com.puppycrawl.tools.checkstyle.checks.sizes

Class LineLengthCheck

java.lang.Object

com.puppycrawl.tools.checkstyle.api.AutomaticBean

com.puppycrawl.tools.checkstyle.api.AbstractViolationReporter

com.puppycrawl.tools.checkstyle.api.AbstractFileSetCheck

com.puppycrawl.tools.checkstyle.checks.sizes.LineLengthCheck

All Implemented Interfaces:

Configurable, Contextualizable, FileSetCheck

public class LineLengthCheck
extends AbstractFileSetCheck

Checks for long lines.

Rationale: Long lines are hard to read in printouts or if developers have limited screen space for the source code, e.g. if the IDE displays additional information like project tree, class hierarchy, etc.

• The calculation of the length of a line takes into account the number of expanded spaces for a tab character ('\t'). The default number of spaces is 8. To specify a different number of spaces, the user can set TreeWalker property tabWidth which applies to all Checks, including LineLength; or can set property tabWidth for LineLength alone.
• Package and import statements (lines matching pattern ^(package|import) .*) are not verified by this check.

• Property fileExtensions - Specify file extensions that are accepted. Type is java.lang.String[]. Default value is all files.
• Property ignorePattern - Specify pattern for lines to ignore. Type is java.util.regex.Pattern. Default value is "^$" (empty).
• Property max - Specify the maximum line length allowed. Type is int. Default value is 80.

To configure the check to accept lines up to 80 characters long:

 <module name="LineLength"/>
 

To configure the check to accept lines up to 120 characters long:

 <module name="LineLength">
   <property name="max" value="120"/>
 </module>
 

To configure the check to ignore lines that begin with " * " code, followed by just one word, such as within a Javadoc comment:

 <module name="LineLength">
   <property name="ignorePattern" value="^ *\* *[^ ]+$"/>
 </module>
 

To configure the check to only validate java files and ignore other extensions:

 <module name="LineLength">
   <property name="fileExtensions" value="java"/>
 </module>
 

To configure the check to only validate xml and property files and ignore other extensions:

 <module name="LineLength">
   <property name="fileExtensions" value="xml, properties"/>
 </module>
 

Parent is com.puppycrawl.tools.checkstyle.Checker

Violation Message Keys:

• maxLineLen

Since:

3.0

Nested Class Summary

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

AutomaticBean.OutputStreamOptions

Field Summary

Fields

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

Constructor Summary

Constructors

Constructor and Description
LineLengthCheck()

Method Summary

Modifier and Type	Method and Description
protected void	processFiltered(File file, FileText fileText) Called to process a file that matches the specified file extensions.
void	setIgnorePattern(Pattern pattern) Setter to specify pattern for lines to ignore.
void	setMax(int length) Setter to specify the maximum line length allowed.

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

addMessages, beginProcessing, destroy, finishProcessing, fireErrors, getFileContents, getFileExtensions, getMessageDispatcher, getMessages, getTabWidth, init, log, log, process, setFileContents, setFileExtensions, setMessageDispatcher, setTabWidth

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

Methods inherited from interface com.puppycrawl.tools.checkstyle.api.Configurable

configure

Methods inherited from interface com.puppycrawl.tools.checkstyle.api.Contextualizable

contextualize

Field Detail

MSG_KEY

public static final String MSG_KEY

A key is pointing to the warning message text in "messages.properties" file.

See Also:

Constant Field Values

Constructor Detail

LineLengthCheck

public LineLengthCheck()

Method Detail

processFiltered

protected void processFiltered(File file,
                               FileText fileText)

Description copied from class: AbstractFileSetCheck

Called to process a file that matches the specified file extensions.

Specified by:

processFiltered in class AbstractFileSetCheck

Parameters:

file - the file to be processed

fileText - the contents of the file.

setMax

public void setMax(int length)

Setter to specify the maximum line length allowed.

Parameters:

length - the maximum length of a line

setIgnorePattern

public final void setIgnorePattern(Pattern pattern)

Setter to specify pattern for lines to ignore.

Parameters:

pattern - a pattern.