Class FitsFile

java.lang.Object

nom.tam.util.ArrayDataFile

nom.tam.util.FitsFile

All Implemented Interfaces:

Closeable, DataInput, DataOutput, Flushable, AutoCloseable, ArrayDataInput, ArrayDataOutput, FitsIO, FitsOutput, InputReader, OutputWriter, RandomAccess, ReadWriteAccess

Direct Known Subclasses:

BufferedFile

public class FitsFile
extends ArrayDataFile
implements FitsOutput, RandomAccess

For reading and writing FITS files. It provides buffered random access and efficient handling of arrays. Primitive arrays may be written using a single method call. Large buffers are used to minimize synchronization overheads since methods of this class are not synchronized.

Note that although this class supports most of the contract of RandomAccessFile it does not (and can not) extend that class since many of the methods of RandomAccessFile are final. In practice this method works much like the StreamFilter classes. All methods are implemented in this class but some are simply delegated to an underlying RandomAccessFile member.

Testing and timing routines are available in the nom.tam.util.test.BufferedFileTester class.

Prior versions of this class under the old BufferedFile name:

• Version 1.1 -- October 12, 2000: Fixed handling of EOF in array reads so that a partial array will be returned when an EOF is detected. Excess bytes that cannot be used to construct array elements will be discarded (e.g., if there are 2 bytes left and the user is reading an int array).
• Version 1.2 -- December 8, 2002: Added getChannel method.
• Version 1.3 -- March 2, 2007: Added File based constructors.
• Version 1.4 -- July 20, 2009: Added support for >2G Object reads. This is still a bit problematic in that we do not support primitive arrays larger than 2 GB/atomsize. However except in the case of bytes this is not currently a major issue.

Version 2.0 -- Oct 30, 2021: New hierarchy for more digestible code. Improved buffering, and renamed from BufferedFile to the more appropriate name of FitsFile. Performance is 2-4 times better than before.

Since:

1.16

See Also:

• FitsInputStream
• FitsOutputStream

Field Summary

Fields inherited from interface FitsIO

BITS_OF_1_BYTE, BITS_OF_2_BYTES, BITS_OF_3_BYTES, BITS_OF_4_BYTES, BITS_OF_5_BYTES, BITS_OF_6_BYTES, BITS_OF_7_BYTES, BYTE_1_OF_LONG_MASK, BYTE_2_OF_LONG_MASK, BYTE_3_OF_LONG_MASK, BYTE_4_OF_LONG_MASK, BYTE_MASK, BYTES_IN_BOOLEAN, BYTES_IN_BYTE, BYTES_IN_CHAR, BYTES_IN_DOUBLE, BYTES_IN_FLOAT, BYTES_IN_INTEGER, BYTES_IN_LONG, BYTES_IN_SHORT, DEFAULT_BUFFER_SIZE, HIGH_INTEGER_MASK, INTEGER_MASK, SHORT_MASK, SHORT_OF_LONG_MASK

Modifier and Type	Field	Description
static final int	BITS_OF_1_BYTE	number of bits in one byte.
static final int	BITS_OF_2_BYTES	number of bits in two byte.
static final int	BITS_OF_3_BYTES	number of bits in three byte.
static final int	BITS_OF_4_BYTES	number of bits in four byte.
static final int	BITS_OF_5_BYTES	number of bits in five byte.
static final int	BITS_OF_6_BYTES	number of bits in six byte.
static final int	BITS_OF_7_BYTES	number of bits in seven byte.
static final long	BYTE_1_OF_LONG_MASK	bit mask to get the lowest byte of a long.
static final long	BYTE_2_OF_LONG_MASK	bit mask to get the second lowest byte of a long.
static final long	BYTE_3_OF_LONG_MASK	bit mask to get the third lowest byte of a long.
static final long	BYTE_4_OF_LONG_MASK	bit mask to get the fourth lowest byte of a long.
static final int	BYTE_MASK	bit mask to get the lowest byte from an integer.
static final int	BYTES_IN_BOOLEAN	number of bytes occupied by a boolean.
static final int	BYTES_IN_BYTE	number of bytes occupied by a byte.
static final int	BYTES_IN_CHAR	number of bytes occupied by a char.
static final int	BYTES_IN_DOUBLE	number of bytes occupied by a double.
static final int	BYTES_IN_FLOAT	number of bytes occupied by a float.
static final int	BYTES_IN_INTEGER	number of bytes occupied by a integer.
static final int	BYTES_IN_LONG	number of bytes occupied by a long.
static final int	BYTES_IN_SHORT	number of bytes occupied by a short.
static final int	DEFAULT_BUFFER_SIZE	default buffer size to use unless specified otherwise.
static final long	HIGH_INTEGER_MASK	bit mask to get the highest integer from an long.
static final long	INTEGER_MASK	bit mask to get the lowest integer from an long.
static final int	SHORT_MASK	bit mask to get the lowest short of a integer.
static final long	SHORT_OF_LONG_MASK	bit mask to get the lowest short of a long.

Constructor Summary

Constructors

Constructor	Description
FitsFile(File file)	Create a buffered file from a File descriptor
FitsFile(File file, String mode)	Create a buffered file from a File descriptor
FitsFile(File file, String mode, int bufferSize)	Create a buffered file from a file descriptor
FitsFile(String filename)	Create a read-only buffered file
FitsFile(String filename, String mode)	Create a buffered file with the given mode.
FitsFile(String filename, String mode, int bufferSize)	Create a buffered file with the given mode and a specified dataBuffer.buffer size.
FitsFile(RandomAccessFileIO src, int bufferSize)	Create a buffered file from a random access data object.

Method Summary

Modifier and Type	Method	Description
void	close()
void	flush()
final FileChannel	getChannel()	Get the channel associated with this file.
FitsDecoder	getDecoder()	Returns the conversion from the binary representation of arrays in file to Java arrays.
FitsEncoder	getEncoder()	Returns the conversion from Java arrays to their binary representation in file.
final FileDescriptor	getFD()	Get the file descriptor associated with this stream.
final long	getFilePointer()	Gets the current read/write position in the file.
final boolean	hasAvailable(int need)	Checks if there are the required number of bytes available to read from this file.
boolean	isAtStart()	Checks whether we are currently at the start of this output file or stream.
final long	length()	Returns the current length of the file.
void	mark(int readlimit)	See the general contract of the mark method of InputStream.
boolean	markSupported()	See the general contract of the markSupported method of InputStream.
final int	read()	Reads a byte.
int	read(boolean[] b, int start, int length)	Read a segment of an array of boolean's.
final int	read(byte[] b)	Read as many bytes into a byte array as possible.
final int	read(byte[] b, int from, int len)	Reads up to the specified number of bytes into a buffer.
int	read(char[] c, int start, int length)	Read a segment of an array of char's.
int	read(double[] d, int start, int length)	Read a segment of an array of double's.
int	read(float[] f, int start, int length)	Read a segment of an array of float's.
int	read(int[] i, int start, int length)	Read a segment of an array of int's.
int	read(long[] l, int start, int length)	Read a segment of an array of long's.
int	read(short[] s, int start, int length)	Read a segment of an array of short's.
int	read(Boolean[] buf, int offset, int size)	Reads into an array of booleans, possibly including legal null values.
final int	readArray(Object o)	Deprecated.
boolean	readBoolean()
final byte	readByte()
char	readChar()
final double	readDouble()
final float	readFloat()
final void	readFully(byte[] b)	Reads bytes to completely fill the supplied buffer.
void	readFully(byte[] b, int off, int len)	Reads bytes to fill the supplied buffer with the requested number of bytes from the given starting buffer index.
final int	readInt()
String	readLine()
final long	readLong()
final short	readShort()
final int	readUnsignedByte()
final int	readUnsignedShort()
final String	readUTF()	Same as RandomAccessFile.readUTF().
void	reset()	See the general contract of the reset method of InputStream.
final void	seek(long newPos)	Sets a new position in the file for subsequent reading or writing.
void	setLength(long newLength)	Sets the length of the file.
final long	skip(long n)	Moves the file pointer by a number of bytes from its current position.
void	skipAllBytes(long toSkip)	Skips a number of bytes from the input.
int	skipBytes(int toSkip)
void	write(boolean[] b, int start, int length)	Write a segment of an array of boolean's.
final void	write(byte[] b)	Writes the contents of a byte array into the file.
final void	write(byte[] b, int from, int len)	Writes up to the specified number of bytes from a buffer to the stream.
void	write(char[] c, int start, int length)	Write a segment of an array of char's.
void	write(double[] d, int start, int length)	Write a segment of an array of double's.
void	write(float[] f, int start, int length)	Write a segment of an array of float's.
final void	write(int b)	Writes a byte.
void	write(int[] i, int start, int length)	Write a segment of an array of int's.
void	write(long[] l, int start, int length)	Write a segment of an array of longs.
void	write(short[] s, int start, int length)	Write a segment of an array of shorts.
void	write(Boolean[] buf, int offset, int size)	Write a segment of an array of booleans, possibly including legal null values.
void	write(String[] s, int start, int length)	Write a segment of an array of Strings.
void	writeBoolean(boolean v)
final void	writeByte(int v)
final void	writeBytes(String s)
void	writeChar(int v)
final void	writeChars(String s)
final void	writeDouble(double v)
final void	writeFloat(float v)
final void	writeInt(int v)
final void	writeLong(long v)
final void	writeShort(int v)
final void	writeUTF(String s)	Same as RandomAccessFile.writeUTF(String)

Methods inherited from class ArrayDataFile

readArrayFully, readImage, readLArray, writeArray

Modifier and Type	Method	Description
void	readArrayFully(Object o)	See ArrayDataInput.readArrayFully(Object) for a contract of this method.
void	readImage(Object o)	Like ArrayDataFile.readArrayFully(Object) but strictly for numerical types only.
long	readLArray(Object o)	See ArrayDataInput.readLArray(Object) for a contract of this method.
void	writeArray(Object o)	See ArrayDataOutput.writeArray(Object) for a contract of this method.

Methods inherited from class Object

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

Methods inherited from interface ArrayDataInput

read, read, read, read, read, read, read, read, read, readArrayFully, readFully, readImage, readLArray, skip, skipAllBytes

Modifier and Type	Method	Description
default int	read(boolean[] buf)	Read an array of boolean's.
int	read(byte[] buf)	Read an array of byte's.
default int	read(char[] buf)	Read an array of char's.
default int	read(double[] buf)	Read an array of double's.
default int	read(float[] buf)	Read an array of float's.
default int	read(int[] buf)	Read an array of int's.
default int	read(long[] buf)	Read a segment of an array of long's.
default int	read(short[] buf)	Read an array of short's.
default int	read(Boolean[] buf)	Read an array of booleans, possibly including legal null values.
default void	readArrayFully(Object o)	Reads a Java array from the input, populating all elements, or else throwing and EOFException.
void	readFully(byte[] b, int off, int len)
default void	readImage(Object o)	Like ArrayDataInput.readArrayFully(Object) but strictly for numerical types only.
long	readLArray(Object o)	Reads a Java array from the input, translating it from its binary representation to Java data format.
long	skip(long distance)	Skip the number of bytes.
default void	skipAllBytes(int toSkip)	Deprecated. This call is handled by ArrayDataInput.skipAllBytes(long), without the need for a separate implementation.

Methods inherited from interface ArrayDataOutput

flush, write, write, write, write, write, write, write, write, write, writeArray

Modifier and Type	Method	Description
void	flush()	Flush the output buffer
default void	write(boolean[] buf)	Write an array of boolean's.
default void	write(char[] buf)	Write an array of char's.
default void	write(double[] buf)	Write an array of double's.
default void	write(float[] buf)	Write an array of float's.
default void	write(int[] buf)	Write an array of int's.
default void	write(long[] buf)	Write an array of longs.
default void	write(short[] buf)	Write an array of shorts.
default void	write(Boolean[] buf)	Write an array of booleans, including legal null values.
default void	write(String[] buf)	Write an array of Strings.
void	writeArray(Object o)	Writes the contents of a Java array to the output translating the data to the required binary representation.

Methods inherited from interface DataInput

readFully, readUTF

Methods inherited from interface DataOutput

write, write, write, writeUTF

Methods inherited from interface FitsIO

close

Modifier and Type	Method	Description
void	close()

Methods inherited from interface RandomAccess

getFilePointer, position, position, seek

Modifier and Type	Method	Description
long	getFilePointer()	Returns the current offset from the beginning of the input.
default long	position()	Returns the current read/write position in this instance.
default void	position(long pos)	Sets a new position for the next read or write in this instance.
void	seek(long offsetFromStart)	Move to a specified location in the stream.

Methods inherited from interface ReadWriteAccess

length

Modifier and Type	Method	Description
long	length()	Returns the current total length of this instance, that is the total number of bytes that may be read from it.

Constructor Details

FitsFile

public FitsFile(File file)
         throws IOException

Create a buffered file from a File descriptor

Parameters:

file - the file to open.

Throws:

IOException - if the file could not be opened

FitsFile

public FitsFile(File file,
 String mode)
         throws IOException

Create a buffered file from a File descriptor

Parameters:

file - the file to open.

mode - the mode to open the file in

Throws:

IOException - if the file could not be opened

FitsFile

public FitsFile(File file,
 String mode,
 int bufferSize)
         throws IOException

Create a buffered file from a file descriptor

Parameters:

file - the file to open.

mode - the mode to open the file in

bufferSize - the dataBuffer.buffer size to use

Throws:

IOException - if the file could not be opened

FitsFile

public FitsFile(RandomAccessFileIO src,
 int bufferSize)
         throws IOException

Create a buffered file from a random access data object.

Parameters:

src - random access data

bufferSize - the dataBuffer's buffer size to use

Throws:

IOException - if data could not be read

FitsFile

public FitsFile(String filename)
         throws IOException

Create a read-only buffered file

Parameters:

filename - the name of the file to open

Throws:

IOException - if the file could not be opened

FitsFile

public FitsFile(String filename,
 String mode)
         throws IOException

Create a buffered file with the given mode.

Parameters:

filename - The file to be accessed.

mode - A string composed of "r" and "w" for read and write access.

Throws:

IOException - if the file could not be opened

FitsFile

public FitsFile(String filename,
 String mode,
 int bufferSize)
         throws IOException

Create a buffered file with the given mode and a specified dataBuffer.buffer size.

Parameters:

filename - The file to be accessed.

mode - A string composed of "r" and "w" indicating read or write access.

bufferSize - The dataBuffer.buffer size to be used. This should be substantially larger than 100 bytes and defaults to 32768 bytes in the other constructors.

Throws:

IOException - if the file could not be opened

Method Details

getEncoder

public FitsEncoder getEncoder()

Description copied from class: ArrayDataFile

Returns the conversion from Java arrays to their binary representation in file. Subclass implementations can use this to access the required conversion when writing data to file.

Overrides:

getEncoder in class ArrayDataFile

Returns:

the conversion from Java arrays to their binary representation in file

See Also:

• ArrayDataFile.setEncoder(OutputEncoder)
• ArrayDataFile.getDecoder()

getDecoder

public FitsDecoder getDecoder()

Description copied from class: ArrayDataFile

Returns the conversion from the binary representation of arrays in file to Java arrays. Subclass implementeations can use this to access the required conversion when writing data to file.

Overrides:

getDecoder in class ArrayDataFile

Returns:

the conversion from the binary representation of arrays in the file to Java arrays

See Also:

• ArrayDataFile.setDecoder(InputDecoder)
• ArrayDataFile.getEncoder()

isAtStart

public boolean isAtStart()

Description copied from interface: FitsOutput

Checks whether we are currently at the start of this output file or stream.

Specified by:

isAtStart in interface FitsOutput

Returns:

true if we are currently at the start of stream (where a primary HDU is to be written), or false if we are further along, where HDUs should be written as extensions.

See Also:

• RandomAccess.position()
• OutputEncoder.getCount()

readUnsignedByte

public final int readUnsignedByte()
                           throws IOException

Specified by:

readUnsignedByte in interface DataInput

Throws:

IOException

readByte

public final byte readByte()
                    throws IOException

Specified by:

readByte in interface DataInput

Throws:

IOException

readBoolean

public boolean readBoolean()
                    throws IOException

Specified by:

readBoolean in interface DataInput

Throws:

IOException

readChar

public char readChar()
              throws IOException

Specified by:

readChar in interface DataInput

Throws:

IOException

readUnsignedShort

public final int readUnsignedShort()
                            throws IOException

Specified by:

readUnsignedShort in interface DataInput

Throws:

IOException

readShort

public final short readShort()
                      throws IOException

Specified by:

readShort in interface DataInput

Throws:

IOException

readInt

public final int readInt()
                  throws IOException

Specified by:

readInt in interface DataInput

Throws:

IOException

readLong

public final long readLong()
                    throws IOException

Specified by:

readLong in interface DataInput

Throws:

IOException

readFloat

public final float readFloat()
                      throws IOException

Specified by:

readFloat in interface DataInput

Throws:

IOException

readDouble

public final double readDouble()
                        throws IOException

Specified by:

readDouble in interface DataInput

Throws:

IOException

readLine

public String readLine()
                throws IOException

Specified by:

readLine in interface DataInput

Throws:

IOException

read

public int read(boolean[] b,
 int start,
 int length)
         throws IOException

Description copied from interface: ArrayDataInput

Read a segment of an array of boolean's.

Specified by:

read in interface ArrayDataInput

Parameters:

b - array of boolean's.

start - start index in the array

length - number of array elements to read

Returns:

number of bytes read.

Throws:

IOException - if one of the underlying read operations failed

read

public int read(Boolean[] buf,
 int offset,
 int size)
         throws IOException

Description copied from interface: ArrayDataInput

Reads into an array of booleans, possibly including legal null values. The method has a default implementation, calls DataInput.readBoolean() element by element. Classes that implement this interface might want to replace that with a more efficient block read implementation and/or to add the desired translation for null values.

Specified by:

read in interface ArrayDataInput

Parameters:

buf - array of boolean's.

offset - start index in the array

size - number of array elements to read

Returns:

number of bytes read.

Throws:

IOException - if one of the underlying read operations failed

read

public int read(char[] c,
 int start,
 int length)
         throws IOException

Description copied from interface: ArrayDataInput

Read a segment of an array of char's.

Specified by:

read in interface ArrayDataInput

Parameters:

c - array of char's.

start - start index in the array

length - number of array elements to read

Returns:

number of bytes read.

Throws:

IOException - if one of the underlying read operations failed

read

public int read(short[] s,
 int start,
 int length)
         throws IOException

Description copied from interface: ArrayDataInput

Read a segment of an array of short's.

Specified by:

read in interface ArrayDataInput

Parameters:

s - array of short's.

start - start index in the array

length - number of array elements to read

Returns:

number of bytes read.

Throws:

IOException - if one of the underlying read operations failed

read

public int read(int[] i,
 int start,
 int length)
         throws IOException

Description copied from interface: ArrayDataInput

Read a segment of an array of int's.

Specified by:

read in interface ArrayDataInput

Parameters:

i - array of int's.

start - start index in the array

length - number of array elements to read

Returns:

number of bytes read.

Throws:

IOException - if one of the underlying read operations failed

read

public int read(long[] l,
 int start,
 int length)
         throws IOException

Description copied from interface: ArrayDataInput

Read a segment of an array of long's.

Specified by:

read in interface ArrayDataInput

Parameters:

l - array of long's.

start - start index in the array

length - number of array elements to read

Returns:

number of bytes read.

Throws:

IOException - if one of the underlying read operations failed

read

public int read(float[] f,
 int start,
 int length)
         throws IOException

Description copied from interface: ArrayDataInput

Read a segment of an array of float's.

Specified by:

read in interface ArrayDataInput

Parameters:

f - array of float's.

start - start index in the array

length - number of array elements to read

Returns:

number of bytes read.

Throws:

IOException - if one of the underlying read operations failed

read

public int read(double[] d,
 int start,
 int length)
         throws IOException

Description copied from interface: ArrayDataInput

Read a segment of an array of double's.

Specified by:

read in interface ArrayDataInput

Parameters:

d - array of double's.

start - start index in the array

length - number of array elements to read

Returns:

number of bytes read, or -1 if at the end of file/stream

Throws:

IOException - if one of the underlying read operations failed

readArray

@Deprecated
public final int readArray(Object o)
                    throws IOException

Deprecated.

Specified by:

readArray in interface ArrayDataInput

Parameters:

o - a Java array object, including heterogeneous arrays of arrays. If null, nothing will be read from the output.

Returns:

the number of bytes read from the input.

Throws:

IOException - if there was an IO error, other than the end-of-file, while reading from the input

markSupported

public boolean markSupported()

Description copied from interface: ArrayDataInput

See the general contract of the markSupported method of InputStream.

Specified by:

markSupported in interface ArrayDataInput

Returns:

true if this stream instance supports the mark and reset methods; false otherwise.

mark

public void mark(int readlimit)
          throws IOException

Description copied from interface: ArrayDataInput

See the general contract of the mark method of InputStream.

Specified by:

mark in interface ArrayDataInput

Parameters:

readlimit - the maximum limit of bytes that can be read before the mark position becomes invalid.

Throws:

IOException - if the operation failed

See Also:

• BufferedInputStream.reset()

reset

public void reset()
           throws IOException

Description copied from interface: ArrayDataInput

See the general contract of the reset method of InputStream.

If markpos is -1 (no mark has been set or the mark has been invalidated), an IOException is thrown. Otherwise, pos is set equal to markpos.

Specified by:

reset in interface ArrayDataInput

Throws:

IOException - if this stream has not been marked or, if the mark has been invalidated, or the stream has been closed by invoking its FitsIO.close() method, or an I/O error occurs.

See Also:

• BufferedInputStream.mark(int)

skipBytes

public int skipBytes(int toSkip)
              throws IOException

Specified by:

skipBytes in interface DataInput

Throws:

IOException

skipAllBytes

public void skipAllBytes(long toSkip)
                  throws EOFException,
IOException

Description copied from interface: ArrayDataInput

Skips a number of bytes from the input. This differs from the ArrayDataInput.skip(long) method in that it will throw an EOF if the skip cannot be fully accomplished as requested...

Specified by:

skipAllBytes in interface ArrayDataInput

Parameters:

toSkip - the number of bytes to skip forward. Subclass implementations may support negative valued arguments for a backward skip also.

Throws:

EOFException - if the end (or beginning) of the stream was reached before skipping the required number of bytes. This does not happen typically with forward skips on random access files, where positioning beyond the EOF is generally allowed for writing.

IOException - if there was an underlying IO failure.

See Also:

• ArrayDataInput.skip(long)

writeByte

public final void writeByte(int v)
                     throws IOException

Specified by:

writeByte in interface DataOutput

Throws:

IOException

writeBoolean

public void writeBoolean(boolean v)
                  throws IOException

Specified by:

writeBoolean in interface DataOutput

Throws:

IOException

writeChar

public void writeChar(int v)
               throws IOException

Specified by:

writeChar in interface DataOutput

Throws:

IOException

writeShort

public final void writeShort(int v)
                      throws IOException

Specified by:

writeShort in interface DataOutput

Throws:

IOException

writeInt

public final void writeInt(int v)
                    throws IOException

Specified by:

writeInt in interface DataOutput

Throws:

IOException

writeLong

public final void writeLong(long v)
                     throws IOException

Specified by:

writeLong in interface DataOutput

Throws:

IOException

writeFloat

public final void writeFloat(float v)
                      throws IOException

Specified by:

writeFloat in interface DataOutput

Throws:

IOException

writeDouble

public final void writeDouble(double v)
                       throws IOException

Specified by:

writeDouble in interface DataOutput

Throws:

IOException

writeBytes

public final void writeBytes(String s)
                      throws IOException

Specified by:

writeBytes in interface DataOutput

Throws:

IOException

writeChars

public final void writeChars(String s)
                      throws IOException

Specified by:

writeChars in interface DataOutput

Throws:

IOException

write

public void write(boolean[] b,
 int start,
 int length)
           throws IOException

Description copied from interface: ArrayDataOutput

Write a segment of an array of boolean's.

Specified by:

write in interface ArrayDataOutput

Parameters:

b - array of boolean's.

start - start index in the array

length - number of array elements to write

Throws:

IOException - if one of the underlying write operations failed

write

public void write(Boolean[] buf,
 int offset,
 int size)
           throws IOException

Description copied from interface: ArrayDataOutput

Write a segment of an array of booleans, possibly including legal null values. The method has a default implementation, which calls DataOutput.writeBoolean(boolean) element by element. Classes that implement this interface might want to replace that with a more efficient block read implementation/

Specified by:

write in interface ArrayDataOutput

Parameters:

buf - array of booleans.

offset - start index in the array

size - number of array elements to write

Throws:

IOException - if one of the underlying write operations failed

write

public void write(char[] c,
 int start,
 int length)
           throws IOException

Description copied from interface: ArrayDataOutput

Write a segment of an array of char's.

Specified by:

write in interface ArrayDataOutput

Parameters:

c - array of char's.

start - start index in the array

length - number of array elements to write

Throws:

IOException - if one of the underlying write operations failed

write

public void write(short[] s,
 int start,
 int length)
           throws IOException

Description copied from interface: ArrayDataOutput

Write a segment of an array of shorts.

Specified by:

write in interface ArrayDataOutput

Parameters:

s - the value to write

start - start index in the array

length - number of array elements to write

Throws:

IOException - if one of the underlying write operations failed

write

public void write(int[] i,
 int start,
 int length)
           throws IOException

Description copied from interface: ArrayDataOutput

Write a segment of an array of int's.

Specified by:

write in interface ArrayDataOutput

Parameters:

i - array of int's

start - start index in the array

length - number of array elements to write

Throws:

IOException - if one of the underlying write operations failed

write

public void write(long[] l,
 int start,
 int length)
           throws IOException

Description copied from interface: ArrayDataOutput

Write a segment of an array of longs.

Specified by:

write in interface ArrayDataOutput

Parameters:

l - array of longs

start - start index in the array

length - number of array elements to write

Throws:

IOException - if one of the underlying write operations failed

write

public void write(float[] f,
 int start,
 int length)
           throws IOException

Description copied from interface: ArrayDataOutput

Write a segment of an array of float's.

Specified by:

write in interface ArrayDataOutput

Parameters:

f - array of float's.

start - start index in the array

length - number of array elements to write

Throws:

IOException - if one of the underlying write operations failed

write

public void write(double[] d,
 int start,
 int length)
           throws IOException

Description copied from interface: ArrayDataOutput

Write a segment of an array of double's.

Specified by:

write in interface ArrayDataOutput

Parameters:

d - array of double's.

start - start index in the array

length - number of array elements to write

Throws:

IOException - if one of the underlying write operations failed

write

public void write(String[] s,
 int start,
 int length)
           throws IOException

Description copied from interface: ArrayDataOutput

Write a segment of an array of Strings. Equivalent to calling writeBytes for the selected elements.

Specified by:

write in interface ArrayDataOutput

Parameters:

s - the array to write

start - start index in the array

length - number of array elements to write

Throws:

IOException - if one of the underlying write operations failed

seek

public final void seek(long newPos)
                throws IOException

Sets a new position in the file for subsequent reading or writing.

Parameters:

newPos - the new byte offset from the beginning of the file. It may be beyond the current end of the file, for example for writing more data after some 'gap'.

Throws:

IOException - if the position is negative or cannot be set.

getChannel

public final FileChannel getChannel()

Get the channel associated with this file. Note that this returns the channel of the associated RandomAccessFile. Note that since the BufferedFile buffers the I/O's to the underlying file, the offset of the channel may be different from the offset of the BufferedFile. This is different for a RandomAccessFile where the offsets are guaranteed to be the same.

Returns:

the file channel

getFD

public final FileDescriptor getFD()
                           throws IOException

Get the file descriptor associated with this stream. Note that this returns the file descriptor of the associated RandomAccessFile.

Returns:

the file descriptor

Throws:

IOException - if the descriptor could not be accessed.

getFilePointer

public final long getFilePointer()

Gets the current read/write position in the file.

Returns:

the current byte offset from the beginning of the file.

hasAvailable

public final boolean hasAvailable(int need)
                           throws IOException

Checks if there are the required number of bytes available to read from this file.

Parameters:

need - the number of bytes we need.

Returns:

true if the needed number of bytes can be read from the file or else false.

Throws:

IOException - if there was an IO error accessing the file.

length

public final long length()
                  throws IOException

Returns the current length of the file.

Returns:

the current length of the file.

Throws:

IOException - if the operation failed

setLength

public void setLength(long newLength)
               throws IOException

Sets the length of the file. This method calls the method of the same name in RandomAccessFileIO.

Parameters:

newLength - The number of bytes at which the file is set.

Throws:

IOException - if the resizing of the underlying stream fails

close

public void close()
           throws IOException

Specified by:

close in interface AutoCloseable

Specified by:

close in interface Closeable

Throws:

IOException

flush

public void flush()
           throws IOException

Specified by:

flush in interface Flushable

Throws:

IOException

write

public final void write(int b)
                 throws IOException

Description copied from interface: OutputWriter

Writes a byte. See the general contract of DataOutputStream.write(int).

Specified by:

write in interface OutputWriter

Parameters:

b - the (unsigned) byte value to write.

Throws:

IOException - if there was an underlying IO error

See Also:

• DataOutputStream.write(int)

read

public final int read()
               throws IOException

Description copied from interface: InputReader

Reads a byte. See the general contract of FilterInputStream.read().

Specified by:

read in interface InputReader

Returns:

the (unsigned) byte value or -1 if there is nothing left to read.

Throws:

IOException - if there was an underlying IO error

See Also:

• FilterInputStream.read()

write

public final void write(byte[] b,
 int from,
 int len)
                 throws IOException

Description copied from interface: OutputWriter

Writes up to the specified number of bytes from a buffer to the stream. See the general contract of DataOutputStream.write(byte[], int, int).

Specified by:

write in interface OutputWriter

Parameters:

b - the buffer

from - the starting buffer index

len - the number of bytes to write.

Throws:

IOException - if there was an underlying IO error

See Also:

• DataOutputStream.write(byte[], int, int)

read

public final int read(byte[] b,
 int from,
 int len)
               throws IOException

Description copied from interface: InputReader

Reads up to the specified number of bytes into a buffer. See the general contract of DataInputStream.read(byte[], int, int).

Specified by:

read in interface InputReader

Parameters:

b - the buffer

from - the starting buffer index

len - the number of bytes to read.

Returns:

the number of bytes actually read, or -1 if there is nothing left to read.

Throws:

IOException - if there was an underlying IO error

See Also:

• DataInputStream.read(byte[], int, int)

readFully

public final void readFully(byte[] b)
                     throws EOFException,
IOException

Reads bytes to completely fill the supplied buffer. If not enough bytes are avaialable in the file to fully fill the buffer, an EOFException will be thrown.

Parameters:

b - the buffer

Throws:

EOFException - if already at the end of file.

IOException - if there was an IO error before the buffer could be fully populated.

readFully

public void readFully(byte[] b,
 int off,
 int len)
               throws EOFException,
IOException

Reads bytes to fill the supplied buffer with the requested number of bytes from the given starting buffer index. If not enough bytes are avaialable in the file to deliver the reqauested number of bytes the buffer, an EOFException will be thrown.

Parameters:

b - the buffer

off - the buffer index at which to start reading data

len - the total number of bytes to read.

Throws:

EOFException - if already at the end of file.

IOException - if there was an IO error before the requested number of bytes could all be read.

readUTF

public final String readUTF()
                     throws IOException

Same as RandomAccessFile.readUTF().

Returns:

a string

Throws:

IOException - if there was an IO error while reading from the file.

writeUTF

public final void writeUTF(String s)
                    throws IOException

Same as RandomAccessFile.writeUTF(String)

Parameters:

s - a string

Throws:

IOException - if there was an IO error while writing to the file.

skip

public final long skip(long n)
                throws IOException

Moves the file pointer by a number of bytes from its current position.

Parameters:

n - the number of byter to move. Negative values are allowed and result in moving the pointer backward.

Returns:

the actual number of bytes that the pointer moved, which may be fewer than requested if the file boundary was reached.

Throws:

IOException - if there was an IO error.

read

public final int read(byte[] b)
               throws IOException

Read as many bytes into a byte array as possible. The number of bytes read may be fewer than the size of the array, for example because the end-of-file is reached during the read.

Parameters:

b - the byte buffer to fill with data from the file.

Returns:

the number of bytes actually read.

Throws:

IOException - if there was an IO error while reading, other than the end-of-file.

write

public final void write(byte[] b)
                 throws IOException

Writes the contents of a byte array into the file.

Parameters:

b - the byte buffer to write into the file.

Throws:

IOException - if there was an IO error while writing to the file...