Supported Values for @SuppressWarnings & How to use @SuppressWarnings

Supported Values for @SuppressWarnings

http://jinchun1223.javaeye.com/blog/454140
http://www.breakitdownblog.com/supported-values-for-suppresswarnings/

Update #1: All these annotations are still valid in Eclipse 3.4 and 3.5, there have been no new SuppressWarning arguments added in those versions of the JDT compiler.

If you are a Java developer and use the new @SuppressWarnings annotation in your code from time-to-time to suppress compiler warnings you, like me, have wondered probably about a million times already just exactly what are the supported values that can be used with this annotation.

The reason the list isn’t easy to find is because it’s compiler specific, which means Sun may have a different set of supported values than say IBM, GCJ or Apache Harmony.

Fortunately for us, the Eclipse folks have documented the values they support (As of Eclipse 3.3), here they are for reference:

    * all to suppress all warnings
    * boxing to suppress warnings relative to boxing/unboxing operations
    * cast to suppress warnings relative to cast operations
    * dep-ann to suppress warnings relative to deprecated annotation
    * deprecation to suppress warnings relative to deprecation
    * fallthrough to suppress warnings relative to missing breaks in switch statements
    * finally to suppress warnings relative to finally block that don’t return
    * hiding to suppress warnings relative to locals that hide variable
    * incomplete-switch to suppress warnings relative to missing entries in a switch statement (enum case)
    * nls to suppress warnings relative to non-nls string literals
    * null to suppress warnings relative to null analysis
    * restriction to suppress warnings relative to usage of discouraged or forbidden references
    * serial to suppress warnings relative to missing serialVersionUID field for a serializable class
    * static-access to suppress warnings relative to incorrect static access
    * synthetic-access to suppress warnings relative to unoptimized access from inner classes
    * unchecked to suppress warnings relative to unchecked operations
    * unqualified-field-access to suppress warnings relative to field access unqualified
    * unused to suppress warnings relative to unused code

TIP: For the folks that haven’t used @SuppressWarnings before, the syntax looks like this:

    @SuppressWarnings(”unused”)

and can be placed above almost any piece of code that is causing a compiler warning to popup for your class.

 

How to use @SuppressWarnings

 

Sometimes you will got the warning in Java when you are using the eclipse. And this is kind of annoying. Now you can use this to eliminate it:

@SuppressWarnings(option)

This can be categorized into two categories:

• Put this notation right before the code with warning:
• • @SuppressWarnings("unused") String unused = "never";
• Put this notation right before the class declaration
• • @SuppressWarnings("deprecation")
  • class DeprecationExample{ ... }

I think the warning options in red should be categoried into category 2.

You can simply try this out!

Warning options-warn:

allDeprecation
allJavadoc
assertIdentifier
boxing
charConcat
conditionAssign
constructorName
dep-ann
deprecation
discouraged
emptyBlock
enumSwitch
fallthrough
fieldHiding
finalBound
finally
forbidden
hiding
incomplete-switch
indirectStatic
intfAnnotation
intfNonInherited
javadoc
localHiding
maskedCatchBlocks
nls
noEffectAssign
null
over-ann
paramAssign
pkgDefaultMethod
raw
semicolon
serial
specialParamHiding
static-access
staticReceiver
suppress
synthetic-access
syntheticAccess
tasks(<task1>|...|<taskN>)
typeHiding
unchecked
unnecessaryElse
unqualified-field-access
unqualifiedField
unused
unusedArgument
unusedImport
unusedLabel
unusedLocal
unusedPrivate
unusedThrown
uselessTypeCheck
varargsCast
warningToken

Set warning level.
e.g. -warn:unusedLocal,deprecation

In red are the default settings.

 -warn:none disable all warnings -warn:<warnings separated by ,> enable exactly the listed warnings -warn:+<warnings separated by ,> enable additional warnings -warn:-<warnings separated by ,> disable specific warnings

allDeprecationdeprecation even inside deprecated codeallJavadocinvalid or missing javadocassertIdentifieroccurrence of assert used as identifierboxingautoboxing conversioncharConcatwhen a char array is used in a string concatenation without being converted explicitly to a stringconditionAssignpossible accidental boolean assignmentconstructorNamemethod with constructor namedep-annmissing @Deprecated annotationdeprecationusage of deprecated type or member outside deprecated codediscourageduse of types matching a discouraged access ruleemptyBlockundocumented empty blockenumSwitch,
incomplete-switchincomplete enum switchfallthroughpossible fall-through casefieldHidingfield hiding another variablefinalBoundtype parameter with final boundfinallyfinally block not completing normallyforbiddenuse of types matching a forbidden access rulehidingmacro for fieldHiding, localHiding, typeHiding and maskedCatchBlockindirectStaticindirect reference to static memberintfAnnotationannotation type used as super interfaceintfNonInheritedinterface non-inherited method compatibilityjavadocinvalid javadoclocalHidinglocal variable hiding another variablemaskedCatchBlockshidden catch blocknlsnon-nls string literals (lacking of tags //$NON-NLS-<n>)noEffectAssignassignment with no effectnullmissing or redundant null checkover-annmissing @Override annotationparamAssignassignment to a parameterpkgDefaultMethodattempt to override package-default methodrawusage a of raw type (instead of a parametrized type)semicolonunnecessary semicolon or empty statementserialmissing serialVersionUIDspecialParamHidingconstructor or setter parameter hiding another fieldstatic-accessmacro for indirectStatic and staticReceiverstaticReceiverif a non static receiver is used to get a static field or call a static methodsuppressenable @SuppressWarningssyntheticAccess,
synthetic-accesswhen performing synthetic access for innerclasstasksenable support for tasks tags in source codetypeHidingtype parameter hiding another typeuncheckedunchecked type operationunnecessaryElseunnecessary else clauseunqualified-field-access,
unqualifiedFieldunqualified reference to fieldunusedmacro for unusedArgument, unusedImport, unusedLabel, unusedLocal, unusedPrivate and unusedThrownunusedArgumentunused method argumentunusedImportunused import referenceunusedLabelunused labelunusedLocalunused local variableunusedPrivateunused private member declarationunusedThrownunused declared thrown exceptionuselessTypeCheckunnecessary cast/instanceof operationvarargsCastvarargs argument need explicit castwarningTokenunhandled warning token in @SuppressWarnings