Class ThrowsCountCheck
- java.lang.Object
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- com.puppycrawl.tools.checkstyle.api.AutomaticBean
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- com.puppycrawl.tools.checkstyle.api.AbstractViolationReporter
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- com.puppycrawl.tools.checkstyle.api.AbstractCheck
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- com.puppycrawl.tools.checkstyle.checks.design.ThrowsCountCheck
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- All Implemented Interfaces:
Configurable
,Contextualizable
public final class ThrowsCountCheck extends AbstractCheck
Restricts throws statements to a specified count (default = 4). Methods with "Override" or "java.lang.Override" annotation are skipped from validation as current class cannot change signature of these methods.
Rationale: Exceptions form part of a methods interface. Declaring a method to throw too many differently rooted exceptions makes exception handling onerous and leads to poor programming practices such as catch (Exception). 4 is the empirical value which is based on reports that we had for the ThrowsCountCheck over big projects such as OpenJDK. This check also forces developers to put exceptions into a hierarchy such that in the simplest case, only one type of exception need be checked for by a caller but allows any sub-classes to be caught specifically if necessary. For more information on rules for the exceptions and their issues, see Effective Java: Programming Language Guide Second Edition by Joshua Bloch pages 264-273.
ignorePrivateMethods - allows to skip private methods as they do not cause problems for other classes.
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Nested Class Summary
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Nested classes/interfaces inherited from class com.puppycrawl.tools.checkstyle.api.AutomaticBean
AutomaticBean.OutputStreamOptions
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Constructor Summary
Constructors Constructor Description ThrowsCountCheck()
Creates new instance of the check.
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Method Summary
All Methods Instance Methods Concrete Methods Modifier and Type Method Description int[]
getAcceptableTokens()
The configurable token set.int[]
getDefaultTokens()
Returns the default token a check is interested in.int[]
getRequiredTokens()
The tokens that this check must be registered for.void
setIgnorePrivateMethods(boolean ignorePrivateMethods)
Sets whether private methods must be ignored.void
setMax(int max)
Setter for max property.void
visitToken(DetailAST ast)
Called to process a token.-
Methods inherited from class com.puppycrawl.tools.checkstyle.api.AbstractCheck
beginTree, clearMessages, destroy, finishTree, getClassLoader, getFileContents, getLine, getLines, getMessages, getTabWidth, getTokenNames, init, isCommentNodesRequired, leaveToken, log, log, log, setClassLoader, setFileContents, setTabWidth, setTokens
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Methods inherited from class com.puppycrawl.tools.checkstyle.api.AbstractViolationReporter
finishLocalSetup, getCustomMessages, getId, getMessageBundle, getSeverity, getSeverityLevel, setId, setSeverity
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Methods inherited from class com.puppycrawl.tools.checkstyle.api.AutomaticBean
configure, contextualize, getConfiguration, setupChild
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Field Detail
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MSG_KEY
public static final String MSG_KEY
A key is pointing to the warning message text in "messages.properties" file.- See Also:
- Constant Field Values
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Method Detail
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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:
TokenTypes
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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:
TokenTypes
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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:
TokenTypes
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setIgnorePrivateMethods
public void setIgnorePrivateMethods(boolean ignorePrivateMethods)
Sets whether private methods must be ignored.- Parameters:
ignorePrivateMethods
- whether private methods must be ignored.
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setMax
public void setMax(int max)
Setter for max property.- Parameters:
max
- maximum allowed throws statements.
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visitToken
public void visitToken(DetailAST ast)
Description copied from class:AbstractCheck
Called to process a token.- Overrides:
visitToken
in classAbstractCheck
- Parameters:
ast
- the token to process
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