com.github.sevntu.checkstyle.checks.coding

Class NoNullForCollectionReturnCheck

java.lang.Object

com.puppycrawl.tools.checkstyle.api.AutomaticBean

com.puppycrawl.tools.checkstyle.api.AbstractViolationReporter

com.puppycrawl.tools.checkstyle.api.AbstractCheck

com.github.sevntu.checkstyle.checks.coding.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 and Description
static String	MSG_KEY Warning message key.

Constructor Summary

Constructors

Constructor and Description
NoNullForCollectionReturnCheck() Default constructor.

Method Summary

Modifier and Type	Method and 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

clearMessages, destroy, finishTree, getFileContents, getLine, getLines, getMessages, getTabWidth, getTokenNames, 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

Methods inherited from class java.lang.Object

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

Field Detail

MSG_KEY

public static final String MSG_KEY

Warning message key.

See Also:

Constant Field Values

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