Package org.codehaus.plexus.util

Class DirectoryScanner

java.lang.Object
org.codehaus.plexus.util.AbstractScanner
org.codehaus.plexus.util.DirectoryScanner
All Implemented Interfaces:
Scanner
public class DirectoryScanner extends AbstractScanner

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 < files.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"

Author:
Arnout J. Kuiper ajkuiper@wxs.nl, Magesh Umasankar, Bruce Atherton, Antoine Levy-Lambert

  • Field Details

    • basedir

      protected File basedir
      The base directory to be scanned.

    • filesIncluded

      protected ArrayList<String> filesIncluded
      The files which matched at least one include and no excludes and were selected.

    • filesNotIncluded

      protected ArrayList<String> filesNotIncluded
      The files which did not match any includes or selectors.

    • filesExcluded

      protected ArrayList<String> filesExcluded
      The files which matched at least one include and at least one exclude.

    • dirsIncluded

      protected ArrayList<String> dirsIncluded
      The directories which matched at least one include and no excludes and were selected.

    • dirsNotIncluded

      protected ArrayList<String> dirsNotIncluded
      The directories which were found and did not match any includes.

    • dirsExcluded

      protected ArrayList<String> dirsExcluded
      The directories which matched at least one include and at least one exclude.

    • filesDeselected

      protected ArrayList<String> filesDeselected
      The files which matched at least one include and no excludes and which a selector discarded.

    • dirsDeselected

      protected ArrayList<String> dirsDeselected
      The directories which matched at least one include and no excludes but which a selector discarded.

    • haveSlowResults

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

    • everythingIncluded

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

  • Constructor Details

    • DirectoryScanner

      public DirectoryScanner()
      Sole constructor.

  • Method Details

    • 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.

    • 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.

    • 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

    • 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

    • 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.

    • 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.
      Throws:
      IllegalStateException - if the base directory was set incorrectly (i.e. if it is null, doesn't exist, or isn't a directory).

    • 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.

    • 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.
      See Also:

    • 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.

    • 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.

    • 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.
      See Also:

    • 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.
      See Also:

    • 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.
      See Also:

    • 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.

    • 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.
      See Also:

    • 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.
      See Also:

    • 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.
      See Also:

    • 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.
      Returns:
      true if it's a symbolic link
      Throws:
      IOException - .
      Since:
      Ant 1.5

    • isParentSymbolicLink

      public boolean isParentSymbolicLink(File parent, String name) throws IOException

      Checks whether the parent of this file is a symbolic link.

      For java versions prior to 7 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.
      Returns:
      true if it's a symbolic link
      Throws:
      IOException - .
      Since:
      Ant 1.5