jenkins.util

Class VirtualFile

java.lang.Object

jenkins.util.VirtualFile

All Implemented Interfaces:

Serializable, Comparable<VirtualFile>

public abstract class VirtualFile
extends Object
implements Comparable<VirtualFile>, Serializable

Abstraction over File, FilePath, or other items such as network resources or ZIP entries. Assumed to be read-only and makes very limited assumptions, just enough to display content and traverse directories.

To obtain a VirtualFile representation for an existing file, use forFile(File) or FilePath.toVirtualFile()

How are VirtualFile and FilePath different?

FilePath abstracts away Files on machines that are connected over Channel, whereas VirtualFile makes no assumption about where the actual files are, or whether there really exists Files somewhere. This makes VirtualFile more abstract.

Opening files from other machines

While VirtualFile is marked Serializable, it is not safe in general to transfer over a Remoting channel. (For example, an implementation from forFilePath(hudson.FilePath) could be sent on the same channel, but an implementation from forFile(java.io.File) will not.) Thus callers should assume that methods such as open() will work only on the node on which the object was created.

Since some implementations may in fact use external file storage, callers may request optional APIs to access those services more efficiently. Otherwise, for example, a plugin copying a file previously saved by ArtifactManager to an external storage service which tunneled a stream from open() using RemoteInputStream would wind up transferring the file from the service to the Jenkins master and then on to an agent. Similarly, if DirectoryBrowserSupport rendered a link to an in-Jenkins URL, a large file could be transferred from the service to the Jenkins master and then on to the browser. To avoid this overhead, callers may check whether an implementation supports toExternalURL().

Since:

1.532

See Also:

DirectoryBrowserSupport, FilePath, Serialized Form

Constructor Summary

Constructors

Constructor and Description
VirtualFile()

Method Summary

Modifier and Type	Method and Description
abstract boolean	canRead() Checks whether this file can be read.
abstract VirtualFile	child(String name) Obtains a child file.
int	compareTo(VirtualFile o) Does case-insensitive comparison.
boolean	containsSymLinkChild(boolean noFollowLinks)
boolean	equals(Object obj) Compares according to toURI().
abstract boolean	exists() Checks whether this file exists.
static VirtualFile	forFile(File f) Creates a virtual file wrapper for a local file.
static VirtualFile	forFilePath(FilePath f) Creates a virtual file wrapper for a remotable file.
abstract String	getName() Gets the base name, meaning just the last portion of the path name without any directories.
abstract VirtualFile	getParent() Gets the parent file.
int	hashCode() Hashes according to toURI().
boolean	hasSymlink(boolean noFollowLinks) Determines when a VirtualFile has a recognized symlink.
boolean	isDescendant(String childRelativePath) Check if the relative path is really a descendant of this folder, following the symbolic links.
abstract boolean	isDirectory() Checks whether this file exists and is a directory.
abstract boolean	isFile() Checks whether this file exists and is a plain file.
abstract long	lastModified() Gets the file timestamp.
abstract long	length() Gets the file length.
abstract VirtualFile[]	list() Lists children of this directory.
VirtualFile[]	list(boolean noFollowLinks) Lists children of this directory.
String[]	list(String glob) Deprecated. use list(String, String, boolean) instead
Collection<String>	list(String includes, String excludes, boolean useDefaultExcludes) Lists recursive files of this directory with pattern matching.
Collection<String>	list(String includes, String excludes, boolean useDefaultExcludes, boolean noFollowLinks) Lists recursive files of this directory with pattern matching.
List<VirtualFile>	listOnlyDescendants() Lists only the children that are descendant of the root directory (not necessarily the current VirtualFile).
int	mode() Gets the file’s Unix mode, if meaningful.
abstract InputStream	open() Opens an input stream on the file so its contents can be read.
InputStream	open(boolean noFollowLinks) Opens an input stream on the file so its contents can be read.
String	readLink() If this file is a symlink, returns the link target.
<V> V	run(hudson.remoting.Callable<V,IOException> callable) Does some calculations in batch.
boolean	supportIsDescendant() Determine if the implementation supports the isDescendant(String) method TODO un-restrict it in a weekly after the patch
boolean	supportsQuickRecursiveListing()
URL	toExternalURL() Optionally obtains a URL which may be used to retrieve file contents from any process on any node.
String	toString() Displays toURI().
abstract URI	toURI() Gets a URI.
int	zip(OutputStream outputStream, String includes, String excludes, boolean useDefaultExcludes, boolean noFollowLinks, String prefix) Create a ZIP archive from the list of folders/files using the includes and excludes to filter them.

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Constructor Detail

VirtualFile

public VirtualFile()

Method Detail

getName

@NonNull
public abstract String getName()

Gets the base name, meaning just the last portion of the path name without any directories. For a “root directory” this may be the empty string.

Returns:

a simple name (no slashes)

toURI

@NonNull
public abstract URI toURI()

Gets a URI. Should at least uniquely identify this virtual file within its root, but not necessarily globally.

When toExternalURL() is implemented, that same value could be used here, unless some sort of authentication is also embedded.

Returns:

a URI (need not be absolute)

getParent

public abstract VirtualFile getParent()

Gets the parent file. Need only operate within the originally given root.

Returns:

the parent

isDirectory

public abstract boolean isDirectory()
                             throws IOException

Checks whether this file exists and is a directory.

Returns:

true if it is a directory, false if a file or nonexistent

Throws:

IOException - in case checking status failed

isFile

public abstract boolean isFile()
                        throws IOException

Checks whether this file exists and is a plain file.

Returns:

true if it is a file, false if a directory or nonexistent

Throws:

IOException - in case checking status failed

readLink

@CheckForNull
public String readLink()
                              throws IOException

If this file is a symlink, returns the link target.

The default implementation always returns null. Some implementations may not support symlinks under any conditions.

Returns:

a target (typically a relative path in some format), or null if this is not a link

Throws:

IOException - if reading the link, or even determining whether this file is a link, failed

Since:

2.118

exists

public abstract boolean exists()
                        throws IOException

Checks whether this file exists. The behavior is undefined for symlinks; if in doubt, check readLink() first.

Returns:

true if it is a plain file or directory, false if nonexistent

Throws:

IOException - in case checking status failed

list

@NonNull
public abstract VirtualFile[] list()
                                     throws IOException

Lists children of this directory. Only one level deep.

Returns:

a list of children (files and subdirectories); empty for a file or nonexistent directory

Throws:

IOException - if this directory exists but listing was not possible for some other reason

list

@Restricted(value=org.kohsuke.accmod.restrictions.NoExternalUse.class)
 @NonNull
public VirtualFile[] list(boolean noFollowLinks)
                                                                                                    throws IOException

Lists children of this directory. Only one level deep. This is intended to allow the caller to provide LinkOption.NOFOLLOW_LINKS to ignore symlinks. However, this cannot be enforced. The base implementation here in VirtualFile ignores the openOptions. Some VirtualFile subclasses may not be able to provide an implementation in which NOFOLLOW_LINKS is used or makes sense. Implementations are free to ignore openOptions. Some subclasses of VirtualFile may not have a concept of symlinks.

Parameters:

noFollowLinks - if true then do not follow links.

Returns:

a list of children (files and subdirectories); empty for a file or nonexistent directory

Throws:

IOException - if it could not be opened

supportsQuickRecursiveListing

@Restricted(value=org.kohsuke.accmod.restrictions.NoExternalUse.class)
public boolean supportsQuickRecursiveListing()

hasSymlink

@Restricted(value=org.kohsuke.accmod.restrictions.NoExternalUse.class)
public boolean hasSymlink(boolean noFollowLinks)
                                                                                          throws IOException

Determines when a VirtualFile has a recognized symlink. A recognized symlink can be the file itself or any containing directory between it and the optional root directory. If there is no provided root directory then only the file itself is considered. This base implementation ignores the existence of symlinks.

Parameters:

noFollowLinks - if true, then do not follow links.

Returns:

True if the file is a symlink or is referenced within a containing symlink directory before reaching the root directory.

Throws:

IOException - If there is a problem accessing the file.

listOnlyDescendants

@Restricted(value=org.kohsuke.accmod.restrictions.NoExternalUse.class)
 @NonNull
public List<VirtualFile> listOnlyDescendants()
                                                                                                                       throws IOException

Lists only the children that are descendant of the root directory (not necessarily the current VirtualFile). Only one level deep.

Returns:

a list of descendant children (files and subdirectories); empty for a file or nonexistent directory

Throws:

IOException - if this directory exists but listing was not possible for some other reason

list

@Deprecated
 @NonNull
public String[] list(String glob)
                                    throws IOException

Deprecated. use list(String, String, boolean) instead

Throws:

IOException

list

@NonNull
public Collection<String> list(@NonNull
                                        String includes,
                                        @CheckForNull
                                        String excludes,
                                        boolean useDefaultExcludes)
                                 throws IOException

Lists recursive files of this directory with pattern matching.

The default implementation calls list() recursively inside run(hudson.remoting.Callable<V, java.io.IOException>) and applies filtering to the result. Implementations may wish to override this more efficiently.

Parameters:

includes - comma-separated Ant-style globs as per Util.createFileSet(File, String, String) using / as a path separator; the empty string means no matches (use SelectorUtils.DEEP_TREE_MATCH if you want to match everything except some excludes)

excludes - optional excludes in similar format to includes

useDefaultExcludes - as per AbstractFileSet.setDefaultexcludes(boolean)

Returns:

a list of /-separated relative names of children (files directly inside or in subdirectories)

Throws:

IOException - if this is not a directory, or listing was not possible for some other reason

Since:

2.118

list

@Restricted(value=org.kohsuke.accmod.restrictions.NoExternalUse.class)
 @NonNull
public Collection<String> list(@NonNull
                                                                                                                String includes,
                                                                                                                @CheckForNull
                                                                                                                String excludes,
                                                                                                                boolean useDefaultExcludes,
                                                                                                                boolean noFollowLinks)
                                                                                                         throws IOException

Lists recursive files of this directory with pattern matching.

The default implementation calls list() recursively inside run(hudson.remoting.Callable<V, java.io.IOException>) and applies filtering to the result. Implementations may wish to override this more efficiently. This method allows the user to specify that symlinks should not be followed by passing noFollowLinks as true. However, some implementations may not be able to reliably prevent link following. The base implementation here in VirtualFile ignores this parameter.

Parameters:

includes - comma-separated Ant-style globs as per Util.createFileSet(File, String, String) using / as a path separator; the empty string means no matches (use SelectorUtils.DEEP_TREE_MATCH if you want to match everything except some excludes)

excludes - optional excludes in similar format to includes

useDefaultExcludes - as per AbstractFileSet.setDefaultexcludes(boolean)

noFollowLinks - if true then do not follow links.

Returns:

a list of /-separated relative names of children (files directly inside or in subdirectories)

Throws:

IOException - if this is not a directory, or listing was not possible for some other reason

Since:

TODO

containsSymLinkChild

@Restricted(value=org.kohsuke.accmod.restrictions.NoExternalUse.class)
public boolean containsSymLinkChild(boolean noFollowLinks)
                                                                                                    throws IOException

Throws:

IOException

zip

public int zip(OutputStream outputStream,
               String includes,
               String excludes,
               boolean useDefaultExcludes,
               boolean noFollowLinks,
               String prefix)
        throws IOException

Create a ZIP archive from the list of folders/files using the includes and excludes to filter them.

The default implementation calls other existing methods to list the folders/files, then retrieve them and zip them all.

Parameters:

includes - comma-separated Ant-style globs as per Util.createFileSet(File, String, String) using / as a path separator; the empty string means no matches (use SelectorUtils.DEEP_TREE_MATCH if you want to match everything except some excludes)

excludes - optional excludes in similar format to includes

useDefaultExcludes - as per AbstractFileSet.setDefaultexcludes(boolean)

noFollowLinks - if true then do not follow links.

prefix - the partial path that will be added before each entry inside the archive. If non-empty, a trailing slash will be enforced.

Returns:

the number of files inside the archive (not the folders)

Throws:

IOException - if this is not a directory, or listing was not possible for some other reason

Since:

TODO

child

@NonNull
public abstract VirtualFile child(@NonNull
                                           String name)

Obtains a child file.

Parameters:

name - a relative path, possibly including / (but not ..)

Returns:

a representation of that child, whether it actually exists or not

length

public abstract long length()
                     throws IOException

Gets the file length.

Returns:

a length, or 0 if inapplicable (e.g. a directory)

Throws:

IOException - if checking the length failed

lastModified

public abstract long lastModified()
                           throws IOException

Gets the file timestamp.

Returns:

a length, or 0 if inapplicable

Throws:

IOException - if checking the timestamp failed

mode

public int mode()
         throws IOException

Gets the file’s Unix mode, if meaningful. If the file is symlink (see readLink()), the mode is that of the link target, not the link itself.

Returns:

for example, 0644 ~ rw-r--r--; -1 by default, meaning unknown or inapplicable

Throws:

IOException - if checking the mode failed

Since:

2.118

canRead

public abstract boolean canRead()
                         throws IOException

Checks whether this file can be read.

Returns:

true normally

Throws:

IOException - if checking status failed

open

public abstract InputStream open()
                          throws IOException

Opens an input stream on the file so its contents can be read.

Returns:

an open stream

Throws:

IOException - if it could not be opened

open

@Restricted(value=org.kohsuke.accmod.restrictions.NoExternalUse.class)
public InputStream open(boolean noFollowLinks)
                                                                                        throws IOException

Opens an input stream on the file so its contents can be read.

Parameters:

noFollowLinks - if true do not follow links.

Returns:

an open stream

Throws:

IOException - if it could not be opened

compareTo

public final int compareTo(VirtualFile o)

Does case-insensitive comparison.

Specified by:

compareTo in interface Comparable<VirtualFile>

equals

public final boolean equals(Object obj)

Compares according to toURI().

Overrides:

equals in class Object

hashCode

public final int hashCode()

Hashes according to toURI().

Overrides:

hashCode in class Object

toString

public final String toString()

Displays toURI().

Overrides:

toString in class Object

run

public <V> V run(hudson.remoting.Callable<V,IOException> callable)
          throws IOException

Does some calculations in batch. For a remote file, this can be much faster than doing the corresponding operations one by one as separate requests. The default implementation just calls the block directly.

Type Parameters:

V - a value type

Parameters:

callable - something to run all at once (only helpful if any mentioned files are on the same system)

Returns:

the callable result

Throws:

IOException - if remote communication failed

Since:

1.554

toExternalURL

@CheckForNull
public URL toExternalURL()
                                throws IOException

Optionally obtains a URL which may be used to retrieve file contents from any process on any node. For example, given cloud storage this might produce a permalink to the file.

Only http and https protocols are permitted. It is recommended to use RobustHTTPClient.downloadFile to work with these URLs.

This is only meaningful for isFile(): no ZIP etc. archiving protocol is defined to allow bulk access to directory trees.

Any necessary authentication must be encoded somehow into the URL itself; do not include any tokens or other authentication which might allow access to unrelated files (for example ArtifactManager builds from a different job). Authentication should be limited to download, not upload or any other modifications.

The URL might be valid for only a limited amount of time or even only a single use; this method should be called anew every time an external URL is required.

Returns:

an externally usable URL like https://gist.githubusercontent.com/ACCT/GISTID/raw/COMMITHASH/FILE, or null if there is no such support

Throws:

IOException

Since:

2.118

See Also:

toURI()

supportIsDescendant

@Restricted(value=org.kohsuke.accmod.restrictions.NoExternalUse.class)
public boolean supportIsDescendant()

Determine if the implementation supports the isDescendant(String) method TODO un-restrict it in a weekly after the patch

isDescendant

@Restricted(value=org.kohsuke.accmod.restrictions.NoExternalUse.class)
public boolean isDescendant(String childRelativePath)
                                                                                            throws IOException

Check if the relative path is really a descendant of this folder, following the symbolic links. Meant to be used in coordination with child(String). TODO un-restrict it in a weekly after the patch

Throws:

IOException

forFile

public static VirtualFile forFile(File f)

Creates a virtual file wrapper for a local file.

Parameters:

f - a disk file (need not exist)

Returns:

a wrapper

forFilePath

public static VirtualFile forFilePath(FilePath f)

Creates a virtual file wrapper for a remotable file.

Parameters:

f - a local or remote file (need not exist)

Returns:

a wrapper