Class AvoidNestedBlocksCheck
- java.lang.Object
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- com.puppycrawl.tools.checkstyle.AbstractAutomaticBean
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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.blocks.AvoidNestedBlocksCheck
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- All Implemented Interfaces:
Configurable
,Contextualizable
public class AvoidNestedBlocksCheck extends AbstractCheck
Finds nested blocks (blocks that are used freely in the code).Rationale: Nested blocks are often leftovers from the debugging process, they confuse the reader.
For example, this check finds the obsolete braces in
public void guessTheOutput() { int whichIsWhich = 0; { whichIsWhich = 2; } System.out.println("value = " + whichIsWhich); }
and debugging / refactoring leftovers such as
// if (conditionThatIsNotUsedAnyLonger) { System.out.println("unconditional"); }
A case in a switch statement does not implicitly form a block. Thus, to be able to introduce local variables that have case scope it is necessary to open a nested block. This is supported, set the allowInSwitchCase property to true and include all statements of the case in the block.
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Property
allowInSwitchCase
- Allow nested blocks if they are the only child of a switch case. Type isboolean
. Default value isfalse
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Parent is
com.puppycrawl.tools.checkstyle.TreeWalker
Violation Message Keys:
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block.nested
- Since:
- 3.1
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Nested Class Summary
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Nested classes/interfaces inherited from class com.puppycrawl.tools.checkstyle.AbstractAutomaticBean
AbstractAutomaticBean.OutputStreamOptions
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Field Summary
Fields Modifier and Type Field Description private boolean
allowInSwitchCase
Allow nested blocks if they are the only child of a switch case.static String
MSG_KEY_BLOCK_NESTED
A key is pointing to the warning message text in "messages.properties" file.
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Constructor Summary
Constructors Constructor Description AvoidNestedBlocksCheck()
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Method Summary
All Methods Static 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.private static boolean
hasSiblings(DetailAST ast)
Checks whether the AST node has any siblings or not.void
setAllowInSwitchCase(boolean allowInSwitchCase)
Setter to allow nested blocks if they are the only child of a switch case.void
visitToken(DetailAST ast)
Called to process a token.-
Methods inherited from class com.puppycrawl.tools.checkstyle.api.AbstractCheck
beginTree, clearViolations, destroy, finishTree, getFileContents, getFilePath, getLine, getLineCodePoints, getLines, getTabWidth, getTokenNames, getViolations, init, isCommentNodesRequired, leaveToken, log, log, log, 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.AbstractAutomaticBean
configure, contextualize, getConfiguration, setupChild
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Field Detail
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MSG_KEY_BLOCK_NESTED
public static final String MSG_KEY_BLOCK_NESTED
A key is pointing to the warning message text in "messages.properties" file.- See Also:
- Constant Field Values
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allowInSwitchCase
private boolean allowInSwitchCase
Allow nested blocks if they are the only child of a switch case.
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Constructor Detail
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AvoidNestedBlocksCheck
public AvoidNestedBlocksCheck()
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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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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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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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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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hasSiblings
private static boolean hasSiblings(DetailAST ast)
Checks whether the AST node has any siblings or not.- Parameters:
ast
- node to examine- Returns:
true
if the node has one or more siblings
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setAllowInSwitchCase
public void setAllowInSwitchCase(boolean allowInSwitchCase)
Setter to allow nested blocks if they are the only child of a switch case.- Parameters:
allowInSwitchCase
- whether nested blocks are allowed if they are the only child of a switch case.- Since:
- 3.2
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