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Android - An Open Handset Alliance Project

java.io
public class

java.io.FileInputStream

java.lang.Object
java.io.InputStream Closeable
java.io.FileInputStream Closeable

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

See Also

Summary

Public Constructors

          FileInputStream(File file)
Constructs a new FileInputStream on the File file.
          FileInputStream(FileDescriptor fd)
Constructs a new FileInputStream on the FileDescriptor fd.
          FileInputStream(String fileName)
Constructs a new FileInputStream on the file named fileName.

Public Methods

        int  available()
Answers a int representing then number of bytes that are available before this InputStream will block.
        void  close()
Close the FileInputStream.
        FileChannel  getChannel()
Answers the FileChannel equivalent to this input stream.
    final    FileDescriptor  getFD()
Answers the FileDescriptor representing the operating system resource for this FileInputStream.
        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.
        int  read(byte[] buffer)
Reads bytes from the FileInputStream and stores them in byte array buffer.
        int  read()
Reads a single byte from this FileInputStream and returns the result as an int.
        long  skip(long count)
Skips count number of bytes in this FileInputStream.

Protected Methods

        void  finalize()
This method ensures that all resources for this file are released when it is about to be garbage collected.
Methods inherited from class java.io.InputStream
Methods inherited from class java.lang.Object
Methods inherited from interface java.io.Closeable

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.

Throws

FileNotFoundException If the file is not found.

See Also

public FileInputStream(FileDescriptor fd)

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.

See Also

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.

Throws

FileNotFoundException If the fileName is not found.

Public Methods

public int available()

Answers 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.

Throws

IOException If an error occurs in this stream.

public void close()

Close the FileInputStream.

Throws

IOException If an error occurs attempting to close this FileInputStream.

public FileChannel getChannel()

Answers 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.

public final FileDescriptor getFD()

Answers 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.
Build m5-rc15g - 14 May 2008 12:50