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<html><head> <meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1"> <title>Chapter 10. Annotations</title><meta name="generator" content="DocBook XSL Stylesheets V1.71.1"><link rel="start" href="index.html" title="FindBugs™ Manual"><link rel="up" href="index.html" title="FindBugs™ Manual"><link rel="prev" href="analysisprops.html" title="Chapter 9. Analysis Properties"><link rel="next" href="rejarForAnalysis.html" title="Chapter 11. Using rejarForAnalysis"></head><body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF"><div class="navheader"><table width="100%" summary="Navigation header"><tr><th colspan="3" align="center">Chapter 10. Annotations</th></tr><tr><td width="20%" align="left"><a accesskey="p" href="analysisprops.html">Prev</a> </td><th width="60%" align="center"> </th><td width="20%" align="right"> <a accesskey="n" href="rejarForAnalysis.html">Next</a></td></tr></table><hr></div><div class="chapter" lang="en"><div class="titlepage"><div><div><h2 class="title"><a name="annotations"></a>Chapter 10. Annotations</h2></div></div></div><p><span class="application">FindBugs</span> supports several annotations to express the developer's intentso that FindBugs can issue warnings more appropriately. You need to useJava 5 to use annotations, and must place the annotations.jar and jsr305.jarfiles in the classpath while compiling your program.</p><div class="variablelist"><dl><dt><span class="term"><span><strong class="command">edu.umd.cs.findbugs.annotations.CheckForNull</strong></span></span></dt><dd><span><strong class="command">[Target]</strong></span> Field, Method, Parameter <p>The annotated element might be null, and uses of the element should check for null.When this annotation is applied to a method it applies to the method return value. </p></dd><dt><span class="term"><span><strong class="command">edu.umd.cs.findbugs.annotations.CheckReturnValue</strong></span></span></dt><dd><span><strong class="command">[Target]</strong></span> Method, Constructor <div class="variablelist"><dl><dt><span class="term"><span><strong class="command">[Parameter]</strong></span></span></dt><dd><p> <span><strong class="command">priority:</strong></span>The priority of the warning (HIGH, MEDIUM, LOW, IGNORE). Default value:MEDIUM. </p><p> <span><strong class="command">explanation:</strong></span>A textual explaination of why the return value should be checked. Default value:"". </p></dd></dl></div><p>This annotation is used to denote a method whose return value should always be checked after invoking the method. </p></dd><dt><span class="term"><span><strong class="command">edu.umd.cs.findbugs.annotations.DefaultAnnotation</strong></span></span></dt><dd><span><strong class="command">[Target]</strong></span> Type, Package <div class="variablelist"><dl><dt><span class="term"><span><strong class="command">[Parameter]</strong></span></span></dt><dd><p> <span><strong class="command">value:</strong></span>Annotation class objects. More than one class can be specified. </p><p> <span><strong class="command">priority:</strong></span>Default priority(HIGH, MEDIUM, LOW, IGNORE). Default value:MEDIUM. </p></dd></dl></div><p>Indicates that all members of the class or package should be annotated with the defaultvalue of the supplied annotation classes. This would be used for behavior annotationssuch as @NonNull, @CheckForNull, or @CheckReturnValue. In particular, you can use@DefaultAnnotation(NonNull.class) on a class or package, and then use @Nullable onlyon those parameters, methods or fields that you want to allow to be null. </p></dd><dt><span class="term"><span><strong class="command">edu.umd.cs.findbugs.annotations.DefaultAnnotationForFields</strong></span></span></dt><dd><span><strong class="command">[Target]</strong></span> Type, Package <div class="variablelist"><dl><dt><span class="term"><span><strong class="command">[Parameter]</strong></span></span></dt><dd><p> <span><strong class="command">value:</strong></span>Annotation class objects. More than one class can be specified. </p><p> <span><strong class="command">priority:</strong></span>Default priority(HIGH, MEDIUM, LOW, IGNORE). Default value:MEDIUM. </p></dd></dl></div><p>This is same as the DefaultAnnotation except it only applys to fields. </p></dd><dt><span class="term"><span><strong class="command">edu.umd.cs.findbugs.annotations.DefaultAnnotationForMethods</strong></span></span></dt><dd><span><strong class="command">[Target]</strong></span> Type, Package <div class="variablelist"><dl><dt><span class="term"><span><strong class="command">[Parameter]</strong></span></span></dt><dd><p> <span><strong class="command">value:</strong></span>Annotation class objects. More than one class can be specified. </p><p> <span><strong class="command">priority:</strong></span>Default priority(HIGH, MEDIUM, LOW, IGNORE). Default value:MEDIUM. </p></dd></dl></div><p>This is same as the DefaultAnnotation except it only applys to methods. </p></dd><dt><span class="term"><span><strong class="command">edu.umd.cs.findbugs.annotations.DefaultAnnotationForParameters</strong></span></span></dt><dd><span><strong class="command">[Target]</strong></span> Type, Package <div class="variablelist"><dl><dt><span class="term"><span><strong class="command">[Parameter]</strong></span></span></dt><dd><p> <span><strong class="command">value:</strong></span>Annotation class objects. More than one class can be specified. </p><p> <span><strong class="command">priority:</strong></span>Default priority(HIGH, MEDIUM, LOW, IGNORE). Default value:MEDIUM. </p></dd></dl></div><p>This is same as the DefaultAnnotation except it only applys to method parameters. </p></dd><dt><span class="term"><span><strong class="command">edu.umd.cs.findbugs.annotations.NonNull</strong></span></span></dt><dd><span><strong class="command">[Target]</strong></span> Field, Method, Parameter <p>The annotated element must not be null.Annotated fields must not be null after construction has completed. Annotated methods must have non-null return values. </p></dd><dt><span class="term"><span><strong class="command">edu.umd.cs.findbugs.annotations.Nullable</strong></span></span></dt><dd><span><strong class="command">[Target]</strong></span> Field, Method, Parameter <p>The annotated element could be null under some circumstances. In general, this meansdevelopers will have to read the documentation to determine when a null value isacceptable and whether it is neccessary to check for a null value. FindBugs willtreat the annotated items as though they had no annotation. </p><p>In pratice this annotation is useful only for overriding an overarching NonNullannotation. </p></dd><dt><span class="term"><span><strong class="command">edu.umd.cs.findbugs.annotations.OverrideMustInvoke</strong></span></span></dt><dd><span><strong class="command">[Target]</strong></span> Method <div class="variablelist"><dl><dt><span class="term"><span><strong class="command">[Parameter]</strong></span></span></dt><dd><p> <span><strong class="command">value:</strong></span>Specify when the super invocation should be performed (FIRST, ANYTIME, LAST). Default value:ANYTIME. </p></dd></dl></div><p>Used to annotate a method that, if overridden, must (or should) be invoke superin the overriding method. Examples of such methods include finalize() and clone().The argument to the method indicates when the super invocation should occur:at any time, at the beginning of the overriding method, or at the end of the overriding method.(This anotation is not implmemented in FindBugs as of September 8, 2006). </p></dd><dt><span class="term"><span><strong class="command">edu.umd.cs.findbugs.annotations.PossiblyNull</strong></span></span></dt><dd><p>This annotation is deprecated. Use CheckForNull instead. </p></dd><dt><span class="term"><span><strong class="command">edu.umd.cs.findbugs.annotations.SuppressWarnings</strong></span></span></dt><dd><span><strong class="command">[Target]</strong></span> Type, Field, Method, Parameter, Constructor, Package <div class="variablelist"><dl><dt><span class="term"><span><strong class="command">[Parameter]</strong></span></span></dt><dd><p> <span><strong class="command">value:</strong></span>The name of the warning. More than one name can be specified. </p><p> <span><strong class="command">justification:</strong></span>Reason why the warning should be ignored. Default value:"". </p></dd></dl></div><p>The set of warnings that are to be suppressed by the compiler in the annotated element.Duplicate names are permitted. The second and successive occurrences of a name are ignored.The presence of unrecognized warning names is <span class="emphasis"><em>not</em></span> an error: Compilersmust ignore any warning names they do not recognize. They are, however, free to emit awarning if an annotation contains an unrecognized warning name. Compiler vendors shoulddocument the warning names they support in conjunction with this annotation type. Theyare encouraged to cooperate to ensure that the same names work across multiple compilers. </p></dd><dt><span class="term"><span><strong class="command">edu.umd.cs.findbugs.annotations.UnknownNullness</strong></span></span></dt><dd><span><strong class="command">[Target]</strong></span> Field, Method, Parameter <p>Used to indicate that the nullness of the target is unknown, or my vary in unknown ways in subclasses. </p></dd><dt><span class="term"><span><strong class="command">edu.umd.cs.findbugs.annotations.UnknownNullness</strong></span></span></dt><dd><span><strong class="command">[Target]</strong></span> Field, Method, Parameter <p>Used to indicate that the nullness of the target is unknown, or my vary in unknown ways in subclasses. </p></dd></dl></div><p> <span class="application">FindBugs</span> also supports the following annotations:</p><div class="itemizedlist"><ul type="disc"><li>net.jcip.annotations.GuardedBy</li><li>net.jcip.annotations.Immutable</li><li>net.jcip.annotations.NotThreadSafe</li><li>net.jcip.annotations.ThreadSafe</li></ul></div><p></p><p>You can refer the JCIP annotation <a href="http://jcip.net/annotations/doc/index.html" target="_top">API documentation</a> at <a href="http://jcip.net/" target="_top">Java Concurrency in Practice</a>.</p></div><div class="navfooter"><hr><table width="100%" summary="Navigation footer"><tr><td width="40%" align="left"><a accesskey="p" href="analysisprops.html">Prev</a> </td><td width="20%" align="center"> </td><td width="40%" align="right"> <a accesskey="n" href="rejarForAnalysis.html">Next</a></td></tr><tr><td width="40%" align="left" valign="top">Chapter 9. Analysis Properties </td><td width="20%" align="center"><a accesskey="h" href="index.html">Home</a></td><td width="40%" align="right" valign="top"> Chapter 11. Using rejarForAnalysis</td></tr></table></div></body></html>⌨️ 快捷键说明
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