com.iotize.jvm

Class TapNLinkFS

java.lang.Object

com.iotize.jvm.TapNLinkFS

public final class TapNLinkFS
extends java.lang.Object

The TapNLinkFS file system is very limited. It has been designed to manage: - small files (size < 8000 bytes). Bigger files should be split. - simple operation: typically, write is only possible for the whole contents. - one shot operation: the file is automatically closed after each action. - no directories, but the 'list file' command allows to filter the existing files by specifying a prefix. - simple filenames: file names must comply with DOS format: 8.3 (namemax8.ex3) - case sensitive: file names should always be considered case sensitive. Moreover, the technology of the FLASH limits the number of 'write/erase' operations. Thus, it is NOT recommended to write/erase too often a file (don't use it for data logging). To conclude, use the File system only to store configuration information that is not easily insertable into the lwM2M configuration. For example, the formmat information for the messages and/or topics sent to the Cloud. Note that this space is also used to store some 'system information' such as the Java code itself. It is also planned to use it for the certificates. All the system files are prefixed with '__'. It is also possible to associate a file with a profile (like a bundle). The JVM is not concerned by this limitation since it acts with the rights of the administrator profile.

Constructor Summary

Constructors

Constructor and Description
TapNLinkFS()

Method Summary

Modifier and Type	Method and Description
static int	delete(java.lang.String filename) Delete the file with the given name.
static int	deleteAll() Delete all the existing files.
static int	getSize(java.lang.String filename) Get the size of the file with the given name.
static java.lang.String[]	listFiles(java.lang.String prefix) List the files that match with 'prefix' and return the list as an array of String.
static byte[]	read(java.lang.String filename, int pos, java.lang.Integer size) Read data from the selected file.
static int	write(java.lang.String filename, byte[] buffer, int size) Write data to the NVM (FLASH).
static int	write(java.lang.String filename, byte[] buffer, int size, int userID, int bundleId) Write data to the NVM (FLASH).
static int	write(java.lang.String filename, java.lang.String str) Write data to the NVM (FLASH).
static int	write(java.lang.String filename, java.lang.String str, int userID, int bundleId) Write data to the NVM (FLASH).

Methods inherited from class java.lang.Object

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

Constructor Detail

TapNLinkFS

public TapNLinkFS()

Method Detail

getSize

public static int getSize(java.lang.String filename)

Get the size of the file with the given name.

Returns:

the size of the file. -1 if any error

delete

public static int delete(java.lang.String filename)

Delete the file with the given name.

Returns:

0 if ok, (errorcode!=0) else.

deleteAll

public static int deleteAll()

Delete all the existing files. The system files prefixed with '__' (double underscore) will NOT be destroyed.

Returns:

0 if ok, (errorcode!=0) else.

listFiles

public static java.lang.String[] listFiles(java.lang.String prefix)

List the files that match with 'prefix' and return the list as an array of String.

Returns:

an array of file names.

write

public static int write(java.lang.String filename,
                        java.lang.String str)

Write data to the NVM (FLASH). IMPORTANT NOTE: only a single write of the full contents is possible. File will be closed after a 'write', and any further call to write will overwrite this data.

Parameters:

filename - The String containing the filename to be written.

str - The string to be copied.

Returns:

0 if ok, (errorcode!=0) else.

write

public static int write(java.lang.String filename,
                        byte[] buffer,
                        int size)

Write data to the NVM (FLASH). IMPORTANT NOTE: only a single write of the full contents is possible. File will be closed after a 'write', and any further call to write will overwrite this data.

Parameters:

filename - The String containing the filename to be written.

buffer - The buffer to write.

size - The size to be written.

Returns:

0 if ok, (errorcode!=0) else.

write

public static int write(java.lang.String filename,
                        java.lang.String str,
                        int userID,
                        int bundleId)

Write data to the NVM (FLASH). IMPORTANT NOTE: only a single write of the full contents is possible. File will be closed after a 'write', and any further call to write will overwrite this data.

Parameters:

filename - The String containing the filename to be written.

str - The string to be copied.

userID - In case the file is restricted for a profile/user id

bundleId - In case the file is restricted for a bundleid (and the profile linked to this bundle)

Returns:

0 if ok, (errorcode!=0) else.

write

public static int write(java.lang.String filename,
                        byte[] buffer,
                        int size,
                        int userID,
                        int bundleId)

Write data to the NVM (FLASH). IMPORTANT NOTE: only a single write of the full contents is possible. File will be closed after a 'write', and any further call to write will overwrite this data.

Parameters:

filename - The String containing the filename to be written.

buffer - The buffer to write.

size - The size to be written.

userID - In case the file is restricted for a profile/user id

bundleId - In case the file is restricted for a bundleid (and the profile linked to this bundle)

Returns:

0 if ok, (errorcode!=0) else.

read

public static byte[] read(java.lang.String filename,
                          int pos,
                          java.lang.Integer size)

Read data from the selected file.

Parameters:

pos - is the offset in the file.

size - is an in/out parameter. As input, it contains the size to be read.

Returns:

the read data. The number of read bytes is available in size.