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

java.lang.Object
  extended by com.puppycrawl.tools.checkstyle.api.AutomaticBean
      extended by com.puppycrawl.tools.checkstyle.api.AbstractViolationReporter
          extended by com.puppycrawl.tools.checkstyle.api.Check
              extended by 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
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
 

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 aAST)
Description copied from class: Check
Called to process a token.

Overrides:
visitToken in class Check
Parameters:
aAST - the token to process

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.


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