org.codehaus.plexus.util

Class DirectoryScanner


public class DirectoryScanner
extends java.lang.Object

Class for scanning a directory for files/directories which match certain criteria.

These criteria consist of selectors and patterns which have been specified. With the selectors you can select which files you want to have included. Files which are not selected are excluded. With patterns you can include or exclude files based on their filename.

The idea is simple. A given directory is recursively scanned for all files and directories. Each file/directory is matched against a set of selectors, including special support for matching against filenames with include and and exclude patterns. Only files/directories which match at least one pattern of the include pattern list or other file selector, and don't match any pattern of the exclude pattern list or fail to match against a required selector will be placed in the list of files/directories found.

When no list of include patterns is supplied, "**" will be used, which means that everything will be matched. When no list of exclude patterns is supplied, an empty list is used, such that nothing will be excluded. When no selectors are supplied, none are applied.

The filename pattern matching is done as follows: The name to be matched is split up in path segments. A path segment is the name of a directory or file, which is bounded by File.separator ('/' under UNIX, '\' under Windows). For example, "abc/def/ghi/xyz.java" is split up in the segments "abc", "def","ghi" and "xyz.java". The same is done for the pattern against which should be matched.

The segments of the name and the pattern are then matched against each other. When '**' is used for a path segment in the pattern, it matches zero or more path segments of the name.

There is a special case regarding the use of File.separators at the beginning of the pattern and the string to match:
When a pattern starts with a File.separator, the string to match must also start with a File.separator. When a pattern does not start with a File.separator, the string to match may not start with a File.separator. When one of these rules is not obeyed, the string will not match.

When a name path segment is matched against a pattern path segment, the following special characters can be used:
'*' matches zero or more characters
'?' matches one character.

Examples:

"**\*.class" matches all .class files/dirs in a directory tree.

"test\a??.java" matches all files/dirs which start with an 'a', then two more characters and then ".java", in a directory called test.

"**" matches everything in a directory tree.

"**\test\**\XYZ*" matches all files/dirs which start with "XYZ" and where there is a parent directory called test (e.g. "abc\test\def\ghi\XYZ123").

Case sensitivity may be turned off if necessary. By default, it is turned on.

Example of usage:

   String[] includes = {"**\\*.class"};
   String[] excludes = {"modules\\*\\**"};
   ds.setIncludes(includes);
   ds.setExcludes(excludes);
   ds.setBasedir(new File("test"));
   ds.setCaseSensitive(true);
   ds.scan();

   System.out.println("FILES:");
   String[] files = ds.getIncludedFiles();
   for (int i = 0; i <32files.length; i++) {
     System.out.println(files[i]);
   }
 
This will scan a directory called test for .class files, but excludes all files in all proper subdirectories of a directory called "modules"
Authors:
Arnout J. Kuiper ajkuiper@wxs.nl
Magesh Umasankar
Bruce Atherton
Antoine Levy-Lambert

Field Summary

static String[]
DEFAULTEXCLUDES
Patterns which should be excluded by default.
protected File
basedir
The base directory to be scanned.
protected Vector
dirsDeselected
The directories which matched at least one include and no excludes but which a selector discarded.
protected Vector
dirsExcluded
The directories which matched at least one include and at least one exclude.
protected Vector
dirsIncluded
The directories which matched at least one include and no excludes and were selected.
protected Vector
dirsNotIncluded
The directories which were found and did not match any includes.
protected boolean
everythingIncluded
Whether or not everything tested so far has been included.
protected String[]
excludes
The patterns for the files to be excluded.
protected Vector
filesDeselected
The files which matched at least one include and no excludes and which a selector discarded.
protected Vector
filesExcluded
The files which matched at least one include and at least one exclude.
protected Vector
filesIncluded
The files which matched at least one include and no excludes and were selected.
protected Vector
filesNotIncluded
The files which did not match any includes or selectors.
private boolean
followSymlinks
Whether or not symbolic links should be followed.
protected boolean
haveSlowResults
Whether or not our results were built by a slow scan.
protected String[]
includes
The patterns for the files to be included.
protected boolean
isCaseSensitive
Whether or not the file system should be treated as a case sensitive one.

Constructor Summary

DirectoryScanner()
Sole constructor.

Method Summary

void
addDefaultExcludes()
Adds default exclusions to the current exclusions set.
protected boolean
couldHoldIncluded(String name)
Tests whether or not a name matches the start of at least one include pattern.
File
getBasedir()
Returns the base directory to be scanned.
String[]
getDeselectedDirectories()
Returns the names of the directories which were selected out and therefore not ultimately included.
String[]
getDeselectedFiles()
Returns the names of the files which were selected out and therefore not ultimately included.
String[]
getExcludedDirectories()
Returns the names of the directories which matched at least one of the include patterns and at least one of the exclude patterns.
String[]
getExcludedFiles()
Returns the names of the files which matched at least one of the include patterns and at least one of the exclude patterns.
String[]
getIncludedDirectories()
Returns the names of the directories which matched at least one of the include patterns and none of the exclude patterns.
String[]
getIncludedFiles()
Returns the names of the files which matched at least one of the include patterns and none of the exclude patterns.
String[]
getNotIncludedDirectories()
Returns the names of the directories which matched none of the include patterns.
String[]
getNotIncludedFiles()
Returns the names of the files which matched none of the include patterns.
boolean
isEverythingIncluded()
Returns whether or not the scanner has included all the files or directories it has come across so far.
protected boolean
isExcluded(String name)
Tests whether or not a name matches against at least one exclude pattern.
protected boolean
isIncluded(String name)
Tests whether or not a name matches against at least one include pattern.
protected boolean
isSelected(String name, File file)
Tests whether a name should be selected.
boolean
isSymbolicLink(File parent, String name)
Checks whether a given file is a symbolic link.
static boolean
match(String pattern, String str)
Tests whether or not a string matches against a pattern.
protected static boolean
match(String pattern, String str, boolean isCaseSensitive)
Tests whether or not a string matches against a pattern.
protected static boolean
matchPath(String pattern, String str)
Tests whether or not a given path matches a given pattern.
protected static boolean
matchPath(String pattern, String str, boolean isCaseSensitive)
Tests whether or not a given path matches a given pattern.
protected static boolean
matchPatternStart(String pattern, String str)
Tests whether or not a given path matches the start of a given pattern up to the first "**".
protected static boolean
matchPatternStart(String pattern, String str, boolean isCaseSensitive)
Tests whether or not a given path matches the start of a given pattern up to the first "**".
void
scan()
Scans the base directory for files which match at least one include pattern and don't match any exclude patterns.
protected void
scandir(File dir, String vpath, boolean fast)
Scans the given directory for files and directories.
void
setBasedir(File basedir)
Sets the base directory to be scanned.
void
setBasedir(String basedir)
Sets the base directory to be scanned.
void
setCaseSensitive(boolean isCaseSensitive)
Sets whether or not the file system should be regarded as case sensitive.
void
setExcludes(String[] excludes)
Sets the list of exclude patterns to use.
void
setFollowSymlinks(boolean followSymlinks)
Sets whether or not symbolic links should be followed.
void
setIncludes(String[] includes)
Sets the list of include patterns to use.
protected void
slowScan()
Top level invocation for a slow scan.

Field Details

DEFAULTEXCLUDES

public static final String[] DEFAULTEXCLUDES
Patterns which should be excluded by default.

basedir

protected File basedir
The base directory to be scanned.

dirsDeselected

protected Vector dirsDeselected
The directories which matched at least one include and no excludes but which a selector discarded.

dirsExcluded

protected Vector dirsExcluded
The directories which matched at least one include and at least one exclude.

dirsIncluded

protected Vector dirsIncluded
The directories which matched at least one include and no excludes and were selected.

dirsNotIncluded

protected Vector dirsNotIncluded
The directories which were found and did not match any includes.

everythingIncluded

protected boolean everythingIncluded
Whether or not everything tested so far has been included.

excludes

protected String[] excludes
The patterns for the files to be excluded.

filesDeselected

protected Vector filesDeselected
The files which matched at least one include and no excludes and which a selector discarded.

filesExcluded

protected Vector filesExcluded
The files which matched at least one include and at least one exclude.

filesIncluded

protected Vector filesIncluded
The files which matched at least one include and no excludes and were selected.

filesNotIncluded

protected Vector filesNotIncluded
The files which did not match any includes or selectors.

followSymlinks

private boolean followSymlinks
Whether or not symbolic links should be followed.
Since:
Ant 1.5

haveSlowResults

protected boolean haveSlowResults
Whether or not our results were built by a slow scan.

includes

protected String[] includes
The patterns for the files to be included.

isCaseSensitive

protected boolean isCaseSensitive
Whether or not the file system should be treated as a case sensitive one.

Constructor Details

DirectoryScanner

public DirectoryScanner()
Sole constructor.

Method Details

addDefaultExcludes

public void addDefaultExcludes()
Adds default exclusions to the current exclusions set.

couldHoldIncluded

protected boolean couldHoldIncluded(String name)
Tests whether or not a name matches the start of at least one include pattern.
Parameters:
name - The name to match. Must not be null.
Returns:
true when the name matches against the start of at least one include pattern, or false otherwise.

getBasedir

public File getBasedir()
Returns the base directory to be scanned. This is the directory which is scanned recursively.
Returns:
the base directory to be scanned

getDeselectedDirectories

public String[] getDeselectedDirectories()
Returns the names of the directories which were selected out and therefore not ultimately included.

The names are relative to the base directory. This involves performing a slow scan if one has not already been completed.

Returns:
the names of the directories which were deselected.

getDeselectedFiles

public String[] getDeselectedFiles()
Returns the names of the files which were selected out and therefore not ultimately included.

The names are relative to the base directory. This involves performing a slow scan if one has not already been completed.

Returns:
the names of the files which were deselected.

getExcludedDirectories

public String[] getExcludedDirectories()
Returns the names of the directories which matched at least one of the include patterns and at least one of the exclude patterns. The names are relative to the base directory. This involves performing a slow scan if one has not already been completed.
Returns:
the names of the directories which matched at least one of the include patterns and at least one of the exclude patterns.

getExcludedFiles

public String[] getExcludedFiles()
Returns the names of the files which matched at least one of the include patterns and at least one of the exclude patterns. The names are relative to the base directory. This involves performing a slow scan if one has not already been completed.
Returns:
the names of the files which matched at least one of the include patterns and at at least one of the exclude patterns.

getIncludedDirectories

public String[] getIncludedDirectories()
Returns the names of the directories which matched at least one of the include patterns and none of the exclude patterns. The names are relative to the base directory.
Returns:
the names of the directories which matched at least one of the include patterns and none of the exclude patterns.

getIncludedFiles

public String[] getIncludedFiles()
Returns the names of the files which matched at least one of the include patterns and none of the exclude patterns. The names are relative to the base directory.
Returns:
the names of the files which matched at least one of the include patterns and none of the exclude patterns.

getNotIncludedDirectories

public String[] getNotIncludedDirectories()
Returns the names of the directories which matched none of the include patterns. The names are relative to the base directory. This involves performing a slow scan if one has not already been completed.
Returns:
the names of the directories which matched none of the include patterns.

getNotIncludedFiles

public String[] getNotIncludedFiles()
Returns the names of the files which matched none of the include patterns. The names are relative to the base directory. This involves performing a slow scan if one has not already been completed.
Returns:
the names of the files which matched none of the include patterns.

isEverythingIncluded

public boolean isEverythingIncluded()
Returns whether or not the scanner has included all the files or directories it has come across so far.
Returns:
true if all files and directories which have been found so far have been included.

isExcluded

protected boolean isExcluded(String name)
Tests whether or not a name matches against at least one exclude pattern.
Parameters:
name - The name to match. Must not be null.
Returns:
true when the name matches against at least one exclude pattern, or false otherwise.

isIncluded

protected boolean isIncluded(String name)
Tests whether or not a name matches against at least one include pattern.
Parameters:
name - The name to match. Must not be null.
Returns:
true when the name matches against at least one include pattern, or false otherwise.

isSelected

protected boolean isSelected(String name,
                             File file)
Tests whether a name should be selected.
Parameters:
name - the filename to check for selecting
file - the java.io.File object for this filename
Returns:
false when the selectors says that the file should not be selected, true otherwise.

isSymbolicLink

public boolean isSymbolicLink(File parent,
                              String name)
            throws IOException
Checks whether a given file is a symbolic link.

It doesn't really test for symbolic links but whether the canonical and absolute paths of the file are identical - this may lead to false positives on some platforms.

Parameters:
parent - the parent directory of the file to test
name - the name of the file to test.
Since:
Ant 1.5

match

public static boolean match(String pattern,
                            String str)
Tests whether or not a string matches against a pattern. The pattern may contain two special characters:
'*' means zero or more characters
'?' means one and only one character
Parameters:
pattern - The pattern to match against. Must not be null.
str - The string which must be matched against the pattern. Must not be null.
Returns:
true if the string matches against the pattern, or false otherwise.

match

protected static boolean match(String pattern,
                               String str,
                               boolean isCaseSensitive)
Tests whether or not a string matches against a pattern. The pattern may contain two special characters:
'*' means zero or more characters
'?' means one and only one character
Parameters:
pattern - The pattern to match against. Must not be null.
str - The string which must be matched against the pattern. Must not be null.
isCaseSensitive - Whether or not matching should be performed case sensitively.
Returns:
true if the string matches against the pattern, or false otherwise.

matchPath

protected static boolean matchPath(String pattern,
                                   String str)
Tests whether or not a given path matches a given pattern.
Parameters:
pattern - The pattern to match against. Must not be null.
str - The path to match, as a String. Must not be null.
Returns:
true if the pattern matches against the string, or false otherwise.

matchPath

protected static boolean matchPath(String pattern,
                                   String str,
                                   boolean isCaseSensitive)
Tests whether or not a given path matches a given pattern.
Parameters:
pattern - The pattern to match against. Must not be null.
str - The path to match, as a String. Must not be null.
isCaseSensitive - Whether or not matching should be performed case sensitively.
Returns:
true if the pattern matches against the string, or false otherwise.

matchPatternStart

protected static boolean matchPatternStart(String pattern,
                                           String str)
Tests whether or not a given path matches the start of a given pattern up to the first "**".

This is not a general purpose test and should only be used if you can live with false positives. For example, pattern=**\a and str=b will yield true.

Parameters:
pattern - The pattern to match against. Must not be null.
str - The path to match, as a String. Must not be null.
Returns:
whether or not a given path matches the start of a given pattern up to the first "**".

matchPatternStart

protected static boolean matchPatternStart(String pattern,
                                           String str,
                                           boolean isCaseSensitive)
Tests whether or not a given path matches the start of a given pattern up to the first "**".

This is not a general purpose test and should only be used if you can live with false positives. For example, pattern=**\a and str=b will yield true.

Parameters:
pattern - The pattern to match against. Must not be null.
str - The path to match, as a String. Must not be null.
isCaseSensitive - Whether or not matching should be performed case sensitively.
Returns:
whether or not a given path matches the start of a given pattern up to the first "**".

scan

public void scan()
            throws IllegalStateException
Scans the base directory for files which match at least one include pattern and don't match any exclude patterns. If there are selectors then the files must pass muster there, as well.

scandir

protected void scandir(File dir,
                       String vpath,
                       boolean fast)
Scans the given directory for files and directories. Found files and directories are placed in their respective collections, based on the matching of includes, excludes, and the selectors. When a directory is found, it is scanned recursively.
Parameters:
dir - The directory to scan. Must not be null.
vpath - The path relative to the base directory (needed to prevent problems with an absolute path when using dir). Must not be null.
fast - Whether or not this call is part of a fast scan.

setBasedir

public void setBasedir(File basedir)
Sets the base directory to be scanned. This is the directory which is scanned recursively.
Parameters:
basedir - The base directory for scanning. Should not be null.

setBasedir

public void setBasedir(String basedir)
Sets the base directory to be scanned. This is the directory which is scanned recursively. All '/' and '\' characters are replaced by File.separatorChar, so the separator used need not match File.separatorChar.
Parameters:
basedir - The base directory to scan. Must not be null.

setCaseSensitive

public void setCaseSensitive(boolean isCaseSensitive)
Sets whether or not the file system should be regarded as case sensitive.
Parameters:
isCaseSensitive - whether or not the file system should be regarded as a case sensitive one

setExcludes

public void setExcludes(String[] excludes)
Sets the list of exclude patterns to use. All '/' and '\' characters are replaced by File.separatorChar, so the separator used need not match File.separatorChar.

When a pattern ends with a '/' or '\', "**" is appended.

Parameters:
excludes - A list of exclude patterns. May be null, indicating that no files should be excluded. If a non-null list is given, all elements must be non-null.

setFollowSymlinks

public void setFollowSymlinks(boolean followSymlinks)
Sets whether or not symbolic links should be followed.
Parameters:
followSymlinks - whether or not symbolic links should be followed

setIncludes

public void setIncludes(String[] includes)
Sets the list of include patterns to use. All '/' and '\' characters are replaced by File.separatorChar, so the separator used need not match File.separatorChar.

When a pattern ends with a '/' or '\', "**" is appended.

Parameters:
includes - A list of include patterns. May be null, indicating that all files should be included. If a non-null list is given, all elements must be non-null.

slowScan

protected void slowScan()
Top level invocation for a slow scan. A slow scan builds up a full list of excluded/included files/directories, whereas a fast scan will only have full results for included files, as it ignores directories which can't possibly hold any included files/directories.

Returns immediately if a slow scan has already been completed.