Added in API level 1

Summary: Ctors | Methods | Protected Methods | Inherited Methods

FileInputStream

public class FileInputStream
extends InputStream

java.lang.Object
↳	java.io.InputStream
	↳	java.io.FileInputStream

Known direct subclasses

ParcelFileDescriptor.AutoCloseInputStream

ParcelFileDescriptor.AutoCloseInputStream An InputStream you can create on a ParcelFileDescriptor, which will take care of calling ParcelFileDescriptor.close() for you when the stream is closed.

Known indirect subclasses

AssetFileDescriptor.AutoCloseInputStream

AssetFileDescriptor.AutoCloseInputStream An InputStream you can create on a ParcelFileDescriptor, which will take care of calling ParcelFileDescriptor.close() for you when the stream is closed.

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:

Summary

Public constructors
`FileInputStream(File 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(FileDescriptor fdObj)` Creates a `FileInputStream` by using the file descriptor `fdObj`, which represents an existing connection to an actual file in the file system.
`FileInputStream(String name)` Creates a `FileInputStream` by opening a connection to an actual file, the file named by the path name `name` in the file system.

Public methods
`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.
`FileChannel`	`getChannel()` Returns the unique `FileChannel` object associated with this file input stream.
`final FileDescriptor`	`getFD()` Returns the `FileDescriptor` object that represents the connection to the actual file in the file system being used by this `FileInputStream`.
`int`	`read()` Reads a byte of data from this input stream.
`int`	`read(byte[] b, int off, int len)` Reads up to `len` bytes of data from this input stream into an array of bytes.
`int`	`read(byte[] b)` Reads up to `b.length` bytes of data from this input stream into an array of bytes.
`long`	`skip(long n)` Skips over and discards `n` bytes of data from the input stream.

Protected methods
`void`	`finalize()` Ensures that the `close` method of this file input stream is called when there are no more references to it.

Inherited methods

From class


        
          java.io.InputStream

`int`	`available()` Returns an estimate of the number of bytes that can be read (or skipped over) from this input stream without blocking, which may be 0, or 0 when end of stream is detected.
`void`	`close()` Closes this input stream and releases any system resources associated with the stream.
`void`	`mark(int readlimit)` Marks the current position in this input stream.
`boolean`	`markSupported()` Tests if this input stream supports the `mark` and `reset` methods.
`static InputStream`	`nullInputStream()` Returns a new `InputStream` that reads no bytes.
`int`	`read(byte[] b)` Reads some number of bytes from the input stream and stores them into the buffer array `b`.
`abstract int`	`read()` Reads the next byte of data from the input stream.
`int`	`read(byte[] b, int off, int len)` Reads up to `len` bytes of data from the input stream into an array of bytes.
`byte[]`	`readAllBytes()` Reads all remaining bytes from the input stream.
`int`	`readNBytes(byte[] b, int off, int len)` Reads the requested number of bytes from the input stream into the given byte array.
`byte[]`	`readNBytes(int len)` Reads up to a specified number of bytes from the input stream.
`void`	`reset()` Repositions this stream to the position at the time the `mark` method was last called on this input stream.
`long`	`skip(long n)` Skips over and discards `n` bytes of data from this input stream.
`void`	`skipNBytes(long n)` Skips over and discards exactly `n` bytes of data from this input stream.
`long`	`transferTo(OutputStream out)` Reads all bytes from this input stream and writes the bytes to the given output stream in the order that they are read.

From class


        
          java.lang.Object

`Object`	`clone()` Creates and returns a copy of this object.
`boolean`	`equals(Object obj)` Indicates whether some other object is "equal to" this one.
`void`	`finalize()` Called by the garbage collector on an object when garbage collection determines that there are no more references to the object.
`final Class<?>`	`getClass()` Returns the runtime class of this `Object`.
`int`	`hashCode()` Returns a hash code value for the object.
`final void`	`notify()` Wakes up a single thread that is waiting on this object's monitor.
`final void`	`notifyAll()` Wakes up all threads that are waiting on this object's monitor.
`String`	`toString()` Returns a string representation of the object.
`final void`	`wait(long timeoutMillis, int nanos)` Causes the current thread to wait until it is awakened, typically by being notified or interrupted, or until a certain amount of real time has elapsed.
`final void`	`wait(long timeoutMillis)` Causes the current thread to wait until it is awakened, typically by being notified or interrupted, or until a certain amount of real time has elapsed.
`final void`	`wait()` Causes the current thread to wait until it is awakened, typically by being notified or interrupted.

From interface


        
          java.io.Closeable


      close()

Closes this stream and releases any system resources associated with it.

From interface


        
          java.lang.AutoCloseable


      close()

Closes this resource, relinquishing any underlying resources.

Public constructors

FileInputStream

Added in API level 1

public FileInputStream (File 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`	`File`: the file to be opened for reading.

Throws
`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.

See also:

FileInputStream

Added in API level 1

public FileInputStream (FileDescriptor 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 invalid. However, if the methods are invoked on the resulting stream to attempt I/O on the stream, an IOException is thrown.

Android-specific warning: close() method doesn't close the fdObj provided, because this object doesn't own the file descriptor, but the caller does. The caller can call Os.close(FileDescriptor) to close the fd.

Parameters
`fdObj`	`FileDescriptor`: the file descriptor to be opened for reading.

Throws
`SecurityException`	if a security manager exists and its `checkRead` method denies read access to the file descriptor.

See also:

SecurityManager.checkRead(java.io.FileDescriptor)

FileInputStream

Added in API level 1

public FileInputStream (String 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`	`String`: the system-dependent file name.

Throws
`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.

See also:

SecurityManager.checkRead(java.lang.String)

Public methods

available

Added in API level 1

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

Throws
`IOException`	if this file input stream has been closed by calling `close` or an I/O error occurs.

close

Added in API level 1

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.

API Note:

Overriding close() to perform cleanup actions is reliable only when called directly or when called by try-with-resources. Do not depend on finalization to invoke close; finalization is not reliable and is deprecated. If cleanup of native resources is needed, other mechanisms such as Cleaner should be used.

Throws
`IOException`	if an I/O error occurs.

getChannel

Added in API level 1

public FileChannel getChannel ()

Returns the unique 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.

Returns
`FileChannel`	the file channel associated with this file input stream

getFD

Added in API level 1

public final FileDescriptor getFD ()

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

Returns
`FileDescriptor`	the file descriptor object associated with this stream.

Throws
`IOException`	if an I/O error occurs.

See also:

FileDescriptor

read

Added in API level 1

public int read ()

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

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

Throws
`IOException`	if an I/O error occurs.

read

Added in API level 1

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

Returns
`int`	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`	If `b` is `null`.
`IndexOutOfBoundsException`	If `off` is negative, `len` is negative, or `len` is greater than `b.length - off`
`IOException`	if an I/O error occurs.

read

Added in API level 1

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`	`byte`: the buffer into which the data is read.

Returns
`int`	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`	if an I/O error occurs.

skip

Added in API level 1

public long skip (long n)

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
`n`	`long`: the number of bytes to be skipped.

Returns
`long`	the actual number of bytes skipped.

Throws
`IOException`	if n is negative, if the stream does not support seek, or if an I/O error occurs.

Protected methods

finalize

Added in API level 1

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`	if an I/O error occurs.

See also:

close()