totalcross.io

Class File

java.lang.Object

totalcross.io.Stream

totalcross.io.RandomAccessStream

totalcross.io.File

All Implemented Interfaces:

java.io.Closeable, java.lang.AutoCloseable, FileStates

public class File
extends RandomAccessStream
implements FileStates

File represents a file or directory.

Note that writing to a storage card can be 5x slower than writing to the main memory.

Here is an example showing data being read from a file:

 File file = new File("/temp/tempfile", File.READ_WRITE);
 byte b[] = new byte[10];
 file.readBytes(b, 0, 10);
 file.close();
 file = new File("/temp/tempfile"); // opens in DONT_OPEN mode
 file.delete();
 

When creating a new file, you may start the path using the alias "device/", which evaluates to the platform's base user directory:

• PalmOS, WinCE and iPhone - "/" (root)
• BlackBerry - "/store/home/user/"
• Java - "/" (current directory)
• Win32 - "/" (root of the current drive)
• iOS - "/private/var/" in a installation using .deb (on a jailbroken device) or in the documents folder of the application in a installation using .ipa
• Android - "/data/data/totalcross.app.<mainclass name>" or "/data/data/totalcross.app.<application id> if using single package

The alias is ALWAYS relative to the built in storage, regardless of the value passed to the argument slot.
On iOS and Android, if you don't specify a path, the file will be open in device/ path.

Field Summary

Fields

Modifier and Type	Field and Description
static int	ATTR_ARCHIVE Used in the getAttributes and setAttributes method.
static int	ATTR_HIDDEN Used in the getAttributes and setAttributes method.
static int	ATTR_READ_ONLY Used in the getAttributes and setAttributes method.
static int	ATTR_SYSTEM Used in the getAttributes and setAttributes method.
protected java.lang.String	path The path that represents this file
static byte	TIME_ACCESSED Used in the setTime method.
static byte	TIME_ALL Used in the setTime method, in parameter whichTime.
static byte	TIME_CREATED Used in the setTime method.
static byte	TIME_MODIFIED Used in the setTime method.
static java.lang.String[]	winceVols These are the volumes that getCardVolume search to find the available one.

Fields inherited from class totalcross.io.RandomAccessStream

pos, SEEK_CUR, SEEK_END, SEEK_SET

Fields inherited from class totalcross.io.Stream

skipBuffer

Fields inherited from interface totalcross.io.FileStates

CLOSED, CREATE, CREATE_EMPTY, DONT_OPEN, INVALID, READ_ONLY, READ_WRITE

Constructor Summary

Constructors

Constructor and Description
File(java.lang.String path) Opens a file with the given path and mode=DONT_OPEN and slot=-1.
File(java.lang.String path, int mode) Creates a file with the given path, mode and slot=-1.
File(java.lang.String path, int mode, int slot) Deprecated. TotalCross 2 no longer uses slot

Method Summary

Modifier and Type	Method and Description
int	chmod(int mod) Applies the given permissions to this file.
void	close() Closes the file.
static void	copy(java.lang.String src, java.lang.String dst) A handy method to call copyTo creating two File instances and closing them.
void	copyTo(File dest) Copies the current file to the given one.
void	createDir() Recursively creates a directory that is represented by the current file.
void	delete() Deletes the file or directory (which must be empty).
static void	deleteDir(java.lang.String dir) Deletes a directory and all its subdirectories and files.
boolean	exists() Returns true if the file exists and false otherwise. Example:
protected void	finalize()
void	flush() Flushes a file.
int	getAttributes() Gets this file attributes.
static java.lang.String	getCardSerialNumber(int slot) Returns the card serial number for the given slot.
static File	getCardVolume() Returns the volume File for the Windows CE and Pocket PC, and BlackBerry devices.
File	getParent() Returns the file's parent, or null if its the root.
java.lang.String	getPath() Return the file's path passed in the constructor.
int	getPos() Returns the current offset in this stream.
int	getSize() Returns the size of the file in bytes.
int	getSlot() Returns the slot number passed in the constructor, or -1 if no slot was given.
Time	getTime(byte whichTime) Retrieves the specified time attribute of the opened file - cannot be used with DONT_OPEN. JDK - If the object state and the received argument are valid, it will always return the time of the last modification.
static boolean	isCardInserted(int slot) Can be used to verify if a card is inserted into the given slot.
boolean	isDir() Returns true if the file is a directory and false otherwise.
boolean	isEmpty() If this is a file, returns true if the file has 0 bytes.
java.lang.String[]	listFiles() Lists the files contained in a directory.
static java.lang.String[]	listFiles(java.lang.String dir) Returns a recursive list of all files inside the given directory (including it).
static java.lang.String[]	listFiles(java.lang.String dir, boolean recursive) Lists all the files in the specified directory, and also the files in the subdirectories if recursive is true.
static java.lang.String[]	listRoots() List the root drives.
static void	move(java.lang.String src, java.lang.String dst) A handy method to call moveTo creating two File instances and closing them.
void	moveTo(File dest) Moves the current file to the given one (the original file is deleted).
byte[]	read() Deprecated.
byte[]	readAndClose() Deprecated.
byte[]	readAndDelete() Deprecated.
int	readBytes(byte[] b, int off, int len) Reads bytes from the stream.
void	rename(java.lang.String path) Renames the file.
void	setAttributes(int attr) Sets the attributes of the opened file - cannot be used with DONT_OPEN. Platform specific notes: JDK - This method has no effect on any file when running on JDK, it only checks if the object state and the received argument are valid.
void	setPos(int pos) Sets the file pointer for read and write operations to the given position.
void	setPos(int offset, int origin) Sets the file pointer for read and write operations to a new position defined by adding offset to a reference position specified by origin.
void	setSize(int newSize) Sets the file size, growing the size or truncating it.
void	setTime(byte whichTime, Time time) Sets the time attribute of the opened filed - cannot be used with DONT_OPEN or READ_ONLY. Platform specific notes: JDK - This method has no effect on any file when running on JDK, it only checks if the object state and the received arguments are valid.
void	writeAndClose(byte[] bytes) Deprecated.
int	writeBytes(byte[] b, int off, int len) Writes bytes to the stream.

Methods inherited from class totalcross.io.Stream

asInputStream, asOutputStream, asStream, asStream, skipBytes, wrapInputStream, wrapInputStreamToStream, write, writeBytes, writeBytes, writeBytes

Methods inherited from class java.lang.Object

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

Field Detail

path

protected java.lang.String path

The path that represents this file

TIME_ALL

public static final byte TIME_ALL

Used in the setTime method, in parameter whichTime. This sets all times at once.

See Also:

setTime(byte, totalcross.sys.Time), Constant Field Values

TIME_CREATED

public static final byte TIME_CREATED

Used in the setTime method. These values are platform independent, and can be ORed together in the setTime method.

See Also:

setTime(byte, totalcross.sys.Time), Constant Field Values

TIME_MODIFIED

public static final byte TIME_MODIFIED

Used in the setTime method. These values are platform independent, and can be ORed together in the setTime method.

See Also:

setTime(byte, totalcross.sys.Time), Constant Field Values

TIME_ACCESSED

public static final byte TIME_ACCESSED

Used in the setTime method. These values are platform independent, and can be ORed together in the setTime method.

See Also:

setTime(byte, totalcross.sys.Time), Constant Field Values

ATTR_ARCHIVE

public static final int ATTR_ARCHIVE

Used in the getAttributes and setAttributes method. These values are platform independent.

See Also:

setAttributes(int), getAttributes(), Constant Field Values

ATTR_HIDDEN

public static final int ATTR_HIDDEN

Used in the getAttributes and setAttributes method. These values are platform independent.

See Also:

setAttributes(int), getAttributes(), Constant Field Values

ATTR_READ_ONLY

public static final int ATTR_READ_ONLY

Used in the getAttributes and setAttributes method. These values are platform independent. Palm specific: Avoid using this attribute on a file located on the Built-in storage, because some devices do not allow this attribute to be changed after it is first set. This results in a read-only file that cannot be changed or deleted.

See Also:

setAttributes(int), getAttributes(), Constant Field Values

ATTR_SYSTEM

public static final int ATTR_SYSTEM

Used in the getAttributes and setAttributes method. These values are platform independent.

See Also:

setAttributes(int), getAttributes(), Constant Field Values

winceVols

public static java.lang.String[] winceVols

These are the volumes that getCardVolume search to find the available one.

To access the card in Android devices, prefix the path with /sdcard. Be sure that the sdcard is NOT MOUNTED, otherwise your application will not have access to it.

See Also:

getCardVolume()

Constructor Detail

File

@Deprecated
public File(java.lang.String path,
                        int mode,
                        int slot)
                 throws IllegalArgumentIOException,
                        FileNotFoundException,
                        IOException

Deprecated. TotalCross 2 no longer uses slot

Opens a file with the given name, mode and in the given card number.

Note that it's not advised to use accentuated characters in the file name. Also, the slash / MUST be the path separator. It is not forbidden to use the backslash \, but its support might be discontinued in the future to increase performance. Note also that some OSes may not allow the creation of files in the ROOT directory.

Parameters:

path - the file's path. Always use slashes (/) instead of backslashes (\\).
To access the card in Android devices, prefix the path with /sdcard. Be sure that the sdcard is NOT MOUNTED, otherwise your application will not have access to it.

mode - one of open modes.

slot - The card slot number. This currently works only on Palm OS devices, because other OSes use a different approach to specify the card. The number may be -1 to use the last available card, or a number between 0 and the number of cards supported by the device. Usually, slot 0 is the main memory (CAUTION: cannot be used with File!), slot 1 is the NVFS volume, slot 2 the external card volume. This may vary on some Palm devices, so use prefer using the Settings.nvfsVolume property. You can find the available slots using this code:

 for (int i = 0; i < 10; i++)
    if (File.isCardInserted(i))
       add(new Label("found " + i), LEFT, AFTER); // Zire 22 returns 1 only
 

Throws:

IllegalArgumentIOException

FileNotFoundException

IOException

Since:

SuperWaba 5.52

See Also:

File(String), File(String,int), FileStates.DONT_OPEN, FileStates.READ_WRITE, FileStates.READ_ONLY, FileStates.CREATE, FileStates.CREATE_EMPTY, Settings.nvfsVolume

File

public File(java.lang.String path,
            int mode)
     throws IllegalArgumentIOException,
            FileNotFoundException,
            IOException

Creates a file with the given path, mode and slot=-1.

Parameters:

path - the file's path

mode - one of open modes

Throws:

IllegalArgumentIOException

FileNotFoundException

IOException

See Also:

File(String), File(String,int,int)

File

public File(java.lang.String path)
     throws IllegalArgumentIOException,
            IOException

Opens a file with the given path and mode=DONT_OPEN and slot=-1. This constructor is useful for directory manipulation and/or check if file exists. No read/write operation can be done with a file created in this mode.

Parameters:

path - the file's path

Throws:

IllegalArgumentIOException

FileNotFoundException

IOException

See Also:

File(String, int, int)

Method Detail

isCardInserted

public static final boolean isCardInserted(int slot)
                                    throws IllegalArgumentIOException

Can be used to verify if a card is inserted into the given slot. Only works on Palm OS and Android devices. In all other platforms, always returns true.

Parameters:

slot - The slot number, or -1 to use the last slot number (which, in most devices, will be the only slot available).

Throws:

IllegalArgumentIOException

Since:

SuperWaba 5.52

close

public void close()
           throws IOException

Closes the file.

Specified by:

close in interface java.io.Closeable

Specified by:

close in interface java.lang.AutoCloseable

Throws:

IOException - If a file is closed more than once,

flush

public void flush()
           throws IOException

Flushes a file. This causes any pending data to be written to disk. Calling this method too much may decrease the performance. Has no effect on JavaSE.

Throws:

IOException

createDir

public final void createDir()
                     throws IOException

Recursively creates a directory that is represented by the current file. The file must have been open in DONT_OPEN mode (remember that the constructor File(String) already opens the file in DONT_OPEN mode).

Throws:

IOException - If the file was closed, or if it was open in anything else than DONT_OPEN, or if the directory already exists, or if the directories could not be created.

Example:

 new File("/my/new/recursive/folder").createDir();
 

delete

public final void delete()
                  throws FileNotFoundException,
                         IOException

Deletes the file or directory (which must be empty). The file is automatically closed before it is deleted. The file could have been opened in any of the available modes, except READ_ONLY. Example:

 new File("/my/file.c").delete();
 

Throws:

FileNotFoundException

IOException

exists

public final boolean exists()
                     throws IOException

Returns true if the file exists and false otherwise.

Example:

 if (new File("dummy.txt").exists())
    ...
 

Throws:

IOException

getSize

public final int getSize()
                  throws IOException

Returns the size of the file in bytes. If the file is a directory (ends with slash, not backslash), it returns the amount of free space in bytes of the card/file system (also works on JDK 1.6 and above).

If the total amount is greater than 2 GB, 2 GB is returned. In other cases, if the file is not opened, an exception will be thrown.

Examples:

 int freeSpace;
 if (Settings.platform.equals("Win32") || Settings.platform.equals("Java"))
    freeSpace = new File("c:\\").getSize();
 else if (Settings.platform.equals("PalmOS"))
    freeSpace = new File("\\", 1).getSize(); // hidden volume
 else
    freeSpace = new File("\\").getSize(); // WinCE and Posix
 

Throws:

IOException

getPath

public java.lang.String getPath()

Return the file's path passed in the constructor.

getParent

public File getParent()
               throws IOException

Returns the file's parent, or null if its the root.

Throws:

IOException

isDir

public final boolean isDir()
                    throws IOException

Returns true if the file is a directory and false otherwise. The file must have been open in DONT_OPEN mode.

Throws:

IOException

listFiles

public final java.lang.String[] listFiles()
                                   throws IOException

Lists the files contained in a directory. The strings returned are the names of the files and directories contained within this directory. Paths are suffixed by a slash.

Throws:

IOException

isEmpty

public final boolean isEmpty()
                      throws IOException

If this is a file, returns true if the file has 0 bytes. If this is a folder, returns true if there are no files nor folders inside of it.

Throws:

IOException

Since:

TotalCross 1.27

readBytes

public final int readBytes(byte[] b,
                           int off,
                           int len)
                    throws IOException

Description copied from class: Stream

Reads bytes from the stream. Returns the number of bytes actually read or -1 if the end of the stream was reached. (if applicable to the stream)

Specified by:

readBytes in class Stream

Parameters:

b - the byte array to read data into

off - the start position in the array

len - the number of bytes to read

Throws:

IOException

rename

public final void rename(java.lang.String path)
                  throws IllegalArgumentIOException,
                         IOException

Renames the file. You must give the full directory specification for the file, to keep compatibility between all platforms. WinCE platform lets you move a file using rename, while Palm OS does not let you move the file. File is automatically closed prior to renaming. After this operation, this File object is invalid. Cannot be used in READ_ONLY mode.

Parameters:

path - the new name of the file.

Throws:

IllegalArgumentIOException

IOException

getPos

public int getPos()
           throws IOException

Description copied from class: RandomAccessStream

Returns the current offset in this stream.

Overrides:

getPos in class RandomAccessStream

Returns:

the offset from the beginning of the stream, in bytes, at which the next read or write occurs.

Throws:

IOException - if an I/O error has occurred.

setPos

public final void setPos(int pos)
                  throws IOException

Sets the file pointer for read and write operations to the given position. The position passed is an absolute position, in bytes, from the beginning of the file. To set the position to just after the end of the file, you can call:

 file.setPos(file.getSize());
 

Note: if you plan to change the file size using setPos, you must write something on the new size to effectively change the size. For example, on some devices if you call setPos and then read (assuming that the new pos is past the end of the file, the read method will fail. Here's a code that will change the size for sure:

 private static byte[] zeros = new byte[4096];
 
 public void setSize(int newSize)
 {
    int size = f.getSize();
    f.setPos(newSize - 1); // note: setPos(1) makes the file 2 bytes long (0, 1)
    f.setPos(size);
    for (int dif = newSize - size, n = 0; dif > 0; dif -= n)
       n = f.writeBytes(zeros, 0, dif > zeros.length ? zeros.length : dif);
 }
 

Specified by:

setPos in class RandomAccessStream

Parameters:

pos - the offset position, measured in bytes from the beginning of the file, at which to set the file pointer.

Throws:

IOException - if pos is negative or if an I/O error occurs.

setPos

public final void setPos(int offset,
                         int origin)
                  throws IOException

Description copied from class: RandomAccessStream

Sets the file pointer for read and write operations to a new position defined by adding offset to a reference position specified by origin.

Specified by:

setPos in class RandomAccessStream

Parameters:

offset - number of bytes to offset from origin.

origin - position from where offset is added. It is specified by one of the SEEK_* constants.

Throws:

IOException - if the new position is negative or if an I/O error occurs.

writeBytes

public final int writeBytes(byte[] b,
                            int off,
                            int len)
                     throws IOException

Description copied from class: Stream

Writes bytes to the stream. Returns the number of bytes actually written or throws an IOException if an error prevented the write operation from occurring.

Specified by:

writeBytes in class Stream

Parameters:

b - the byte array to write data from

off - the start position in the byte array

len - the number of bytes to write

Returns:

the number of bytes actually written

Throws:

IOException

setAttributes

public final void setAttributes(int attr)
                         throws IllegalArgumentIOException,
                                IOException

Sets the attributes of the opened file - cannot be used with DONT_OPEN.
Platform specific notes:

• JDK - This method has no effect on any file when running on JDK, it only checks if the object state and the received argument are valid.
• BLACKBERRY - Supports only ATTR_HIDDEN and ATTR_READ_ONLY.
• LINUX, IPHONE, and ANDROID - The attributes ATTR_HIDDEN and ATTR_ARCHIVE are not supported by Unix based systems. Using them will not throw an exception, but it will have no effect on the file.
• PALMOS - Avoid using the attribute ATTR_READ_ONLY on files located in the device's internal storage. Marking a file as read only affects also its attributes, which means it can't be undone. The only way to remove a file marked as read only is performing a hard reset.

Parameters:

attr - one ore more ATTR_xxx constants ORed together.

Throws:

IllegalArgumentIOException

IOException

See Also:

ATTR_ARCHIVE, ATTR_HIDDEN, ATTR_READ_ONLY, ATTR_SYSTEM

getAttributes

public final int getAttributes()
                        throws IOException

Gets this file attributes. The file must be opened in a mode different of DONT_OPEN.

This method does not work on desktop, but the arguments are still checked.

Returns:

The file attributes ORed together.

Throws:

IOException

See Also:

ATTR_ARCHIVE, ATTR_HIDDEN, ATTR_READ_ONLY, ATTR_SYSTEM

setTime

public final void setTime(byte whichTime,
                          Time time)
                   throws IllegalArgumentIOException,
                          IOException

Sets the time attribute of the opened filed - cannot be used with DONT_OPEN or READ_ONLY.
Platform specific notes:

• JDK - This method has no effect on any file when running on JDK, it only checks if the object state and the received arguments are valid.
• WINCE - Supports only TIME_MODIFIED if the file is stored on the device's non-volatile memory. If the file is stored in an external FAT storage, it also supports TIME_CREATED.
• BLACKBERRY - Not supported.
• LINUX, IPHONE and ANDROID - Unix based systems do not keep record of the file's creation time. Attempting to do so will not thrown an exception, but it will have no effect on the file.

Parameters:

whichTime - One or more of the TIME_xxx constants, ORed together.

time - The new time.

Throws:

IllegalArgumentIOException

IOException

See Also:

TIME_ALL, TIME_ACCESSED, TIME_CREATED, TIME_MODIFIED

getTime

public final Time getTime(byte whichTime)
                   throws IllegalArgumentIOException,
                          IOException

Retrieves the specified time attribute of the opened file - cannot be used with DONT_OPEN.

• JDK - If the object state and the received argument are valid, it will always return the time of the last modification.
• WINCE - Supports only TIME_MODIFIED if the file is stored on the device's non-volatile memory. If the file is stored in an external FAT storage, it also supports TIME_CREATED.
• BLACKBERRY - Supports only TIME_MODIFIED.
• LINUX, IPHONE and ANDROID - Unix based systems do not keep record of the file's creation time. Using the constant TIME_CREATED will return the last time the file was changed, which is updated when changes are made to the file's inode (owner, permissions, etc.), and also when the contents of the file are modified.
  The constant TIME_MODIFIED returns the last time the contents of the file were modified.
  

Parameters:

whichTime - value must be TIME_ACCESSED, TIME_CREATED or TIME_MODIFIED. Any other value will result in an exception.

Throws:

IllegalArgumentIOException

IOException

See Also:

TIME_ACCESSED, TIME_CREATED, TIME_MODIFIED

getCardVolume

public static final File getCardVolume()
                                throws IOException

Returns the volume File for the Windows CE and Pocket PC, and BlackBerry devices. On these devices, the volume has a special folder name, but since there's no system call that informs this, we must just test the existence of each folder, returning the first one that exists. You can set the winceVols string array to the ones you want to be searched.

To access the card on Android devices, prefix the path with /sdcard. Be sure that the sdcard is NOT MOUNTED, otherwise your application will not have access to it. Some android devices have more than one sdcard, an internal and an external ones. On such devices, /sdcard is the internal one; to find the external path, you must get into the device because there's no API to get it. For example, on Galaxy devices, it is /mnt/extSdCard.

Returns:

The File object which references the volume, ended with backslash, or null if none found.

Throws:

IOException

See Also:

winceVols

setSize

public final void setSize(int newSize)
                   throws IOException

Sets the file size, growing the size or truncating it.

Parameters:

newSize - The new file size.

Throws:

IOException

Since:

SuperWaba 5.83

getCardSerialNumber

public static final java.lang.String getCardSerialNumber(int slot)
                                                  throws IllegalArgumentIOException,
                                                         IOException

Returns the card serial number for the given slot.

This method only works on Palm OS.

Parameters:

slot - The slot number, or -1 to use the last slot (which is usually an external card if the device has such slot).

Throws:

IllegalArgumentIOException

IOException

Since:

TotalCross 1.0

finalize

protected void finalize()

Overrides:

finalize in class java.lang.Object

getSlot

public int getSlot()

Returns the slot number passed in the constructor, or -1 if no slot was given.

Since:

TotalCross 1.0

listFiles

public static java.lang.String[] listFiles(java.lang.String dir)
                                    throws IOException

Returns a recursive list of all files inside the given directory (including it). The array is sorted upon return.

Throws:

IOException

Since:

TotalCross 1.15

listFiles

public static java.lang.String[] listFiles(java.lang.String dir,
                                           boolean recursive)
                                    throws IOException

Lists all the files in the specified directory, and also the files in the subdirectories if recursive is true.

Parameters:

dir -

recursive -

Throws:

IOException

deleteDir

public static void deleteDir(java.lang.String dir)
                      throws IOException

Deletes a directory and all its subdirectories and files. If you have problems trying to recreate the directory, be sure to call Vm.gc() after calling this method.

Throws:

IOException

Since:

TotalCross 1.15

listRoots

public static java.lang.String[] listRoots()

List the root drives. If there are no roots, returns null. Works on Win32, Java, and Blackberry platforms.

Since:

TotalCross 1.22

copyTo

public void copyTo(File dest)
            throws IOException

Copies the current file to the given one. You must close both files after calling this method. Here's a sample of how to copy a file:

      File src = new File(srcFileName,File.READ_WRITE);
      File dest = new File(destFileName,File.CREATE_EMPTY);
      src.copyTo(dest);
      src.close();
      dest.close();
 

This method is thread-safe.

Throws:

IOException

Since:

TotalCross 1.27

See Also:

moveTo(File)

moveTo

public void moveTo(File dest)
            throws IOException

Moves the current file to the given one (the original file is deleted). You must explicitly close the destination file after this operation is done. Here's a sample of how to move a file:

      File src = new File(srcFileName,File.READ_WRITE);
      File dest = new File(destFileName,File.CREATE_EMPTY);
      src.moveTo(dest);
      // src.close(); - not needed! src was deleted
      dest.close();
 

This method is thread-safe.

Throws:

IOException

Since:

TotalCross 1.27

See Also:

copyTo(File)

copy

public static void copy(java.lang.String src,
                        java.lang.String dst)
                 throws IOException

A handy method to call copyTo creating two File instances and closing them. The target file is erased if it exists. This method is thread-safe. If you want to have more control, use the copyTo method

Throws:

IOException

Since:

TotalCross 1.27

See Also:

copyTo(File)

move

public static void move(java.lang.String src,
                        java.lang.String dst)
                 throws IOException

A handy method to call moveTo creating two File instances and closing them. The target file is erased if it exists. This method is thread-safe. If you want to have more control, use the other moveTo method

Throws:

IOException

Since:

TotalCross 1.27

See Also:

moveTo(File)

chmod

public int chmod(int mod)
          throws IOException

Applies the given permissions to this file. Works only on Unix-based operating systems: Linux, Android, and iOS. On JDK 1.6, the first number (user) is applied to all groups. Below you see a table with some chmod values (r = read, w = write, x = execute).

 Number   Permission
       000     ---------
       400     r--------
       444     r--r--r--
       600     rw-------
       620     rw--w----
       640     rw-r-----
       644     rw-r--r--
       645     rw-r--r-x
       646     rw-r--rw-
       650     rw-r-x---
       660     rw-rw----
       661     rw-rw---x
       662     rw-rw--w-
       663     rw-rw--wx
       664     rw-rw-r--
       666     rw-rw-r--
       700     rwx------
       750     rwxr-x---
       755     rwxr-xr-x
       777     rwxrwxrwx
 

The numbers represents a group of 3. The first number is the permission for user, the second number for group, and the third number for others These are the possible permission values for each number:

       Permission   Binary  Decimal
         ---         000       0
         --x         001       1
         -w-         010       2
         -wx         011       3
         r--         100       4
         r-x         101       5
         rw-         110       6
         rwx         111       7    
 

Failing to change the permission returns -1.

Here's a sample:

      try
      {
         // testing in a folder
         File f = new File(Settings.appPath);
         add(new Label("mods of appPath = "+f.chmod(-1)),CENTER,CENTER);
  
         // testing in a file
         String name = "test";
         f = new File(Settings.appPath+'/'+name,File.CREATE_EMPTY);
         int m0 = f.chmod(777); // change it
         int m1 = f.chmod(-1); // retrieve the changed value
         add(new Label("mods of "+name+" = "+m0+" -> "+m1+" (777)"),CENTER,AFTER+5);
      }
      catch (Exception ee)
      {
         MessageBox.showException(ee,true);
      }
 

Parameters:

mod - The modifiers you want to set in DECIMAL, or -1 to just return the current ones.

Returns:

The modifiers that were set before you called this method (or the current modifiers, if -1 is being passed). Some platforms may return more than 3 digits, indicating extra attributes (for example, if it's a file or a directory).

Throws:

IOException

Since:

TotalCross 1.27

readAndClose

@Deprecated
public byte[] readAndClose()
                                throws IOException

Deprecated.

Reads the entire file into a byte array and closes itself. A handy method that can be used like this:

 byte[] bytes = new File(...,File.READ_ONLY).readAndClose();
 

The only drawback is that this method consumes lots of memory if the file is big; use it carefully.

Throws:

IOException

Since:

TotalCross 1.53

readAndDelete

@Deprecated
public byte[] readAndDelete()
                                 throws IOException

Deprecated.

Reads the entire file into a byte array and DELETES itself. A handy method that can be used like this:

 byte[] bytes = new File(...,File.READ_ONLY).readAndDelete();
 

The only drawback is that this method consumes lots of memory if the file is big; use it carefully.

Throws:

IOException

Since:

TotalCross 1.53

writeAndClose

@Deprecated
public void writeAndClose(byte[] bytes)
                               throws IOException

Deprecated.

Writes byte array to this file and closes itself. A handy method that can be used like this:

 new File(...,File.CREATE_EMPTY).writeAndClose(Vm.getFile("myfile.txt"));
 

The only drawback is that this method consumes lots of memory if the file is big; use it carefully.

Throws:

IOException

Since:

TotalCross 1.53

read

@Deprecated
public byte[] read()
                        throws IOException

Deprecated.

Reads the file and returns a byte array with its contents.

Throws:

IOException

Since:

TotalCross 3.1