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).

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();
 

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 (with line breaks) to the specified underlying output stream.
Base64OutputStream(java.io.OutputStream out, boolean includeLineBreaks) Creates a new Base64OutputStream to write Base64 encoded data (with or without line breaks) to the specified underlying output stream.

Method Summary

Modifier and Type	Method and Description
int	countCRLFBytesWritten() Returns the number of CRLF bytes (carriage return '\r' and line feed '\n') that were written to the underlying output stream.
void	flush() Performs final processing and output to the output stream.
void	write(byte[] in, int inOff, int inLen) Base64 encodes the 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 (with line breaks) to the specified underlying output stream.

A line break (CRLF) is inserted after every 64th character; this style of Base64 encoding is used in Privacy Enhanced Mail (PEM).

Parameters:

out - - the underlying output stream.

Base64OutputStream

public Base64OutputStream(java.io.OutputStream out,
                          boolean includeLineBreaks)

Creates a new Base64OutputStream to write Base64 encoded data (with or without line breaks) to the specified underlying output stream.

If configured to do so via includeLineBreaks, a line break (CRLF) is inserted after every 64th character; this style of Base64 encoding is used in Privacy Enhanced Mail (PEM).

Parameters:

out - - the underlying output stream.

includeLineBreaks - indicates whether or not line breaks should be included in the Base64 encoded value

Method Detail

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 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.

Specified by:

flush in interface java.io.Flushable

Overrides:

flush in class java.io.FilterOutputStream

Throws:

java.io.IOException - If an error occurs.

countCRLFBytesWritten

public int countCRLFBytesWritten()

Returns the number of CRLF bytes (carriage return '\r' and line feed '\n') that were written to the underlying output stream.

For example, if one CRLF was written, this API will return 2 (each CRLF consists of two bytes).

Returns:

the number of CRLF bytes that were written to the underlying output stream