OWFileInputStream
obtains input bytes from a file in a 1-Wire Filesystem.
What files are available depends on the 1-Wire device.
Note that the 1-Wire File system can reside across multiple 1-Wire devices. In this case only one of the devices need be supplied to the constructor. Each device in a multi-device file system contains information to reacquire the entire list.
File and directory name limitations
Read from a 1-Wire file on device 'owd':
// get an input stream to the 1-Wire file
OWFileInputStream instream = new OWFileInputStream(owd, "DEMO.0");
// read some data
byte[] data = new byte[2000];
int len = instream.read(data);
// close the stream to release system resources
instream.close();
Public Member Functions | |
OWFileInputStream (OneWireContainer owd, String name) throws OWFileNotFoundException | |
Creates a FileInputStream by opening a connection to an actual file, the file named by the path name name in the Filesystem. | |
OWFileInputStream (OneWireContainer[] owd, String name) throws OWFileNotFoundException | |
Creates a FileInputStream by opening a connection to an actual file, the file named by the path name name in the Filesystem. | |
OWFileInputStream (OWFile file) throws OWFileNotFoundException | |
Creates a OWFileInputStream by opening a connection to an actual file, the file named by the File object file in the Filesystem. | |
OWFileInputStream (OWFileDescriptor fdObj) | |
Creates a OWFileInputStream by using the file descriptor fdObj , which represents an existing connection to an actual file in the Filesystem. | |
int | read () throws IOException |
Reads a byte of data from this input stream. | |
int | read (byte b[]) throws IOException |
Reads up to b.length bytes of data from this input stream into an array of bytes. | |
int | read (byte b[], int off, int len) throws IOException |
Reads up to len bytes of data from this input stream into an array of bytes. | |
long | skip (long n) throws IOException |
Skips over and discards n bytes of data from the input stream. | |
int | available () throws IOException |
Returns the number of bytes that can be read from this file input stream without blocking. | |
void | close () throws IOException |
Closes this file input stream and releases any system resources associated with the stream. | |
final OWFileDescriptor | getFD () throws IOException |
Returns the OWFileDescriptor object that represents the connection to the actual file in the Filesystem being used by this FileInputStream . | |
void | finalize () throws IOException |
Ensures that the close method of this file input stream is called when there are no more references to it. | |
void | mark (int readlimit) |
Marks the current position in this input stream. | |
void | reset () throws IOException |
Repositions this stream to the position at the time the mark method was last called on this input stream. | |
boolean | markSupported () |
Tests if this input stream supports the mark and reset methods. |
OWFileInputStream | ( | OneWireContainer | owd, | |
String | name | |||
) | throws OWFileNotFoundException |
Creates a FileInputStream
by opening a connection to an actual file, the file named by the path name name
in the Filesystem.
A new OWFileDescriptor
object is created to represent this file connection.
First, if there is a security manager, its checkRead
method is called with the name
argument as its argument.
If the named file does not exist, is a directory rather than a regular file, or for some other reason cannot be opened for reading then a FileNotFoundException
is thrown.
owd | OneWireContainer that this Filesystem resides on | |
name | the system-dependent file name. |
FileNotFoundException | if the file does not exist, is a directory rather than a regular file, or for some other reason cannot be opened for reading. |
OWFileInputStream | ( | OneWireContainer[] | owd, | |
String | name | |||
) | throws OWFileNotFoundException |
Creates a FileInputStream
by opening a connection to an actual file, the file named by the path name name
in the Filesystem.
A new OWFileDescriptor
object is created to represent this file connection.
First, if there is a security manager, its checkRead
method is called with the name
argument as its argument.
If the named file does not exist, is a directory rather than a regular file, or for some other reason cannot be opened for reading then a FileNotFoundException
is thrown.
owd | array of OneWireContainers that this Filesystem resides on | |
name | the system-dependent file name. |
FileNotFoundException | if the file does not exist, is a directory rather than a regular file, or for some other reason cannot be opened for reading. |
OWFileInputStream | ( | OWFile | file | ) | throws OWFileNotFoundException |
Creates a OWFileInputStream
by opening a connection to an actual file, the file named by the File
object file
in the Filesystem.
A new OWFileDescriptor
object is created to represent this file connection.
If the named file does not exist, is a directory rather than a regular file, or for some other reason cannot be opened for reading then a FileNotFoundException
is thrown.
file | the file to be opened for reading. |
FileNotFoundException | if the file does not exist, is a directory rather than a regular file, or for some other reason cannot be opened for reading. |
OWFileInputStream | ( | OWFileDescriptor | fdObj | ) |
Creates a OWFileInputStream
by using the file descriptor fdObj
, which represents an existing connection to an actual file in the Filesystem.
If fdObj
is null then a NullPointerException
is thrown.
fdObj | the file descriptor to be opened for reading. |
int read | ( | ) | throws IOException |
Reads a byte of data from this input stream.
This method blocks if no input is yet available.
-1
if the end of the file is reached. IOException | if an I/O error occurs. |
int read | ( | byte | b[] | ) | throws IOException |
Reads up to b.length
bytes of data from this input stream into an array of bytes.
This method blocks until some input is available.
b | the buffer into which the data is read. |
-1
if there is no more data because the end of the file has been reached. IOException | if an I/O error occurs. |
int read | ( | byte | b[], | |
int | off, | |||
int | len | |||
) | throws IOException |
Reads up to len
bytes of data from this input stream into an array of bytes.
This method blocks until some input is available.
b | the buffer into which the data is read. | |
off | the start offset of the data. | |
len | the maximum number of bytes read. |
-1
if there is no more data because the end of the file has been reached. IOException | if an I/O error occurs. |
long skip | ( | long | n | ) | throws IOException |
Skips over and discards n
bytes of data from the input stream.
The skip
method may, for a variety of reasons, end up skipping over some smaller number of bytes, possibly 0
. The actual number of bytes skipped is returned.
n | the number of bytes to be skipped. |
IOException | if an I/O error occurs. |
int available | ( | ) | throws IOException |
Returns the number of bytes that can be read from this file input stream without blocking.
IOException | if an I/O error occurs. |
void close | ( | ) | throws IOException |
Closes this file input stream and releases any system resources associated with the stream.
IOException | if an I/O error occurs. |
final OWFileDescriptor getFD | ( | ) | throws IOException |
Returns the OWFileDescriptor
object that represents the connection to the actual file in the Filesystem being used by this FileInputStream
.
IOException | if an I/O error occurs. |
void finalize | ( | ) | throws IOException |
Ensures that the close
method of this file input stream is called when there are no more references to it.
IOException | if an I/O error occurs. |
void mark | ( | int | readlimit | ) |
Marks the current position in this input stream.
A subsequent call to the reset
method repositions this stream at the last marked position so that subsequent reads re-read the same bytes.
The readlimit
arguments tells this input stream to allow that many bytes to be read before the mark position gets invalidated.
The general contract of mark
is that, if the method markSupported
returns true
, the stream somehow remembers all the bytes read after the call to mark
and stands ready to supply those same bytes again if and whenever the method reset
is called. However, the stream is not required to remember any data at all if more than readlimit
bytes are read from the stream before reset
is called.
The mark
method of InputStream
does nothing.
readlimit | the maximum limit of bytes that can be read before the mark position becomes invalid. |
void reset | ( | ) | throws IOException |
Repositions this stream to the position at the time the mark
method was last called on this input stream.
The general contract of reset
is:
markSupported
returns true
, then:
mark
has not been called since the stream was created, or the number of bytes read from the stream since mark
was last called is larger than the argument to mark
at that last call, then an IOException
might be thrown.
IOException
is not thrown, then the stream is reset to a state such that all the bytes read since the most recent call to mark
(or since the start of the file, if mark
has not been called) will be resupplied to subsequent callers of the read
method, followed by any bytes that otherwise would have been the next input data as of the time of the call to reset
.
markSupported
returns false
, then:
reset
may throw an IOException
.
IOException
is not thrown, then the stream is reset to a fixed state that depends on the particular type of the input stream and how it was created. The bytes that will be supplied to subsequent callers of the read
method depend on the particular type of the input stream.
The method reset
for class InputStream
does nothing and always throws an IOException
.
IOException | if this stream has not been marked or if the mark has been invalidated. |
java.io.IOException
boolean markSupported | ( | ) |
Tests if this input stream supports the mark
and reset
methods.
The markSupported
method of InputStream
returns false
.
true
if this true type supports the mark and reset method; false
otherwise. java.io.InputStream.reset()