eve.io

Class ByteArrayRandomStream

java.lang.Object

java.io.InputStream

eve.io.RandomStream

eve.io.ByteArrayRandomStream

public class ByteArrayRandomStream
extends RandomStream

This is a RandomStream object that uses a ByteArray for storage of data.

Field Summary

Fields

Modifier and Type	Field and Description
ByteArray	data This is the data being read from or written to.

Fields inherited from class eve.io.RandomStream

READ_ONLY, READ_WRITE

Constructor Summary

Constructors

Constructor and Description
ByteArrayRandomStream() Create a new ByteArrayRandomStream that you can read and write to.
ByteArrayRandomStream(byte[] bytes, int start, int length, String mode) Create a ByteArray random stream from an array of bytes.
ByteArrayRandomStream(ByteArray dataToUse, String mode)
ByteArrayRandomStream(InputStream in, String mode) This creates a ByteArrayRandomStream from an input File.

Method Summary

Modifier and Type	Method and Description
void	close() This method closes the stream.
long	getLength() Return the full length of the Stream.
long	getPosition() Return the current read/write stream pointer.
int	read() This method reads an unsigned byte from the input stream and returns it as an int in the range of 0-255.
int	read(byte[] buf, int start, int count) This method read bytes from a stream and stores them into a caller supplied buffer.
void	setLength(long length) Attempt to set the length of the stream if this is supported.
void	setPosition(long pos) Set the Stream position.
void	write(byte[] buf, int start, int count) This method writes len bytes from the specified array b starting at index off into the array.
void	write(int ch) This method writes a single byte to the output stream.

Methods inherited from class eve.io.RandomStream

canSetLength, flush, isOpenForWriting, isReadWrite, mark, markSupported, reset, setMode, skip, throwCantWrite, toOutputStream, validateMode, write

Methods inherited from class java.io.InputStream

available, finalize, hashCode, read

Methods inherited from class java.lang.Object

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

Field Detail

data

public ByteArray data

This is the data being read from or written to. You can access this data at any time.

Constructor Detail

ByteArrayRandomStream

public ByteArrayRandomStream()

Create a new ByteArrayRandomStream that you can read and write to.

ByteArrayRandomStream

public ByteArrayRandomStream(ByteArray dataToUse,
                             String mode)

ByteArrayRandomStream

public ByteArrayRandomStream(byte[] bytes,
                             int start,
                             int length,
                             String mode)

Create a ByteArray random stream from an array of bytes. A copy of the bytes is made.

Parameters:

bytes -

start -

length -

mode - either "r" or "rw".

ByteArrayRandomStream

public ByteArrayRandomStream(InputStream in,
                             String mode)
                      throws IOException

This creates a ByteArrayRandomStream from an input File. All bytes from the stream are read in and written to the memory file. Alterations to the returned ByteArrayRandomStream will not affect the original data source. The original File is closed.

Throws:

IOException

Method Detail

close

public void close()
           throws IOException

Description copied from class: InputStream

This method closes the stream. Any futher attempts to read from the stream may generate an IOException

This method does nothing in this class, but subclasses may override this method in order to provide additional functionality.

Overrides:

close in class InputStream

Throws:

IOException - If an error occurs, which can only happen in a subclass

read

public int read(byte[] buf,
                int start,
                int count)
         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

start - The offset into the array to start storing bytes

count - 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.

read

public int read()
         throws IOException

Description copied from class: InputStream

This method reads an unsigned byte from the input stream and returns it as an int in the range of 0-255. This method also will return -1 if the end of the stream has been reached.

This method will block until the byte can be read.

Overrides:

read in class InputStream

Returns:

The byte read or -1 if end of stream

Throws:

IOException - If an error occurs

write

public void write(byte[] buf,
                  int start,
                  int count)
           throws IOException

Description copied from class: RandomStream

This method writes len bytes from the specified array b starting at index off into the array.

This method in this class calls the single byte write() method in a loop until all bytes have been written. Subclasses should override this method if possible in order to provide a more efficent implementation.

Overrides:

write in class RandomStream

Parameters:

buf - The array of bytes to write from

start - The index into the array to start writing from

count - The number of bytes to write

Throws:

IOException - If an error occurs

write

public void write(int ch)
           throws IOException

Description copied from class: RandomStream

This method writes a single byte to the output stream. The byte written is the low eight bits of the int passed as the argument.

Subclasses must provide an implementation of this method.

Overrides:

write in class RandomStream

Parameters:

ch - The byte to be written to the output stream, passed as the low eight bits of an int

Throws:

IOException - If an error occurs

getLength

public long getLength()
               throws IOException

Description copied from class: RandomStream

Return the full length of the Stream.

Overrides:

getLength in class RandomStream

Throws:

IOException - if an IO error occured.

setPosition

public void setPosition(long pos)
                 throws IOException

Description copied from class: RandomStream

Set the Stream position. This position actually set may be different if, say, the requested position is greater than the actual size of the Stream.

Overrides:

setPosition in class RandomStream

Parameters:

pos - the new position to set.

Throws:

IOException - on error.

getPosition

public long getPosition()
                 throws IOException

Description copied from class: RandomStream

Return the current read/write stream pointer.

Overrides:

getPosition in class RandomStream

Throws:

IOException - on error.

setLength

public void setLength(long length)
               throws IOException

Description copied from class: RandomStream

Attempt to set the length of the stream if this is supported. This will truncate the stream or extend the stream to the requested length.

Overrides:

setLength in class RandomStream

Throws:

IOException - if the length cannot be set or if there was an error.