com.sun.spot.flashmanagement
Class FlashFileInputStream

java.lang.Object
  java.io.InputStream
      com.sun.spot.flashmanagement.FlashFileInputStream

public class FlashFileInputStream
extends InputStream

FlashFileInputStream represents an input stream over some flash memory. There are two uses for this.

The first is to stream over the flash memory allocated to an instance of a FlashFile. In this case, you should construct the input stream accordingly, for example:

 FlashFileInputStream ffis = new FlashFileInputStream(new FlashFile("my file"));

 

In this case, the input stream will signal end of file when the reader reaches the end of the data that has been written to the FlashFile.

The second use of FlashFileInputStream is to stream over the flash memory in an arbitrary sector of the flash memory. In this case, construct the input stream like this:

 FlashFileInputStream ffis = new FlashFileInputStream(new NorFlashSector(mySectorNumber));

 

In this case, the input stream will signal end of file when the reader reaches the end of the physical sector.

Constructor Summary

FlashFileInputStream(FlashFile file)
Construct an input stream over the data previously written to a FlashFile

FlashFileInputStream(IAddressableNorFlashSector sector)
Construct a input stream over the raw data in a sector of the flash memory

Method Summary

int	read() Reads the next byte of data from the input stream.
int	read(byte[] b, int off, int len) Reads up to len bytes of data from the input stream into an array of bytes.

Methods inherited from class java.io.InputStream

available, close, mark, markSupported, read, reset, skip

Methods inherited from class java.lang.Object

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

Constructor Detail

FlashFileInputStream

public FlashFileInputStream(FlashFile file)
                     throws IOException

Construct an input stream over the data previously written to a FlashFile

Parameters:

file - The FlashFile to read data from

Throws:

IOException - If the file does not exist

FlashFileInputStream

public FlashFileInputStream(IAddressableNorFlashSector sector)

Construct a input stream over the raw data in a sector of the flash memory

Parameters:

sector - The sector to read data from

Method Detail

read

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

Description copied from class: InputStream

Reads up to len bytes of data from the input stream into an array of bytes. An attempt is made to read as many as len bytes, but a smaller number may be read, possibly zero. The number of bytes actually read is returned as an integer.

This method blocks until input data is available, end of file is detected, or an exception is thrown.

If b is null, a NullPointerException is thrown.

If off is negative, or len is negative, or off+len is greater than the length of the array b, then an IndexOutOfBoundsException is thrown.

If len is zero, then no bytes are read and 0 is returned; otherwise, there is an attempt to read at least one byte. If no byte is available because the stream is at end of file, the value -1 is returned; otherwise, at least one byte is read and stored into b.

The first byte read is stored into element b[off], the next one into b[off+1], and so on. The number of bytes read is, at most, equal to len. Let k be the number of bytes actually read; these bytes will be stored in elements b[off] through b[off+k-1], leaving elements b[off+k] through b[off+len-1] unaffected.

In every case, elements b[0] through b[off] and elements b[off+len] through b[b.length-1] are unaffected.

If the first byte cannot be read for any reason other than end of file, then an IOException is thrown. In particular, an IOException is thrown if the input stream has been closed.

The read(b, off, len) method for class InputStream simply calls the method read() repeatedly. If the first such call results in an IOException, that exception is returned from the call to the read(b, off, len) method. If any subsequent call to read() results in a IOException, the exception is caught and treated as if it were end of file; the bytes read up to that point are stored into b and the number of bytes read before the exception occurred is returned. Subclasses are encouraged to provide a more efficient implementation of this method.

Overrides:

read in class InputStream

Parameters:

b - the buffer into which the data is read.

off - the start offset in array b at which the data is written.

len - the maximum number of bytes to read.

Returns:

the total number of bytes read into the buffer, or -1 if there is no more data because the end of the stream has been reached.

Throws:

IOException - if an I/O error occurs.

See Also:

InputStream.read(byte[], int, int)

read

public int read()
         throws IOException

Description copied from class: InputStream

Reads the next byte of data from the input stream. The value byte is returned as an int in the range 0 to 255. If no byte is available because the end of the stream has been reached, the value -1 is returned. This method blocks until input data is available, the end of the stream is detected, or an exception is thrown.

A subclass must provide an implementation of this method.

Specified by:

read in class InputStream

Returns:

the next byte of data, or -1 if the end of the stream is reached.

Throws:

IOException - if an I/O error occurs.

See Also:

InputStream.read()