edu.rice.cs.plt.io
Class DirectOutputStream

java.lang.Object
  java.io.OutputStream
      edu.rice.cs.plt.io.DirectOutputStream

All Implemented Interfaces:

Closeable, Flushable

Direct Known Subclasses:

ChecksumOutputStream, MessageDigestOutputStream, OutputStreamSplitter, VoidOutputStream, WrappedDirectOutputStream

public abstract class DirectOutputStream
extends OutputStream

An OutputStream that supports writing directly from an InputStream. This class provides default implementations defined in terms of InputStream and OutputStream methods. Subclasses can override (at least) writeAll(InputStream, byte[]) and write(InputStream, int, byte[]) to provide better implementations (by, for example, not invoking OutputStream.write(byte[])).

Also guarantees that, consistent with the Writer class, all write operations are by default defined in terms of the (declared abstract) write(byte[], int, int) method.

See Also:

DirectWriter, DirectInputStream, DirectReader

Field Summary

protected static int

DEFAULT_BUFFER_SIZE

Constructor Summary

DirectOutputStream()

Method Summary

void	write(byte[] bbuf) Delegate to the more general write(byte[], int, int) method
abstract void	write(byte[] bbuf, int offset, int bytes) Subclasses are, at a minimum, required to implement this method.
int	write(InputStream in, int bytes) Write some number of bytes, using the provided InputStream as input.
int	write(InputStream in, int bytes, byte[] buffer) Write some number of bytes, using the provided InputStream as input.
int	write(InputStream in, int bytes, int bufferSize) Write some number of bytes, using the provided InputStream as input.
void	write(int b) Delegate to the more general write(byte[], int, int) method
int	writeAll(InputStream in) Write the full contents of the given InputStream to this stream.
int	writeAll(InputStream in, byte[] buffer) Write the full contents of the given InputStream to this stream.
int	writeAll(InputStream in, int bufferSize) Write the full contents of the given InputStream to this stream.

Methods inherited from class java.io.OutputStream

close, flush

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

DEFAULT_BUFFER_SIZE

protected static final int DEFAULT_BUFFER_SIZE

See Also:

Constant Field Values

Constructor Detail

DirectOutputStream

public DirectOutputStream()

Method Detail

write

public void write(int b)
           throws IOException

Delegate to the more general write(byte[], int, int) method

Specified by:

write in class OutputStream

Throws:

IOException

write

public void write(byte[] bbuf)
           throws IOException

Delegate to the more general write(byte[], int, int) method

Overrides:

write in class OutputStream

Throws:

IOException

write

public abstract void write(byte[] bbuf,
                           int offset,
                           int bytes)
                    throws IOException

Subclasses are, at a minimum, required to implement this method.

Overrides:

write in class OutputStream

Throws:

IOException

write

public int write(InputStream in,
                 int bytes)
          throws IOException

Write some number of bytes, using the provided InputStream as input. Fewer bytes may be written if the input stream has fewer available. The default implementation invokes write(InputStream, int, int) with the minimum of bytes and DEFAULT_BUFFER_SIZE. Subclasses that do not rely on a buffer in write(InputStream, int, byte[]) should override this method.

Parameters:

in - A stream to be read from

bytes - The number of bytes to write

Returns:

-1 if the input stream is at the end of file; otherwise, the number of characters written

Throws:

IOException - If an error occurs during reading or writing

write

public int write(InputStream in,
                 int bytes,
                 int bufferSize)
          throws IOException

Write some number of bytes, using the provided InputStream as input. Fewer bytes may be written if the input stream has fewer available. The default implementation invokes write(InputStream, int, byte[]) with a newly-allocated array of the given size. Subclasses that do not rely on a buffer in write(InputStream, int, byte[]) should override this method.

Parameters:

in - A stream to be read from

bytes - The number of bytes to write

bufferSize - The size of buffer to use (if necessary). Smaller values may reduce the amount of memory required; larger values may increase performance on large readers

Returns:

-1 if the input stream is at the end of file; otherwise, the number of characters written

Throws:

IOException - If an error occurs during reading or writing

IllegalArgumentException - If bufferSize <= 0

write

public int write(InputStream in,
                 int bytes,
                 byte[] buffer)
          throws IOException

Write some number of bytes, using the provided InputStream as input. Fewer bytes may be written if the input stream has fewer available. The given buffer is useful in repeated write invocations to avoid unnecessary memory allocation. The default implementation repeatedly fills the given buffer via a InputStream.read(byte[], int, int) operation, then writes it via OutputStream.write(byte[], int, int). Subclasses that do not require an external buffer should override this method.

Parameters:

in - A stream to be read from

bytes - The number of bytes to write

buffer - A buffer used to copy bytes from the input stream to this stream. Note that this is only used to avoid unnecessary memory allocation. No assumptions are made about the buffer's contents (which may be overwritten), and no assumptions should be made about the contents of the buffer after the method invocation.

Returns:

-1 if the input stream is at the end of file; otherwise, the number of characters written

Throws:

IOException - If an error occurs during reading or writing

IllegalArgumentException - If buffer has size 0

writeAll

public int writeAll(InputStream in)
             throws IOException

Write the full contents of the given InputStream to this stream. The method will block until an end-of-file is reached. The default implementation invokes writeAll(InputStream, int) with DEFAULT_BUFFER_SIZE. Subclasses that know the size of this stream's remaining contents, or that do not rely on a buffer in writeAll(InputStream, byte[]), should override this method.

Parameters:

in - A stream to be read from

Returns:

-1 if the input stream is at the end of file; otherwise, the number of characters written (or, if the number is too large, Integer.MAX_VALUE)

Throws:

IOException - If an error occurs during reading or writing

writeAll

public int writeAll(InputStream in,
                    int bufferSize)
             throws IOException

Write the full contents of the given InputStream to this stream. The method will block until an end-of-file is reached. The default implementation invokes writeAll(InputStream, byte[]) with a newly-allocated array of the given size. Subclasses that do not rely on a buffer in writeAll(InputStream, byte[]) should override this method.

Parameters:

in - A stream to be read from

bufferSize - The size of buffer to use (if necessary). Smaller values may reduce the amount of memory required; larger values may increase performance on large readers

Returns:

-1 if the input stream is at the end of file; otherwise, the number of characters written (or, if the number is too large, Integer.MAX_VALUE)

Throws:

IOException - If an error occurs during reading or writing

IllegalArgumentException - If bufferSize <= 0

writeAll

public int writeAll(InputStream in,
                    byte[] buffer)
             throws IOException

Write the full contents of the given InputStream to this stream. The given buffer is useful in repeated writeAll invocations to avoid unnecessary memory allocation. The method will block until an end-of-file is reached. The default implementation repeatedly fills the given buffer via a InputStream.read(byte[]) operation, then writes it via OutputStream.write(byte[]). Subclasses that do not require an external buffer should override this method.

Parameters:

in - A stream to be read from

buffer - A buffer used to copy bytes from the input stream to this stream. Note that this is only used to avoid unnecessary memory allocation. No assumptions are made about the buffer's contents (which may be overwritten), and no assumptions should be made about the contents of the buffer after the method invocation.

Returns:

-1 if the input stream is at the end of file; otherwise, the number of characters written (or, if the number is too large, Integer.MAX_VALUE)

Throws:

IOException - If an error occurs during reading or writing

IllegalArgumentException - If buffer has size 0