><code>@AllArgsConstructor</code></a>, <a href="FieldDefaults.html"><code>@FieldDefaults</code></a>, <a href="../GetterSetter.html"><code>@Getter</code></a>, + <a href="Wither.html"><code>@Wither</code></a>. + </p><p> + For classes with generics, it's useful to have a static method which serves as a constructor, because inference of generic parameters via static methods works in java6 and avoids having to use the diamond operator. + While you can force this by applying an explicit <code>@AllArgsConstructor</code> annotation, there's also the <code>@Value(staticConstructor="of")</code> feature, which will make the generated all-arguments constructor + private, and generates a public static method named <code>of</code> which is a wrapper around this private constructor. + </p> + </div> + </div> + <div class="footer"> + <a href="index.html">Back to experimental features</a> | <a href="Wither.html">Previous feature (@Wither)</a> | <span class="disabled">Next feature</span><br /> + <a href="../../credits.html" class="creditsLink">credits</a> | <span class="copyright">Copyright © 2009-2012 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) ? 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