Build 1.1_r1 (from source)

java.io
Class InputStream

java.lang.Object
  extended by java.io.InputStream
All Implemented Interfaces:
Closeable
Direct Known Subclasses:
AmrInputStream, AssetManager.AssetInputStream, ByteArrayInputStream, ChunkedInputStream, ContentLengthInputStream, DrmRawContent.DrmInputStream, EofSensorInputStream, FileInputStream, FilterInputStream, IdentityInputStream, LocalSocketImpl.SocketInputStream, MicrophoneInputStream, ObjectInputStream, PipedInputStream, ReaderInputStream, ResampleInputStream, SequenceInputStream, StringBufferInputStream, UlawEncoderInputStream, ZipFile.RAFStream

public abstract class InputStream
extends Object
implements Closeable

The base class for all input streams. An input stream is a means of reading data from a source in a byte-wise manner.

Some input streams also support marking a position in the input stream and returning to this position later. This abstract class does not provide a fully working implementation, so it needs to be subclassed, and at least the read() method needs to be overridden. Overriding some of the non-abstract methods is also often advised, since it might result in higher efficiency.

Many specialized input streams for purposes like reading from a file already exist in this package.

Since:
Android 1.0
See Also:
OutputStream

Constructor Summary
InputStream()
          This constructor does nothing.
 
Method Summary
 int available()
          Returns the number of bytes that are available before this stream will block.
 void close()
          Closes this stream.
 void mark(int readlimit)
          Sets a mark position in this InputStream.
 boolean markSupported()
          Indicates whether this stream supports the mark() and reset() methods.
abstract  int read()
          Reads a single byte from this stream and returns it as an integer in the range from 0 to 255.
 int read(byte[] b)
          Reads bytes from this stream and stores them in the byte array b.
 int read(byte[] b, int offset, int length)
          Reads at most length bytes from this stream and stores them in the byte array b starting at offset.
 void reset()
          Resets this stream to the last marked location.
 long skip(long n)
          Skips at most n bytes in this stream.
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Constructor Detail

InputStream

public InputStream()
This constructor does nothing. It is provided for signature compatibility.

Since:
Android 1.0
Method Detail

available

public int available()
              throws IOException
Returns the number of bytes that are available before this stream will block. This implementation always returns 0. Subclasses should override and indicate the correct number of bytes available.

Returns:
the number of bytes available before blocking.
Throws:
IOException - if an error occurs in this stream.
Since:
Android 1.0

close

public void close()
           throws IOException
Closes this stream. Concrete implementations of this class should free any resources during close. This implementation does nothing.

Specified by:
close in interface Closeable
Throws:
IOException - if an error occurs while closing this stream.
Since:
Android 1.0

mark

public void mark(int readlimit)
Sets a mark position in this InputStream. The parameter readlimit indicates how many bytes can be read before the mark is invalidated. Sending reset() will reposition the stream back to the marked position provided readLimit has not been surpassed.

This default implementation does nothing and concrete subclasses must provide their own implementation.

Parameters:
readlimit - the number of bytes that can be read from this stream before the mark is invalidated.
Since:
Android 1.0
See Also:
markSupported(), reset()

markSupported

public boolean markSupported()
Indicates whether this stream supports the mark() and reset() methods. The default implementation returns false.

Returns:
always false.
Since:
Android 1.0
See Also:
mark(int), reset()

read

public abstract int read()
                  throws IOException
Reads a single byte from this stream and returns it as an integer in the range from 0 to 255. Returns -1 if the end of the stream has been reached. Blocks until one byte has been read, the end of the source stream is detected or an exception is thrown.

Returns:
the byte read or -1 if the end of stream has been reached.
Throws:
IOException - if the stream is closed or another IOException occurs.
Since:
Android 1.0

read

public int read(byte[] b)
         throws IOException
Reads bytes from this stream and stores them in the byte array b.

Parameters:
b - the byte array in which to store the bytes read.
Returns:
the number of bytes actually read or -1 if the end of the stream has been reached.
Throws:
IOException - if this stream is closed or another IOException occurs.
Since:
Android 1.0

read

public int read(byte[] b,
                int offset,
                int length)
         throws IOException
Reads at most length bytes from this stream and stores them in the byte array b starting at offset.

Parameters:
b - the byte array in which to store the bytes read.
offset - the initial position in buffer to store the bytes read from this stream.
length - the maximum number of bytes to store in b.
Returns:
the number of bytes actually read or -1 if the end of the stream has been reached.
Throws:
IndexOutOfBoundsException - if offset < 0 or length < 0, or if offset + length is greater than the length of b.
IOException - if the stream is closed or another IOException occurs.
Since:
Android 1.0

reset

public void reset()
           throws IOException
Resets this stream to the last marked location. Throws an IOException if the number of bytes read since the mark has been set is greater than the limit provided to mark, or if no mark has been set.

This implementation always throws an IOException and concrete subclasses should provide the proper implementation.

Throws:
IOException - if this stream is closed or another IOException occurs.
Since:
Android 1.0

skip

public long skip(long n)
          throws IOException
Skips at most n bytes in this stream. It does nothing and returns 0 if n is negative. Less than n characters are skipped if the end of this stream is reached before the operation completes.

This default implementation reads n bytes into a temporary buffer. Concrete subclasses should provide their own implementation.

Parameters:
n - the number of bytes to skip.
Returns:
the number of bytes actually skipped.
Throws:
IOException - if this stream is closed or another IOException occurs.
Since:
Android 1.0

Build 1.1_r1 (from source)

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