java.io.InputStream
java.io.ObjectInputStream.PeekInputStream
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java.lang.Object
Input stream supporting single-byte peek operations.
| Field Summary | |
private InputStream |
in
underlying stream |
private int |
peekb
peeked byte |
| Fields inherited from class java.io.InputStream |
|
| Constructor Summary | |
(package private) |
ObjectInputStream.PeekInputStream(InputStream in)
Creates new PeekInputStream on top of given underlying stream. |
| Method Summary | |
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. |
(package private) int |
peek()
Peeks at next byte value in stream. |
int |
read()
Reads the next byte of data from the input stream. |
int |
read(byte[] b,
int off,
int len)
Reads up to len bytes of data from the input stream into
an array of bytes. |
(package private) void |
readFully(byte[] b,
int off,
int len)
|
long |
skip(long n)
Skips over and discards n bytes of data from this input
stream. |
| Methods inherited from class java.io.InputStream |
mark, markSupported, read, reset |
| Methods inherited from class java.lang.Object |
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait |
| Field Detail |
private final InputStream in
private int peekb
| Constructor Detail |
ObjectInputStream.PeekInputStream(InputStream in)
| Method Detail |
int peek() throws IOException
IOException
public int read()
throws IOException
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.
IOException - if an I/O error occurs.
public int read(byte[] b,
int off,
int len)
throws IOException
InputStreamlen bytes of data from the input stream into
an array of bytes. An attempt is made to read as many as
len bytes, but a smaller number may be read, possibly
zero. The number of bytes actually read is returned as an integer.
This method blocks until input data is available, end of file is detected, or an exception is thrown.
If b is null, a
NullPointerException is thrown.
If off is negative, or len is negative, or
off+len is greater than the length of the array
b, then an IndexOutOfBoundsException is
thrown.
If len is zero, then no bytes are read and
0 is returned; otherwise, there is an attempt to read at
least one byte. If no byte is available because the stream is at end of
file, the value -1 is returned; otherwise, at least one
byte is read and stored into b.
The first byte read is stored into element b[off], the
next one into b[off+1], and so on. The number of bytes read
is, at most, equal to len. Let k be the number of
bytes actually read; these bytes will be stored in elements
b[off] through b[off+k-1],
leaving elements b[off+k] through
b[off+len-1] unaffected.
In every case, elements b[0] through
b[off] and elements b[off+len] through
b[b.length-1] are unaffected.
If the first byte cannot be read for any reason other than end of
file, then an IOException is thrown. In particular, an
IOException is thrown if the input stream has been closed.
The read(b, off, len) method
for class InputStream simply calls the method
read() repeatedly. If the first such call results in an
IOException, that exception is returned from the call to
the read(b, off, len) method. If
any subsequent call to read() results in a
IOException, the exception is caught and treated as if it
were end of file; the bytes read up to that point are stored into
b and the number of bytes read before the exception
occurred is returned. Subclasses are encouraged to provide a more
efficient implementation of this method.
read in class InputStreamb - the buffer into which the data is read.off - the start offset in array b
at which the data is written.len - the maximum number of bytes to read.
-1 if there is no more data because the end of
the stream has been reached.
IOException - if an I/O error occurs.InputStream.read()
void readFully(byte[] b,
int off,
int len)
throws IOException
IOException
public long skip(long n)
throws IOException
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, no bytes are skipped.
The skip method of InputStream 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.
skip in class InputStreamn - the number of bytes to be skipped.
IOException - if an I/O error occurs.
public int available()
throws IOException
InputStream The available method for class InputStream
always returns 0.
This method should be overridden by subclasses.
available in class InputStreamIOException - if an I/O error occurs.
public void close()
throws IOException
InputStream The close method of InputStream does
nothing.
close in class InputStreamIOException - if an I/O error occurs.
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