public class Base64InputStream extends FilterInputStream
in| Constructor and Description |
|---|
Base64InputStream(InputStream in,
int flags)
An InputStream that performs Base64 decoding on the data read
from the wrapped stream.
|
Base64InputStream(InputStream in,
int flags,
boolean encode)
Performs Base64 encoding or decoding on the data read from the
wrapped InputStream.
|
| Modifier and Type | Method and Description |
|---|---|
int |
available()
Returns an estimated number of bytes that can be read or skipped without blocking for more
input.
|
void |
close()
Closes this stream.
|
void |
mark(int readlimit)
Sets a mark position in this stream.
|
boolean |
markSupported()
Indicates whether this stream supports
mark() and reset(). |
int |
read()
Reads a single byte from the filtered stream and returns it as an integer
in the range from 0 to 255.
|
int |
read(byte[] b,
int off,
int len)
Reads at most
count bytes from this stream and stores them in the
byte array buffer starting at offset. |
void |
reset()
Resets this stream to the last marked location.
|
long |
skip(long n)
Skips
byteCount bytes in this stream. |
readpublic Base64InputStream(InputStream in, int flags)
in - the InputStream to read the source data fromflags - bit flags for controlling the decoder; see the
constants in Base64public Base64InputStream(InputStream in, int flags, boolean encode)
in - the InputStream to read the source data fromflags - bit flags for controlling the decoder; see the
constants in Base64encode - true to encode, false to decodepublic boolean markSupported()
FilterInputStreammark() and reset().
This implementation returns whether or not the filtered stream supports
marking.markSupported in class FilterInputStreamtrue if mark() and reset() are supported,
false otherwise.FilterInputStream.mark(int),
FilterInputStream.reset(),
FilterInputStream.skip(long)public void mark(int readlimit)
FilterInputStreamreadlimit
indicates how many bytes can be read before the mark is invalidated.
Sending reset() will reposition this stream back to the marked
position, provided that readlimit has not been surpassed.
This implementation sets a mark in the filtered stream.
mark in class FilterInputStreamreadlimit - the number of bytes that can be read from this stream before
the mark is invalidated.FilterInputStream.markSupported(),
FilterInputStream.reset()public void reset()
FilterInputStreamreset in class FilterInputStreamFilterInputStream.mark(int),
FilterInputStream.markSupported()public void close()
throws IOException
FilterInputStreamclose in interface Closeableclose in interface AutoCloseableclose in class FilterInputStreamIOException - if an error occurs while closing this stream.public int available()
InputStreamNote that this method provides such a weak guarantee that it is not very useful in practice.
Firstly, the guarantee is "without blocking for more input" rather than "without blocking": a read may still block waiting for I/O to complete — the guarantee is merely that it won't have to wait indefinitely for data to be written. The result of this method should not be used as a license to do I/O on a thread that shouldn't be blocked.
Secondly, the result is a conservative estimate and may be significantly smaller than the actual number of bytes available. In particular, an implementation that always returns 0 would be correct. In general, callers should only use this method if they'd be satisfied with treating the result as a boolean yes or no answer to the question "is there definitely data ready?".
Thirdly, the fact that a given number of bytes is "available" does not guarantee that a read or skip will actually read or skip that many bytes: they may read or skip fewer.
It is particularly important to realize that you must not use this method to
size a container and assume that you can read the entirety of the stream without needing
to resize the container. Such callers should probably write everything they read to a
ByteArrayOutputStream and convert that to a byte array. Alternatively, if you're
reading from a file, File.length() returns the current length of the file (though
assuming the file's length can't change may be incorrect, reading a file is inherently
racy).
The default implementation of this method in InputStream always returns 0.
Subclasses should override this method if they are able to indicate the number of bytes
available.
available in class FilterInputStreampublic long skip(long n)
throws IOException
FilterInputStreambyteCount bytes in this stream. Subsequent
calls to read will not return these bytes unless reset is
used. This implementation skips byteCount bytes in the
filtered stream.skip in class FilterInputStreamn - the number of bytes to skip.IOException - if this stream is closed or another IOException occurs.FilterInputStream.mark(int),
FilterInputStream.reset()public int read()
throws IOException
FilterInputStreamread in class FilterInputStreamIOException - if the stream is closed or another IOException occurs.public int read(byte[] b,
int off,
int len)
throws IOException
FilterInputStreamcount bytes from this stream and stores them in the
byte array buffer starting at offset. Returns the number
of bytes actually read or -1 if no bytes have been read and the end of
this stream has been reached. This implementation reads bytes from the
filtered stream.read in class FilterInputStreamb - the byte array in which to store the bytes read.off - the initial position in buffer to store the bytes
read from this stream.len - the maximum number of bytes to store in buffer.IOException - if this stream is closed or another I/O error occurs.