com.puppycrawl.tools.checkstyle.checks.blocks

Class AvoidNestedBlocksCheck

java.lang.Object

com.puppycrawl.tools.checkstyle.api.AutomaticBean

com.puppycrawl.tools.checkstyle.api.AbstractViolationReporter

com.puppycrawl.tools.checkstyle.api.Check

com.puppycrawl.tools.checkstyle.checks.blocks.AvoidNestedBlocksCheck

All Implemented Interfaces:

Configurable, Contextualizable

public class AvoidNestedBlocksCheck
extends Check

Finds nested blocks.

For example this Check flags confusing code like

 public void guessTheOutput()
 {
     int whichIsWhich = 0;
     {
         int whichIsWhich = 2;
     }
     System.out.println("value = " + whichIsWhich);
 }
 

and debugging / refactoring leftovers such as

 // if (someOldCondition)
 {
     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.

 switch (a)
 {
     case 0:
         // Never OK, break outside block
         {
             x = 1;
         }
         break;
     case 1:
         // Never OK, statement outside block
         System.out.println("Hello");
         {
             x = 2;
             break;
         }
     case 1:
         // OK if allowInSwitchCase is true
         {
             System.out.println("Hello");
             x = 2;
             break;
         }
 }
 

Author:

lkuehne

Field Summary

Fields

Modifier and Type	Field and Description
static String	MSG_KEY_BLOCK_NESTED A key is pointing to the warning message text in "messages.properties" file.

Constructor Summary

Constructors

Constructor and Description
AvoidNestedBlocksCheck()

Method Summary

Methods

Modifier and Type	Method and Description
int[]	getDefaultTokens() Returns the default token a check is interested in.
void	setAllowInSwitchCase(boolean allowInSwitchCase) Setter for allowInSwitchCase property.
void	visitToken(DetailAST ast) Called to process a token.

Methods inherited from class com.puppycrawl.tools.checkstyle.api.Check

beginTree, destroy, finishTree, getAcceptableTokens, getClassLoader, getFileContents, getLine, getLines, getRequiredTokens, getTabWidth, getTokenNames, init, isCommentNodesRequired, leaveToken, log, log, setClassLoader, setFileContents, setMessages, setTabWidth, setTokens

Methods inherited from class com.puppycrawl.tools.checkstyle.api.AbstractViolationReporter

getCustomMessages, getId, getMessageBundle, getSeverity, getSeverityLevel, log, setId, setSeverity

Methods inherited from class com.puppycrawl.tools.checkstyle.api.AutomaticBean

configure, contextualize, finishLocalSetup, getConfiguration, setupChild

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

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

Constructor Detail

AvoidNestedBlocksCheck

public AvoidNestedBlocksCheck()

Method Detail

getDefaultTokens

public int[] getDefaultTokens()

Description copied from class: Check

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 class Check

Returns:

the default tokens

See Also:

TokenTypes

visitToken

public void visitToken(DetailAST ast)

Description copied from class: Check

Called to process a token.

Overrides:

visitToken in class Check

Parameters:

ast - the token to process

setAllowInSwitchCase

public void setAllowInSwitchCase(boolean allowInSwitchCase)

Setter for allowInSwitchCase property.

Parameters:

allowInSwitchCase - whether nested blocks are allowed if they are the only child of a switch case.