java.lang.Object
- org.apache.tomcat.util.codec.binary.BaseNCodec
- - org.apache.tomcat.util.codec.binary.Base64

```
public class Base64
extends BaseNCodec
```
Provides Base64 encoding and decoding as defined by RFC 2045.
This class implements section 6.8. Base64 Content-Transfer-Encoding from RFC 2045 Multipurpose Internet Mail Extensions (MIME) Part One: Format of Internet Message Bodies by Freed and Borenstein.

The class can be parameterized in the following manner with various constructors:
- URL-safe mode: Default off.
- Line length: Default 76. Line length that aren't multiples of 4 will still essentially end up being multiples of 4 in the encoded data.
- Line separator: Default is CRLF ("\r\n")
The URL-safe parameter is only applied to encode operations. Decoding seamlessly handles both modes.

Since this class operates directly on byte streams, and not character streams, it is hard-coded to only encode/decode character encodings which are compatible with the lower 127 ASCII chart (ISO-8859-1, Windows-1252, UTF-8, etc).

This class is thread-safe.
Since:

1.0

See Also:

RFC 2045

Field Summary
- Fields inherited from class org.apache.tomcat.util.codec.binary.BaseNCodec
  lineLength, MASK_8BITS, MIME_CHUNK_SIZE, pad, PAD_DEFAULT, PEM_CHUNK_SIZE, sm

Constructor Summary

Constructors
Constructor	Description
`Base64()`	Creates a Base64 codec used for decoding (all modes) and encoding in URL-unsafe mode.
`Base64(boolean urlSafe)`	Creates a Base64 codec used for decoding (all modes) and encoding in the given URL-safe mode.
`Base64(int lineLength)`	Creates a Base64 codec used for decoding (all modes) and encoding in URL-unsafe mode.
`Base64(int lineLength, byte[] lineSeparator)`	Creates a Base64 codec used for decoding (all modes) and encoding in URL-unsafe mode.
`Base64(int lineLength, byte[] lineSeparator, boolean urlSafe)`	Creates a Base64 codec used for decoding (all modes) and encoding in URL-unsafe mode.

Method Summary

All Methods Static Methods Instance Methods Concrete Methods
Modifier and Type	Method	Description
`static byte[]`	`decodeBase64(byte[] base64Data)`	Decodes Base64 data into octets.
`static byte[]`	`decodeBase64(byte[] base64Data, int off, int len)`
`static byte[]`	`decodeBase64(java.lang.String base64String)`	Decodes a Base64 String into octets.
`static byte[]`	`decodeBase64URLSafe(java.lang.String base64String)`
`static java.math.BigInteger`	`decodeInteger(byte[] pArray)`	Decodes a byte64-encoded integer according to crypto standards such as W3C's XML-Signature.
`static byte[]`	`encodeBase64(byte[] binaryData)`	Encodes binary data using the base64 algorithm but does not chunk the output.
`static byte[]`	`encodeBase64(byte[] binaryData, boolean isChunked)`	Encodes binary data using the base64 algorithm, optionally chunking the output into 76 character blocks.
`static byte[]`	`encodeBase64(byte[] binaryData, boolean isChunked, boolean urlSafe)`	Encodes binary data using the base64 algorithm, optionally chunking the output into 76 character blocks.
`static byte[]`	`encodeBase64(byte[] binaryData, boolean isChunked, boolean urlSafe, int maxResultSize)`	Encodes binary data using the base64 algorithm, optionally chunking the output into 76 character blocks.
`static byte[]`	`encodeBase64Chunked(byte[] binaryData)`	Encodes binary data using the base64 algorithm and chunks the encoded output into 76 character blocks
`static java.lang.String`	`encodeBase64String(byte[] binaryData)`	Encodes binary data using the base64 algorithm but does not chunk the output.
`static byte[]`	`encodeBase64URLSafe(byte[] binaryData)`	Encodes binary data using a URL-safe variation of the base64 algorithm but does not chunk the output.
`static java.lang.String`	`encodeBase64URLSafeString(byte[] binaryData)`	Encodes binary data using a URL-safe variation of the base64 algorithm but does not chunk the output.
`static byte[]`	`encodeInteger(java.math.BigInteger bigInteger)`	Encodes to a byte64-encoded integer according to crypto standards such as W3C's XML-Signature.
`static boolean`	`isBase64(byte octet)`	Returns whether or not the `octet` is in the base 64 alphabet.
`static boolean`	`isBase64(byte[] arrayOctet)`	Tests a given byte array to see if it contains only valid characters within the Base64 alphabet.
`static boolean`	`isBase64(java.lang.String base64)`	Tests a given String to see if it contains only valid characters within the Base64 alphabet.
`protected boolean`	`isInAlphabet(byte octet)`	Returns whether or not the `octet` is in the Base64 alphabet.
`boolean`	`isUrlSafe()`	Returns our current encode mode.

Methods inherited from class org.apache.tomcat.util.codec.binary.BaseNCodec
containsAlphabetOrPad, decode, decode, decode, encode, encode, encodeAsString, encodeToString, ensureBufferSize, getChunkSeparator, getDefaultBufferSize, getEncodedLength, isInAlphabet, isInAlphabet, isWhiteSpace

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

- Constructor Detail
  - Base64
```
public Base64()
```
    Creates a Base64 codec used for decoding (all modes) and encoding in URL-unsafe mode.
    When encoding the line length is 0 (no chunking), and the encoding table is STANDARD_ENCODE_TABLE.
    
    When decoding all variants are supported.
  - Base64
```
public Base64(boolean urlSafe)
```
    Creates a Base64 codec used for decoding (all modes) and encoding in the given URL-safe mode.
    When encoding the line length is 76, the line separator is CRLF, and the encoding table is STANDARD_ENCODE_TABLE.
    
    When decoding all variants are supported.
    
    Parameters:
    
    urlSafe - if true, URL-safe encoding is used. In most cases this should be set to false.
    
    Since:
    
    1.4
  - Base64
```
public Base64(int lineLength)
```
    Creates a Base64 codec used for decoding (all modes) and encoding in URL-unsafe mode.
    When encoding the line length is given in the constructor, the line separator is CRLF, and the encoding table is STANDARD_ENCODE_TABLE.
    
    Line lengths that aren't multiples of 4 will still essentially end up being multiples of 4 in the encoded data.
    
    When decoding all variants are supported.
    
    Parameters:
    
    lineLength - Each line of encoded data will be at most of the given length (rounded down to nearest multiple of 4). If lineLength <= 0, then the output will not be divided into lines (chunks). Ignored when decoding.
    
    Since:
    
    1.4
  - Base64
```
public Base64(int lineLength,
              byte[] lineSeparator)
```
    Creates a Base64 codec used for decoding (all modes) and encoding in URL-unsafe mode.
    When encoding the line length and line separator are given in the constructor, and the encoding table is STANDARD_ENCODE_TABLE.
    
    Line lengths that aren't multiples of 4 will still essentially end up being multiples of 4 in the encoded data.
    
    When decoding all variants are supported.
    
    Parameters:
    
    lineLength - Each line of encoded data will be at most of the given length (rounded down to nearest multiple of 4). If lineLength <= 0, then the output will not be divided into lines (chunks). Ignored when decoding.
    
    lineSeparator - Each line of encoded data will end with this sequence of bytes.
    
    Throws:
    
    java.lang.IllegalArgumentException - Thrown when the provided lineSeparator included some base64 characters.
    
    Since:
    
    1.4
  - Base64
```
public Base64(int lineLength,
              byte[] lineSeparator,
              boolean urlSafe)
```
    Creates a Base64 codec used for decoding (all modes) and encoding in URL-unsafe mode.
    When encoding the line length and line separator are given in the constructor, and the encoding table is STANDARD_ENCODE_TABLE.
    
    Line lengths that aren't multiples of 4 will still essentially end up being multiples of 4 in the encoded data.
    
    When decoding all variants are supported.
    
    Parameters:
    
    lineLength - Each line of encoded data will be at most of the given length (rounded down to nearest multiple of 4). If lineLength <= 0, then the output will not be divided into lines (chunks). Ignored when decoding.
    
    lineSeparator - Each line of encoded data will end with this sequence of bytes.
    
    urlSafe - Instead of emitting '+' and '/' we emit '-' and '_' respectively. urlSafe is only applied to encode operations. Decoding seamlessly handles both modes. Note: no padding is added when using the URL-safe alphabet.
    
    Throws:
    
    java.lang.IllegalArgumentException - Thrown when the lineSeparator contains Base64 characters.
    
    Since:
    
    1.4
- Method Detail
  - decodeBase64
```
public static byte[] decodeBase64(byte[] base64Data)
```
    Decodes Base64 data into octets.
    Note: this method seamlessly handles data encoded in URL-safe or normal mode.
    
    Parameters:
    
    base64Data - Byte array containing Base64 data
    
    Returns:
    
    Array containing decoded data.
  - decodeBase64
```
public static byte[] decodeBase64(byte[] base64Data,
                                  int off,
                                  int len)
```
  - decodeBase64
```
public static byte[] decodeBase64(java.lang.String base64String)
```
    Decodes a Base64 String into octets.
    Note: this method seamlessly handles data encoded in URL-safe or normal mode.
    
    Parameters:
    
    base64String - String containing Base64 data
    
    Returns:
    
    Array containing decoded data.
    
    Since:
    
    1.4
  - decodeBase64URLSafe
```
public static byte[] decodeBase64URLSafe(java.lang.String base64String)
```
  - decodeInteger
```
public static java.math.BigInteger decodeInteger(byte[] pArray)
```
    Decodes a byte64-encoded integer according to crypto standards such as W3C's XML-Signature.
    
    Parameters:
    
    pArray - a byte array containing base64 character data
    
    Returns:
    
    A BigInteger
    
    Since:
    
    1.4
  - encodeBase64
```
public static byte[] encodeBase64(byte[] binaryData)
```
    Encodes binary data using the base64 algorithm but does not chunk the output.
    
    Parameters:
    
    binaryData - binary data to encode
    
    Returns:
    
    byte[] containing Base64 characters in their UTF-8 representation.
  - encodeBase64
```
public static byte[] encodeBase64(byte[] binaryData,
                                  boolean isChunked)
```
    Encodes binary data using the base64 algorithm, optionally chunking the output into 76 character blocks.
    
    Parameters:
    
    binaryData - Array containing binary data to encode.
    
    isChunked - if true this encoder will chunk the base64 output into 76 character blocks
    
    Returns:
    
    Base64-encoded data.
    
    Throws:
    
    java.lang.IllegalArgumentException - Thrown when the input array needs an output array bigger than Integer.MAX_VALUE
  - encodeBase64
```
public static byte[] encodeBase64(byte[] binaryData,
                                  boolean isChunked,
                                  boolean urlSafe)
```
    Encodes binary data using the base64 algorithm, optionally chunking the output into 76 character blocks.
    
    Parameters:
    
    binaryData - Array containing binary data to encode.
    
    isChunked - if true this encoder will chunk the base64 output into 76 character blocks
    
    urlSafe - if true this encoder will emit - and _ instead of the usual + and / characters. Note: no padding is added when encoding using the URL-safe alphabet.
    
    Returns:
    
    Base64-encoded data.
    
    Throws:
    
    java.lang.IllegalArgumentException - Thrown when the input array needs an output array bigger than Integer.MAX_VALUE
    
    Since:
    
    1.4
  - encodeBase64
```
public static byte[] encodeBase64(byte[] binaryData,
                                  boolean isChunked,
                                  boolean urlSafe,
                                  int maxResultSize)
```
    Encodes binary data using the base64 algorithm, optionally chunking the output into 76 character blocks.
    
    Parameters:
    
    binaryData - Array containing binary data to encode.
    
    isChunked - if true this encoder will chunk the base64 output into 76 character blocks
    
    urlSafe - if true this encoder will emit - and _ instead of the usual + and / characters. Note: no padding is added when encoding using the URL-safe alphabet.
    
    maxResultSize - The maximum result size to accept.
    
    Returns:
    
    Base64-encoded data.
    
    Throws:
    
    java.lang.IllegalArgumentException - Thrown when the input array needs an output array bigger than maxResultSize
    
    Since:
    
    1.4
  - encodeBase64Chunked
```
public static byte[] encodeBase64Chunked(byte[] binaryData)
```
    Encodes binary data using the base64 algorithm and chunks the encoded output into 76 character blocks
    
    Parameters:
    
    binaryData - binary data to encode
    
    Returns:
    
    Base64 characters chunked in 76 character blocks
  - encodeBase64String
```
public static java.lang.String encodeBase64String(byte[] binaryData)
```
    Encodes binary data using the base64 algorithm but does not chunk the output. NOTE: We changed the behavior of this method from multi-line chunking (commons-codec-1.4) to single-line non-chunking (commons-codec-1.5).
    
    Parameters:
    
    binaryData - binary data to encode
    
    Returns:
    
    String containing Base64 characters.
    
    Since:
    
    1.4 (NOTE: 1.4 chunked the output, whereas 1.5 does not).
  - encodeBase64URLSafe
```
public static byte[] encodeBase64URLSafe(byte[] binaryData)
```
    Encodes binary data using a URL-safe variation of the base64 algorithm but does not chunk the output. The url-safe variation emits - and _ instead of + and / characters. Note: no padding is added.
    
    Parameters:
    
    binaryData - binary data to encode
    
    Returns:
    
    byte[] containing Base64 characters in their UTF-8 representation.
    
    Since:
    
    1.4
  - encodeBase64URLSafeString
```
public static java.lang.String encodeBase64URLSafeString(byte[] binaryData)
```
    Encodes binary data using a URL-safe variation of the base64 algorithm but does not chunk the output. The url-safe variation emits - and _ instead of + and / characters. Note: no padding is added.
    
    Parameters:
    
    binaryData - binary data to encode
    
    Returns:
    
    String containing Base64 characters
    
    Since:
    
    1.4
  - encodeInteger
```
public static byte[] encodeInteger(java.math.BigInteger bigInteger)
```
    Encodes to a byte64-encoded integer according to crypto standards such as W3C's XML-Signature.
    
    Parameters:
    
    bigInteger - a BigInteger
    
    Returns:
    
    A byte array containing base64 character data
    
    Throws:
    
    java.lang.NullPointerException - if null is passed in
    
    Since:
    
    1.4
  - isBase64
```
public static boolean isBase64(byte octet)
```
    Returns whether or not the octet is in the base 64 alphabet.
    
    Parameters:
    
    octet - The value to test
    
    Returns:
    
    true if the value is defined in the the base 64 alphabet, false otherwise.
    
    Since:
    
    1.4
  - isBase64
```
public static boolean isBase64(byte[] arrayOctet)
```
    Tests a given byte array to see if it contains only valid characters within the Base64 alphabet. Currently the method treats whitespace as valid.
    
    Parameters:
    
    arrayOctet - byte array to test
    
    Returns:
    
    true if all bytes are valid characters in the Base64 alphabet or if the byte array is empty; false, otherwise
    
    Since:
    
    1.5
  - isBase64
```
public static boolean isBase64(java.lang.String base64)
```
    Tests a given String to see if it contains only valid characters within the Base64 alphabet. Currently the method treats whitespace as valid.
    
    Parameters:
    
    base64 - String to test
    
    Returns:
    
    true if all characters in the String are valid characters in the Base64 alphabet or if the String is empty; false, otherwise
    
    Since:
    
    1.5
  - isInAlphabet
```
protected boolean isInAlphabet(byte octet)
```
    Returns whether or not the octet is in the Base64 alphabet.
    
    Specified by:
    
    isInAlphabet in class BaseNCodec
    
    Parameters:
    
    octet - The value to test
    
    Returns:
    
    true if the value is defined in the the Base64 alphabet false otherwise.
  - isUrlSafe
```
public boolean isUrlSafe()
```
    Returns our current encode mode. True if we're URL-SAFE, false otherwise.
    
    Returns:
    
    true if we're in URL-SAFE mode, false otherwise.
    
    Since:
    
    1.4

Class Base64

Field Summary

Fields inherited from class org.apache.tomcat.util.codec.binary.BaseNCodec

Constructor Summary

Method Summary

Methods inherited from class org.apache.tomcat.util.codec.binary.BaseNCodec

Methods inherited from class java.lang.Object

Constructor Detail

Base64

Base64

Base64

Base64

Base64

Method Detail

decodeBase64

decodeBase64

decodeBase64

decodeBase64URLSafe

decodeInteger

encodeBase64

encodeBase64

encodeBase64

encodeBase64

encodeBase64Chunked

encodeBase64String

encodeBase64URLSafe

encodeBase64URLSafeString

encodeInteger

isBase64

isBase64

isBase64

isInAlphabet

isUrlSafe