iaik.utils

Class Base64OutputStream

java.lang.Object

java.io.OutputStream

java.io.FilterOutputStream

iaik.utils.Base64OutputStream

All Implemented Interfaces:

java.io.Closeable, java.io.Flushable, java.lang.AutoCloseable

Direct Known Subclasses:

PemOutputStream

public class Base64OutputStream
extends java.io.FilterOutputStream

This class represents a FilterOutputStream that Base64 encodes the data passing through it. For writing Base64 encoded data to the underlying output stream, use one of the write methods.

Base64 is the encoding format used by Multipurpose Internet Mail Extension (MIME) for transmitting non-text material over text-only communications channels. Base64 is based on a 65-character subset of US-ASCII, enabling 6 bits to be represented per printable character (see RFC 1521 or RFC 2045).

This class may be used for Base64 encoding some given data and writing it to a file, e.g.:

 FileOutputStream fos = new FileOutputStream("test/base64.enc");
 Base64OutputStream base64os = new Base64OutputStream(fos);
 byte[] data = "Test Data to be Base64 encoded and written to a file".getBytes();
 base64os.write(data);
 base64os.flush();
 base64os.close();
 

Using the constructor Base64OutputStream(OutputStream, byte[]), the application can specify a different line-break than the default, which is carriage return (0xD) plus line feed (0xA). To use not line-break at all, specify the empty array (i.e. new byte[0]) as line-break parameter.

Version:

File Revision 23

See Also:

Base64InputStream

Field Summary

Fields inherited from class java.io.FilterOutputStream

out

Constructor Summary

Constructors

Constructor and Description
Base64OutputStream(java.io.OutputStream out) Creates a new Base64OutputStream to write Base64 encoded data to the specified underlying output stream.
Base64OutputStream(java.io.OutputStream out, byte[] lineBreakChars) Creates a new Base64OutputStream to write Base64 encoded data to the specified underlying output stream and specifies the line break delimiter.
Base64OutputStream(java.io.OutputStream out, byte[] lineBreakChars, boolean urlEncoding, boolean usePadding) Creates a new Base64OutputStream to write Base64 encoded data to the specified underlying output stream, specifies the line break delimiter, and specifies whether to use Base64UrlEncoding and the usage of trailing padding "=" bytes.

Method Summary

Modifier and Type	Method and Description
void	flush() Performs final processing and output to the output stream.
byte[]	getInstanceLineBreak() Gets the line-break delimiter used by this Base64OutputStream instance.
static byte[]	getLineBreak() Gets the default line-break delimiter.
static void	setLineBreak(byte[] lineBreakChars) Sets the line-break delimiter to be used throughout the application; default is CR + LF (0x0D, 0x0A).
void	write(byte[] in, int inOff, int inLen) Base64 encodes the specified number of bytes and writes them to the underlying output stream.
void	write(int b) Base64 encodes the given byte and writes it to the underlying output stream.

Methods inherited from class java.io.FilterOutputStream

close, write

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

Base64OutputStream

public Base64OutputStream(java.io.OutputStream out)

Creates a new Base64OutputStream to write Base64 encoded data to the specified underlying output stream.

Parameters:

out - - the underlying output stream.

Base64OutputStream

public Base64OutputStream(java.io.OutputStream out,
                          byte[] lineBreakChars)

Creates a new Base64OutputStream to write Base64 encoded data to the specified underlying output stream and specifies the line break delimiter.

Parameters:

out - - the underlying output stream.

lineBreakChars - - the lineBreak the line-break delimiter to be used; if null, the currently static set line-break delimiter CRLF (0x0D, 0x0A) will be used. Provide an empty array to disable line breaks.

See Also:

setLineBreak(byte[]), getLineBreak(), getInstanceLineBreak()

Base64OutputStream

public Base64OutputStream(java.io.OutputStream out,
                          byte[] lineBreakChars,
                          boolean urlEncoding,
                          boolean usePadding)

Creates a new Base64OutputStream to write Base64 encoded data to the specified underlying output stream, specifies the line break delimiter, and specifies whether to use Base64UrlEncoding and the usage of trailing padding "=" bytes.

Parameters:

out - - the underlying output stream.

lineBreakChars - - the lineBreak the line-break delimiter to be used; if null, the currently static set line-break delimiter CRLF (0x0D, 0x0A) will be used. Provide an empty array to disable line breaks.

urlEncoding - - iff true, the stream writes Base64UrlEncoding. Standard Base64 otherwise.

usePadding - - iff true, the stream appends trailing "=" if necessary. Iff false, the implementation does not append padding bytes

See Also:

setLineBreak(byte[]), getLineBreak(), getInstanceLineBreak()

Method Detail

setLineBreak

public static void setLineBreak(byte[] lineBreakChars)

Sets the line-break delimiter to be used throughout the application; default is CR + LF (0x0D, 0x0A).

Parameters:

lineBreakChars - The line-break to be used. Specify the empty array to use no line-break.

Throws:

java.lang.IllegalArgumentException - If lineBreakChars is null.

getLineBreak

public static byte[] getLineBreak()

Gets the default line-break delimiter. New objects use it as default.

Returns:

The used line-break .

getInstanceLineBreak

public byte[] getInstanceLineBreak()

Gets the line-break delimiter used by this Base64OutputStream instance.

Returns:

the line-break used by this instance

write

public void write(int b)
           throws java.io.IOException

Base64 encodes the given byte and writes it to the underlying output stream.

Overrides:

write in class java.io.FilterOutputStream

Parameters:

b - the byte to be Base64 encoded.

Throws:

java.io.IOException - if an I/O error occurs.

write

public void write(byte[] in,
                  int inOff,
                  int inLen)
           throws java.io.IOException

Base64 encodes the specified number of bytes and writes them to the underlying output stream.

The data to be processed is given in an input byte array. Beginning at inOff, this method only encodes the first inLen bytes and writes them to the underlying output stream.

Overrides:

write in class java.io.FilterOutputStream

Parameters:

in - the buffer containing the bytes to be Base64 encoded

inOff - the offset indicating the start position within the input byte array

inLen - the number of bytes to be processed

Throws:

java.io.IOException - if an I/O error occurs.

flush

public void flush()
           throws java.io.IOException

Performs final processing and output to the output stream. If necessary this method pads with '='.

Specified by:

flush in interface java.io.Flushable

Overrides:

flush in class java.io.FilterOutputStream

Throws:

java.io.IOException - If an error occurs.