Class Base64

java.lang.Object
com.pnfsoftware.jeb.util.encoding.Base64

public class Base64 extends Object
Encodes and decodes to and from Base64 notation.

Example:

 String encoded = Base64.encode(myByteArray);
 byte[] myByteArray = Base64.decode(encoded);
 

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(byte[], int) the options parameter can be used to indicate such things as first gzipping the bytes before encoding them, not inserting linefeeds, and encoding using the URL-safe and Ordered dialects.

Note, according to RFC3548, Section 2.1, implementations should not add line feeds unless explicitly told to do so. I've got Base64 set to this behavior now, although earlier versions broke lines by default.

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.DO_BREAK_LINES);
 

to compress the data before encoding it and then making the output have newline characters.

Version:
2.3.7
  • Nested Class Summary

    Nested Classes
    Modifier and Type
    Class
    Description
    static class 
    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 
    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
    Description
    static final int
    Specify decoding in first bit.
    static final int
    Do break lines when encoding.
    static final int
    Specify that gzipped data should not be automatically gunzipped.
    static final int
    Specify encoding in first bit.
    static final int
    Specify that data should be gzip-compressed in second bit.
    static final int
    No options specified.
    static final int
    Encode using the special "ordered" dialect of Base64 described here: http://www.faqs.org/qa/rfcc-1940.html.
    static final int
    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

    Modifier and Type
    Method
    Description
    static byte[]
    decode(byte[] source)
    Low-level access to decoding ASCII characters in the form of a byte array.
    static byte[]
    decode(byte[] source, int off, int len, int options)
    Low-level access to decoding ASCII characters in the form of a byte array.
    static byte[]
    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 void
    decodeFileToFile(String infile, String outfile)
    Reads infile and decodes it to outfile.
    static byte[]
    Convenience method for reading a base64-encoded file and decoding it.
    static void
    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.
    static Object
    decodeToObject(String encodedObject, int options, ClassLoader loader)
    Attempts to decode Base64 data and deserialize a Java Object within.
    static void
    encode(ByteBuffer raw, ByteBuffer encoded)
    Performs Base64 encoding on the raw ByteBuffer, writing it to the encoded ByteBuffer.
    static void
    encode(ByteBuffer raw, CharBuffer encoded)
    Performs Base64 encoding on the raw ByteBuffer, writing it to the encoded CharBuffer.
    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 byte[]
    encodeBytesToBytes(byte[] source)
    Similar to encodeBytes(byte[]) but returns a byte array instead of instantiating a String.
    static byte[]
    encodeBytesToBytes(byte[] source, int off, int len, int options)
    Similar to encodeBytes(byte[], int, int, int) but returns a byte array instead of instantiating a String.
    static void
    encodeFileToFile(String infile, String outfile)
    Reads infile and encodes it to outfile.
    static String
    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 void
    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 Details

    • NO_OPTIONS

      public static final int NO_OPTIONS
      No options specified. Value is zero.
      See Also:
    • ENCODE

      public static final int ENCODE
      Specify encoding in first bit. Value is one.
      See Also:
    • DECODE

      public static final int DECODE
      Specify decoding in first bit. Value is zero.
      See Also:
    • GZIP

      public static final int GZIP
      Specify that data should be gzip-compressed in second bit. Value is two.
      See Also:
    • DONT_GUNZIP

      public static final int DONT_GUNZIP
      Specify that gzipped data should not be automatically gunzipped.
      See Also:
    • DO_BREAK_LINES

      public static final int DO_BREAK_LINES
      Do break lines when encoding. Value is 8.
      See Also:
    • 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.
      See Also:
    • ORDERED

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

    • encode

      public static void encode(ByteBuffer raw, ByteBuffer encoded)
      Performs Base64 encoding on the raw ByteBuffer, writing it to the encoded ByteBuffer. This is an experimental feature. Currently it does not pass along any options (such as DO_BREAK_LINES or GZIP.
      Parameters:
      raw - input buffer
      encoded - output buffer
      Since:
      2.3
    • encode

      public static void encode(ByteBuffer raw, CharBuffer encoded)
      Performs Base64 encoding on the raw ByteBuffer, writing it to the encoded CharBuffer. This is an experimental feature. Currently it does not pass along any options (such as DO_BREAK_LINES or GZIP.
      Parameters:
      raw - input buffer
      encoded - output buffer
      Since:
      2.3
    • encodeObject

      public static String encodeObject(Serializable serializableObject) throws IOException
      Serializes an object and returns the Base64-encoded version of that serialized object.

      As of v 2.3, if the object cannot be serialized or there is another error, the method will throw an java.io.IOException. This is new to v2.3! In earlier versions, it just returned a null value, but in retrospect that's a pretty poor way to handle it.

      The object is not GZip-compressed before being encoded.
      Parameters:
      serializableObject - The object to encode
      Returns:
      The Base64-encoded object
      Throws:
      IOException - if there is an error
      NullPointerException - if serializedObject is null
      Since:
      1.4
    • encodeObject

      public static String encodeObject(Serializable serializableObject, int options) throws IOException
      Serializes an object and returns the Base64-encoded version of that serialized object.

      As of v 2.3, if the object cannot be serialized or there is another error, the method will throw an java.io.IOException. This is new to v2.3! In earlier versions, it just returned a null value, but in retrospect that's a pretty poor way to handle it.

      The object is not GZip-compressed before being encoded.

      Example options:

         GZIP: gzip-compresses object before encoding it.
         DO_BREAK_LINES: break lines at 76 characters
       

      Example: encodeObject( myObj, Base64.GZIP ) or

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

      Parameters:
      serializableObject - The object to encode
      options - Specified options
      Returns:
      The Base64-encoded object
      Throws:
      IOException - if there is an error
      Since:
      2.0
      See Also:
    • 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
      Returns:
      The data in Base64-encoded form
      Throws:
      NullPointerException - if source array is null
      Since:
      1.4
    • encodeBytes

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

      Example options:

         GZIP: gzip-compresses object before encoding it.
         DO_BREAK_LINES: 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.DO_BREAK_LINES )

      As of v 2.3, if there is an error with the GZIP stream, the method will throw an java.io.IOException. This is new to v2.3! In earlier versions, it just returned a null value, but in retrospect that's a pretty poor way to handle it.

      Parameters:
      source - The data to convert
      options - Specified options
      Returns:
      The Base64-encoded data as a String
      Throws:
      IOException - if there is an error
      NullPointerException - if source array is null
      Since:
      2.0
      See Also:
    • encodeBytes

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

      As of v 2.3, if there is an error, the method will throw an java.io.IOException. This is new to v2.3! In earlier versions, it just returned a null value, but in retrospect that's a pretty poor way to handle it.

      Parameters:
      source - The data to convert
      off - Offset in array where conversion should begin
      len - Length of data to convert
      Returns:
      The Base64-encoded data as a String
      Throws:
      NullPointerException - if source array is null
      IllegalArgumentException - if source array, offset, or length are invalid
      Since:
      1.4
    • encodeBytes

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

      Example options:

         GZIP: gzip-compresses object before encoding it.
         DO_BREAK_LINES: 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.DO_BREAK_LINES )

      As of v 2.3, if there is an error with the GZIP stream, the method will throw an java.io.IOException. This is new to v2.3! In earlier versions, it just returned a null value, but in retrospect that's a pretty poor way to handle it.

      Parameters:
      source - The data to convert
      off - Offset in array where conversion should begin
      len - Length of data to convert
      options - Specified options
      Returns:
      The Base64-encoded data as a String
      Throws:
      IOException - if there is an error
      NullPointerException - if source array is null
      IllegalArgumentException - if source array, offset, or length are invalid
      Since:
      2.0
      See Also:
    • encodeBytesToBytes

      public static byte[] encodeBytesToBytes(byte[] source)
      Similar to encodeBytes(byte[]) but returns a byte array instead of instantiating a String. This is more efficient if you're working with I/O streams and have large data sets to encode.
      Parameters:
      source - The data to convert
      Returns:
      The Base64-encoded data as a byte[] (of ASCII characters)
      Throws:
      NullPointerException - if source array is null
      Since:
      2.3.1
    • encodeBytesToBytes

      public static byte[] encodeBytesToBytes(byte[] source, int off, int len, int options) throws IOException
      Similar to encodeBytes(byte[], int, int, int) but returns a byte array instead of instantiating a String. This is more efficient if you're working with I/O streams and have large data sets to encode.
      Parameters:
      source - The data to convert
      off - Offset in array where conversion should begin
      len - Length of data to convert
      options - Specified options
      Returns:
      The Base64-encoded data as a String
      Throws:
      IOException - if there is an error
      NullPointerException - if source array is null
      IllegalArgumentException - if source array, offset, or length are invalid
      Since:
      2.3.1
      See Also:
    • decode

      public static byte[] decode(byte[] source) throws IOException
      Low-level access to decoding ASCII characters in the form of a byte array. Ignores GUNZIP option, if it's set. This is not generally a recommended method, although it is used internally as part of the decoding process. Special case: if len = 0, an empty array is returned. Still, if you need more speed and reduced memory footprint (and aren't gzipping), consider this method.
      Parameters:
      source - The Base64 encoded data
      Returns:
      decoded data
      Throws:
      IOException
      Since:
      2.3.1
    • decode

      public static byte[] decode(byte[] source, int off, int len, int options) throws IOException
      Low-level access to decoding ASCII characters in the form of a byte array. Ignores GUNZIP option, if it's set. This is not generally a recommended method, although it is used internally as part of the decoding process. Special case: if len = 0, an empty array is returned. Still, if you need more speed and reduced memory footprint (and aren't gzipping), consider this method.
      Parameters:
      source - The Base64 encoded data
      off - The offset of where to begin decoding
      len - The length of characters to decode
      options - Can specify options such as alphabet type to use
      Returns:
      decoded data
      Throws:
      IOException - If bogus characters exist in source data
      Since:
      1.3
    • decode

      public static byte[] decode(String s) throws IOException
      Decodes data from Base64 notation, automatically detecting gzip-compressed data and decompressing it.
      Parameters:
      s - the string to decode
      Returns:
      the decoded data
      Throws:
      IOException - If there is a problem
      Since:
      1.4
    • decode

      public static byte[] decode(String s, int options) throws IOException
      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
      Throws:
      IOException - if there is an error
      NullPointerException - if s is null
      Since:
      1.4
    • decodeToObject

      public static Object decodeToObject(String encodedObject) throws IOException, ClassNotFoundException
      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
      Throws:
      NullPointerException - if encodedObject is null
      IOException - if there is a general error
      ClassNotFoundException - if the decoded object is of a class that cannot be found by the JVM
      Since:
      1.5
    • decodeToObject

      public static Object decodeToObject(String encodedObject, int options, ClassLoader loader) throws IOException, ClassNotFoundException
      Attempts to decode Base64 data and deserialize a Java Object within. Returns null if there was an error. If loader is not null, it will be the class loader used when deserializing.
      Parameters:
      encodedObject - The Base64 data to decode
      options - Various parameters related to decoding
      loader - Optional class loader to use in deserializing classes.
      Returns:
      The decoded and deserialized object
      Throws:
      NullPointerException - if encodedObject is null
      IOException - if there is a general error
      ClassNotFoundException - if the decoded object is of a class that cannot be found by the JVM
      Since:
      2.3.4
    • encodeToFile

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

      As of v 2.3, if there is a error, the method will throw an java.io.IOException. This is new to v2.3! In earlier versions, it just returned false, but in retrospect that's a pretty poor way to handle it.

      Parameters:
      dataToEncode - byte array of data to encode in base64 form
      filename - Filename for saving encoded data
      Throws:
      IOException - if there is an error
      NullPointerException - if dataToEncode is null
      Since:
      2.1
    • decodeToFile

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

      As of v 2.3, if there is a error, the method will throw an java.io.IOException. This is new to v2.3! In earlier versions, it just returned false, but in retrospect that's a pretty poor way to handle it.

      Parameters:
      dataToDecode - Base64-encoded data as a string
      filename - Filename for saving decoded data
      Throws:
      IOException - if there is an error
      Since:
      2.1
    • decodeFromFile

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

      As of v 2.3, if there is a error, the method will throw an java.io.IOException. This is new to v2.3! In earlier versions, it just returned false, but in retrospect that's a pretty poor way to handle it.

      Parameters:
      filename - Filename for reading encoded data
      Returns:
      decoded byte array
      Throws:
      IOException - if there is an error
      Since:
      2.1
    • encodeFromFile

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

      As of v 2.3, if there is a error, the method will throw an java.io.IOException. This is new to v2.3! In earlier versions, it just returned false, but in retrospect that's a pretty poor way to handle it.

      Parameters:
      filename - Filename for reading binary data
      Returns:
      base64-encoded string
      Throws:
      IOException - if there is an error
      Since:
      2.1
    • encodeFileToFile

      public static void encodeFileToFile(String infile, String outfile) throws IOException
      Reads infile and encodes it to outfile.
      Parameters:
      infile - Input file
      outfile - Output file
      Throws:
      IOException - if there is an error
      Since:
      2.2
    • decodeFileToFile

      public static void decodeFileToFile(String infile, String outfile) throws IOException
      Reads infile and decodes it to outfile.
      Parameters:
      infile - Input file
      outfile - Output file
      Throws:
      IOException - if there is an error
      Since:
      2.2