java.io.FileInputStream
FileInputStream is a class for reading bytes from a file. This class may also
be used with other InputStreams, ie: BufferedInputStream, to read data from a
file with buffering.
Known Direct Subclasses
Summary
Public Constructors
Public Methods
Protected Methods
clone,
equals,
finalize,
getClass,
hashCode,
notify,
notifyAll,
toString,
wait,
wait,
wait
Details
Public Constructors
public
FileInputStream(File file)
Constructs a new FileInputStream on the File
file
. If the
file does not exist, the
FileNotFoundException
is thrown.
Parameters
file
| the File on which to stream reads. |
Constructs a new FileInputStream on the FileDescriptor
fd
.
The file must already be open, therefore no
FileNotFoundException
will be thrown.
Parameters
fd
| the FileDescriptor on which to stream reads. |
public
FileInputStream(String fileName)
Constructs a new FileInputStream on the file named
fileName
.
If the file does not exist, the
FileNotFoundException
is
thrown. The
fileName
may be absolute or relative to the
System property
"user.dir"
.
Parameters
fileName
| the file on which to stream reads. |
Public Methods
public
int
available()
Returns a int representing then number of bytes that are available before
this InputStream will block. This method always returns the size of the
file minus the current position.
Returns
- the number of bytes available before blocking.
public
void
close()
Close the FileInputStream.
Throws
IOException
| If an error occurs attempting to close this FileInputStream.
|
Returns the FileChannel equivalent to this input stream.
The file channel is read-only and has an initial position within the file
that is the same as the current position of the FileInputStream within
the file. All changes made to the underlying file descriptor state via
the channel are visible by the input stream and vice versa.
Returns
- the file channel representation for this FileInputStream.
Returns the FileDescriptor representing the operating system resource for
this FileInputStream.
Returns
- the FileDescriptor for this FileInputStream.
Throws
IOException
| If an error occurs attempting to get the FileDescriptor of
this FileInputStream.
|
public
int
read(byte[] buffer, int offset, int count)
Reads at most
count
bytes from the FileInputStream and
stores them in byte array
buffer
starting at
offset
. Answer the number of bytes actually read or -1 if
no bytes were read and end of stream was encountered.
Parameters
buffer
| the byte array in which to store the read bytes. |
offset
| the offset in buffer to store the read bytes. |
count
| the maximum number of bytes to store in buffer . |
Returns
- the number of bytes actually read or -1 if end of stream.
Throws
IOException
| If the stream is already closed or another IOException
occurs.
|
public
int
read(byte[] buffer)
Reads bytes from the FileInputStream and stores them in byte array
buffer
. Answer the number of bytes actually read or -1 if
no bytes were read and end of stream was encountered.
Parameters
buffer
| the byte array in which to store the read bytes. |
Returns
- the number of bytes actually read or -1 if end of stream.
Throws
IOException
| If the stream is already closed or another IOException
occurs.
|
public
int
read()
Reads a single byte from this FileInputStream and returns the result as
an int. The low-order byte is returned or -1 of the end of stream was
encountered.
Returns
- the byte read or -1 if end of stream.
Throws
IOException
| If the stream is already closed or another IOException
occurs.
|
public
long
skip(long count)
Skips
count
number of bytes in this FileInputStream.
Subsequent
read()
's will not return these bytes unless
reset()
is used. This method may perform multiple reads to
read
count
bytes.
Parameters
count
| the number of bytes to skip. |
Returns
- the number of bytes actually skipped.
Throws
IOException
| If the stream is already closed or another IOException
occurs.
|
Protected Methods
protected
void
finalize()
This method ensures that all resources for this file are released when it
is about to be garbage collected.
Throws
IOException
| If an error occurs attempting to finalize this
FileInputStream.
|