# FileInputStream

public class **FileInputStream** extends [InputStream](https://developers.google.com/j2objc/javadoc/jre/reference/java/io/InputStream.html)  
A `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`.

##### See Also

- `https://developers.google.com/j2objc/javadoc/jre/reference/java/io/File.html`
- `https://developers.google.com/j2objc/javadoc/jre/reference/java/io/FileDescriptor.html`
- `https://developers.google.com/j2objc/javadoc/jre/reference/java/io/FileOutputStream.html`
- `https://developers.google.com/j2objc/javadoc/jre/reference/java/nio/file/Files.html#newInputStream(java.nio.file.Path,%20java.nio.file.OpenOption...)`

### Public Constructor Summary

|---|---|
|   | [FileInputStream](https://developers.google.com/j2objc/javadoc/jre/reference/java/io/FileInputStream.html#FileInputStream(java.lang.String))([String](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/String.html) name) Creates a `FileInputStream` by opening a connection to an actual file, the file named by the path name `name` in the file system. |
|   | [FileInputStream](https://developers.google.com/j2objc/javadoc/jre/reference/java/io/FileInputStream.html#FileInputStream(java.io.File))([File](https://developers.google.com/j2objc/javadoc/jre/reference/java/io/File.html) file) Creates a `FileInputStream` by opening a connection to an actual file, the file named by the `File` object `file` in the file system. |
|   | [FileInputStream](https://developers.google.com/j2objc/javadoc/jre/reference/java/io/FileInputStream.html#FileInputStream(java.io.FileDescriptor))([FileDescriptor](https://developers.google.com/j2objc/javadoc/jre/reference/java/io/FileDescriptor.html) fdObj) Creates a `FileInputStream` by using the file descriptor `fdObj`, which represents an existing connection to an actual file in the file system. |

### Public Method Summary

|---|---|
| int | [available](https://developers.google.com/j2objc/javadoc/jre/reference/java/io/FileInputStream.html#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](https://developers.google.com/j2objc/javadoc/jre/reference/java/io/FileInputStream.html#close())() Closes this file input stream and releases any system resources associated with the stream. |
| [FileChannel](https://developers.google.com/j2objc/javadoc/jre/reference/java/nio/channels/FileChannel.html) | [getChannel](https://developers.google.com/j2objc/javadoc/jre/reference/java/io/FileInputStream.html#getChannel())() Returns the unique `https://developers.google.com/j2objc/javadoc/jre/reference/java/nio/channels/FileChannel.html` object associated with this file input stream. |
| final [FileDescriptor](https://developers.google.com/j2objc/javadoc/jre/reference/java/io/FileDescriptor.html) | [getFD](https://developers.google.com/j2objc/javadoc/jre/reference/java/io/FileInputStream.html#getFD())() Returns the `FileDescriptor` object that represents the connection to the actual file in the file system being used by this `FileInputStream`. |
| int | [read](https://developers.google.com/j2objc/javadoc/jre/reference/java/io/FileInputStream.html#read())() Reads a byte of data from this input stream. |
| int | [read](https://developers.google.com/j2objc/javadoc/jre/reference/java/io/FileInputStream.html#read(byte[],%20int,%20int))(byte\[\] b, int off, int len) Reads up to `len` bytes of data from this input stream into an array of bytes. |
| int | [read](https://developers.google.com/j2objc/javadoc/jre/reference/java/io/FileInputStream.html#read(byte[]))(byte\[\] b) Reads up to `b.length` bytes of data from this input stream into an array of bytes. |
| long | [skip](https://developers.google.com/j2objc/javadoc/jre/reference/java/io/FileInputStream.html#skip(long))(long byteCount) Skips over and discards `n` bytes of data from the input stream. |

### Protected Method Summary

|---|---|
| void | [finalize](https://developers.google.com/j2objc/javadoc/jre/reference/java/io/FileInputStream.html#finalize())() Ensures that the `close` method of this file input stream is called when there are no more references to it. |

### Inherited Method Summary

From class [java.io.InputStream](https://developers.google.com/j2objc/javadoc/jre/reference/java/io/InputStream.html)

|---|---|
| int | [available](https://developers.google.com/j2objc/javadoc/jre/reference/java/io/InputStream.html#available())() Returns an estimate of the number of 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](https://developers.google.com/j2objc/javadoc/jre/reference/java/io/InputStream.html#close())() Closes this input stream and releases any system resources associated with the stream. |
| synchronized void | [mark](https://developers.google.com/j2objc/javadoc/jre/reference/java/io/InputStream.html#mark(int))(int readlimit) Marks the current position in this input stream. |
| boolean | [markSupported](https://developers.google.com/j2objc/javadoc/jre/reference/java/io/InputStream.html#markSupported())() Tests if this input stream supports the `mark` and `reset` methods. |
| abstract int | [read](https://developers.google.com/j2objc/javadoc/jre/reference/java/io/InputStream.html#read())() Reads the next byte of data from the input stream. |
| int | [read](https://developers.google.com/j2objc/javadoc/jre/reference/java/io/InputStream.html#read(byte[],%20int,%20int))(byte\[\] b, int off, int len) Reads up to `len` bytes of data from the input stream into an array of bytes. |
| int | [read](https://developers.google.com/j2objc/javadoc/jre/reference/java/io/InputStream.html#read(byte[]))(byte\[\] b) Reads some number of bytes from the input stream and stores them into the buffer array `b`. |
| synchronized void | [reset](https://developers.google.com/j2objc/javadoc/jre/reference/java/io/InputStream.html#reset())() Repositions this stream to the position at the time the `mark` method was last called on this input stream. |
| long | [skip](https://developers.google.com/j2objc/javadoc/jre/reference/java/io/InputStream.html#skip(long))(long n) Skips over and discards `n` bytes of data from this input stream. |

From class [java.lang.Object](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/Object.html)

|---|---|
| [Object](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/Object.html) | [clone](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/Object.html#clone())() Creates and returns a copy of this `Object`. |
| boolean | [equals](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/Object.html#equals(java.lang.Object))([Object](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/Object.html) obj) Compares this instance with the specified object and indicates if they are equal. |
| void | [finalize](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/Object.html#finalize())() Invoked when the garbage collector has detected that this instance is no longer reachable. |
| final [Class](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/Class.html)\<?\> | [getClass](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/Object.html#getClass())() Returns the unique instance of `https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/Class.html` that represents this object's class. |
| int | [hashCode](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/Object.html#hashCode())() Returns an integer hash code for this object. |
| final void | [notify](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/Object.html#notify())() Causes a thread which is waiting on this object's monitor (by means of calling one of the `wait()` methods) to be woken up. |
| final void | [notifyAll](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/Object.html#notifyAll())() Causes all threads which are waiting on this object's monitor (by means of calling one of the `wait()` methods) to be woken up. |
| [String](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/String.html) | [toString](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/Object.html#toString())() Returns a string containing a concise, human-readable description of this object. |
| final void | [wait](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/Object.html#wait(long,%20int))(long timeout, int nanos) Causes the calling thread to wait until another thread calls the `notify()` or `notifyAll()` method of this object or until the specified timeout expires. |
| final void | [wait](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/Object.html#wait(long))(long timeout) Causes the calling thread to wait until another thread calls the `notify()` or `notifyAll()` method of this object or until the specified timeout expires. |
| final void | [wait](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/Object.html#wait())() Causes the calling thread to wait until another thread calls the `notify()` or `notifyAll()` method of this object. |

From interface [java.io.Closeable](https://developers.google.com/j2objc/javadoc/jre/reference/java/io/Closeable.html)

|---|---|
| abstract void | [close](https://developers.google.com/j2objc/javadoc/jre/reference/java/io/Closeable.html#close())() Closes this stream and releases any system resources associated with it. |

From interface [java.lang.AutoCloseable](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/AutoCloseable.html)

|---|---|
| abstract void | [close](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/AutoCloseable.html#close())() Closes this resource, relinquishing any underlying resources. |

## Public Constructors

#### public
**FileInputStream**
([String](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/String.html) name)

Creates a `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.

##### Parameters

| name | the system-dependent file name. |
|---|---|

##### Throws

| [FileNotFoundException](https://developers.google.com/j2objc/javadoc/jre/reference/java/io/FileNotFoundException.html) | 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](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/SecurityException.html) | if a security manager exists and its `checkRead` method denies read access to the file. |
|---|---|

##### See Also

- `https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/SecurityManager.html#checkRead(java.lang.String)`

#### public
**FileInputStream**
([File](https://developers.google.com/j2objc/javadoc/jre/reference/java/io/File.html) file)

Creates a `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.

##### Parameters

| file | the file to be opened for reading. |
|---|---|

##### Throws

| [FileNotFoundException](https://developers.google.com/j2objc/javadoc/jre/reference/java/io/FileNotFoundException.html) | 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](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/SecurityException.html) | if a security manager exists and its `checkRead` method denies read access to the file. |
|---|---|

##### See Also

- `https://developers.google.com/j2objc/javadoc/jre/reference/java/io/File.html#getPath()`
- `https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/SecurityManager.html#checkRead(java.lang.String)`

#### public
**FileInputStream**
([FileDescriptor](https://developers.google.com/j2objc/javadoc/jre/reference/java/io/FileDescriptor.html) fdObj)

Creates a `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 `https://developers.google.com/j2objc/javadoc/jre/reference/java/io/FileDescriptor.html#valid()`.
However, if the methods are invoked on the resulting stream to attempt
I/O on the stream, an `IOException` is thrown.

##### Parameters

| fdObj | the file descriptor to be opened for reading. |
|---|---|

## Public Methods

#### public 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. Returns 0 when the file
position is beyond EOF. The next invocation might be the same thread
or another thread. A single read or skip of this many bytes will not
block, but may read or skip fewer bytes.

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.

##### Returns

- an estimate of the number of remaining bytes that can be read (or skipped over) from this input stream without blocking.

##### Throws

| [IOException](https://developers.google.com/j2objc/javadoc/jre/reference/java/io/IOException.html) | if this file input stream has been closed by calling `close` or an I/O error occurs. |
|---|---|

#### public void
**close**
()

Closes this file input stream and releases any system resources
associated with the stream.

If this stream has an associated channel then the channel is closed
as well.

##### Throws

| [IOException](https://developers.google.com/j2objc/javadoc/jre/reference/java/io/IOException.html) | if an I/O error occurs. |
|---|---|

#### public [FileChannel](https://developers.google.com/j2objc/javadoc/jre/reference/java/nio/channels/FileChannel.html)
**getChannel**
()

Returns the unique `https://developers.google.com/j2objc/javadoc/jre/reference/java/nio/channels/FileChannel.html`
object associated with this file input stream.

The initial `https://developers.google.com/j2objc/javadoc/jre/reference/java/nio/channels/FileChannel.html#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.

##### Returns

- the file channel associated with this file input stream

#### public final [FileDescriptor](https://developers.google.com/j2objc/javadoc/jre/reference/java/io/FileDescriptor.html)
**getFD**
()

Returns the `FileDescriptor`
object that represents the connection to
the actual file in the file system being
used by this `FileInputStream`.

##### Returns

- the file descriptor object associated with this stream.

##### Throws

| [IOException](https://developers.google.com/j2objc/javadoc/jre/reference/java/io/IOException.html) | if an I/O error occurs. |
|---|---|

##### See Also

- `https://developers.google.com/j2objc/javadoc/jre/reference/java/io/FileDescriptor.html`

#### public int
**read**
()

Reads a byte of data from this input stream. This method blocks
if no input is yet available.

##### Returns

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

##### Throws

| [IOException](https://developers.google.com/j2objc/javadoc/jre/reference/java/io/IOException.html) | if an I/O error occurs. |
|---|---|

#### public int
**read**
(byte\[\] b, int off, int len)

Reads up to `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.

##### Parameters

| b | the buffer into which the data is read. |
| off | the start offset in the destination array `b` |
| len | the maximum number of bytes read. |
|---|---|

##### Returns

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

##### Throws

| [NullPointerException](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/NullPointerException.html) | If `b` is `null`. |
| [IndexOutOfBoundsException](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/IndexOutOfBoundsException.html) | If `off` is negative, `len` is negative, or `len` is greater than `b.length - off` |
| [IOException](https://developers.google.com/j2objc/javadoc/jre/reference/java/io/IOException.html) | if an I/O error occurs. |
|---|---|

#### public int
**read**
(byte\[\] b)

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.

##### Parameters

| b | the buffer into which the data is read. |
|---|---|

##### Returns

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

##### Throws

| [IOException](https://developers.google.com/j2objc/javadoc/jre/reference/java/io/IOException.html) | if an I/O error occurs. |
|---|---|

#### public long
**skip**
(long byteCount)

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`. 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.

##### Parameters

| byteCount | the number of bytes to be skipped. |
|---|---|

##### Returns

- the actual number of bytes skipped.

##### Throws

| [IOException](https://developers.google.com/j2objc/javadoc/jre/reference/java/io/IOException.html) | if n is negative, if the stream does not support seek, or if an I/O error occurs. |
|---|---|

## Protected Methods

#### protected void
**finalize**
()

Ensures that the `close` method of this file input stream is
called when there are no more references to it.

##### Throws

| [IOException](https://developers.google.com/j2objc/javadoc/jre/reference/java/io/IOException.html) | if an I/O error occurs. |
|---|---|

##### See Also

- `https://developers.google.com/j2objc/javadoc/jre/reference/java/io/FileInputStream.html#close()`