public class FileInputStream extends InputStream
FileInputStream obtains input bytes
 from a file in a file system. What files
 are  available depends on the host environment.
 FileInputStream is meant for reading streams of raw bytes
 such as image data. For reading streams of characters, consider using
 FileReader.
File, 
FileDescriptor, 
FileOutputStream, 
Files.newInputStream(java.nio.file.Path, java.nio.file.OpenOption...)| Constructor and Description | 
|---|
| FileInputStream(File file)Creates a  FileInputStreamby
 opening a connection to an actual file,
 the file named by theFileobjectfilein the file system. | 
| FileInputStream(FileDescriptor fdObj)Creates a  FileInputStreamby using the file descriptorfdObj, which represents an existing connection to an
 actual file in the file system. | 
| FileInputStream(String name)Creates a  FileInputStreamby
 opening a connection to an actual file,
 the file named by the path namenamein the file system. | 
| Modifier and Type | Method and Description | 
|---|---|
| int | available()Returns an estimate of the number of remaining bytes that can be read (or
 skipped over) from this input stream without blocking by the next
 invocation of a method for this input stream. | 
| void | close()Closes this file input stream and releases any system resources
 associated with the stream. | 
| protected void | finalize()Ensures that the  closemethod of this file input stream is
 called when there are no more references to it. | 
| FileChannel | getChannel()Returns the unique  FileChannelobject associated with this file input stream. | 
| FileDescriptor | getFD()Returns the  FileDescriptorobject  that represents the connection to
 the actual file in the file system being
 used by thisFileInputStream. | 
| int | read()Reads a byte of data from this input stream. | 
| int | read(byte[] b)Reads up to  b.lengthbytes of data from this input
 stream into an array of bytes. | 
| int | read(byte[] b,
    int off,
    int len)Reads up to  lenbytes of data from this input stream
 into an array of bytes. | 
| long | skip(long n)Skips over and discards  nbytes of data from the
 input stream. | 
mark, markSupported, resetpublic FileInputStream(String name) throws FileNotFoundException
FileInputStream by
 opening a connection to an actual file,
 the file named by the path name name
 in the file system.  A new FileDescriptor
 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.
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.SecurityException - if a security manager exists and its
               checkRead method denies read access
               to the file.SecurityManager.checkRead(java.lang.String)public FileInputStream(File file) throws FileNotFoundException
FileInputStream by
 opening a connection to an actual file,
 the file named by the File
 object file in the file system.
 A new FileDescriptor object
 is created to represent this file connection.
 
 First, if there is a security manager,
 its checkRead method  is called
 with the path represented by the file
 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.
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.SecurityException - if a security manager exists and its
               checkRead method denies read access to the file.File.getPath(), 
SecurityManager.checkRead(java.lang.String)public FileInputStream(FileDescriptor fdObj)
FileInputStream by using the file descriptor
 fdObj, which represents an existing connection to an
 actual file in the file system.
 
 If there is a security manager, its checkRead method is
 called with the file descriptor fdObj as its argument to
 see if it's ok to read the file descriptor. If read access is denied
 to the file descriptor a SecurityException is thrown.
 
 If fdObj is null then a NullPointerException
 is thrown.
 
 This constructor does not throw an exception if fdObj
 is invalid.
 However, if the methods are invoked on the resulting stream to attempt
 I/O on the stream, an IOException is thrown.
fdObj - the file descriptor to be opened for reading.SecurityException - if a security manager exists and its
                 checkRead method denies read access to the
                 file descriptor.SecurityManager.checkRead(java.io.FileDescriptor)public int read()
         throws IOException
read in class InputStream-1 if the end of the
             file is reached.IOException - if an I/O error occurs.public int read(byte[] b)
         throws IOException
b.length bytes of data from this input
 stream into an array of bytes. This method blocks until some input
 is available.read in class InputStreamb - 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.InputStream.read(byte[], int, int)public int read(byte[] b,
                int off,
                int len)
         throws IOException
len bytes of data from this input stream
 into an array of bytes. If len is not zero, the method
 blocks until some input is available; otherwise, no
 bytes are read and 0 is returned.read in class InputStreamb - the buffer into which the data is read.off - the start offset in the destination array blen - the maximum number of bytes read.-1 if there is no more data because the end of
             the file has been reached.NullPointerException - If b is null.IndexOutOfBoundsException - If off is negative,
 len is negative, or len is greater than
 b.length - offIOException - if an I/O error occurs.InputStream.read()public long skip(long n)
          throws IOException
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. If n is negative, the method
 will try to skip backwards. In case the backing file does not support
 backward skip at its current position, an IOException is
 thrown. The actual number of bytes skipped is returned. If it skips
 forwards, it returns a positive value. If it skips backwards, it
 returns a negative value.
 
This method may skip more bytes than what are remaining in the backing file. This produces no exception and the number of bytes skipped may include some number of bytes that were beyond the EOF of the backing file. Attempting to read from the stream after skipping past the end will result in -1 indicating the end of the file.
skip in class InputStreamn - the number of bytes to be skipped.IOException - if n is negative, if the stream does not
             support seek, or if an I/O error occurs.public int available()
              throws IOException
In some cases, a non-blocking read (or skip) may appear to be blocked when it is merely slow, for example when reading large files over slow networks.
available in class InputStreamIOException - if this file input stream has been closed by calling
             close or an I/O error occurs.public void close()
           throws IOException
If this stream has an associated channel then the channel is closed as well.
close in interface Closeableclose in interface AutoCloseableclose in class InputStreamIOException - if an I/O error occurs.public final FileDescriptor getFD() throws IOException
FileDescriptor
 object  that represents the connection to
 the actual file in the file system being
 used by this FileInputStream.IOException - if an I/O error occurs.FileDescriptorpublic FileChannel getChannel()
FileChannel
 object associated with this file input stream.
  The initial position of the returned channel will be equal to the
 number of bytes read from the file so far.  Reading bytes from this
 stream will increment the channel's position.  Changing the channel's
 position, either explicitly or by reading, will change this stream's
 file position.
protected void finalize()
                 throws IOException
close method of this file input stream is
 called when there are no more references to it.finalize in class ObjectIOException - if an I/O error occurs.close() Submit a bug or feature 
For further API reference and developer documentation, see Java SE Documentation. That documentation contains more detailed, developer-targeted descriptions, with conceptual overviews, definitions of terms, workarounds, and working code examples.
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