SHOW Signed
 

net.rim.device.api.io
Class FileInputStream

java.lang.Object
  |
  +--java.io.InputStream
        |
        +--net.rim.device.api.io.FileInputStream

public final class FileInputStream
extends InputStream

Provides low-level access to various file systems. This class provides acces to only the iDEN file system. To access file systems such as the device store or SDCard use the javax.microedition.io.file classes.

Category:
Signed: This element is only accessible by signed applications. If you intend to use this element, please visit http://www.blackberry.com/go/codesigning to obtain a set of code signing keys. Code signing is only required for applications running on BlackBerry smartphones; development on BlackBerry Smartphone Simulators can occur without code signing.

Since:
JDE 4.0.2

Constructor Summary
 Category: Signed FileInputStream(int fs, String fileName)
          Constructs input stream for the specified file.
 
Method Summary
 Category: Signed  void close()
          Closes this input stream and releases any system resources associated with the stream.
 Category: Signed  int read()
          Reads the next byte of data from the input stream.
 Category: Signed  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, mark, markSupported, read, reset, skip
 
Methods inherited from class java.lang.Object
equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Constructor Detail

FileInputStream

public FileInputStream(int fs,
                       String fileName)
                throws IOException
Constructs input stream for the specified file.
Parameters:
fs - One of the FILESYSTEM_ values.
fileName - The name of the file.
Throws:
IllegalArgumentException - If fs is an invalid filesystem (not one of the net.rim.device.api.io.File.FILESYSTEM_constants).
IOException - if an I/O error occurs.
Since:
JDE 4.0.2
Category:
Signed: This element is only accessible by signed applications. If you intend to use this element, please visit http://www.blackberry.com/go/codesigning to obtain a set of code signing keys. Code signing is only required for applications running on BlackBerry smartphones; development on BlackBerry Smartphone Simulators can occur without code signing.
Method Detail

close

public void close()
           throws IOException
Description copied from class: InputStream
Closes this input stream and releases any system resources associated with the stream.

The close method of InputStream does nothing.

Overrides:
close in class InputStream
Throws:
IOException - if an I/O error occurs.
Since:
JDE 4.0.2
Category:
Signed: This element is only accessible by signed applications. If you intend to use this element, please visit http://www.blackberry.com/go/codesigning to obtain a set of code signing keys. Code signing is only required for applications running on BlackBerry smartphones; development on BlackBerry Smartphone Simulators can occur without code signing.

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.

Overrides:
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.
Since:
JDE 4.0.2
Category:
Signed: This element is only accessible by signed applications. If you intend to use this element, please visit http://www.blackberry.com/go/codesigning to obtain a set of code signing keys. Code signing is only required for applications running on BlackBerry smartphones; development on BlackBerry Smartphone Simulators can occur without code signing.

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.
Since:
JDE 4.0.2
Category:
Signed: This element is only accessible by signed applications. If you intend to use this element, please visit http://www.blackberry.com/go/codesigning to obtain a set of code signing keys. Code signing is only required for applications running on BlackBerry smartphones; development on BlackBerry Smartphone Simulators can occur without code signing.



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