com.puppycrawl.tools.checkstyle.checks.duplicates

Class StrictDuplicateCodeCheck

Implemented Interfaces:
Configurable, Contextualizable, FileSetCheck

public final class StrictDuplicateCodeCheck
extends AbstractFileSetCheck

Checks for duplicate code.

There are many approaches for detecting duplicate code. Some involve parsing a file of a programming language and analyzing the source trees of all files. This is a very powerful approach for a specific programming language (such as Java), as it can potentially even detect duplicate code where linebreaks have been changed, variables have been renamed, etc.

This copy and paste detection implementation works differently. It cannot detect copy and paste code where the author deliberately tries to hide his copy+paste action. Instead it focusses on the standard corporate problem of reuse by copy and paste. Usually this leaves linebreaks and variable names intact. Since we do not need to analyse a parse tree our tool is not tied to a particular programming language.

Simian is a very good commercial duplicate code detection tool. It comes with a Checkstyle module, so we encourage all users to evaluate Simian as an alternative to this check.

Author:
Lars Kühne

Constructor Summary

StrictDuplicateCodeCheck()
Creates a new instance of this class.

Method Summary

void
process(File[] aFiles)
void
setBasedir(String aBasedir)
void
setMin(int aMin)
Sets the minimum number of lines that must be equivalent before the check complains.

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

destroy, filter, fireErrors, getCharset, getMessageCollector, getMessageDispatcher, log, log, setCharset, setFileExtensions, setMessageDispatcher

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

getMessageBundle, getSeverity, getSeverityLevel, log, log, 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

Constructor Details

StrictDuplicateCodeCheck

public StrictDuplicateCodeCheck()
Creates a new instance of this class.

Method Details

process

public void process(File[] aFiles)
Specified by:
process in interface FileSetCheck

See Also:
AbstractFileSetCheck


setBasedir

public void setBasedir(String aBasedir)

Parameters:
aBasedir - the base directory to strip off in filenames


setMin

public void setMin(int aMin)
Sets the minimum number of lines that must be equivalent before the check complains.

Parameters:
aMin - the number of lines that must be equal before triggering a 'duplicate code' message.