What is fileinputstream class in java

File Input Stream Class

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A FileInputStream obtains input bytes from a file in a file system.

[Android.Runtime.Register("java/io/FileInputStream", DoNotGenerateAcw=true)] public class FileInputStream : Java.IO.InputStream, IDisposable, Java.Interop.IJavaPeerable

[] type FileInputStream = class inherit InputStream interface ICloseable interface IJavaObject interface IDisposable interface IJavaPeerable

Remarks

Portions of this page are modifications based on work created and shared by the Android Open Source Project and used according to terms described in the Creative Commons 2.5 Attribution License.

Constructors

Creates a FileInputStream by opening a connection to an actual file, the file named by the File object file in the file system.

Creates a FileInputStream by using the file descriptor fdObj , which represents an existing connection to an actual file in the file system.

A constructor used when creating managed representations of JNI objects; called by the runtime.

Creates a FileInputStream by opening a connection to an actual file, the file named by the path name name in the file system.

Properties

Returns the unique java.nio.channels.FileChannel FileChannel object associated with this file input stream.

Returns the runtime class of this Object .

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

The handle to the underlying Android instance.

This API supports the Mono for Android infrastructure and is not intended to be used directly from your code.

This API supports the Mono for Android infrastructure and is not intended to be used directly from your code.

Methods

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.

Creates and returns a copy of this object.

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

Indicates whether some other object is «equal to» this one.

Returns a hash code value for the object.

Called by the garbage collector on an object when garbage collection determines that there are no more references to the object.

Marks the current position in this input stream.

Tests if this input stream supports the mark and reset methods.

Wakes up a single thread that is waiting on this object’s monitor.

Wakes up all threads that are waiting on this object’s monitor.

Reads a byte of data from this input stream.

Reads some number of bytes from the input stream and stores them into the buffer array b .

Reads up to len bytes of data from the input stream into an array of bytes.

Reads all remaining bytes from the input stream.

Reads the requested number of bytes from the input stream into the given byte array.

Reads up to a specified number of bytes from the input stream.

Repositions this stream to the position at the time the mark method was last called on this input stream.

Skips over and discards n bytes of data from this input stream.

Returns a string representation of the object.

Reads all bytes from this input stream and writes the bytes to the given output stream in the order that they are read.

Causes the current thread to wait until another thread invokes the java.lang.Object#notify() method or the java.lang.Object#notifyAll() method for this object.

Causes the current thread to wait until either another thread invokes the java.lang.Object#notify() method or the java.lang.Object#notifyAll() method for this object, or a specified amount of time has elapsed.

Causes the current thread to wait until another thread invokes the java.lang.Object#notify() method or the java.lang.Object#notifyAll() method for this object, or some other thread interrupts the current thread, or a certain amount of real time has elapsed.

Explicit Interface Implementations

IJavaPeerable.Disposed()	(Inherited from Object)
IJavaPeerable.DisposeUnlessReferenced()	(Inherited from Object)
IJavaPeerable.Finalized()	(Inherited from Object)
IJavaPeerable.JniManagedPeerState	(Inherited from Object)
IJavaPeerable.SetJniIdentityHashCode(Int32)	(Inherited from Object)
IJavaPeerable.SetJniManagedPeerState(JniManagedPeerStates)	(Inherited from Object)
IJavaPeerable.SetPeerReference(JniObjectReference)	(Inherited from Object)

Extension Methods

Performs an Android runtime-checked type conversion.

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Class FileInputStream

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 .

Constructor Summary

Creates a FileInputStream by opening a connection to an actual file, the file named by the File object file in the file system.

Creates a FileInputStream by using the file descriptor fdObj , which represents an existing connection to an actual file in the file system.

Creates a FileInputStream by opening a connection to an actual file, the file named by the path name name in the file system.

Method Summary

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

Methods declared in class java.io.InputStream

Methods declared in class java.lang.Object

Constructor Details

FileInputStream

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.

FileInputStream

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.

FileInputStream

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.

Method Details

read

read

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.

read

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.

skip

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.

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.

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.

getFD

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

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.

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