FileSystemStorage (Codename One API)

java.lang.Object
- com.codename1.io.FileSystemStorage

```
public class FileSystemStorage
extends Object
```
Unlike networking, the file system storage mostly tries to emulate java.io.File with some simplifications for mobile devices.
Check out a more thorough discussion of this API here.
A lot of API's rely on FileSystemStorage as its the API native code usually uses consistently. E.g. in this sample below the FileSystemStorage is used to save a screenshot image for sharing on social media:

The sample below shows the FileSystemStorage as a tree:

Field Summary

Fields
Modifier and Type	Field and Description
`static int`	`ROOT_TYPE_MAINSTORAGE` Represents the type for the get root type method, this type generally represents the main phone memory
`static int`	`ROOT_TYPE_SDCARD` Represents the type for the get root type method, this type generally represents an SD card although due to variability in phone standards an SD card might be detected incorrectly.
`static int`	`ROOT_TYPE_UNKNOWN` Returned for different types of root for which there is no specific knowledge one way or the other.

Method Summary

All Methods Static Methods Instance Methods Concrete Methods Deprecated Methods
Modifier and Type	Method and Description
`void`	`delete(String file)` Deletes the specific file or empty directory.
`void`	`deleteRetry(String file, int retryCount)` Deletes the specific file or empty directory, if the platform supports a delete on exit this method will activate it.
`boolean`	`exists(String file)` Indicates whether a file exists
`String`	`getAppHomePath()` The application home directory is a "safe place" to store files for this application in a portable way.
`String`	`getCachesDir()` Returns a device specific directory designed for cache style files, or null if `hasCachesDir()` is false
`char`	`getFileSystemSeparator()` Returns the file system separator char normally '/'
`static FileSystemStorage`	`getInstance()` This class is a singleton
`long`	`getLastModified(String file)` Deprecated. this API requires additional privacy permissions on iOS and might cause problems with iOS submissions
`long`	`getLength(String file)` Returns the length of the file
`long`	`getRootAvailableSpace(String root)` Returns the available space in the given root directory
`String[]`	`getRoots()` Returns the filesystem roots from which the structure of the file system can be traversed
`long`	`getRootSizeBytes(String root)` Returns the size of the given root directory
`int`	`getRootType(String root)` Returns the type of the root often by guessing
`boolean`	`hasCachesDir()` Returns true if the device has a directory dedicated for "cache" files
`boolean`	`isDirectory(String file)` Indicates whether the given file is a directory
`boolean`	`isHidden(String file)` Indicates the hidden state of the file
`String[]`	`listFiles(String directory)` Lists the files within the given directory, returns relative file names and not full file names.
`void`	`mkdir(String directory)` Creates the given directory
`InputStream`	`openInputStream(String file)` Opens an input stream to the given file
`OutputStream`	`openOutputStream(String file)` Opens an output stream to the given file
`OutputStream`	`openOutputStream(String file, int offset)` Opens an output stream to the given file
`void`	`rename(String file, String newName)` Renames a file to the given name, expects the new name to be relative to the current directory
`void`	`setHidden(String file, boolean h)` Toggles the hidden state of the file
`String`	`toNativePath(String path)` Converts a file system path to a native path.

Methods inherited from class java.lang.Object
clone, equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Field Detail
  - ROOT_TYPE_MAINSTORAGE
```
public static final int ROOT_TYPE_MAINSTORAGE
```
    Represents the type for the get root type method, this type generally represents the main phone memory
    
    See Also:
    
    Constant Field Values
  - ROOT_TYPE_SDCARD
```
public static final int ROOT_TYPE_SDCARD
```
    Represents the type for the get root type method, this type generally represents an SD card although due to variability in phone standards an SD card might be detected incorrectly. E.g. newer Nokia devices such as N97 have a large storage area that is marked as "E:" but is really internal storage. If an SD card isn't physically in the phone the "F:" won't be returned and it will be impossible to detect that "E:" is not the actual SD card.
    
    See Also:
    
    Constant Field Values
  - ROOT_TYPE_UNKNOWN
```
public static final int ROOT_TYPE_UNKNOWN
```
    Returned for different types of root for which there is no specific knowledge one way or the other.
    
    See Also:
    
    Constant Field Values
- Method Detail
  - getInstance
```
public static FileSystemStorage getInstance()
```
    This class is a singleton
    
    Returns:
    
    instance of this class
  - getRoots
```
public String[] getRoots()
```
    Returns the filesystem roots from which the structure of the file system can be traversed
    
    Returns:
    
    the roots of the filesystem
  - getRootType
```
public int getRootType(String root)
```
    Returns the type of the root often by guessing
    
    Parameters:
    
    root - the root whose type we are checking
    
    Returns:
    
    one of the type constants above
  - listFiles
```
public String[] listFiles(String directory)
                   throws IOException
```
    Lists the files within the given directory, returns relative file names and not full file names.
    
    Parameters:
    
    directory - the directory in which files should be listed
    
    Returns:
    
    array of file names
    
    Throws:
    
    IOException
  - getRootSizeBytes
```
public long getRootSizeBytes(String root)
```
    Returns the size of the given root directory
    
    Parameters:
    
    root - the root directory in the filesystem
    
    Returns:
    
    the byte size of the directory
  - getRootAvailableSpace
```
public long getRootAvailableSpace(String root)
```
    Returns the available space in the given root directory
    
    Parameters:
    
    root - the root directory in the filesystem
    
    Returns:
    
    the bytes available in the directory
  - mkdir
```
public void mkdir(String directory)
```
    Creates the given directory
    
    Parameters:
    
    directory - the directory name to create
  - delete
```
public void delete(String file)
```
    Deletes the specific file or empty directory.
    
    Parameters:
    
    file - file or empty directory to delete
  - deleteRetry
```
public void deleteRetry(String file,
                        int retryCount)
```
    Deletes the specific file or empty directory, if the platform supports a delete on exit this method will activate it. Regardless it will retry deleting (with delay) several times to allow streams time to close.
    
    Parameters:
    
    file - file to delete
    
    retryCount - the number of times to retry
  - exists
```
public boolean exists(String file)
```
    Indicates whether a file exists
    
    Parameters:
    
    file - the file to check
    
    Returns:
    
    true if the file exists and false otherwise
  - isHidden
```
public boolean isHidden(String file)
```
    Indicates the hidden state of the file
    
    Parameters:
    
    file - file
    
    Returns:
    
    true for a hidden file
  - setHidden
```
public void setHidden(String file,
                      boolean h)
```
    Toggles the hidden state of the file
    
    Parameters:
    
    file - file
    
    h - hidden state
  - rename
```
public void rename(String file,
                   String newName)
```
    Renames a file to the given name, expects the new name to be relative to the current directory
    
    Parameters:
    
    file - absolute file name
    
    newName - relative new name
  - getLength
```
public long getLength(String file)
```
    Returns the length of the file
    
    Parameters:
    
    file - file
    
    Returns:
    
    length of said file
  - getLastModified
```
public long getLastModified(String file)
```
    Deprecated. this API requires additional privacy permissions on iOS and might cause problems with iOS submissions
    
    Returns the time that the file denoted by this abstract pathname was last modified.
    
    Returns:
    
    A long value representing the time the file was last modified, measured in milliseconds
  - isDirectory
```
public boolean isDirectory(String file)
```
    Indicates whether the given file is a directory
    
    Parameters:
    
    file - file
    
    Returns:
    
    true if its a directory
  - getFileSystemSeparator
```
public char getFileSystemSeparator()
```
    Returns the file system separator char normally '/'
    
    Returns:
    
    the separator char
  - openOutputStream
```
public OutputStream openOutputStream(String file)
                              throws IOException
```
    Opens an output stream to the given file
    
    Parameters:
    
    file - the file
    
    Returns:
    
    the output stream
    
    Throws:
    
    IOException
  - openInputStream
```
public InputStream openInputStream(String file)
                            throws IOException
```
    Opens an input stream to the given file
    
    Parameters:
    
    file - the file
    
    Returns:
    
    the input stream
    
    Throws:
    
    IOException
  - openOutputStream
```
public OutputStream openOutputStream(String file,
                                     int offset)
                              throws IOException
```
    Opens an output stream to the given file
    
    Parameters:
    
    file - the file
    
    offset - position in the file
    
    Returns:
    
    the output stream
    
    Throws:
    
    IOException
  - getAppHomePath
```
public String getAppHomePath()
```
    The application home directory is a "safe place" to store files for this application in a portable way. On some platforms such as Android & iOS this path may be visible only to the application itself, other apps won't have permission to access this path.
    The sample below uses the app home directory to save a file so we can share it using the ShareButton:
    
    Returns:
    
    a writable directory that represent the application home directory
  - hasCachesDir
```
public boolean hasCachesDir()
```
    Returns true if the device has a directory dedicated for "cache" files
    
    Returns:
    
    true if a caches style directory exists in this device type
  - getCachesDir
```
public String getCachesDir()
```
    Returns a device specific directory designed for cache style files, or null if hasCachesDir() is false
    
    Returns:
    
    file URL or null
  - toNativePath
```
public String toNativePath(String path)
```
    Converts a file system path to a native path.
    
    Parameters:
    
    path - A file system path.
    
    Returns:
    
    The native path.

Class FileSystemStorage

Field Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

ROOT_TYPE_MAINSTORAGE

ROOT_TYPE_SDCARD

ROOT_TYPE_UNKNOWN

Method Detail

getInstance

getRoots

getRootType

listFiles

getRootSizeBytes

getRootAvailableSpace

mkdir

delete

deleteRetry

exists

isHidden

setHidden

rename

getLength

getLastModified

isDirectory

getFileSystemSeparator

openOutputStream

openInputStream

openOutputStream

getAppHomePath

hasCachesDir

getCachesDir

toNativePath