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java.lang.Objectcom.trolltech.qt.QSignalEmitter
com.trolltech.qt.QtJambiObject
com.trolltech.qt.core.QFileInfo
public class QFileInfo
The QFileInfo class provides system-independent file information.
QFileInfo provides information about a file's name and position (path) in the file system, its access rights and whether it is a directory or symbolic link, etc. The file's size and last modified/read times are also available. QFileInfo can also be used to obtain information about a Qt resource.
A QFileInfo can point to a file with either a relative or an absolute file path. Absolute file paths begin with the directory separator "/" (or with a drive specification on Windows). Relative file names begin with a directory name or a file name and specify a path relative to the current working directory. An example of an absolute path is the string "/tmp/quartz". A relative path might look like "src/fatlib". You can use the function isRelative to check whether a QFileInfo is using a relative or an absolute file path. You can call the function makeAbsolute to convert a relative QFileInfo's path to an absolute path.
The file that the QFileInfo works on is set in the constructor or later with setFile. Use exists to see if the file exists and size to get its size.
Some of QFileInfo's functions query the file system, but for performance reasons, some functions only operate on the file name itself. For example: To return the absolute path of a relative file name, absolutePath has to query the file system. The path function, however, can work on the file name directly, and so it is faster. By convention, QFileInfo interprets any path that ends with a slash '/' as a directory (e.g., "C:/WINDOWS/"), and those without a trailing slash (e.g., "C:/WINDOWS/hosts.txt") are treated as files.
To speed up performance, QFileInfo caches information about the file. Because files can be changed by other users or programs, or even by other parts of the same program, there is a function that refreshes the file information: refresh. If you want to switch off a QFileInfo's caching and force it to access the file system every time you request information from it call setCaching(false).
The file's type is obtained with isFile, isDir and isSymLink. The symLinkTarget function provides the name of the file the symlink points to.
On Unix (including Mac OS X), the symlink has the same size has the file it points to, because Unix handles symlinks transparently; similarly, opening a symlink using QFile effectively opens the link's target. For example:
#ifdef Q_OS_UNIX QFileInfo info1("/home/bob/bin/untabify"); info1.isSymLink(); // returns true info1.absoluteFilePath(); // returns "/home/bob/bin/untabify" info1.size(); // returns 56201 info1.symLinkTarget(); // returns "/opt/pretty++/bin/untabify" QFileInfo info2(info1.symLinkTarget()); info1.isSymLink(); // returns false info1.absoluteFilePath(); // returns "/opt/pretty++/bin/untabify" info1.size(); // returns 56201 #endif
On Windows, symlinks (shortcuts) are .lnk files. The reported size is that of the symlink (not the link's target), and opening a symlink using QFile opens the .lnk file. For example:
#ifdef Q_OS_WIN QFileInfo info1("C:\\Documents and Settings\\Bob\\untabify.lnk"); info1.isSymLink(); // returns true info1.absoluteFilePath(); // returns "C:/Documents and Settings/Bob/untabify.lnk" info1.size(); // returns 743 info1.symLinkTarget(); // returns "C:/Pretty++/untabify" QFileInfo info2(info1.symLinkTarget()); info1.isSymLink(); // returns false info1.absoluteFilePath(); // returns "C:/Pretty++/untabify" info1.size(); // returns 63942 #endif
Elements of the file's name can be extracted with path and fileName. The fileName's parts can be extracted with baseName and extension().
The file's dates are returned by created, lastModified and lastRead. Information about the file's access permissions is obtained with isReadable, isWritable and isExecutable. The file's ownership is available from owner, ownerId, group and groupId. You can examine a file's permissions and ownership in a single statement using the permission function.
Nested Class Summary |
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Nested classes/interfaces inherited from class com.trolltech.qt.QSignalEmitter |
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QSignalEmitter.Signal0, QSignalEmitter.Signal1<A>, QSignalEmitter.Signal2<A,B>, QSignalEmitter.Signal3<A,B,C>, QSignalEmitter.Signal4<A,B,C,D>, QSignalEmitter.Signal5<A,B,C,D,E>, QSignalEmitter.Signal6<A,B,C,D,E,F>, QSignalEmitter.Signal7<A,B,C,D,E,F,G>, QSignalEmitter.Signal8<A,B,C,D,E,F,G,H>, QSignalEmitter.Signal9<A,B,C,D,E,F,G,H,I> |
Constructor Summary | |
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QFileInfo()
Constructs an empty QFileInfo object. |
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QFileInfo(QDir dir,
java.lang.String file)
Constructs a new QFileInfo that gives information about the given file in the directory dir. |
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QFileInfo(QFile file)
Constructs a new QFileInfo that gives information about file file. |
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QFileInfo(QFileInfo fileinfo)
Constructs a new QFileInfo that is a copy of the given fileinfo. |
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QFileInfo(java.lang.String file)
Constructs a new QFileInfo that gives information about the given file. |
Method Summary | |
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QDir |
absoluteDir()
Returns the file's absolute path as a QDir object. |
java.lang.String |
absoluteFilePath()
Returns the absolute path including the file name. |
java.lang.String |
absolutePath()
Returns the file's path absolute path. |
java.lang.String |
baseName()
Returns the base name of the file without the path. |
java.lang.String |
bundleName()
Returns the name of the bundle. |
boolean |
caching()
Returns true if caching is enabled; otherwise returns false. |
java.lang.String |
canonicalFilePath()
Returns the canonical path, i.e. a path without symbolic links or redundant "." or ".." elements. |
java.lang.String |
canonicalPath()
Returns the canonical path, i.e. a path without symbolic links or redundant "." or ".." elements. |
java.lang.String |
completeBaseName()
Returns the complete base name of the file without the path. |
java.lang.String |
completeSuffix()
Returns the complete suffix of the file. |
QDateTime |
created()
Returns the date and time when the file was created. |
QDir |
dir()
Returns the path of the object's parent directory as a QDir object. |
boolean |
equals(java.lang.Object other)
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boolean |
exists()
Returns true if the file exists; otherwise returns false. |
java.lang.String |
fileName()
Returns the name of the file, excluding the path. |
java.lang.String |
filePath()
Returns the file name, including the path (which may be absolute or relative). |
static QFileInfo |
fromNativePointer(QNativePointer nativePointer)
This function returns the QFileInfo instance pointed to by nativePointer |
java.lang.String |
group()
Returns the group of the file. |
int |
groupId()
Returns the id of the group the file belongs to. |
boolean |
isAbsolute()
Returns true if the file path name is absolute, otherwise returns false if the path is relative. |
boolean |
isBundle()
Returns true if this object points to a bundle or to a symbolic link to a bundle on Mac OS X; otherwise returns false. |
boolean |
isDir()
Returns true if this object points to a directory or to a symbolic link to a directory; otherwise returns false. |
boolean |
isExecutable()
Returns true if the file is executable; otherwise returns false. |
boolean |
isFile()
Returns true if this object points to a file or to a symbolic link to a file. |
boolean |
isHidden()
Returns true if this is a `hidden' file; otherwise returns false. |
boolean |
isReadable()
Returns true if the user can read the file; otherwise returns false. |
boolean |
isRelative()
Returns true if the file path name is relative, otherwise returns false if the path is absolute (e.g. under Unix a path is absolute if it begins with a "/"). |
boolean |
isRoot()
Returns true if the object points to a directory or to a symbolic link to a directory, and that directory is the root directory; otherwise returns false. |
boolean |
isSymLink()
Returns true if this object points to a symbolic link (or to a shortcut on Windows); otherwise returns false. |
boolean |
isWritable()
Returns true if the user can write to the file; otherwise returns false. |
QDateTime |
lastModified()
Returns the date and time when the file was last modified. |
QDateTime |
lastRead()
Returns the date and time when the file was last read (accessed). |
boolean |
makeAbsolute()
Converts the file's path to an absolute path if it is not already in that form. |
static QNativePointer |
nativePointerArray(QFileInfo[] array)
This function returns a QNativePointer that is pointing to the specified QFileInfo array. |
java.lang.String |
owner()
Returns the owner of the file. |
int |
ownerId()
Returns the id of the owner of the file. |
java.lang.String |
path()
Returns the file's path. |
boolean |
permission(QFile.Permission... permissions)
Tests for file permissions. |
boolean |
permission(QFile.Permissions permissions)
Tests for file permissions. |
QFile.Permissions |
permissions()
Returns the complete OR-ed together combination of QFile::Permissions for the file. |
void |
refresh()
Refreshes the information about the file, i.e. reads in information from the file system the next time a cached property is fetched. |
void |
setCaching(boolean on)
If on is true, enables caching of file information. |
void |
setFile(QDir dir,
java.lang.String file)
Sets the file that the QFileInfo provides information about to file in directory dir. |
void |
setFile(QFile file)
Sets the file that the QFileInfo provides information about to file. |
void |
setFile(java.lang.String file)
Sets the file that the QFileInfo provides information about to file. |
long |
size()
Returns the file size in bytes. |
java.lang.String |
suffix()
Returns the suffix of the file. |
java.lang.String |
symLinkTarget()
Returns the absolute path to the file or directory a symlink (or shortcut on Windows) points to, or a an empty string if the object isn't a symbolic link. |
Methods inherited from class com.trolltech.qt.QtJambiObject |
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dispose, disposed, finalize, reassignNativeResources, tr, tr, tr |
Methods inherited from class com.trolltech.qt.QSignalEmitter |
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blockSignals, disconnect, disconnect, signalsBlocked, signalSender, thread |
Methods inherited from class java.lang.Object |
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clone, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait |
Methods inherited from interface com.trolltech.qt.QtJambiInterface |
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disableGarbageCollection, nativeId, nativePointer, reenableGarbageCollection, setJavaOwnership |
Constructor Detail |
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public QFileInfo(QDir dir, java.lang.String file)
Constructs a new QFileInfo that gives information about the given file in the directory dir.
If dir has a relative path, the QFileInfo will also have a relative path.
public QFileInfo(QFile file)
Constructs a new QFileInfo that gives information about file file.
If the file has a relative path, the QFileInfo will also have a relative path.
public QFileInfo(QFileInfo fileinfo)
Constructs a new QFileInfo that is a copy of the given fileinfo.
public QFileInfo(java.lang.String file)
Constructs a new QFileInfo that gives information about the given file. The file can also include an absolute or relative path.
public QFileInfo()
Constructs an empty QFileInfo object.
Note that an empty QFileInfo object contain no file reference.
Method Detail |
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public final QDir absoluteDir()
Returns the file's absolute path as a QDir object.
public final java.lang.String absoluteFilePath()
Returns the absolute path including the file name.
The absolute path name consists of the full path and the file name. On Unix this will always begin with the root, '/', directory. On Windows this will always begin 'D:/' where D is a drive letter, except for network shares that are not mapped to a drive letter, in which case the path will begin '//sharename/'.
This function returns the same as filePath, unless isRelative is true.
If the QFileInfo is empty it returns QDir::currentPath().
This function can be time consuming under Unix (in the order of milliseconds).
public final java.lang.String absolutePath()
Returns the file's path absolute path. This doesn't include the file name.
public final java.lang.String baseName()
Returns the base name of the file without the path.
The base name consists of all characters in the file up to (but not including) the first '.' character.
Example:
QFileInfo fi("/tmp/archive.tar.gz");
QString base = fi.baseName(); // base = "archive"
The base name of a file is computed equally on all platforms, independent of file naming conventions (e.g., ".bashrc" on Unix has an empty base name, and the suffix is "bashrc").
public final java.lang.String bundleName()
Returns the name of the bundle.
On Mac OS X this returns the proper localized name for a bundle if the path isBundle. On all other platforms an empty QString is returned.
Example:
QFileInfo fi("/Applications/Safari.app");
QString bundle = fi.bundleName(); // name = "Safari"
public final boolean caching()
Returns true if caching is enabled; otherwise returns false.
public final java.lang.String canonicalFilePath()
Returns the canonical path, i.e. a path without symbolic links or redundant "." or ".." elements.
On systems that do not have symbolic links this function will always return the same string that absoluteFilePath returns. If the canonical path does not exist (normally due to dangling symbolic links) canonicalFilePath returns an empty string.
public final java.lang.String canonicalPath()
Returns the canonical path, i.e. a path without symbolic links or redundant "." or ".." elements.
On systems that do not have symbolic links this function will always return the same string that absolutePath returns. If the canonical path does not exist (normally due to dangling symbolic links) canonicalPath returns an empty string.
public final java.lang.String completeBaseName()
Returns the complete base name of the file without the path.
The complete base name consists of all characters in the file up to (but not including) the last '.' character.
Example:
QFileInfo fi("/tmp/archive.tar.gz");
QString base = fi.completeBaseName(); // base = "archive.tar"
public final java.lang.String completeSuffix()
Returns the complete suffix of the file.
The complete suffix consists of all characters in the file after (but not including) the first '.'.
Example:
QFileInfo fi("/tmp/archive.tar.gz");
QString ext = fi.completeSuffix(); // ext = "tar.gz"
public final QDateTime created()
Returns the date and time when the file was created.
On most Unix systems, this function returns the time of the last status change. A status change occurs when the file is created, but it also occurs whenever the user writes or sets inode information (for example, changing the file permissions).
If neither creation time nor "last status change" time are not available, returns the same as lastModified.
public final QDir dir()
Returns the path of the object's parent directory as a QDir object.
Note: The QDir returned always corresponds to the object's parent directory, even if the QFileInfo represents a directory.
public final boolean exists()
Returns true if the file exists; otherwise returns false.
public final java.lang.String fileName()
Returns the name of the file, excluding the path.
Example:
QFileInfo fi("/tmp/archive.tar.gz");
QString name = fi.fileName(); // name = "archive.tar.gz"
public final java.lang.String filePath()
Returns the file name, including the path (which may be absolute or relative).
public final java.lang.String group()
Returns the group of the file. On Windows, on systems where files do not have groups, or if an error occurs, an empty string is returned.
This function can be time consuming under Unix (in the order of milliseconds).
public final int groupId()
Returns the id of the group the file belongs to.
On Windows and on systems where files do not have groups this function always returns (uint) -2.
public final boolean isAbsolute()
Returns true if the file path name is absolute, otherwise returns false if the path is relative.
public final boolean isBundle()
Returns true if this object points to a bundle or to a symbolic link to a bundle on Mac OS X; otherwise returns false.
public final boolean isDir()
Returns true if this object points to a directory or to a symbolic link to a directory; otherwise returns false.
public final boolean isExecutable()
Returns true if the file is executable; otherwise returns false.
public final boolean isFile()
Returns true if this object points to a file or to a symbolic link to a file. Returns false if the object points to something which isn't a file, such as a directory.
public final boolean isHidden()
Returns true if this is a `hidden' file; otherwise returns false.
Note: This function returns true for the special entries "." and ".." on Unix, even though QDir::entryList threats them as shown.
public final boolean isReadable()
Returns true if the user can read the file; otherwise returns false.
public final boolean isRelative()
Returns true if the file path name is relative, otherwise returns false if the path is absolute (e.g. under Unix a path is absolute if it begins with a "/").
public final boolean isRoot()
Returns true if the object points to a directory or to a symbolic link to a directory, and that directory is the root directory; otherwise returns false.
public final boolean isSymLink()
Returns true if this object points to a symbolic link (or to a shortcut on Windows); otherwise returns false.
On Unix (including Mac OS X), opening a symlink effectively opens the link's target. On Windows, it opens the .lnk file itself.
Example:
QFileInfo info(fileName); if (info.isSymLink()) fileName = info.symLinkTarget();
public final boolean isWritable()
Returns true if the user can write to the file; otherwise returns false.
public final QDateTime lastModified()
Returns the date and time when the file was last modified.
public final QDateTime lastRead()
Returns the date and time when the file was last read (accessed).
On platforms where this information is not available, returns the same as lastModified.
public final boolean makeAbsolute()
Converts the file's path to an absolute path if it is not already in that form. Returns true to indicate that the path was converted; otherwise returns false to indicate that the path was already absolute.
public final java.lang.String owner()
Returns the owner of the file. On systems where files do not have owners, or if an error occurs, an empty string is returned.
This function can be time consuming under Unix (in the order of milliseconds).
public final int ownerId()
Returns the id of the owner of the file.
On Windows and on systems where files do not have owners this function returns ((uint) -2).
public final java.lang.String path()
Returns the file's path. This doesn't include the file name.
public final boolean permission(QFile.Permission... permissions)
Tests for file permissions. The permissions argument can be several flags of type QFile::Permissions OR-ed together to check for permission combinations.
On systems where files do not have permissions this function always returns true.
Example:
QFileInfo fi("/tmp/archive.tar.gz"); if (fi.permission(QFile::WriteUser | QFile::ReadGroup)) qWarning("I can change the file; my group can read the file"); if (fi.permission(QFile::WriteGroup | QFile::WriteOther)) qWarning("The group or others can change the file");
public final boolean permission(QFile.Permissions permissions)
Tests for file permissions. The permissions argument can be several flags of type QFile::Permissions OR-ed together to check for permission combinations.
On systems where files do not have permissions this function always returns true.
Example:
QFileInfo fi("/tmp/archive.tar.gz"); if (fi.permission(QFile::WriteUser | QFile::ReadGroup)) qWarning("I can change the file; my group can read the file"); if (fi.permission(QFile::WriteGroup | QFile::WriteOther)) qWarning("The group or others can change the file");
public final QFile.Permissions permissions()
Returns the complete OR-ed together combination of QFile::Permissions for the file.
public final void refresh()
Refreshes the information about the file, i.e. reads in information from the file system the next time a cached property is fetched.
public final void setCaching(boolean on)
If on is true, enables caching of file information. If on is false caching is disabled.
When caching is enabled, QFileInfo reads the file information from the file system the first time it's needed, but generally not later.
Caching is enabled by default.
public final void setFile(QDir dir, java.lang.String file)
Sets the file that the QFileInfo provides information about to file in directory dir.
If file includes a relative path, the QFileInfo will also have a relative path.
public final void setFile(java.lang.String file)
Sets the file that the QFileInfo provides information about to file.
The file can also include an absolute or relative file path. Absolute paths begin with the directory separator (e.g. "/" under Unix) or a drive specification (under Windows). Relative file names begin with a directory name or a file name and specify a path relative to the current directory.
Example:
QString absolute = "/local/bin"; QString relative = "local/bin"; QFileInfo absFile(absolute); QFileInfo relFile(relative); QDir::setCurrent(QDir::rootPath()); // absFile and relFile now point to the same file QDir::setCurrent("/tmp"); // absFile now points to "/local/bin", // while relFile points to "/tmp/local/bin"
public final void setFile(QFile file)
Sets the file that the QFileInfo provides information about to file.
If file includes a relative path, the QFileInfo will also have a relative path.
public final long size()
Returns the file size in bytes. If the file does not exist or cannot be fetched, 0 is returned.
public final java.lang.String suffix()
Returns the suffix of the file.
The suffix consists of all characters in the file after (but not including) the last '.'.
Example:
QFileInfo fi("/tmp/archive.tar.gz");
QString ext = fi.suffix(); // ext = "gz"
The suffix of a file is computed equally on all platforms, independent of file naming conventions (e.g., ".bashrc" on Unix has an empty base name, and the suffix is "bashrc").
public final java.lang.String symLinkTarget()
Returns the absolute path to the file or directory a symlink (or shortcut on Windows) points to, or a an empty string if the object isn't a symbolic link.
This name may not represent an existing file; it is only a string. QFileInfo::exists() returns true if the symlink points to an existing file.
public static QFileInfo fromNativePointer(QNativePointer nativePointer)
nativePointer
- the QNativePointer of which object should be returned.public static QNativePointer nativePointerArray(QFileInfo[] array)
array
- the array that the returned pointer will point to.
public boolean equals(java.lang.Object other)
equals
in class java.lang.Object
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