Base64

java.lang.Object
- com.fr.ftp.util.Base64

```
public class Base64
extends java.lang.Object
```
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")
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).
从以下版本开始:

2.2

版本:

$Id: Base64.java 1697293 2015-08-24 01:01:00Z sebb $

另请参阅:
RFC 2045

构造器概要

构造器
构造器和说明
`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.

方法概要

方法
限定符和类型	方法和说明
`byte[]`	`decode(byte[] pArray)` Decodes a byte[] containing containing characters in the Base64 alphabet.
`byte[]`	`decode(java.lang.String pArray)` Decodes a String containing containing characters in the Base64 alphabet.
`static byte[]`	`decodeBase64(byte[] base64Data)` Decodes Base64 data into octets
`static byte[]`	`decodeBase64(java.lang.String base64String)` Decodes a Base64 String into octets
`static java.math.BigInteger`	`decodeInteger(byte[] pArray)` Decodes a byte64-encoded integer according to crypto standards such as W3C's XML-Signature
`byte[]`	`encode(byte[] pArray)` Encodes a byte[] containing binary data, into a byte[] containing characters in the Base64 alphabet.
`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 into 76 character blocks separated by CRLF.
`static java.lang.String`	`encodeBase64String(byte[] binaryData, boolean useChunking)` Encodes binary data using the base64 algorithm.
`static java.lang.String`	`encodeBase64StringUnChunked(byte[] binaryData)` Encodes binary data using the base64 algorithm, without using chunking.
`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 bigInt)` Encodes to a byte64-encoded integer according to crypto standards such as W3C's XML-Signature
`java.lang.String`	`encodeToString(byte[] pArray)` Encodes a byte[] containing binary data, into a String containing characters in the Base64 alphabet.
`static boolean`	`isArrayByteBase64(byte[] arrayOctet)` Tests a given byte array to see if it contains only valid characters within the Base64 alphabet.
`static boolean`	`isBase64(byte octet)` Returns whether or not the `octet` is in the base 64 alphabet.
`boolean`	`isUrlSafe()` Returns our current encode mode.

从类继承的方法 java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- 构造器详细资料
  - Base64
```
public Base64()
```
    Creates a Base64 codec used for decoding (all modes) and encoding in URL-unsafe 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.
  - 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.
    
    参数:
    urlSafe - if true, URL-safe encoding is used. In most cases this should be set to false.
    从以下版本开始:
    
    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.
    
    参数:
    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.
    从以下版本开始:
    
    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.
    
    参数:
    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.
    
    抛出:
    
    java.lang.IllegalArgumentException - Thrown when the provided lineSeparator included some base64 characters.
    从以下版本开始:
    
    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.
    
    参数:
    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.
    
    抛出:
    
    java.lang.IllegalArgumentException - The provided lineSeparator included some base64 characters. That's not going to work!
    从以下版本开始:
    
    1.4
- 方法详细资料
  - isUrlSafe
```
public boolean isUrlSafe()
```
    Returns our current encode mode. True if we're URL-SAFE, false otherwise.
    
    返回:
    true if we're in URL-SAFE mode, false otherwise.
    从以下版本开始:
    
    1.4
  - isBase64
```
public static boolean isBase64(byte octet)
```
    Returns whether or not the octet is in the base 64 alphabet.
    
    参数:
    octet - The value to test
    
    返回:
    true if the value is defined in the the base 64 alphabet, false otherwise.
    从以下版本开始:
    
    1.4
  - isArrayByteBase64
```
public static boolean isArrayByteBase64(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.
    
    参数:
    arrayOctet - byte array to test
    
    返回:
    true if all bytes are valid characters in the Base64 alphabet or if the byte array is empty; false, otherwise
  - encodeBase64
```
public static byte[] encodeBase64(byte[] binaryData)
```
    Encodes binary data using the base64 algorithm but does not chunk the output.
    
    参数:
    binaryData - binary data to encode
    
    返回:
    byte[] containing Base64 characters in their UTF-8 representation.
  - encodeBase64String
```
public static java.lang.String encodeBase64String(byte[] binaryData)
```
    Encodes binary data using the base64 algorithm into 76 character blocks separated by CRLF.
    For a non-chunking version, see encodeBase64StringUnChunked(byte[]).
    
    参数:
    binaryData - binary data to encode
    
    返回:
    String containing Base64 characters.
    从以下版本开始:
    
    1.4
  - encodeBase64StringUnChunked
```
public static java.lang.String encodeBase64StringUnChunked(byte[] binaryData)
```
    Encodes binary data using the base64 algorithm, without using chunking.
    For a chunking version, see encodeBase64String(byte[]).
    
    参数:
    binaryData - binary data to encode
    
    返回:
    String containing Base64 characters.
    从以下版本开始:
    
    3.2
  - encodeBase64String
```
public static java.lang.String encodeBase64String(byte[] binaryData,
                                  boolean useChunking)
```
    Encodes binary data using the base64 algorithm.
    
    参数:
    binaryData - binary data to encode
    useChunking - whether to split the output into chunks
    
    返回:
    String containing Base64 characters.
    从以下版本开始:
    
    3.2
  - 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.
    
    参数:
    binaryData - binary data to encode
    
    返回:
    byte[] containing Base64 characters in their UTF-8 representation.
    从以下版本开始:
    
    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.
    
    参数:
    binaryData - binary data to encode
    
    返回:
    String containing Base64 characters
    从以下版本开始:
    
    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
    
    参数:
    binaryData - binary data to encode
    
    返回:
    Base64 characters chunked in 76 character blocks
  - decode
```
public byte[] decode(java.lang.String pArray)
```
    Decodes a String containing containing characters in the Base64 alphabet.
    
    参数:
    pArray - A String containing Base64 character data
    
    返回:
    a byte array containing binary data
    从以下版本开始:
    
    1.4
  - decode
```
public byte[] decode(byte[] pArray)
```
    Decodes a byte[] containing containing characters in the Base64 alphabet.
    
    参数:
    pArray - A byte array containing Base64 character data
    
    返回:
    a byte array containing binary data
  - encodeBase64
```
public static byte[] encodeBase64(byte[] binaryData,
                  boolean isChunked)
```
    Encodes binary data using the base64 algorithm, optionally chunking the output into 76 character blocks.
    
    参数:
    binaryData - Array containing binary data to encode.
    isChunked - if true this encoder will chunk the base64 output into 76 character blocks
    
    返回:
    Base64-encoded data.
    
    抛出:
    
    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.
    
    参数:
    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.
    
    返回:
    Base64-encoded data.
    
    抛出:
    
    java.lang.IllegalArgumentException - Thrown when the input array needs an output array bigger than Integer.MAX_VALUE
    从以下版本开始:
    
    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.
    
    参数:
    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.
    maxResultSize - The maximum result size to accept.
    
    返回:
    Base64-encoded data.
    
    抛出:
    
    java.lang.IllegalArgumentException - Thrown when the input array needs an output array bigger than maxResultSize
    从以下版本开始:
    
    1.4
  - decodeBase64
```
public static byte[] decodeBase64(java.lang.String base64String)
```
    Decodes a Base64 String into octets
    
    参数:
    base64String - String containing Base64 data
    
    返回:
    Array containing decoded data.
    从以下版本开始:
    
    1.4
  - decodeBase64
```
public static byte[] decodeBase64(byte[] base64Data)
```
    Decodes Base64 data into octets
    
    参数:
    base64Data - Byte array containing Base64 data
    
    返回:
    Array containing decoded data.
  - encodeToString
```
public java.lang.String encodeToString(byte[] pArray)
```
    Encodes a byte[] containing binary data, into a String containing characters in the Base64 alphabet.
    
    参数:
    pArray - a byte array containing binary data
    
    返回:
    A String containing only Base64 character data
    从以下版本开始:
    
    1.4
  - encode
```
public byte[] encode(byte[] pArray)
```
    Encodes a byte[] containing binary data, into a byte[] containing characters in the Base64 alphabet.
    
    参数:
    pArray - a byte array containing binary data
    
    返回:
    A byte array containing only Base64 character data
  - decodeInteger
```
public static java.math.BigInteger decodeInteger(byte[] pArray)
```
    Decodes a byte64-encoded integer according to crypto standards such as W3C's XML-Signature
    
    参数:
    pArray - a byte array containing base64 character data
    
    返回:
    A BigInteger
    从以下版本开始:
    
    1.4
  - encodeInteger
```
public static byte[] encodeInteger(java.math.BigInteger bigInt)
```
    Encodes to a byte64-encoded integer according to crypto standards such as W3C's XML-Signature
    
    参数:
    bigInt - a BigInteger
    
    返回:
    A byte array containing base64 character data
    
    抛出:
    
    java.lang.NullPointerException - if null is passed in
    从以下版本开始:
    
    1.4

类 Base64

构造器概要

方法概要

从类继承的方法 java.lang.Object

构造器详细资料

Base64

Base64

Base64

Base64

Base64

方法详细资料

isUrlSafe

isBase64

isArrayByteBase64

encodeBase64

encodeBase64String

encodeBase64StringUnChunked

encodeBase64String

encodeBase64URLSafe

encodeBase64URLSafeString

encodeBase64Chunked

decode

decode

encodeBase64

encodeBase64

encodeBase64

decodeBase64

decodeBase64

encodeToString

encode

decodeInteger

encodeInteger