public class BufferedInputStream extends FilterInputStream
FilterInputStream buffers input from an
underlying implementation to provide a possibly more efficient read
mechanism. It maintains the buffer and buffer state in instance
variables that are available to subclasses. The default buffer size
of 2048 bytes can be overridden by the creator of the stream.
This class also implements mark/reset functionality. It is capable
of remembering any number of input bytes, to the limits of
system memory or the size of Integer.MAX_VALUE
Please note that this class does not properly handle character
encodings. Consider using the BufferedReader class which
does.
| Constructor and Description |
|---|
BufferedInputStream(InputStream in)
This method initializes a new
BufferedInputStream that will
read from the specified subordinate stream with a default buffer size
of 2048 bytes |
BufferedInputStream(InputStream in,
int size)
This method initializes a new
BufferedInputStream that will
read from the specified subordinate stream with a buffer size that
is specified by the caller. |
| Modifier and Type | Method and Description |
|---|---|
int |
available()
This method returns the number of bytes that can be read from this
stream before a read can block.
|
void |
close()
This method closes the underlying input stream and frees any
resources associated with it.
|
void |
mark(int readlimit)
This method marks a position in the input to which the stream can be
"reset" by calling the
reset() method. |
boolean |
markSupported()
This method returns
true to indicate that this class
supports mark/reset functionality. |
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[] b,
int off,
int len)
This method reads bytes from a stream and stores them into a caller
supplied buffer.
|
void |
reset()
This method resets a stream to the point where the
mark()
method was called. |
long |
skip(long n)
This method skips the specified number of bytes in the stream.
|
readpublic BufferedInputStream(InputStream in)
BufferedInputStream that will
read from the specified subordinate stream with a default buffer size
of 2048 bytesin - The subordinate stream to read frompublic BufferedInputStream(InputStream in, int size)
BufferedInputStream that will
read from the specified subordinate stream with a buffer size that
is specified by the caller.in - The subordinate stream to read fromsize - The buffer size to useIllegalArgumentException - when size is smaller then 1public int available()
throws IOException
The number of available bytes will be the number of read ahead bytes stored in the internal buffer plus the number of available bytes in the underlying stream.
available in class FilterInputStreamIOException - If an error occurspublic void close()
throws IOException
buf to null.close in interface Closeableclose in class FilterInputStreamIOException - If an error occurs.public void mark(int readlimit)
reset() method. The parameter
readlimit is the number of bytes that can be read from the
stream after setting the mark before the mark becomes invalid. For
example, if mark() is called with a read limit of 10, then
when 11 bytes of data are read from the stream before the
reset() method is called, then the mark is invalid and the
stream object instance is not required to remember the mark.
Note that the number of bytes that can be remembered by this method can be greater than the size of the internal read buffer. It is also not dependent on the subordinate stream supporting mark/reset functionality.
mark in class FilterInputStreamreadlimit - The number of bytes that can be read before the mark
becomes invalidpublic boolean markSupported()
true to indicate that this class
supports mark/reset functionality.markSupported in class FilterInputStreamtrue to indicate that mark/reset functionality is
supportedpublic int read()
throws IOException
This method will block until the byte can be read.
read in class FilterInputStreamIOException - If an error occurspublic int read(byte[] b,
int off,
int len)
throws IOException
off
into the buffer and attempts to read len bytes. This method
can return before reading the number of bytes requested, but it will try
to read the requested number of bytes by repeatedly calling the underlying
stream as long as available() for this stream continues to return a
non-zero value (or until the requested number of bytes have been read).
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.
read in class FilterInputStreamb - The array into which the bytes read should be storedoff - The offset into the array to start storing byteslen - The requested number of bytes to readIOException - If an error occurs.IndexOutOfBoundsException - when off or
len are negative, or when off + len
is larger then the size of b,public void reset()
throws IOException
mark()
method was called. Any bytes that were read after the mark point was
set will be re-read during subsequent reads.
This method will throw an IOException if the number of bytes read from
the stream since the call to mark() exceeds the mark limit
passed when establishing the mark.
reset in class FilterInputStreamIOException - If mark() was never called or more
then marklimit bytes were read since the last
call to mark()public long skip(long n)
throws IOException
skip in class FilterInputStreamn - The requested number of bytes to skipIOException - If an error occurs