net.freeutils.tnef

Class RawInputStream

java.lang.Object

java.io.InputStream

net.freeutils.tnef.RawInputStream

All Implemented Interfaces:

java.io.Closeable, java.lang.AutoCloseable

public class RawInputStream
extends java.io.InputStream

The RawInputStream class is an InputStream which can provide raw byte data from several underlying sources, including a byte array, a partial section of a byte array, a file, a partial section of a file, another RawInputStream, or a partial section of another RawInputStream.

Since:

2003-04-29

Author:

Amichai Rothman

Constructor Summary

Constructors

Constructor and Description
RawInputStream(byte[] buf) Constructs a RawInputStream which provides data from a byte array.
RawInputStream(byte[] buf, long offset, long length) Constructs a RawInputStream which provides data from a byte array.
RawInputStream(java.io.File file) Constructs a RawInputStream which provides data from a file.
RawInputStream(java.io.File file, long offset, long length) Constructs a RawInputStream which provides data from a file.
RawInputStream(RawInputStream ris) Constructs a RawInputStream which provides data from another RawInputStream.
RawInputStream(RawInputStream ris, long offset, long length) Constructs a RawInputStream which provides data from another RawInputStream.
RawInputStream(java.lang.String filename) Constructs a RawInputStream which provides data from a file.
RawInputStream(java.lang.String filename, long offset, long length) Constructs a RawInputStream which provides data from a file.

Method Summary

Modifier and Type	Method and Description
int	available() Returns the number of bytes that can be read (or skipped over) from this input stream without blocking by the next caller of a method for this input stream.
void	close() Closes this input stream and releases any system resources associated with the stream.
protected void	finalize() Finalizes this object and frees its resources (called by the JVM garbage collector when this object is discarded).
long	getLength() Gets the length of the raw data in bytes.
long	getPosition() Return the current position in the InputStream, as an offset from the beginning of the underlying InputStream.
void	mark(int readlimit) Marks the current position in this input stream.
boolean	markSupported() Tests if this input stream supports the mark and reset methods.
java.io.InputStream	newStream(long start, long end) Return a new InputStream representing a subset of the data from this InputStream, starting at start (inclusive) up to end (exclusive).
int	read() Reads the next byte of data from the input stream.
byte[]	readBytes(int length) Reads a given number of bytes from the stream.
java.lang.String	readString(int length) Reads a C-style null terminated byte sequence from the stream, as a standard String.
java.lang.String	readStringUnicode(int length) Reads a C-style null terminated Unicode byte sequence from the stream, as a standard String.
int	readU16() Reads an unsigned 16-bit value (little-endian ordered) from the stream.
long	readU32() Reads an unsigned 32-bit value (little-endian ordered) from the stream.
long	readU64() Reads a 64-bit value (little-endian ordered) from the stream.
int	readU8() Reads an unsigned 8-bit value from the stream.
void	reset() Repositions this stream to the position at the time the mark method was last called on this input stream.
long	skip(long n) Skips over and discards n bytes of data from this input stream.
byte[]	toByteArray() Gets the raw data as a byte array, starting at the current position and ending at the end of the stream.
byte[]	toByteArray(int max) Gets the raw data as a byte array, starting at the current position and ending either at the end of the stream, or after the given maximum number of bytes, whichever comes first.
java.lang.String	toString() Returns a string representation of this object.

Methods inherited from class java.io.InputStream

read, read

Methods inherited from class java.lang.Object

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

Constructor Detail

RawInputStream

public RawInputStream(byte[] buf,
                      long offset,
                      long length)
               throws java.io.IOException

Constructs a RawInputStream which provides data from a byte array.

Parameters:

buf - the byte array to retrieve data from

offset - the offset within the array to start getting data at

length - the length of the partial stream to create (in bytes)

Throws:

java.io.IOException - if an I/O error occurs

RawInputStream

public RawInputStream(byte[] buf)
               throws java.io.IOException

Constructs a RawInputStream which provides data from a byte array.

Parameters:

buf - the byte array to retrieve data from

Throws:

java.io.IOException - if an I/O error occurs

RawInputStream

public RawInputStream(java.lang.String filename,
                      long offset,
                      long length)
               throws java.io.IOException

Constructs a RawInputStream which provides data from a file.

Parameters:

filename - the fully qualified path of the file to retrieve data from

offset - the offset within the file to start getting data at

length - the length of the partial stream to create (in bytes)

Throws:

java.io.IOException - if an I/O error occurs

RawInputStream

public RawInputStream(java.lang.String filename)
               throws java.io.IOException

Constructs a RawInputStream which provides data from a file.

Parameters:

filename - the fully qualified path of the file to retrieve data from

Throws:

java.io.IOException - if an I/O error occurs

RawInputStream

public RawInputStream(java.io.File file)
               throws java.io.IOException

Constructs a RawInputStream which provides data from a file.

Parameters:

file - the file to retrieve data from

Throws:

java.io.IOException - if an I/O error occurs

RawInputStream

public RawInputStream(java.io.File file,
                      long offset,
                      long length)
               throws java.io.IOException

Constructs a RawInputStream which provides data from a file.

Parameters:

file - the file to retrieve data from

offset - the offset within the file to start getting data at

length - the length of the partial stream to create (in bytes)

Throws:

java.io.IOException - if an I/O error occurs

RawInputStream

public RawInputStream(RawInputStream ris)
               throws java.io.IOException

Constructs a RawInputStream which provides data from another RawInputStream. The new stream begins at the current position of the original stream, and contains all of the remaining bytes.

Parameters:

ris - the RawInputStream to retrieve data from

Throws:

java.io.IOException - if an I/O error occurs

RawInputStream

public RawInputStream(RawInputStream ris,
                      long offset,
                      long length)
               throws java.io.IOException

Constructs a RawInputStream which provides data from another RawInputStream. The new stream begins at the current position of the original stream plus the given offset, and its length is set to given length.

Parameters:

ris - the RawInputStream to retrieve data from

offset - the offset from the current position at which the new stream will begin

length - the length of the partial stream to create (in bytes)

Throws:

java.io.IOException - if an I/O error occurs

Method Detail

getLength

public long getLength()

Gets the length of the raw data in bytes. Unlike the available() method, this method is not affected by reading or skipping, and always returns the total number of bytes that this stream contains.

Returns:

the length of the raw data in bytes

toByteArray

public byte[] toByteArray(int max)
                   throws java.io.IOException

Gets the raw data as a byte array, starting at the current position and ending either at the end of the stream, or after the given maximum number of bytes, whichever comes first.

Parameters:

max - the maximum number of returned bytes; if negative, there is no limit

Returns:

the raw data as a byte array

Throws:

java.io.IOException - if an I/O error occurs

toByteArray

public byte[] toByteArray()
                   throws java.io.IOException

Gets the raw data as a byte array, starting at the current position and ending at the end of the stream.

Returns:

the raw data as a byte array

Throws:

java.io.IOException - if an I/O error occurs

read

public int read()
         throws java.io.IOException

Reads the next byte of data from the input stream. The value byte is returned as an int in the range 0 to 255. If no byte is available because the end of the stream has been reached, the value -1 is returned. This method blocks until input data is available, the end of the stream is detected, or an exception is thrown.

Specified by:

read in class java.io.InputStream

Returns:

the next byte of data, or -1 if the end of the stream is reached

Throws:

java.io.IOException - if an I/O error occurs

skip

public long skip(long n)
          throws java.io.IOException

Skips over and discards n bytes of data from this input stream. The skip method may, for a variety of reasons, end up skipping over some smaller number of bytes, possibly 0. This may result from any of a number of conditions; reaching end of file before n bytes have been skipped is only one possibility. The actual number of bytes skipped is returned. If n is negative, no bytes are skipped.

Overrides:

skip in class java.io.InputStream

Parameters:

n - the number of bytes to be skipped

Returns:

the actual number of bytes skipped

Throws:

java.io.IOException - if an I/O error occurs

available

public int available()
              throws java.io.IOException

Returns the number of bytes that can be read (or skipped over) from this input stream without blocking by the next caller of a method for this input stream. The next caller might be the same thread or another thread.

Overrides:

available in class java.io.InputStream

Returns:

the number of bytes that can be read from this input stream without blocking

Throws:

java.io.IOException - if an I/O error occurs

close

public void close()
           throws java.io.IOException

Closes this input stream and releases any system resources associated with the stream.

Specified by:

close in interface java.io.Closeable

Specified by:

close in interface java.lang.AutoCloseable

Overrides:

close in class java.io.InputStream

Throws:

java.io.IOException - if an I/O error occurs

mark

public void mark(int readlimit)

Marks the current position in this input stream. A subsequent call to the reset method repositions this stream at the last marked position so that subsequent reads re-read the same bytes.

The readlimit arguments tells this input stream to allow that many bytes to be read before the mark position gets invalidated.

The general contract of mark is that, if the method markSupported returns true, the stream somehow remembers all the bytes read after the call to mark and stands ready to supply those same bytes again if and whenever the method reset is called. However, the stream is not required to remember any data at all if more than readlimit bytes are read from the stream before reset is called.

Overrides:

mark in class java.io.InputStream

Parameters:

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

See Also:

InputStream.reset()

reset

public void reset()
           throws java.io.IOException

Repositions this stream to the position at the time the mark method was last called on this input stream.

The general contract of reset is:

• If the method markSupported returns true, then:
  • If the method mark has not been called since the stream was created, or the number of bytes read from the stream since mark was last called is larger than the argument to mark at that last call, then an IOException might be thrown.
  • If such an IOException is not thrown, then the stream is reset to a state such that all the bytes read since the most recent call to mark (or since the start of the file, if mark has not been called) will be resupplied to subsequent callers of the read method, followed by any bytes that otherwise would have been the next input data as of the time of the call to reset.
• If the method markSupported returns false, then:
  • The call to reset may throw an IOException.
  • If an IOException is not thrown, then the stream is reset to a fixed state that depends on the particular type of the input stream and how it was created. The bytes that will be supplied to subsequent callers of the read method depend on the particular type of the input stream.

Overrides:

reset in class java.io.InputStream

Throws:

java.io.IOException - if this stream has not been marked or if the mark has been invalidated

See Also:

InputStream.mark(int), IOException

markSupported

public boolean markSupported()

Tests if this input stream supports the mark and reset methods.

Overrides:

markSupported in class java.io.InputStream

Returns:

true if this true type supports the mark and reset method; false otherwise

See Also:

InputStream.mark(int), InputStream.reset()

getPosition

public long getPosition()

Return the current position in the InputStream, as an offset from the beginning of the underlying InputStream.

Returns:

the current position

newStream

public java.io.InputStream newStream(long start,
                                     long end)

Return a new InputStream representing a subset of the data from this InputStream, starting at start (inclusive) up to end (exclusive). start must be non-negative. If end is -1, the new stream ends at the same place as this stream.

Parameters:

start - the starting position, relative to current position

end - the ending position + 1

Returns:

the new stream, or null if an error occurs

Throws:

java.lang.IllegalArgumentException - if start < 0

readU8

public int readU8()
           throws java.io.IOException

Reads an unsigned 8-bit value from the stream.

Returns:

an unsigned 8-bit value as an int

Throws:

java.io.IOException - if the end of stream has been reached, or if an I/O error occurs

readU16

public int readU16()
            throws java.io.IOException

Reads an unsigned 16-bit value (little-endian ordered) from the stream.

Returns:

an unsigned 16-bit value as an int

Throws:

java.io.IOException - if the end of stream has been reached, or if an I/O error occurs

readU32

public long readU32()
             throws java.io.IOException

Reads an unsigned 32-bit value (little-endian ordered) from the stream.

Returns:

an unsigned 32-bit value as a long

Throws:

java.io.IOException - if the end of stream has been reached, or if an I/O error occurs

readU64

public long readU64()
             throws java.io.IOException

Reads a 64-bit value (little-endian ordered) from the stream.

Returns:

a 64-bit value as a long

Throws:

java.io.IOException - if the end of stream has been reached, or if an I/O error occurs

readBytes

public byte[] readBytes(int length)
                 throws java.io.IOException

Reads a given number of bytes from the stream.

Parameters:

length - the number of bytes to read

Returns:

the read bytes

Throws:

java.io.IOException - if the end of stream has been reached, or if an I/O error occurs

readString

public java.lang.String readString(int length)
                            throws java.io.IOException

Reads a C-style null terminated byte sequence from the stream, as a standard String. The null terminated byte sequence is interpreted as 8-bit ISO-8859-1 characters (a.k.a. ISO-Latin-1), which is a superset of US-ASCII. This way we don't lose any 8-bit values and remain fully compatible: If the source charset is unknown, a str.getBytes("ISO8859_1") will reconstruct the exact original byte sequence which the application can then process in any charset it sees fit.

Parameters:

length - the length of the C-style string in bytes, which may include any number of terminating null ('\0') characters

Returns:

a String containing the C-style string's characters, interpreted as ISO-8859-1 characters

Throws:

java.io.IOException - if the end of stream has been reached, or if an I/O error occurs

readStringUnicode

public java.lang.String readStringUnicode(int length)
                                   throws java.io.IOException

Reads a C-style null terminated Unicode byte sequence from the stream, as a standard String. The null terminated byte sequence is interpreted as 16-bit Unicode characters (UTF-16), stored in Little Endian order.

Parameters:

length - the length of the C-style string in bytes, which may include any number of terminating null ('\0') characters

Returns:

a String containing the C-style string's characters, interpreted as Unicode (UTF-16 Little Endian) characters

Throws:

java.io.IOException - if the end of stream has been reached, or if an I/O error occurs

toString

public java.lang.String toString()

Returns a string representation of this object.

Overrides:

toString in class java.lang.Object

Returns:

a string representation of this object

finalize

protected void finalize()
                 throws java.lang.Throwable

Finalizes this object and frees its resources (called by the JVM garbage collector when this object is discarded).

Overrides:

finalize in class java.lang.Object

Throws:

java.lang.Throwable - the Exception raised by this method