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| <title>Excluding warnings using @SuppressWarnings</title> |
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| <a name="t_suppress_warnings"></a> |
| <h1>Excluding warnings using @SuppressWarnings</h1> |
| <p>Since Java 5.0, you can disable compilation warnings relative to a subset of a compilation unit using the <code>java.lang.SuppressWarning</code> annotation.</p> |
| |
| <pre> |
| @SuppressWarning("unused") public void foo() { |
| String s; |
| } |
| </pre> |
| <p>Without the annotation, the compiler would complain that the local variable <code>s</code> is never used. With the annotation, the compiler silently ignores this warning locally to the |
| <code>foo</code> method. This enables to keep the warnings in other locations of the same compilation unit or the same project.</p> |
| <p>The list of tokens that can be used inside a <code>SuppressWarnings</code> annotation is:</p> |
| |
| <table border="1" cellspacing="0" cellpadding="5" width="100%" summary="SuppressWarnings tokens"> |
| <tr> |
| <th> |
| <p>Token</p> |
| </th> |
| <th> |
| <p>Description</p> |
| </th> |
| <th> |
| <p>Suppressed compiler option(s)</p> |
| </th> |
| </tr> |
| <tr> |
| <td valign="top"> |
| <p><span class="token">all</span></p> |
| </td> |
| <td valign="top"> |
| <p>to suppress all warnings</p> |
| </td> |
| <td valign="top"> |
| <p>All compiler options</p> |
| </td> |
| </tr> |
| <tr> |
| <td valign="top"> |
| <p><span class="token">boxing</span></p> |
| </td> |
| <td valign="top"> |
| <p>to suppress warnings relative to boxing/unboxing operations</p> |
| </td> |
| <td valign="top"> |
| <p>Boxing and unboxing conversions</p> |
| </td> |
| </tr> |
| <tr> |
| <td valign="top"> |
| <p><span class="token">cast</span></p> |
| </td> |
| <td valign="top"> |
| <p>to suppress warnings relative to cast operations</p> |
| </td> |
| <td valign="top"> |
| <p>Unnecessary cast or 'instanceof' operation</p> |
| </td> |
| </tr> |
| <tr> |
| <td valign="top"> |
| <p><span class="token">dep-ann</span></p> |
| </td> |
| <td valign="top"> |
| <p>to suppress warnings relative to deprecated annotation</p> |
| </td> |
| <td valign="top"> |
| <p>Missing '@Deprecated' annotation</p> |
| </td> |
| </tr> |
| <tr> |
| <td valign="top"> |
| <p><span class="token">deprecation</span></p> |
| </td> |
| <td valign="top"> |
| <p>to suppress warnings relative to deprecation</p> |
| </td> |
| <td valign="top"> |
| <p>Deprecated API</p> |
| </td> |
| </tr> |
| <tr> |
| <td valign="top"> |
| <p><span class="token">fallthrough</span></p> |
| </td> |
| <td valign="top"> |
| <p>to suppress warnings relative to missing breaks in switch statements</p> |
| </td> |
| <td valign="top"> |
| <p>'switch' case fall-through</p> |
| </td> |
| </tr> |
| <tr> |
| <td valign="top"> |
| <p><span class="token">finally</span></p> |
| </td> |
| <td valign="top"> |
| <p>to suppress warnings relative to finally block that don't return</p> |
| </td> |
| <td valign="top"> |
| <p>'finally' does not complete normally</p> |
| </td> |
| </tr> |
| <tr> |
| <td valign="top"> |
| <p><span class="token">hiding</span></p> |
| </td> |
| <td valign="top"> |
| <p>to suppress warnings relative to locals that hide variable</p> |
| </td> |
| <td valign="top"> |
| <p>Local variable declaration hides another field or variable</p> |
| </td> |
| </tr> |
| <tr> |
| <td valign="top"> |
| <p><span class="token">incomplete-switch</span></p> |
| </td> |
| <td valign="top"> |
| <p>to suppress warnings relative to missing entries in a switch statement (enum case)</p> |
| </td> |
| <td valign="top"> |
| <p>Incomplete 'switch' cases on enum</p> |
| </td> |
| </tr> |
| <tr> |
| <td valign="top"> |
| <p><span class="token">javadoc</span></p> |
| </td> |
| <td valign="top"> |
| <p>to suppress warnings relative to javadoc warnings</p> |
| </td> |
| <td valign="top"> |
| <p>All options in <a href="../reference/preferences/java/compiler/ref-preferences-javadoc.htm">Java Compiler Javadoc Preferences</a></p> |
| </td> |
| </tr> |
| <tr> |
| <td valign="top"> |
| <p><span class="token">nls</span></p> |
| </td> |
| <td valign="top"> |
| <p>to suppress warnings relative to non-nls string literals</p> |
| </td> |
| <td valign="top"> |
| <p>Non-externalized strings</p> |
| </td> |
| </tr> |
| <tr> |
| <td valign="top"> |
| <p><span class="token">null</span></p> |
| </td> |
| <td valign="top"> |
| <p>to suppress warnings relative to null analysis</p> |
| </td> |
| <td valign="top"> |
| <p>All options in <a href="../reference/preferences/java/compiler/ref-preferences-errors-warnings.htm#null_analysis">Java Compile Errors/Warnings Preferences for Null Analysis</a></p> |
| </td> |
| </tr> |
| <tr> |
| <td valign="top"> |
| <p><span class="token">rawtypes</span></p> |
| </td> |
| <td valign="top"> |
| <p>to suppress warnings relative to usage of raw types</p> |
| </td> |
| <td valign="top"> |
| <p>Usage of a raw type</p> |
| </td> |
| </tr> |
| <tr> |
| <td valign="top"> |
| <p><span class="token">resource</span></p> |
| </td> |
| <td valign="top"> |
| <p>to suppress warnings relative to usage of resources of type Closeable</p> |
| </td> |
| <td valign="top"> |
| <p>Resource leak<br/> |
| Potential resource leak<br/> |
| Resource not managed via try-with-resource</p> |
| </td> |
| </tr> |
| <tr> |
| <td valign="top"> |
| <p><span class="token">restriction</span></p> |
| </td> |
| <td valign="top"> |
| <p>to suppress warnings relative to usage of discouraged or forbidden references</p> |
| </td> |
| <td valign="top"> |
| <p>Forbidden reference (access rules)<br/> |
| Discouraged reference (access rules)</p> |
| </td> |
| </tr> |
| <tr> |
| <td valign="top"> |
| <p><span class="token">removal</span></p> |
| </td> |
| <td valign="top"> |
| <p>to suppress warnings relative to usage of terminally deprecated API</p> |
| </td> |
| <td valign="top"> |
| <p>Forbidden reference (access rules)<br/> |
| Discouraged reference (access rules)</p> |
| </td> |
| </tr> |
| <tr> |
| <td valign="top"> |
| <p><span class="token">serial</span></p> |
| </td> |
| <td valign="top"> |
| <p>to suppress warnings relative to missing serialVersionUID field for a serializable class</p> |
| </td> |
| <td valign="top"> |
| <p>Serializable class without serialVersionUID</p> |
| </td> |
| </tr> |
| <tr> |
| <td valign="top"> |
| <p><span class="token">static-access</span></p> |
| </td> |
| <td valign="top"> |
| <p>to suppress warnings relative to incorrect static access</p> |
| </td> |
| <td valign="top"> |
| <p>Non-static access to a static member<br/> |
| Indirect access to a static member</p> |
| </td> |
| </tr> |
| <tr> |
| <td valign="top"> |
| <p><span class="token">static-method</span></p> |
| </td> |
| <td valign="top"> |
| <p>to suppress warnings relative to methods that could be declared as static</p> |
| </td> |
| <td valign="top"> |
| <p>Method can be static<br/> |
| Method can potentially be static</p> |
| </td> |
| </tr> |
| <tr> |
| <td valign="top"> |
| <p><span class="token">super</span></p> |
| </td> |
| <td valign="top"> |
| <p>to suppress warnings relative to overriding a method without super invocations</p> |
| </td> |
| <td valign="top"> |
| <p></p> |
| </td> |
| </tr> |
| <tr> |
| <td valign="top"> |
| <p><span class="token">synthetic-access</span></p> |
| </td> |
| <td valign="top"> |
| <p>to suppress warnings relative to unoptimized access from inner classes</p> |
| </td> |
| <td valign="top"> |
| <p></p> |
| </td> |
| </tr> |
| <tr> |
| <td valign="top"> |
| <p><span class="token">sync-override</span></p> |
| </td> |
| <td valign="top"> |
| <p>to suppress warnings because of missing synchronize when overriding a synchronized method</p> |
| </td> |
| <td valign="top"> |
| <p>Missing synchronized modifier on inherited method</p> |
| </td> |
| </tr> |
| <tr> |
| <td valign="top"> |
| <p><span class="token">unchecked</span></p> |
| </td> |
| <td valign="top"> |
| <p>to suppress warnings relative to unchecked operations</p> |
| </td> |
| <td valign="top"> |
| <p>Unchecked generic type operation</p> |
| </td> |
| </tr> |
| <tr> |
| <td valign="top"> |
| <p><span class="token">unqualified-field-access</span></p> |
| </td> |
| <td valign="top"> |
| <p>to suppress warnings relative to field access unqualified</p> |
| </td> |
| <td valign="top"> |
| <p>Unqualified access to instance field</p> |
| </td> |
| </tr> |
| <tr> |
| <td valign="top"> |
| <p><span class="token">unlikely-arg-type</span></p> |
| </td> |
| <td valign="top"> |
| <p>to suppress warnings relative to unlikely argument types</p> |
| </td> |
| <td valign="top"> |
| <p>Unqualified access to instance field</p> |
| </td> |
| </tr> |
| <tr> |
| <td valign="top"> |
| <p><span class="token">unused</span></p> |
| </td> |
| <td valign="top"> |
| <p>to suppress warnings relative to unused code and dead code</p> |
| </td> |
| <td valign="top"> |
| <p>Dead code<br/> |
| Unused object allocation<br/> |
| Value of local variable is not used<br/> |
| Value of method parameter is not used<br/> |
| Value of exception parameter is not used<br/> |
| Unused type parameter<br/> |
| Unused import<br/> |
| Unused private member<br/> |
| Unused 'break' or 'continue' label |
| </p> |
| </td> |
| </tr> |
| </table> |
| |
| <p> |
| <img border="0" src="../images/ngrelr.png" alt="Related reference"/><br/> |
| <a href="../reference/preferences/java/compiler/ref-preferences-errors-warnings.htm#annotations">Java Compile Errors/Warnings Preferences</a> |
| </p> |
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