Base64 (XMLTooling-J 1.4.6 API)

java.lang.Object
- org.opensaml.xml.util.Base64

```
public class Base64
extends Object
```
Encodes and decodes to and from Base64 notation.
Change Log:
- v2.1 - Cleaned up javadoc comments and unused variables and methods. Added some convenience methods for reading and writing to and from files.
- v2.0.2 - Now specifies UTF-8 encoding in places where the code fails on systems with other encodings (like EBCDIC).
- v2.0.1 - Fixed an error when decoding a single byte, that is, when the encoded data was a single byte.
- v2.0 - I got rid of methods that used booleans to set options. Now everything is more consolidated and cleaner. The code now detects when data that's being decoded is gzip-compressed and will decompress it automatically. Generally things are cleaner. You'll probably have to change some method calls that you were making to support the new options format (ints that you "OR" together).
- v1.5.1 - Fixed bug when decompressing and decoding to a byte[] using decode( String s, boolean gzipCompressed ). Added the ability to "suspend" encoding in the Output Stream so you can turn on and off the encoding if you need to embed base64 data in an otherwise "normal" stream (like an XML file).
- v1.5 - Output stream pases on flush() command but doesn't do anything itself. This helps when using GZIP streams. Added the ability to GZip-compress objects before encoding them.
- v1.4 - Added helper methods to read/write files.
- v1.3.6 - Fixed OutputStream.flush() so that 'position' is reset.
- v1.3.5 - Added flag to turn on and off line breaks. Fixed bug in input stream where last buffer being read, if not completely full, was not returned.
- v1.3.4 - Fixed when "improperly padded stream" error was thrown at the wrong time.
- v1.3.3 - Fixed I/O streams which were totally messed up.
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:

2.1

Nested Class Summary

Nested Classes
Modifier and Type	Class and Description
`static class`	`Base64.InputStream` A `Base64.InputStream` will read data from another `java.io.InputStream`, given in the constructor, and encode/decode to/from Base64 notation on the fly.
`static class`	`Base64.OutputStream` A `Base64.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

Fields
Modifier and Type	Field and Description
`private static byte[]`	`_NATIVE_ALPHABET`
`private static byte[]`	`ALPHABET` The 64 valid Base64 values.
`private static byte[]`	`DECODABET` Translates a Base64 value to either its 6-bit reconstruction value or a negative number indicating some other meaning.
`static int`	`DECODE` Specify decoding.
`static int`	`DONT_BREAK_LINES` Don't break lines when encoding (violates strict Base64 specification)
`static int`	`ENCODE` Specify encoding.
`private static byte`	`EQUALS_SIGN` The equals sign (=) as a byte.
`private static byte`	`EQUALS_SIGN_ENC`
`static int`	`GZIP` Specify that data should be gzip-compressed.
`private static int`	`MAX_LINE_LENGTH` Maximum line length (76) of Base64 output.
`private static byte`	`NEW_LINE` The new line character (\n) as a byte.
`static int`	`NO_OPTIONS` No options specified.
`private static String`	`PREFERRED_ENCODING` Preferred encoding.
`private static byte`	`WHITE_SPACE_ENC`

Constructor Summary

Constructors
Modifier Constructor and Description

private Base64()
Defeats instantiation.

Constructors
Modifier	Constructor and Description
`private`	`Base64()` Defeats instantiation.

Method Summary

Methods
Modifier and Type	Method and Description
`static byte[]`	`decode(byte[] source, int off, int len)` 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.
`private static int`	`decode4to3(byte[] source, int srcOffset, byte[] destination, int destOffset)` Decodes four bytes from array `source` and writes the resulting bytes (up to three of them) to `destination`.
`static byte[]`	`decodeFromFile(String filename)` Convenience method for reading a base64-encoded file and decoding it.
`static boolean`	`decodeToFile(String dataToDecode, String filename)` Convenience method for decoding data to a file.
`static Object`	`decodeToObject(String encodedObject)` Attempts to decode Base64 data and deserialize a Java Object within.
`private static byte[]`	`encode3to4(byte[] b4, byte[] threeBytes, int numSigBytes)` Encodes up to the first three bytes of array `threeBytes` and returns a four-byte array in Base64 notation.
`private static byte[]`	`encode3to4(byte[] source, int srcOffset, int numSigBytes, byte[] destination, int destOffset)` Encodes up to three bytes of the array `source` and writes the resulting four Base64 bytes to `destination`.
`static String`	`encodeBytes(byte[] source)` Encodes a byte array into Base64 notation.
`static String`	`encodeBytes(byte[] source, int options)` Encodes a byte array into Base64 notation.
`static String`	`encodeBytes(byte[] source, int off, int len)` Encodes a byte array into Base64 notation.
`static String`	`encodeBytes(byte[] source, int off, int len, int options)` Encodes a byte array into Base64 notation.
`static String`	`encodeFromFile(String filename)` Convenience method for reading a binary file and base64-encoding it.
`static String`	`encodeObject(Serializable serializableObject)` Serializes an object and returns the Base64-encoded version of that serialized object.
`static String`	`encodeObject(Serializable serializableObject, int options)` Serializes an object and returns the Base64-encoded version of that serialized object.
`static boolean`	`encodeToFile(byte[] dataToEncode, String filename)` Convenience method for encoding data to a file.

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Field Detail
 - NO_OPTIONS
```
public static final int NO_OPTIONS
```
 No options specified. Value is zero.
 
 See Also:
 Constant Field Values
 - ENCODE
```
public static final int ENCODE
```
 Specify encoding.
 
 See Also:
 Constant Field Values
 - DECODE
```
public static final int DECODE
```
 Specify decoding.
 
 See Also:
 Constant Field Values
 - GZIP
```
public static final int GZIP
```
 Specify that data should be gzip-compressed.
 
 See Also:
 Constant Field Values
 - DONT_BREAK_LINES
```
public static final int DONT_BREAK_LINES
```
 Don't break lines when encoding (violates strict Base64 specification)
 
 See Also:
 Constant Field Values
 - MAX_LINE_LENGTH
```
private static final int MAX_LINE_LENGTH
```
 Maximum line length (76) of Base64 output.
 
 See Also:
 Constant Field Values
 - EQUALS_SIGN
```
private static final byte EQUALS_SIGN
```
 The equals sign (=) as a byte.
 
 See Also:
 Constant Field Values
 - NEW_LINE
```
private static final byte NEW_LINE
```
 The new line character (\n) as a byte.
 
 See Also:
 Constant Field Values
 - PREFERRED_ENCODING
```
private static final String PREFERRED_ENCODING
```
 Preferred encoding.
 
 See Also:
 Constant Field Values
 - ALPHABET
```
private static final byte[] ALPHABET
```
 The 64 valid Base64 values.
 - _NATIVE_ALPHABET
```
private static final byte[] _NATIVE_ALPHABET
```
 - DECODABET
```
private static final byte[] DECODABET
```
 Translates a Base64 value to either its 6-bit reconstruction value or a negative number indicating some other meaning.
 - WHITE_SPACE_ENC
```
private static final byte WHITE_SPACE_ENC
```
 See Also:
 Constant Field Values
 - EQUALS_SIGN_ENC
```
private static final byte EQUALS_SIGN_ENC
```
 See Also:
 Constant Field Values
- Constructor Detail
 - Base64
```
private Base64()
```
 Defeats instantiation.
- Method Detail
 - encode3to4
```
private static byte[] encode3to4(byte[] b4,
 byte[] threeBytes,
 int numSigBytes)
```
 Encodes up to the first three bytes of array threeBytes and returns a four-byte array in Base64 notation. The actual number of significant bytes in your array is given by numSigBytes. The array threeBytes needs only be as big as numSigBytes. Code can reuse a byte array by passing a four-byte array as b4.
 
 Parameters:
 b4 - A reusable byte array to reduce array instantiation
 threeBytes - the array to convert
 numSigBytes - the number of significant bytes in your array
 
 Returns:
 four byte array in Base64 notation.
 Since:
 
 1.5.1
 - encode3to4
```
private static byte[] encode3to4(byte[] source,
 int srcOffset,
 int numSigBytes,
 byte[] destination,
 int destOffset)
```
 Encodes up to three bytes of the array source and writes the resulting four Base64 bytes to destination. The source and destination arrays can be manipulated anywhere along their length by specifying srcOffset and destOffset. This method does not check to make sure your arrays are large enough to accomodate srcOffset + 3 for the source array or destOffset + 4 for the destination array. The actual number of significant bytes in your array is given by numSigBytes.
 
 Parameters:
 source - the array to convert
 srcOffset - the index where conversion begins
 numSigBytes - the number of significant bytes in your array
 destination - the array to hold the conversion
 destOffset - the index where output will be put
 
 Returns:
 the destination array
 Since:
 
 1.3
 - 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
 - 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
 Since:
 
 2.0
 
 See Also:
 GZIP, DONT_BREAK_LINES
 - decode4to3
```
private static int decode4to3(byte[] source,
 int srcOffset,
 byte[] destination,
 int destOffset)
```
 Decodes four bytes from array source and writes the resulting bytes (up to three of them) to destination. The source and destination arrays can be manipulated anywhere along their length by specifying srcOffset and destOffset. This method does not check to make sure your arrays are large enough to accomodate srcOffset + 4 for the source array or destOffset + 3 for the destination array. This method returns the actual number of bytes that were converted from the Base64 encoding.
 
 Parameters:
 source - the array to convert
 srcOffset - the index where conversion begins
 destination - the array to hold the conversion
 destOffset - the index where output will be put
 
 Returns:
 the number of decoded bytes converted
 Since:
 
 1.3
 - decode
```
public static byte[] decode(byte[] source,
 int off,
 int len)
```
 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
 - 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
 - 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
 - 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
 - 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
 - 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

Class Base64

Nested Class Summary

Field Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

NO_OPTIONS

ENCODE

DECODE

GZIP

DONT_BREAK_LINES

MAX_LINE_LENGTH

EQUALS_SIGN

NEW_LINE

PREFERRED_ENCODING

ALPHABET

_NATIVE_ALPHABET

DECODABET

WHITE_SPACE_ENC

EQUALS_SIGN_ENC

Constructor Detail

Base64

Method Detail

encode3to4

encode3to4

encodeObject

encodeObject

encodeBytes

encodeBytes

encodeBytes

encodeBytes

decode4to3

decode

decode

decodeToObject

encodeToFile

decodeToFile

decodeFromFile

encodeFromFile