javax.sound.sampled
Class AudioInputStream

java.lang.Object
  extended by java.io.InputStream
      extended by javax.sound.sampled.AudioInputStream
All Implemented Interfaces:
Closeable

public class AudioInputStream
extends InputStream

This is an InputStream which is specialized for reading audio files. In particular it only allows operations to act on a multiple of the audio stream's frame size.

Since:
1.3

Field Summary
protected  AudioFormat format
          The format of the audio stream.
protected  long frameLength
          The length of the audio stream in frames.
protected  long framePos
          The current frame position, starting from frame zero.
protected  int frameSize
          The size of a frame in bytes.
 
Constructor Summary
AudioInputStream(InputStream is, AudioFormat fmt, long length)
          Create a new AudioInputStream given an underlying InputStream, the audio format, and the length of the data in frames.
AudioInputStream(TargetDataLine line)
          Create a new AudioInputStream given a TargetDataLine.
 
Method Summary
 int available()
          Return the number of bytes available to be read from the underlying stream.
 void close()
          Close the stream.
 AudioFormat getFormat()
          Get the format associated with this stream.
 long getFrameLength()
          Get the length of this stream in frames.
 void mark(int limit)
          This method marks a position in the input to which the stream can be "reset" by calling the reset() method.
 boolean markSupported()
          Return true if the underlying stream supports mark and reset, false otherwise.
 int read()
          Read a single byte from the underlying stream.
 int read(byte[] buf)
          This method reads bytes from a stream and stores them into a caller supplied buffer.
 int read(byte[] buf, int offset, int length)
          This method read bytes from a stream and stores them into a caller supplied buffer.
 void reset()
          This method resets a stream to the point where the mark() method was called.
 long skip(long n)
          This method skips the specified number of bytes in the stream.
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Field Detail

format

protected AudioFormat format
The format of the audio stream.


frameLength

protected long frameLength
The length of the audio stream in frames.


framePos

protected long framePos
The current frame position, starting from frame zero.


frameSize

protected int frameSize
The size of a frame in bytes.

Constructor Detail

AudioInputStream

public AudioInputStream(InputStream is,
                        AudioFormat fmt,
                        long length)
Create a new AudioInputStream given an underlying InputStream, the audio format, and the length of the data in frames. The frame size is taken from the format.

Parameters:
is - the underlying input stream
fmt - the format of the data
length - the length of the data in frames

AudioInputStream

public AudioInputStream(TargetDataLine line)
Create a new AudioInputStream given a TargetDataLine. The audio format and the frame size are taken from the line.

Parameters:
line - the TargetDataLine
Method Detail

available

public int available()
              throws IOException
Return the number of bytes available to be read from the underlying stream. This wrapper method ensures that the result is always a multiple of the frame size.

Overrides:
available in class InputStream
Returns:
The number of bytes that can be read before blocking could occur
Throws:
IOException - If an error occurs

close

public void close()
           throws IOException
Close the stream.

Specified by:
close in interface Closeable
Overrides:
close in class InputStream
Throws:
IOException - If an error occurs, which can only happen in a subclass

getFormat

public AudioFormat getFormat()
Get the format associated with this stream.

Returns:
the AudioFormat

getFrameLength

public long getFrameLength()
Get the length of this stream in frames. Note that this may be AudioSystem#NOT_SPECIFIED.

Returns:
the length of the stream in frames

mark

public void mark(int limit)
Description copied from class: InputStream
This method marks a position in the input to which the stream can be "reset" by calling the reset() method. The parameter @code{readlimit} is the number of bytes that can be read from the stream after setting the mark before the mark becomes invalid. For example, if mark() is called with a read limit of 10, then when 11 bytes of data are read from the stream before the reset() method is called, then the mark is invalid and the stream object instance is not required to remember the mark.

This method does nothing in this class, but subclasses may override it to provide mark/reset functionality.

Overrides:
mark in class InputStream
Parameters:
limit - The number of bytes that can be read before the mark becomes invalid

markSupported

public boolean markSupported()
Return true if the underlying stream supports mark and reset, false otherwise.

Overrides:
markSupported in class InputStream
Returns:
true if mark/reset functionality is supported, false otherwise

read

public int read()
         throws IOException
Read a single byte from the underlying stream. If the frame size is set, and is not one byte, an IOException will be thrown.

Specified by:
read in class InputStream
Returns:
The byte read or -1 if end of stream
Throws:
IOException - If an error occurs

read

public int read(byte[] buf)
         throws IOException
Description copied from class: InputStream
This method reads bytes from a stream and stores them into a caller supplied buffer. This method attempts to completely fill the buffer, but can return before doing so. The actual number of bytes read is returned as an int. A -1 is returned to indicate the end of the stream.

This method will block until some data can be read.

This method operates by calling an overloaded read method like so: read(b, 0, b.length)

Overrides:
read in class InputStream
Parameters:
buf - The buffer into which the bytes read will be stored.
Returns:
The number of bytes read or -1 if end of stream.
Throws:
IOException - If an error occurs.

read

public int read(byte[] buf,
                int offset,
                int length)
         throws IOException
Description copied from class: InputStream
This method read bytes from a stream and stores them into a caller supplied buffer. It starts storing the data at index off into the buffer and attempts to read len bytes. This method can return before reading the number of bytes requested. The actual number of bytes read is returned as an int. A -1 is returned to indicate the end of the stream.

This method will block until some data can be read.

This method operates by calling the single byte read() method in a loop until the desired number of bytes are read. The read loop stops short if the end of the stream is encountered or if an IOException is encountered on any read operation except the first. If the first attempt to read a bytes fails, the IOException is allowed to propagate upward. And subsequent IOException is caught and treated identically to an end of stream condition. Subclasses can (and should if possible) override this method to provide a more efficient implementation.

Overrides:
read in class InputStream
Parameters:
buf - The array into which the bytes read should be stored
offset - The offset into the array to start storing bytes
length - The requested number of bytes to read
Returns:
The actual number of bytes read, or -1 if end of stream.
Throws:
IOException - If an error occurs.

reset

public void reset()
           throws IOException
Description copied from class: InputStream
This method resets a stream to the point where the mark() method was called. Any bytes that were read after the mark point was set will be re-read during subsequent reads.

This method always throws an IOException in this class, but subclasses can override this method if they provide mark/reset functionality.

Overrides:
reset in class InputStream
Throws:
IOException - Always thrown for this class

skip

public long skip(long n)
          throws IOException
Description copied from class: InputStream
This method skips the specified number of bytes in the stream. It returns the actual number of bytes skipped, which may be less than the requested amount.

This method reads and discards bytes into a byte array until the specified number of bytes were skipped or until either the end of stream is reached or a read attempt returns a short count. Subclasses can override this metho to provide a more efficient implementation where one exists.

Overrides:
skip in class InputStream
Parameters:
n - The requested number of bytes to skip
Returns:
The actual number of bytes skipped.
Throws:
IOException - If an error occurs