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 whichIsWich = 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

Constructor Summary

AvoidNestedBlocksCheck()

Method Summary

int[]	getDefaultTokens() Returns the default token a check is interested in.
void	setAllowInSwitchCase(boolean aAllowInSwitchCase) Setter for allowInSwitchCase property.
void	visitToken(DetailAST aAST) Called to process a token.

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

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

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

getMessageBundle, getSeverity, getSeverityLevel, log, log, log, log, log, log, log, log, log, 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

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:

Check

visitToken

public void visitToken(DetailAST aAST)

Description copied from class: Check

Called to process a token.

Overrides:

visitToken in class Check

Parameters:

aAST - the token to process

See Also:

Check

setAllowInSwitchCase

public void setAllowInSwitchCase(boolean aAllowInSwitchCase)

Setter for allowInSwitchCase property.

Parameters:

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