writer2latex.util

Class Base64

public class Base64 extends Object

This is Robert Harders public domain Base64 class. It is unmodified, except for the package name.

Encodes and decodes to and from Base64 notation.

Homepage: http://iharder.net/base64.

The options parameter, which appears in a few places, is used to pass several pieces of information to the encoder. In the "higher level" methods such as encodeBytes( bytes, options ) the options parameter can be used to indicate such things as first gzipping the bytes before encoding them, not inserting linefeeds (though that breaks strict Base64 compatibility), and encoding using the URL-safe and Ordered dialects.

The constants defined in Base64 can be OR-ed together to combine options, so you might make a call like this:

String encoded = Base64.encodeBytes( mybytes, Base64.GZIP | Base64.DONT_BREAK_LINES );

to compress the data before encoding it and then making the output have no newline characters.

Change Log:

I am placing this code in the Public Domain. Do with it as you will. This software comes with no guarantees or warranties but with plenty of well-wishing instead! Please visit http://iharder.net/base64 periodically to check for updates or to contribute improvements.

Version: 2.2.2

Author: Robert Harder rob@iharder.net

Nested Class Summary
static classBase64.InputStream
A InputStream will read data from another java.io.InputStream, given in the constructor, and encode/decode to/from Base64 notation on the fly.
static classBase64.OutputStream
A OutputStream will write data to another java.io.OutputStream, given in the constructor, and encode/decode to/from Base64 notation on the fly.
Field Summary
static intDECODE
Specify decoding.
static intDONT_BREAK_LINES
Don't break lines when encoding (violates strict Base64 specification)
static intENCODE
Specify encoding.
static intGZIP
Specify that data should be gzip-compressed.
static intNO_OPTIONS
No options specified.
static intORDERED
Encode using the special "ordered" dialect of Base64 described here: http://www.faqs.org/qa/rfcc-1940.html.
static intURL_SAFE
Encode using Base64-like encoding that is URL- and Filename-safe as described in Section 4 of RFC3548: http://www.faqs.org/rfcs/rfc3548.html.
Method Summary
static byte[]decode(byte[] source, int off, int len, int options)
Very low-level access to decoding ASCII characters in the form of a byte array.
static byte[]decode(String s)
Decodes data from Base64 notation, automatically detecting gzip-compressed data and decompressing it.
static byte[]decode(String s, int options)
Decodes data from Base64 notation, automatically detecting gzip-compressed data and decompressing it.
static booleandecodeFileToFile(String infile, String outfile)
Reads infile and decodes it to outfile.
static byte[]decodeFromFile(String filename)
Convenience method for reading a base64-encoded file and decoding it.
static booleandecodeToFile(String dataToDecode, String filename)
Convenience method for decoding data to a file.
static ObjectdecodeToObject(String encodedObject)
Attempts to decode Base64 data and deserialize a Java Object within.
static StringencodeBytes(byte[] source)
Encodes a byte array into Base64 notation.
static StringencodeBytes(byte[] source, int options)
Encodes a byte array into Base64 notation.
static StringencodeBytes(byte[] source, int off, int len)
Encodes a byte array into Base64 notation.
static StringencodeBytes(byte[] source, int off, int len, int options)
Encodes a byte array into Base64 notation.
static booleanencodeFileToFile(String infile, String outfile)
Reads infile and encodes it to outfile.
static StringencodeFromFile(String filename)
Convenience method for reading a binary file and base64-encoding it.
static StringencodeObject(Serializable serializableObject)
Serializes an object and returns the Base64-encoded version of that serialized object.
static StringencodeObject(Serializable serializableObject, int options)
Serializes an object and returns the Base64-encoded version of that serialized object.
static booleanencodeToFile(byte[] dataToEncode, String filename)
Convenience method for encoding data to a file.
static voidmain(String[] args)
Encodes or decodes two files from the command line; feel free to delete this method (in fact you probably should) if you're embedding this code into a larger program.

Field Detail

DECODE

public static final int DECODE
Specify decoding.

DONT_BREAK_LINES

public static final int DONT_BREAK_LINES
Don't break lines when encoding (violates strict Base64 specification)

ENCODE

public static final int ENCODE
Specify encoding.

GZIP

public static final int GZIP
Specify that data should be gzip-compressed.

NO_OPTIONS

public static final int NO_OPTIONS
No options specified. Value is zero.

ORDERED

public static final int ORDERED
Encode using the special "ordered" dialect of Base64 described here: http://www.faqs.org/qa/rfcc-1940.html.

URL_SAFE

public static final int URL_SAFE
Encode using Base64-like encoding that is URL- and Filename-safe as described in Section 4 of RFC3548: http://www.faqs.org/rfcs/rfc3548.html. It is important to note that data encoded this way is not officially valid Base64, or at the very least should not be called Base64 without also specifying that is was encoded using the URL- and Filename-safe dialect.

Method Detail

decode

public static byte[] decode(byte[] source, int off, int len, int options)
Very low-level access to decoding ASCII characters in the form of a byte array. Does not support automatically gunzipping or any other "fancy" features.

Parameters: source The Base64 encoded data off The offset of where to begin decoding len The length of characters to decode

Returns: decoded data

Since: 1.3

decode

public static byte[] decode(String s)
Decodes data from Base64 notation, automatically detecting gzip-compressed data and decompressing it.

Parameters: s the string to decode

Returns: the decoded data

Since: 1.4

decode

public static byte[] decode(String s, int options)
Decodes data from Base64 notation, automatically detecting gzip-compressed data and decompressing it.

Parameters: s the string to decode options encode options such as URL_SAFE

Returns: the decoded data

Since: 1.4

decodeFileToFile

public static boolean decodeFileToFile(String infile, String outfile)
Reads infile and decodes it to outfile.

Parameters: infile Input file outfile Output file

Returns: true if the operation is successful

Since: 2.2

decodeFromFile

public static byte[] decodeFromFile(String filename)
Convenience method for reading a base64-encoded file and decoding it.

Parameters: filename Filename for reading encoded data

Returns: decoded byte array or null if unsuccessful

Since: 2.1

decodeToFile

public static boolean decodeToFile(String dataToDecode, String filename)
Convenience method for decoding data to a file.

Parameters: dataToDecode Base64-encoded data as a string filename Filename for saving decoded data

Returns: true if successful, false otherwise

Since: 2.1

decodeToObject

public static Object decodeToObject(String encodedObject)
Attempts to decode Base64 data and deserialize a Java Object within. Returns null if there was an error.

Parameters: encodedObject The Base64 data to decode

Returns: The decoded and deserialized object

Since: 1.5

encodeBytes

public static String encodeBytes(byte[] source)
Encodes a byte array into Base64 notation. Does not GZip-compress data.

Parameters: source The data to convert

Since: 1.4

encodeBytes

public static String encodeBytes(byte[] source, int options)
Encodes a byte array into Base64 notation.

Valid options:

   GZIP: gzip-compresses object before encoding it.
   DONT_BREAK_LINES: don't break lines at 76 characters
     Note: Technically, this makes your encoding non-compliant.
 

Example: encodeBytes( myData, Base64.GZIP ) or

Example: encodeBytes( myData, Base64.GZIP | Base64.DONT_BREAK_LINES )

Parameters: source The data to convert options Specified options

Since: 2.0

See Also: GZIP DONT_BREAK_LINES

encodeBytes

public static String encodeBytes(byte[] source, int off, int len)
Encodes a byte array into Base64 notation. Does not GZip-compress data.

Parameters: source The data to convert off Offset in array where conversion should begin len Length of data to convert

Since: 1.4

encodeBytes

public static String encodeBytes(byte[] source, int off, int len, int options)
Encodes a byte array into Base64 notation.

Valid options:

   GZIP: gzip-compresses object before encoding it.
   DONT_BREAK_LINES: don't break lines at 76 characters
     Note: Technically, this makes your encoding non-compliant.
 

Example: encodeBytes( myData, Base64.GZIP ) or

Example: encodeBytes( myData, Base64.GZIP | Base64.DONT_BREAK_LINES )

Parameters: source The data to convert off Offset in array where conversion should begin len Length of data to convert options Specified options options alphabet type is pulled from this (standard, url-safe, ordered)

Since: 2.0

See Also: GZIP DONT_BREAK_LINES

encodeFileToFile

public static boolean encodeFileToFile(String infile, String outfile)
Reads infile and encodes it to outfile.

Parameters: infile Input file outfile Output file

Returns: true if the operation is successful

Since: 2.2

encodeFromFile

public static String encodeFromFile(String filename)
Convenience method for reading a binary file and base64-encoding it.

Parameters: filename Filename for reading binary data

Returns: base64-encoded string or null if unsuccessful

Since: 2.1

encodeObject

public static String encodeObject(Serializable serializableObject)
Serializes an object and returns the Base64-encoded version of that serialized object. If the object cannot be serialized or there is another error, the method will return null. The object is not GZip-compressed before being encoded.

Parameters: serializableObject The object to encode

Returns: The Base64-encoded object

Since: 1.4

encodeObject

public static String encodeObject(Serializable serializableObject, int options)
Serializes an object and returns the Base64-encoded version of that serialized object. If the object cannot be serialized or there is another error, the method will return null.

Valid options:

   GZIP: gzip-compresses object before encoding it.
   DONT_BREAK_LINES: don't break lines at 76 characters
     Note: Technically, this makes your encoding non-compliant.
 

Example: encodeObject( myObj, Base64.GZIP ) or

Example: encodeObject( myObj, Base64.GZIP | Base64.DONT_BREAK_LINES )

Parameters: serializableObject The object to encode options Specified options

Returns: The Base64-encoded object

Since: 2.0

See Also: GZIP DONT_BREAK_LINES

encodeToFile

public static boolean encodeToFile(byte[] dataToEncode, String filename)
Convenience method for encoding data to a file.

Parameters: dataToEncode byte array of data to encode in base64 form filename Filename for saving encoded data

Returns: true if successful, false otherwise

Since: 2.1

main

public static final void main(String[] args)
Encodes or decodes two files from the command line; feel free to delete this method (in fact you probably should) if you're embedding this code into a larger program.