com.puppycrawl.tools.checkstyle.checks.duplicates
Class StrictDuplicateCodeCheck

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.duplicates.StrictDuplicateCodeCheck

All 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(java.io.File[] aFiles) Processes a set of files and fires errors to the MessageDispatcher.
void	setBasedir(java.lang.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, 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

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

configure

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

contextualize

Constructor Detail

StrictDuplicateCodeCheck

public StrictDuplicateCodeCheck()

Creates a new instance of this class.

Method Detail

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.

setBasedir

public void setBasedir(java.lang.String aBasedir)

Parameters:

aBasedir - the base directory to strip off in filenames

process

public void process(java.io.File[] aFiles)

Description copied from interface: FileSetCheck

Processes a set of files and fires errors to the MessageDispatcher. The file set to process might contain files that are not interesting to the FileSetCheck. Such files should be ignored, no error message should be fired for them. For example a FileSetCheck that checks java files should ignore html or properties files. Once processiong is done, it is highly recommended to call for the destroy method to close and remove the listeners.

Parameters:

aFiles - the files to be audited.

See Also:

FileSetCheck.process(java.io.File[])