public class FastByteArrayInputStream extends MeasurableInputStream implements RepositionableStream
Warning: this class implements the correct semantics
of read(byte[], int, int) as described in InputStream.
The implementation given in ByteArrayInputStream is broken,
but it will never be fixed because it's too late.
| Modifier and Type | Field and Description |
|---|---|
byte[] |
array
The array backing the input stream.
|
int |
length
|
int |
offset
The first valid entry.
|
| Constructor and Description |
|---|
FastByteArrayInputStream(byte[] array)
Creates a new array input stream using a given array.
|
FastByteArrayInputStream(byte[] array,
int offset,
int length)
Creates a new array input stream using a given array fragment.
|
| Modifier and Type | Method and Description |
|---|---|
int |
available()
Returns an estimate of the number of bytes that can be read (or
skipped over) from this input stream without blocking by the next
invocation of a method for this input stream.
|
void |
close()
Closing a fast byte array input stream has no effect.
|
long |
length()
Returns the overall length of this stream (optional operation).
|
void |
mark(int dummy)
Marks the current position in this input stream.
|
boolean |
markSupported()
Tests if this input stream supports the
mark and
reset methods. |
long |
position()
Returns the current stream position.
|
void |
position(long newPosition)
Sets the current stream position.
|
int |
read()
Reads the next byte of data from the input stream.
|
int |
read(byte[] b,
int offset,
int length)
Reads bytes from this byte-array input stream as
specified in
InputStream.read(byte[], int, int). |
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. |
readpublic byte[] array
public int offset
public int length
public FastByteArrayInputStream(byte[] array,
int offset,
int length)
array - the backing array.offset - the first valid entry of the array.length - the number of valid bytes.public FastByteArrayInputStream(byte[] array)
array - the backing array.public boolean markSupported()
java.io.InputStreammark and
reset methods. Whether or not mark and
reset are supported is an invariant property of a
particular input stream instance. The markSupported method
of InputStream returns false.markSupported in class InputStreamtrue if this stream instance supports the mark
and reset methods; false otherwise.InputStream.mark(int),
InputStream.reset()public void reset()
java.io.InputStreammark method was last called on this input stream.
The general contract of reset is:
markSupported returns
true, then:
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.
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. markSupported returns
false, then:
reset may throw an
IOException.
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. The method reset for class InputStream
does nothing except throw an IOException.
reset in class InputStreamInputStream.mark(int),
IOExceptionpublic void close()
close in interface Closeableclose in interface AutoCloseableclose in class InputStreampublic void mark(int dummy)
java.io.InputStreamreset 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.
Marking a closed stream should not have any effect on the stream.
The mark method of InputStream does
nothing.
mark in class InputStreamdummy - the maximum limit of bytes that can be read before
the mark position becomes invalid.InputStream.reset()public int available()
java.io.InputStream Note that while some implementations of InputStream will return
the total number of bytes in the stream, many will not. It is
never correct to use the return value of this method to allocate
a buffer intended to hold all data in this stream.
A subclass' implementation of this method may choose to throw an
IOException if this input stream has been closed by
invoking the InputStream.close() method.
The available method for class InputStream always
returns 0.
This method should be overridden by subclasses.
available in class InputStream0 when
it reaches the end of the input stream.public long skip(long n)
java.io.InputStreamn 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, the skip method for class InputStream always
returns 0, and no bytes are skipped. Subclasses may handle the negative
value differently.
The skip method of this class creates a
byte array and then repeatedly reads into it until n bytes
have been read or the end of the stream has been reached. Subclasses are
encouraged to provide a more efficient implementation of this method.
For instance, the implementation may depend on the ability to seek.
skip in class InputStreamn - the number of bytes to be skipped.public int read()
java.io.InputStreamint 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.
A subclass must provide an implementation of this method.
read in class InputStream-1 if the end of the
stream is reached.public int read(byte[] b,
int offset,
int length)
InputStream.read(byte[], int, int).
Note that the implementation given in ByteArrayInputStream.read(byte[], int, int)
will return -1 on a zero-length read at EOF, contrarily to the specification. We won't.read in class InputStreamb - the buffer into which the data is read.offset - the start offset in array b
at which the data is written.length - the maximum number of bytes to read.-1 if there is no more data because the end of
the stream has been reached.InputStream.read()public long position()
RepositionableStreamposition in interface MeasurableStreamposition in interface RepositionableStreampublic void position(long newPosition)
RepositionableStreamposition in interface RepositionableStreamnewPosition - the new stream position.public long length()
MeasurableStreamlength in interface MeasurableStream