public class Base64InputStream extends FilterInputStream
The default behaviour of the Base64InputStream is to DECODE, whereas the default behaviour of the Base64OutputStream is to ENCODE, but this behaviour can be overridden by using a different constructor.
This class implements section 6.8. Base64 Content-Transfer-Encoding from RFC 2045 Multipurpose Internet Mail Extensions (MIME) Part One: Format of Internet Message Bodies by Freed and Borenstein.
Since this class operates directly on byte streams, and not character streams, it is hard-coded to only encode/decode character encodings which are compatible with the lower 127 ASCII chart (ISO-8859-1, Windows-1252, UTF-8, etc).
Modifier and Type | Field and Description |
---|---|
private Base64 |
base64 |
private boolean |
doEncode |
private byte[] |
singleByte |
in
Constructor and Description |
---|
Base64InputStream(InputStream in)
Creates a Base64InputStream such that all data read is Base64-decoded from the original provided InputStream.
|
Base64InputStream(InputStream in,
boolean doEncode)
Creates a Base64InputStream such that all data read is either Base64-encoded or Base64-decoded from the original
provided InputStream.
|
Base64InputStream(InputStream in,
boolean doEncode,
int lineLength,
byte[] lineSeparator)
Creates a Base64InputStream such that all data read is either Base64-encoded or Base64-decoded from the original
provided InputStream.
|
Modifier and Type | Method and Description |
---|---|
boolean |
markSupported() |
int |
read()
Reads one
byte from this input stream. |
int |
read(byte[] b,
int offset,
int len)
Attempts to read
len bytes into the specified b array starting at offset
from this InputStream. |
private final boolean doEncode
private final byte[] singleByte
public Base64InputStream(InputStream in)
in
- InputStream to wrap.public Base64InputStream(InputStream in, boolean doEncode)
in
- InputStream to wrap.doEncode
- true if we should encode all data read from us, false if we should decode.public Base64InputStream(InputStream in, boolean doEncode, int lineLength, byte[] lineSeparator)
in
- InputStream to wrap.doEncode
- true if we should encode all data read from us, false if we should decode.lineLength
- If doEncode is true, each line of encoded data will contain lineLength characters (rounded down to
nearest multiple of 4). If lineLength <=0, the encoded data is not divided into lines. If doEncode is
false, lineLength is ignored.lineSeparator
- If doEncode is true, each line of encoded data will be terminated with this byte sequence (e.g. \r\n).
If lineLength <= 0, the lineSeparator is not used. If doEncode is false lineSeparator is ignored.public int read() throws IOException
byte
from this input stream.read
in class FilterInputStream
IOException
- if an I/O error occurs.public int read(byte[] b, int offset, int len) throws IOException
len
bytes into the specified b
array starting at offset
from this InputStream.read
in class FilterInputStream
b
- destination byte arrayoffset
- where to start writing the byteslen
- maximum number of bytes to readIOException
- if an I/O error occurs.NullPointerException
- if the byte array parameter is nullIndexOutOfBoundsException
- if offset, len or buffer size are invalidpublic boolean markSupported()
markSupported
in class FilterInputStream