Class IllegalCatchCheck
java.lang.Object
com.puppycrawl.tools.checkstyle.api.AutomaticBean
com.puppycrawl.tools.checkstyle.api.AbstractViolationReporter
com.puppycrawl.tools.checkstyle.api.AbstractCheck
com.puppycrawl.tools.checkstyle.checks.coding.IllegalCatchCheck
- All Implemented Interfaces:
Configurable
,Contextualizable
Checks that certain exception types do not appear in a catch
statement.
Rationale: catching java.lang.Exception
, java.lang.Error
or
java.lang.RuntimeException
is almost never acceptable.
Novice developers often simply catch Exception in an attempt to handle
multiple exception classes. This unfortunately leads to code that inadvertently
catches NullPointerException
, OutOfMemoryError
, etc.
-
Property
illegalClassNames
- Specify exception class names to reject. Type isjava.lang.String[]
. Default value isError, Exception, RuntimeException, Throwable, java.lang.Error, java.lang.Exception, java.lang.RuntimeException, java.lang.Throwable
.
To configure the check:
<module name="IllegalCatch"/>
Example:
try { // some code here } catch (Exception e) { // violation } try { // some code here } catch (ArithmeticException e) { // OK } catch (Exception e) { // violation, catching Exception is illegal and order of catch blocks doesn't matter } try { // some code here } catch (ArithmeticException | Exception e) { // violation, catching Exception is illegal } try { // some code here } catch (ArithmeticException e) { // OK }
To configure the check to override the default list with ArithmeticException and OutOfMemoryError:
<module name="IllegalCatch"> <property name="illegalClassNames" value="ArithmeticException, OutOfMemoryError"/> </module>
Example:
try { // some code here } catch (OutOfMemoryError e) { // violation } try { // some code here } catch (ArithmeticException e) { // violation } try { // some code here } catch (NullPointerException e) { // OK } catch (OutOfMemoryError e) { // violation } try { // some code here } catch (ArithmeticException | Exception e) { // violation } try { // some code here } catch (Exception e) { // OK }
Parent is com.puppycrawl.tools.checkstyle.TreeWalker
Violation Message Keys:
-
illegal.catch
- Since:
- 3.2
-
Nested Class Summary
Nested classes/interfaces inherited from class com.puppycrawl.tools.checkstyle.api.AutomaticBean
AutomaticBean.OutputStreamOptions
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Field Summary
Fields -
Constructor Summary
Constructors -
Method Summary
Modifier and TypeMethodDescriptionint[]
The configurable token set.int[]
Returns the default token a check is interested in.int[]
The tokens that this check must be registered for.void
setIllegalClassNames
(String... classNames) Setter to specify exception class names to reject.void
visitToken
(DetailAST detailAST) Called to process a token.Methods inherited from class com.puppycrawl.tools.checkstyle.api.AbstractCheck
beginTree, clearMessages, destroy, finishTree, getFileContents, getLine, getLines, getMessages, getTabWidth, getTokenNames, init, isCommentNodesRequired, leaveToken, log, log, log, setFileContents, setTabWidth, setTokens
Methods inherited from class com.puppycrawl.tools.checkstyle.api.AbstractViolationReporter
finishLocalSetup, getCustomMessages, getId, getMessageBundle, getSeverity, getSeverityLevel, setId, setSeverity
Methods inherited from class com.puppycrawl.tools.checkstyle.api.AutomaticBean
configure, contextualize, getConfiguration, setupChild
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Field Details
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MSG_KEY
A key is pointing to the warning message text in "messages.properties" file.- See Also:
-
-
Constructor Details
-
IllegalCatchCheck
public IllegalCatchCheck()
-
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Method Details
-
setIllegalClassNames
Setter to specify exception class names to reject.- Parameters:
classNames
- array of illegal exception classes
-
getDefaultTokens
public int[] getDefaultTokens()Description copied from class:AbstractCheck
Returns the default token a check is interested in. Only used if the configuration for a check does not define the tokens.- Specified by:
getDefaultTokens
in classAbstractCheck
- Returns:
- the default tokens
- See Also:
-
getRequiredTokens
public int[] getRequiredTokens()Description copied from class:AbstractCheck
The tokens that this check must be registered for.- Specified by:
getRequiredTokens
in classAbstractCheck
- Returns:
- the token set this must be registered for.
- See Also:
-
getAcceptableTokens
public int[] getAcceptableTokens()Description copied from class:AbstractCheck
The configurable token set. Used to protect Checks against malicious users who specify an unacceptable token set in the configuration file. The default implementation returns the check's default tokens.- Specified by:
getAcceptableTokens
in classAbstractCheck
- Returns:
- the token set this check is designed for.
- See Also:
-
visitToken
Description copied from class:AbstractCheck
Called to process a token.- Overrides:
visitToken
in classAbstractCheck
- Parameters:
detailAST
- the token to process
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