org.apache.sshd.common.util

Class DirectoryScanner

java.lang.Object

org.apache.sshd.common.util.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 < 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 Summary

Fields

Modifier and Type	Field and Description
protected java.io.File	basedir The base directory to be scanned.
protected java.util.List<java.lang.String>	filesIncluded The files which matched at least one include and no excludes and were selected.
protected java.lang.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

Constructors

Constructor and Description
DirectoryScanner()
DirectoryScanner(java.lang.String basedir, java.lang.String... includes)

Method Summary

Methods

Modifier and Type	Method and Description
protected boolean	couldHoldIncluded(java.lang.String name) Tests whether or not a name matches the start of at least one include pattern.
java.io.File	getBasedir() Returns the base directory to be scanned.
java.lang.String[]	getIncludedFiles() Returns the names of the files which matched at least one of the include patterns and none of the exclude patterns.
protected boolean	isIncluded(java.lang.String name) Tests whether or not a name matches against at least one include pattern.
static java.lang.String	replace(java.lang.String text, java.lang.String repl, java.lang.String with, int max) Replace a String with another String inside a larger String, for the first max values of the search String.
java.lang.String[]	scan() Scans the base directory for files which match at least one include pattern and don't match any exclude patterns.
protected void	scandir(java.io.File dir, java.lang.String vpath) Scans the given directory for files and directories.
void	setBasedir(java.io.File basedir) Sets the base directory to be scanned.
void	setBasedir(java.lang.String basedir) Sets the base directory to be scanned.
void	setIncludes(java.lang.String[] includes) Sets the list of include patterns to use.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

basedir

protected java.io.File basedir

The base directory to be scanned.

includes

protected java.lang.String[] includes

The patterns for the files to be included.

filesIncluded

protected java.util.List<java.lang.String> filesIncluded

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

isCaseSensitive

protected boolean isCaseSensitive

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

Constructor Detail

DirectoryScanner

public DirectoryScanner()

DirectoryScanner

public DirectoryScanner(java.lang.String basedir,
                java.lang.String... includes)

Method Detail

setBasedir

public void setBasedir(java.lang.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(java.io.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 java.io.File getBasedir()

Returns the base directory to be scanned. This is the directory which is scanned recursively.

Returns:

the base directory to be scanned

setIncludes

public void setIncludes(java.lang.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.

scan

public java.lang.String[] scan()
                        throws java.lang.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:

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

scandir

protected void scandir(java.io.File dir,
           java.lang.String vpath)

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.

Throws:

java.io.IOException

getIncludedFiles

public java.lang.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.

isIncluded

protected boolean isIncluded(java.lang.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.

couldHoldIncluded

protected boolean couldHoldIncluded(java.lang.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.

replace

public static java.lang.String replace(java.lang.String text,
                       java.lang.String repl,
                       java.lang.String with,
                       int max)

Replace a String with another String inside a larger String, for the first max values of the search String.

A null reference passed to this method is a no-op.

Parameters:

text - text to search and replace in

repl - String to search for

with - String to replace with

max - maximum number of values to replace, or -1 if no maximum

Returns:

the text with any replacements processed