Package com.github.sevntu.checkstyle.checks.coding

Class NoNullForCollectionReturnCheck

  • All Implemented Interfaces:
    com.puppycrawl.tools.checkstyle.api.Configurable, com.puppycrawl.tools.checkstyle.api.Contextualizable
    public class NoNullForCollectionReturnCheck
extends com.puppycrawl.tools.checkstyle.api.AbstractCheck

    This check report you, when method, that must return array or collection, return null value instead of empty collection or empty array.

    Returning Null is error prone as developers forget to review method implementation or Java doc for nuances of Null meaning.

    List of collections set by default: AbstractCollection, AbstractList, AbstractQueue, AbstractSequentialList, AbstractSet, ArrayBlockingQueue, ArrayDeque, ArrayList, AttributeList, BeanContextServicesSupport, BeanContextSupport, ConcurrentLinkedDeque, ConcurrentLinkedQueue, ConcurrentSkipListSet, CopyOnWriteArrayList, CopyOnWriteArraySet, DelayQueue, EnumSet, HashSet, JobStateReasons, LinkedBlockingDeque, LinkedBlockingQueue, LinkedHashSet, LinkedList, LinkedTransferQueue, PriorityBlockingQueue, PriorityQueue, RoleList, RoleUnresolvedList, Stack, SynchronousQueue, TreeSet, Vector, Collection, List, Map, Set.

    Since:
    1.9.0
    Author:
    Ilja Dubinin

    • Nested Class Summary

      • Nested classes/interfaces inherited from class com.puppycrawl.tools.checkstyle.api.AutomaticBean

        com.puppycrawl.tools.checkstyle.api.AutomaticBean.OutputStreamOptions

    • Field Summary

      Fields 
      Modifier and Type Field Description
      static String MSG_KEY
      Warning message key.

    • Method Summary

      All Methods Instance Methods Concrete Methods 
      Modifier and Type Method Description
      void beginTree​(com.puppycrawl.tools.checkstyle.api.DetailAST rootAST)  
      int[] getAcceptableTokens()  
      int[] getDefaultTokens()  
      int[] getRequiredTokens()  
      void setCollectionList​(String collectionList)
      Setter for list of known collections.
      void setSearchThroughMethodBody​(boolean searchThroughMethodBody)
      Setter for searching through body of the method.
      void visitToken​(com.puppycrawl.tools.checkstyle.api.DetailAST detailAST)  

      • Methods inherited from class com.puppycrawl.tools.checkstyle.api.AbstractCheck

        clearViolations, destroy, finishTree, getFileContents, getFilePath, getLine, getLineCodePoints, getLines, getTabWidth, getTokenNames, getViolations, init, isCommentNodesRequired, leaveToken, log, log, log, setFileContents, setTabWidth, setTokens

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

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

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

        configure, contextualize, getConfiguration, setupChild

    • Constructor Detail

      • NoNullForCollectionReturnCheck

        public NoNullForCollectionReturnCheck()
        Default constructor.

    • Method Detail

      • setCollectionList

        public final void setCollectionList​(String collectionList)

        Setter for list of known collections.

        Parameters:
        collectionList - - line contains all collection names.

      • setSearchThroughMethodBody

        public void setSearchThroughMethodBody​(boolean searchThroughMethodBody)

        Setter for searching through body of the method.

        Parameters:
        searchThroughMethodBody - - deep search value.

      • getDefaultTokens

        public int[] getDefaultTokens()
        Specified by:
        getDefaultTokens in class com.puppycrawl.tools.checkstyle.api.AbstractCheck

      • getAcceptableTokens

        public int[] getAcceptableTokens()
        Specified by:
        getAcceptableTokens in class com.puppycrawl.tools.checkstyle.api.AbstractCheck

      • getRequiredTokens

        public int[] getRequiredTokens()
        Specified by:
        getRequiredTokens in class com.puppycrawl.tools.checkstyle.api.AbstractCheck

      • beginTree

        public void beginTree​(com.puppycrawl.tools.checkstyle.api.DetailAST rootAST)
        Overrides:
        beginTree in class com.puppycrawl.tools.checkstyle.api.AbstractCheck

      • visitToken

        public void visitToken​(com.puppycrawl.tools.checkstyle.api.DetailAST detailAST)
        Overrides:
        visitToken in class com.puppycrawl.tools.checkstyle.api.AbstractCheck