Package com.tangosol.io

Class Base64OutputStream

java.lang.Object

java.io.OutputStream

com.tangosol.io.Base64OutputStream

All Implemented Interfaces:

com.oracle.coherence.common.io.OutputStreaming, OutputStreaming, Closeable, Flushable, AutoCloseable

public class Base64OutputStream
extends OutputStream
implements OutputStreaming

Writes binary data into a Writer using IETF RFC 2045 Base64 Content Transfer Encoding. If the Base64OutputStream is not the first to write data into the Writer, it may be desired to write a line feed before Base64 data. According to the specification, Base64 data cannot exceed 76 characters per line. Be careful to avoid calling flush() except when a stream of Base64 content is complete.

Author:

cp 2000.09.06

Field Summary

Fields

Modifier and Type	Field	Description
protected static char[]	BASE64_ALPHABET	Base64 encodes into this "alphabet" of 64 characters.
protected static char	BASE64_LF	The Base64 line feed character.
protected static char	BASE64_PAD	The Base64 padding character.
protected static int	GROUPS_PER_LINE	The number of Base64 character groups in one line.
protected byte[]	m_abAccum	Accumulated bytes.
protected char[]	m_achGroup	An array that is used to send 4 characters at a time to the underlying Writer object.
protected int	m_cAccum	The number of bytes accumulated (0, 1, 2 or 3).
protected int	m_cLineGroups	The number of groups left to write in the current line.
protected boolean	m_fBreakLines	True if lines are to be broken by BASE64_LF;
protected boolean	m_fClosed	True after close is invoked.
protected Writer	m_writer	The Writer object to which the Base64 encoded data is written.

Constructor Summary

Constructors

Constructor	Description
Base64OutputStream(Writer writer)	Construct a Base64OutputStream on a Writer object.
Base64OutputStream(Writer writer, boolean fBreakLines)	Construct a Base64OutputStream on a Writer object and specifying a line-break option.

Method Summary

Modifier and Type	Method	Description
void	close()	Close the stream, flushing any accumulated bytes.
static char[]	encode(byte[] ab)	Encode the passed binary data using Base64 encoding.
static char[]	encode(byte[] ab, boolean fBreakLines)	Encode the passed binary data using Base64 encoding.
static char[]	encode(byte[] ab, int ofb, int cb, boolean fBreakLines)	Encode the passed binary data using Base64 encoding.
void	flush()	Close the stream, flushing any accumulated bytes.
protected void	flushAccumulator()	Flushes the bytes accumulated by the write(int) method.
void	write(byte[] ab, int ofb, int cb)	Writes len bytes from the specified byte array starting at offset off to this output stream.
void	write(int b)	Writes the specified byte to this output stream.

Methods inherited from class java.io.OutputStream

nullOutputStream, write

Methods inherited from class java.lang.Object

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

Methods inherited from interface com.oracle.coherence.common.io.OutputStreaming

write

Field Detail

BASE64_ALPHABET

protected static final char[] BASE64_ALPHABET

Base64 encodes into this "alphabet" of 64 characters.

BASE64_PAD

protected static final char BASE64_PAD

The Base64 padding character. Base64 is encoded into 4-character chunks; if the last chunk does not contain 4 characters, it is filled with this padding character.

See Also:

Constant Field Values

BASE64_LF

protected static final char BASE64_LF

The Base64 line feed character. Base64 is encoded into 76-character lines unless .

See Also:

Constant Field Values

GROUPS_PER_LINE

protected static final int GROUPS_PER_LINE

The number of Base64 character groups in one line. This number prevents a line from exceeding 76 characters.

See Also:

Constant Field Values

m_fClosed

protected boolean m_fClosed

True after close is invoked.

m_writer

protected Writer m_writer

The Writer object to which the Base64 encoded data is written.

m_fBreakLines

protected boolean m_fBreakLines

True if lines are to be broken by BASE64_LF;

m_cLineGroups

protected int m_cLineGroups

The number of groups left to write in the current line.

m_abAccum

protected byte[] m_abAccum

Accumulated bytes.

m_cAccum

protected int m_cAccum

The number of bytes accumulated (0, 1, 2 or 3).

m_achGroup

protected char[] m_achGroup

An array that is used to send 4 characters at a time to the underlying Writer object.

Constructor Detail

Base64OutputStream

public Base64OutputStream(Writer writer)

Construct a Base64OutputStream on a Writer object.

Parameters:

writer - the Writer to write the Base64 encoded data to

Base64OutputStream

public Base64OutputStream(Writer writer,
                          boolean fBreakLines)

Construct a Base64OutputStream on a Writer object and specifying a line-break option.

Parameters:

writer - the Writer to write the Base64 encoded data to

fBreakLines - true to break the output into 76-character lines

Method Detail

write

public void write(int b)
           throws IOException

Writes the specified byte to this output stream.

Specified by:

write in interface com.oracle.coherence.common.io.OutputStreaming

Specified by:

write in class OutputStream

Parameters:

b - the byte.

Throws:

IOException - if an I/O error occurs. In particular, an IOException may be thrown if the output stream has been closed.

write

public void write(byte[] ab,
                  int ofb,
                  int cb)
           throws IOException

Writes len bytes from the specified byte array starting at offset off to this output stream.

If b is null, a NullPointerException is thrown.

If off is negative, or len is negative, or off+len is greater than the length of the array b, then an IndexOutOfBoundsException is thrown.

Specified by:

write in interface com.oracle.coherence.common.io.OutputStreaming

Overrides:

write in class OutputStream

Parameters:

ab - the data

ofb - the start offset in the data

cb - the number of bytes to write

Throws:

IOException - if an I/O error occurs. In particular, an IOException is thrown if the output stream is closed.

flush

public void flush()
           throws IOException

Close the stream, flushing any accumulated bytes. The underlying writer is not closed.

Specified by:

flush in interface Flushable

Specified by:

flush in interface com.oracle.coherence.common.io.OutputStreaming

Overrides:

flush in class OutputStream

Throws:

IOException - if an I/O error occurs

close

public void close()
           throws IOException

Close the stream, flushing any accumulated bytes. The underlying writer is not closed.

Specified by:

close in interface AutoCloseable

Specified by:

close in interface Closeable

Specified by:

close in interface com.oracle.coherence.common.io.OutputStreaming

Overrides:

close in class OutputStream

Throws:

IOException - if an I/O error occurs

flushAccumulator

protected void flushAccumulator()
                         throws IOException

Flushes the bytes accumulated by the write(int) method.

Throws:

IOException - if an I/O error occurs

encode

public static char[] encode(byte[] ab)

Encode the passed binary data using Base64 encoding.

Parameters:

ab - the array containing the bytes to encode

Returns:

the encoded data as a char array

encode

public static char[] encode(byte[] ab,
                            boolean fBreakLines)

Encode the passed binary data using Base64 encoding.

Parameters:

ab - the array containing the bytes to encode

fBreakLines - true to break the output into 76-character lines

Returns:

the encoded data as a char array

encode

public static char[] encode(byte[] ab,
                            int ofb,
                            int cb,
                            boolean fBreakLines)

Encode the passed binary data using Base64 encoding.

Parameters:

ab - the array containing the bytes to encode

ofb - the start offset in the byte array

cb - the number of bytes to encode

fBreakLines - true to break the output into 76-character lines

Returns:

the encoded data as a char array