DES和Base64加密解密类
一、DES加密和解密
import java.io.UnsupportedEncodingException;
import java.security.InvalidKeyException;
import java.security.NoSuchAlgorithmException;
import java.security.SecureRandom;
import java.security.spec.InvalidKeySpecException;
import javax.crypto.BadPaddingException;
import javax.crypto.Cipher;
import javax.crypto.IllegalBlockSizeException;
import javax.crypto.KeyGenerator;
import javax.crypto.NoSuchPaddingException;
import javax.crypto.SecretKey;
import javax.crypto.SecretKeyFactory;
import javax.crypto.spec.DESKeySpec;
/**
* DES加密和解密。
*/
public class DESUtil {
/** 安全密钥 */
private String keyData = "ABCDEFGHIJKLMNOPQRSTWXYZabcdefghijklmnopqrstwxyz0123456789-_.";
/**
* 功能：构造
*/
public DESUtil() {
}
/**
* 功能：构造
* @param keyData
* key
*/
public DESUtil(String key) {
this.keyData = key;
}
/**
* 功能：加密 (UTF-8)
* @param source
* 源字符串
* @param charSet
* 编码
* @return String
* @throws UnsupportedEncodingException
* 编码异常
*/
public String encrypt(String source) throws UnsupportedEncodingException {
return encrypt(source, "UTF-8");
}
/**
*
* 功能：解密 (UTF-8)
* @param encryptedData
* 被加密后的字符串
* @return String
* @throws UnsupportedEncodingException
* 编码异常
*/
public String decrypt(String encryptedData)
throws UnsupportedEncodingException {
return decrypt(encryptedData, "UTF-8");
}
/**
* 功能：加密
* @param source
* 源字符串
* @param charSet
* 编码
* @return String
* @throws UnsupportedEncodingException
* 编码异常
*/
public String encrypt(String source, String charSet)
throws UnsupportedEncodingException {
String encrypt = null;
byte[] ret = encrypt(source.getBytes(charSet));
encrypt = new String(Base64.encode(ret));
return encrypt;
}
/**
*
* 功能：解密
* @param encryptedData
* 被加密后的字符串
* @param charSet
* 编码
* @return String
* @throws UnsupportedEncodingException
* 编码异常
*/
public String decrypt(String encryptedData, String charSet)
throws UnsupportedEncodingException {
String descryptedData = null;
byte[] ret = descrypt(Base64.decode(encryptedData.toCharArray()));
descryptedData = new String(ret, charSet);
return descryptedData;
}
/**
* 加密数据 用生成的密钥加密原始数据
*
* @param primaryData
* 原始数据
* @return byte[]
*/
private byte[] encrypt(byte[] primaryData) {
/** 取得安全密钥 */
byte rawKeyData[] = getKey();
/** DES算法要求有一个可信任的随机数源 */
SecureRandom sr = new SecureRandom();
/** 使用原始密钥数据创建DESKeySpec对象 */
DESKeySpec dks = null;
try {
dks = new DESKeySpec(keyData.getBytes());
} catch (InvalidKeyException e) {
e.printStackTrace();
}
/** 创建一个密钥工厂 */
SecretKeyFactory keyFactory = null;
try {
keyFactory = SecretKeyFactory.getInstance("DES");
} catch (NoSuchAlgorithmException e) {
e.printStackTrace();
}
/** 用密钥工厂把DESKeySpec转换成一个SecretKey对象 */
SecretKey key = null;
try {
key = keyFactory.generateSecret(dks);
} catch (InvalidKeySpecException e) {
e.printStackTrace();
}
/** Cipher对象实际完成加密操作 */
Cipher cipher = null;
try {
cipher = Cipher.getInstance("DES");
} catch (NoSuchAlgorithmException e) {
e.printStackTrace();
} catch (NoSuchPaddingException e) {
e.printStackTrace();
}
/** 用密钥初始化Cipher对象 */
try {
cipher.init(Cipher.ENCRYPT_MODE, key, sr);
} catch (InvalidKeyException e) {
e.printStackTrace();
}
/** 正式执行加密操作 */
byte encryptedData[] = null;
try {
encryptedData = cipher.doFinal(primaryData);
} catch (IllegalStateException e) {
e.printStackTrace();
} catch (IllegalBlockSizeException e) {
e.printStackTrace();
} catch (BadPaddingException e) {
e.printStackTrace();
}
/** 返回加密数据 */
return encryptedData;
}
/**
* 用密钥解密数据
*
* @param encryptedData
* 加密后的数据
* @return byte[]
*/
private byte[] descrypt(byte[] encryptedData) {
/** DES算法要求有一个可信任的随机数源 */
SecureRandom sr = new SecureRandom();
/** 取得安全密钥 */
byte rawKeyData[] = getKey();
/** 使用原始密钥数据创建DESKeySpec对象 */
DESKeySpec dks = null;
try {
dks = new DESKeySpec(keyData.getBytes());
} catch (InvalidKeyException e) {
e.printStackTrace();
}
/** 创建一个密钥工厂 */
SecretKeyFactory keyFactory = null;
try {
keyFactory = SecretKeyFactory.getInstance("DES");
} catch (NoSuchAlgorithmException e) {
e.printStackTrace();
}
/** 用密钥工厂把DESKeySpec转换成一个SecretKey对象 */
SecretKey key = null;
try {
key = keyFactory.generateSecret(dks);
} catch (InvalidKeySpecException e) {
e.printStackTrace();
}
/** Cipher对象实际完成加密操作 */
Cipher cipher = null;
try {
cipher = Cipher.getInstance("DES");
} catch (NoSuchAlgorithmException e) {
e.printStackTrace();
} catch (NoSuchPaddingException e) {
e.printStackTrace();
}
/** 用密钥初始化Cipher对象 */
try {
cipher.init(Cipher.DECRYPT_MODE, key, sr);
} catch (InvalidKeyException e) {
e.printStackTrace();
}
/** 正式执行解密操作 */
byte decryptedData[] = null;
try {
decryptedData = cipher.doFinal(encryptedData);
} catch (IllegalStateException e) {
e.printStackTrace();
} catch (IllegalBlockSizeException e) {
e.printStackTrace();
} catch (BadPaddingException e) {
e.printStackTrace();
}
return decryptedData;
}
/**
* 取得安全密钥 此方法作废,因为每次key生成都不一样导致解密加密用的密钥都不一样， 从而导致Given final block not
* properly padded错误.
*
* @return byte数组
*/
private byte[] getKey() {
/** DES算法要求有一个可信任的随机数源 */
SecureRandom sr = new SecureRandom();
/** 为我们选择的DES算法生成一个密钥生成器对象 */
KeyGenerator kg = null;
try {
kg = KeyGenerator.getInstance("DES");
} catch (NoSuchAlgorithmException e) {
e.printStackTrace();
}
kg.init(sr);
/** 生成密钥工具类 */
SecretKey key = kg.generateKey();
/** 生成密钥byte数组 */
byte rawKeyData[] = key.getEncoded();
return rawKeyData;
}
}或者使用这个工具：
import java.security.Key;
import java.security.spec.AlgorithmParameterSpec;
import javax.crypto.Cipher;
import javax.crypto.SecretKeyFactory;
import javax.crypto.spec.DESKeySpec;
import javax.crypto.spec.IvParameterSpec;
/**
* 加密解密工具包
*/
public class CyptoUtils {
public static final String ALGORITHM_DES = "DES/CBC/PKCS5Padding";
/**
* DES算法，加密
*
* @param data 待加密字符串
* @param key 加密私钥，长度不能够小于8位
* @return 加密后的字节数组，一般结合Base64编码使用
* @throws InvalidAlgorithmParameterException
* @throws Exception
*/
public static String encode(String key,String data) {
if(data == null)
return null;
try{
DESKeySpec dks = new DESKeySpec(key.getBytes());
SecretKeyFactory keyFactory = SecretKeyFactory.getInstance("DES");
//key的长度不能够小于8位字节
Key secretKey = keyFactory.generateSecret(dks);
Cipher cipher = Cipher.getInstance(ALGORITHM_DES);
IvParameterSpec iv = new IvParameterSpec("12345678".getBytes());
AlgorithmParameterSpec paramSpec = iv;
cipher.init(Cipher.ENCRYPT_MODE, secretKey,paramSpec);
byte[] bytes = cipher.doFinal(data.getBytes());
return byte2hex(bytes);
}catch(Exception e){
e.printStackTrace();
return data;
}
}
/**
* DES算法，解密
*
* @param data 待解密字符串
* @param key 解密私钥，长度不能够小于8位
* @return 解密后的字节数组
* @throws Exception 异常
*/
public static String decode(String key,String data) {
if(data == null)
return null;
try {
DESKeySpec dks = new DESKeySpec(key.getBytes());
SecretKeyFactory keyFactory = SecretKeyFactory.getInstance("DES");
//key的长度不能够小于8位字节
Key secretKey = keyFactory.generateSecret(dks);
Cipher cipher = Cipher.getInstance(ALGORITHM_DES);
IvParameterSpec iv = new IvParameterSpec("12345678".getBytes());
AlgorithmParameterSpec paramSpec = iv;
cipher.init(Cipher.DECRYPT_MODE, secretKey, paramSpec);
return new String(cipher.doFinal(hex2byte(data.getBytes())));
} catch (Exception e){
e.printStackTrace();
return data;
}
}
/**
* 二行制转字符串
* @param b
* @return
*/
private static String byte2hex(byte[] b) {
StringBuilder hs = new StringBuilder();
String stmp;
for (int n = 0; b!=null && n < b.length; n++) {
stmp = Integer.toHexString(b[n] & 0XFF);
if (stmp.length() == 1)
hs.append("0");
hs.append(stmp);
}
return hs.toString().toUpperCase();
}
private static byte[] hex2byte(byte[] b) {
if((b.length%2)!=0)
throw new IllegalArgumentException();
byte[] b2 = new byte[b.length/2];
for (int n = 0; n < b.length; n+=2) {
String item = new String(b,n,2);
b2[n/2] = (byte)Integer.parseInt(item,16);
}
return b2;
}
}
二、Base64加密和解密
/*
* Copyright (C) 2014 Markus Junginger, greenrobot (http://greenrobot.de)
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.greenrobot.essentials;
/**
* <p>
* Encodes and decodes to and from Base64 notation.
* </p>
* <p>
* Homepage: <a href="http://iharder.net/base64">http://iharder.net/base64</a>.
* </p>
*
* <p>
* Example:
* </p>
*
* <code>String encoded = Base64.encode( myByteArray );</code> <br />
* <code>byte[] myByteArray = Base64.decode( encoded );</code>
*
* <p>
* The <tt>options</tt> 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, and encoding using
* the URL-safe and Ordered dialects.
* </p>
*
* <p>
* Note, according to <a href="http://www.faqs.org/rfcs/rfc3548.html">RFC3548</a>, 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.
* </p>
*
* <p>
* The constants defined in Base64 can be OR-ed together to combine options, so you might make a call like this:
* </p>
*
* <code>String encoded = Base64.encodeBytes( mybytes, Base64.GZIP | Base64.DO_BREAK_LINES );</code>
* <p>
* to compress the data before encoding it and then making the output have newline characters.
* </p>
* <p>
* Also...
* </p>
* <code>String encoded = Base64.encodeBytes( crazyString.getBytes() );</code>
*
*
*
* <p>
* Change Log:
* </p>
* <ul>
* <li>v2.3.7 - Fixed subtle bug when base 64 input stream contained the value 01111111, which is an invalid base 64
* character but should not throw an ArrayIndexOutOfBoundsException either. Led to discovery of mishandling (or
* potential for better handling) of other bad input characters. You should now get an IOException if you try decoding
* something that has bad characters in it.</li>
* <li>v2.3.6 - Fixed bug when breaking lines and the final byte of the encoded string ended in the last column; the
* buffer was not properly shrunk and contained an extra (null) byte that made it into the string.</li>
* <li>v2.3.5 - Fixed bug in {@link #encodeFromFile} where estimated buffer size was wrong for files of size 31, 34, and
* 37 bytes.</li>
* <li>v2.3.4 - Fixed bug when working with gzipped streams whereby flushing the Base64.OutputStream closed the Base64
* encoding (by padding with equals signs) too soon. Also added an option to suppress the automatic decoding of gzipped
* streams. Also added experimental support for specifying a class loader when using the
* {@link #decodeToObject(java.lang.String, int, java.lang.ClassLoader)} method.</li>
* <li>v2.3.3 - Changed default char encoding to US-ASCII which reduces the internal Java footprint with its
* CharEncoders and so forth. Fixed some javadocs that were inconsistent. Removed imports and specified things like
* java.io.IOException explicitly inline.</li>
* <li>v2.3.2 - Reduced memory footprint! Finally refined the "guessing" of how big the final encoded data will be so
* that the code doesn"t have to create two output arrays: an oversized initial one and then a final, exact-sized one.
* Big win when using the {@link #encodeBytesToBytes(byte[])} family of methods (and not using the gzip options which
* uses a different mechanism with streams and stuff).</li>
* <li>v2.3.1 - Added {@link #encodeBytesToBytes(byte[], int, int, int)} and some similar helper methods to be more
* efficient with memory by not returning a String but just a byte array.</li>
* <li>v2.3 - <strong>This is not a drop-in replacement!</strong> This is two years of comments and bug fixes queued up
* and finally executed. Thanks to everyone who sent me stuff, and I"m sorry I wasn"t able to distribute your fixes to
* everyone else. Much bad coding was cleaned up including throwing exceptions where necessary instead of returning null
* values or something similar. Here are some changes that may affect you:
* <ul>
* <li><em>Does not break lines, by default.</em> This is to keep in compliance with <a
* href="http://www.faqs.org/rfcs/rfc3548.html">RFC3548</a>.</li>
* <li><em>Throws exceptions instead of returning null values.</em> Because some operations (especially those that may
* permit the GZIP option) use IO streams, there is a possiblity of an java.io.IOException being thrown. After some
* discussion and thought, I"ve changed the behavior of the methods to throw java.io.IOExceptions rather than return
* null if ever there"s an error. I think this is more appropriate, though it will require some changes to your code.
* Sorry, it should have been done this way to begin with.</li>
* <li><em>Removed all references to System.out, System.err, and the like.</em> Shame on me. All I can say is sorry they
* were ever there.</li>
* <li><em>Throws NullPointerExceptions and IllegalArgumentExceptions</em> as needed such as when passed arrays are null
* or offsets are invalid.</li>
* <li>Cleaned up as much javadoc as I could to avoid any javadoc warnings. This was especially annoying before for
* people who were thorough in their own projects and then had gobs of javadoc warnings on this file.</li>
* </ul>
* <li>v2.2.1 - Fixed bug using URL_SAFE and ORDERED encodings. Fixed bug when using very small files (~< 40 bytes).</li>
* <li>v2.2 - Added some helper methods for encoding/decoding directly from one file to the next. Also added a main()
* method to support command line encoding/decoding from one file to the next. Also added these Base64 dialects:
* <ol>
* <li>The default is RFC3548 format.</li>
* <li>Calling Base64.setFormat(Base64.BASE64_FORMAT.URLSAFE_FORMAT) generates URL and file name friendly format as
* described in Section 4 of RFC3548. http://www.faqs.org/rfcs/rfc3548.html</li>
* <li>Calling Base64.setFormat(Base64.BASE64_FORMAT.ORDERED_FORMAT) generates URL and file name friendly format that
* preserves lexical ordering as described in http://www.faqs.org/qa/rfcc-1940.html</li>
* </ol>
* Special thanks to Jim Kellerman at <a href="http://www.powerset.com/">http://www.powerset.com/</a> for contributing
* the new Base64 dialects.</li>
*
* <li>v2.1 - Cleaned up javadoc comments and unused variables and methods. Added some convenience methods for reading
* and writing to and from files.</li>
* <li>v2.0.2 - Now specifies UTF-8 encoding in places where the code fails on systems with other encodings (like
* EBCDIC).</li>
* <li>v2.0.1 - Fixed an error when decoding a single byte, that is, when the encoded data was a single byte.</li>
* <li>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 (<tt>int</tt>s that you "OR" together).</li>
* <li>v1.5.1 - Fixed bug when decompressing and decoding to a byte[] using
* <tt>decode( String s, boolean gzipCompressed )</tt>. 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).</li>
* <li>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.</li>
* <li>v1.4 - Added helper methods to read/write files.</li>
* <li>v1.3.6 - Fixed OutputStream.flush() so that "position" is reset.</li>
* <li>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.</li>
* <li>v1.3.4 - Fixed when "improperly padded stream" error was thrown at the wrong time.</li>
* <li>v1.3.3 - Fixed I/O streams which were totally messed up.</li>
* </ul>
*
* <p>
* 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 <a
* href="http://iharder.net/base64">http://iharder.net/base64</a> periodically to check for updates or to contribute
* improvements.
* </p>
*
* @author Robert Harder
* @author rob@iharder.net
* @version 2.3.7
*/
public class Base64 {
/* ******** P U B L I C F I E L D S ******** */
/** No options specified. Value is zero. */
public final static int NO_OPTIONS = 0;
/** Specify encoding in first bit. Value is one. */
public final static int ENCODE = 1;
/** Specify decoding in first bit. Value is zero. */
public final static int DECODE = 0;
/** Specify that data should be gzip-compressed in second bit. Value is two. */
public final static int GZIP = 2;
/** Specify that gzipped data should <em>not</em> be automatically gunzipped. */
public final static int DONT_GUNZIP = 4;
/** Do break lines when encoding. Value is 8. */
public final static int DO_BREAK_LINES = 8;
/**
* Encode using Base64-like encoding that is URL- and Filename-safe as described in Section 4 of RFC3548: <a
* href="http://www.faqs.org/rfcs/rfc3548.html">http://www.faqs.org/rfcs/rfc3548.html</a>. It is important to note
* that data encoded this way is <em>not</em> 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.
*/
public final static int URL_SAFE = 16;
/**
* Encode using the special "ordered" dialect of Base64 described here: <a
* href="http://www.faqs.org/qa/rfcc-1940.html">http://www.faqs.org/qa/rfcc-1940.html</a>.
*/
public final static int ORDERED = 32;
/* ******** P R I V A T E F I E L D S ******** */
/** Maximum line length (76) of Base64 output. */
private final static int MAX_LINE_LENGTH = 76;
/** The equals sign (=) as a byte. */
private final static byte EQUALS_SIGN = (byte) "=";
/** The new line character (
) as a byte. */
private final static byte NEW_LINE = (byte) "
";
/** Preferred encoding. */
private final static String PREFERRED_ENCODING = "US-ASCII";
private final static byte WHITE_SPACE_ENC = -5; // Indicates white space in encoding
private final static byte EQUALS_SIGN_ENC = -1; // Indicates equals sign in encoding
/* ******** S T A N D A R D B A S E 6 4 A L P H A B E T ******** */
/** The 64 valid Base64 values. */
/* Host platform me be something funny like EBCDIC, so we hardcode these values. */
private final static byte[] _STANDARD_ALPHABET = {(byte) "A", (byte) "B", (byte) "C", (byte) "D", (byte) "E",
(byte) "F", (byte) "G", (byte) "H", (byte) "I", (byte) "J", (byte) "K", (byte) "L", (byte) "M", (byte) "N",
(byte) "O", (byte) "P", (byte) "Q", (byte) "R", (byte) "S", (byte) "T", (byte) "U", (byte) "V", (byte) "W",
(byte) "X", (byte) "Y", (byte) "Z", (byte) "a", (byte) "b", (byte) "c", (byte) "d", (byte) "e", (byte) "f",
(byte) "g", (byte) "h", (byte) "i", (byte) "j", (byte) "k", (byte) "l", (byte) "m", (byte) "n", (byte) "o",
(byte) "p", (byte) "q", (byte) "r", (byte) "s", (byte) "t", (byte) "u", (byte) "v", (byte) "w", (byte) "x",
(byte) "y", (byte) "z", (byte) "0", (byte) "1", (byte) "2", (byte) "3", (byte) "4", (byte) "5", (byte) "6",
(byte) "7", (byte) "8", (byte) "9", (byte) "+", (byte) "/"};
/**
* Translates a Base64 value to either its 6-bit reconstruction value or a negative number indicating some other
* meaning.
**/
private final static byte[] _STANDARD_DECODABET = {-9, -9, -9, -9, -9, -9, -9, -9, -9, // Decimal 0 - 8
-5, -5, // Whitespace: Tab and Linefeed
-9, -9, // Decimal 11 - 12
-5, // Whitespace: Carriage Return
-9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, // Decimal 14 - 26
-9, -9, -9, -9, -9, // Decimal 27 - 31
-5, // Whitespace: Space
-9, -9, -9, -9, -9, -9, -9, -9, -9, -9, // Decimal 33 - 42
62, // Plus sign at decimal 43
-9, -9, -9, // Decimal 44 - 46
63, // Slash at decimal 47
52, 53, 54, 55, 56, 57, 58, 59, 60, 61, // Numbers zero through nine
-9, -9, -9, // Decimal 58 - 60
-1, // Equals sign at decimal 61
-9, -9, -9, // Decimal 62 - 64
0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, // Letters "A" through "N"
14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, // Letters "O" through "Z"
-9, -9, -9, -9, -9, -9, // Decimal 91 - 96
26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, // Letters "a" through "m"
39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, // Letters "n" through "z"
-9, -9, -9, -9, -9 // Decimal 123 - 127
, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, // Decimal 128 - 139
-9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, // Decimal 140 - 152
-9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, // Decimal 153 - 165
-9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, // Decimal 166 - 178
-9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, // Decimal 179 - 191
-9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, // Decimal 192 - 204
-9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, // Decimal 205 - 217
-9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, // Decimal 218 - 230
-9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, // Decimal 231 - 243
-9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9 // Decimal 244 - 255
};
/* ******** U R L S A F E B A S E 6 4 A L P H A B E T ******** */
/**
* Used in the URL- and Filename-safe dialect described in Section 4 of RFC3548: <a
* href="http://www.faqs.org/rfcs/rfc3548.html">http://www.faqs.org/rfcs/rfc3548.html</a>. Notice that the last two
* bytes become "hyphen" and "underscore" instead of "plus" and "slash."
*/
private final static byte[] _URL_SAFE_ALPHABET = {(byte) "A", (byte) "B", (byte) "C", (byte) "D", (byte) "E",
(byte) "F", (byte) "G", (byte) "H", (byte) "I", (byte) "J", (byte) "K", (byte) "L", (byte) "M", (byte) "N",
(byte) "O", (byte) "P", (byte) "Q", (byte) "R", (byte) "S", (byte) "T", (byte) "U", (byte) "V", (byte) "W",
(byte) "X", (byte) "Y", (byte) "Z", (byte) "a", (byte) "b", (byte) "c", (byte) "d", (byte) "e", (byte) "f",
(byte) "g", (byte) "h", (byte) "i", (byte) "j", (byte) "k", (byte) "l", (byte) "m", (byte) "n", (byte) "o",
(byte) "p", (byte) "q", (byte) "r", (byte) "s", (byte) "t", (byte) "u", (byte) "v", (byte) "w", (byte) "x",
(byte) "y", (byte) "z", (byte) "0", (byte) "1", (byte) "2", (byte) "3", (byte) "4", (byte) "5", (byte) "6",
(byte) "7", (byte) "8", (byte) "9", (byte) "-", (byte) "_"};
/**
* Used in decoding URL- and Filename-safe dialects of Base64.
*/
private final static byte[] _URL_SAFE_DECODABET = {-9, -9, -9, -9, -9, -9, -9, -9, -9, // Decimal 0 - 8
-5, -5, // Whitespace: Tab and Linefeed
-9, -9, // Decimal 11 - 12
-5, // Whitespace: Carriage Return
-9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, // Decimal 14 - 26
-9, -9, -9, -9, -9, // Decimal 27 - 31
-5, // Whitespace: Space
-9, -9, -9, -9, -9, -9, -9, -9, -9, -9, // Decimal 33 - 42
-9, // Plus sign at decimal 43
-9, // Decimal 44
62, // Minus sign at decimal 45
-9, // Decimal 46
-9, // Slash at decimal 47
52, 53, 54, 55, 56, 57, 58, 59, 60, 61, // Numbers zero through nine
-9, -9, -9, // Decimal 58 - 60
-1, // Equals sign at decimal 61
-9, -9, -9, // Decimal 62 - 64
0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, // Letters "A" through "N"
14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, // Letters "O" through "Z"
-9, -9, -9, -9, // Decimal 91 - 94
63, // Underscore at decimal 95
-9, // Decimal 96
26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, // Letters "a" through "m"
39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, // Letters "n" through "z"
-9, -9, -9, -9, -9 // Decimal 123 - 127
, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, // Decimal 128 - 139
-9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, // Decimal 140 - 152
-9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, // Decimal 153 - 165
-9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, // Decimal 166 - 178
-9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, // Decimal 179 - 191
-9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, // Decimal 192 - 204
-9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, // Decimal 205 - 217
-9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, // Decimal 218 - 230
-9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, // Decimal 231 - 243
-9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9 // Decimal 244 - 255
};
/* ******** O R D E R E D B A S E 6 4 A L P H A B E T ******** */
/**
* I don"t get the point of this technique, but someone requested it, and it is described here: <a
* href="http://www.faqs.org/qa/rfcc-1940.html">http://www.faqs.org/qa/rfcc-1940.html</a>.
*/
private final static byte[] _ORDERED_ALPHABET = {(byte) "-", (byte) "0", (byte) "1", (byte) "2", (byte) "3",
(byte) "4", (byte) "5", (byte) "6", (byte) "7", (byte) "8", (byte) "9", (byte) "A", (byte) "B", (byte) "C",
(byte) "D", (byte) "E", (byte) "F", (byte) "G", (byte) "H", (byte) "I", (byte) "J", (byte) "K", (byte) "L",
(byte) "M", (byte) "N", (byte) "O", (byte) "P", (byte) "Q", (byte) "R", (byte) "S", (byte) "T", (byte) "U",
(byte) "V", (byte) "W", (byte) "X", (byte) "Y", (byte) "Z", (byte) "_", (byte) "a", (byte) "b", (byte) "c",
(byte) "d", (byte) "e", (byte) "f", (byte) "g", (byte) "h", (byte) "i", (byte) "j", (byte) "k", (byte) "l",
(byte) "m", (byte) "n", (byte) "o", (byte) "p", (byte) "q", (byte) "r", (byte) "s", (byte) "t", (byte) "u",
(byte) "v", (byte) "w", (byte) "x", (byte) "y", (byte) "z"};
/**
* Used in decoding the "ordered" dialect of Base64.
*/
private final static byte[] _ORDERED_DECODABET = {-9, -9, -9, -9, -9, -9, -9, -9, -9, // Decimal 0 - 8
-5, -5, // Whitespace: Tab and Linefeed
-9, -9, // Decimal 11 - 12
-5, // Whitespace: Carriage Return
-9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, // Decimal 14 - 26
-9, -9, -9, -9, -9, // Decimal 27 - 31
-5, // Whitespace: Space
-9, -9, -9, -9, -9, -9, -9, -9, -9, -9, // Decimal 33 - 42
-9, // Plus sign at decimal 43
-9, // Decimal 44
0, // Minus sign at decimal 45
-9, // Decimal 46
-9, // Slash at decimal 47
1, 2, 3, 4, 5, 6, 7, 8, 9, 10, // Numbers zero through nine
-9, -9, -9, // Decimal 58 - 60
-1, // Equals sign at decimal 61
-9, -9, -9, // Decimal 62 - 64
11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, // Letters "A" through "M"
24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, // Letters "N" through "Z"
-9, -9, -9, -9, // Decimal 91 - 94
37, // Underscore at decimal 95
-9, // Decimal 96
38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, // Letters "a" through "m"
51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, // Letters "n" through "z"
-9, -9, -9, -9, -9 // Decimal 123 - 127
, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, // Decimal 128 - 139
-9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, // Decimal 140 - 152
-9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, // Decimal 153 - 165
-9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, // Decimal 166 - 178
-9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, // Decimal 179 - 191
-9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, // Decimal 192 - 204
-9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, // Decimal 205 - 217
-9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, // Decimal 218 - 230
-9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, // Decimal 231 - 243
-9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9 // Decimal 244 - 255
};
/* ******** D E T E R M I N E W H I C H A L H A B E T ******** */
/**
* Returns one of the _SOMETHING_ALPHABET byte arrays depending on the options specified. It"s possible, though
* silly, to specify ORDERED <b>and</b> URLSAFE in which case one of them will be picked, though there is no
* guarantee as to which one will be picked.
*/
private final static byte[] getAlphabet(int options) {
if ((options & URL_SAFE) == URL_SAFE) {
return _URL_SAFE_ALPHABET;
} else if ((options & ORDERED) == ORDERED) {
return _ORDERED_ALPHABET;
} else {
return _STANDARD_ALPHABET;
}
} // end getAlphabet
/**
* Returns one of the _SOMETHING_DECODABET byte arrays depending on the options specified. It"s possible, though
* silly, to specify ORDERED and URL_SAFE in which case one of them will be picked, though there is no guarantee as
* to which one will be picked.
*/
private final static byte[] getDecodabet(int options) {
if ((options & URL_SAFE) == URL_SAFE) {
return _URL_SAFE_DECODABET;
} else if ((options & ORDERED) == ORDERED) {
return _ORDERED_DECODABET;
} else {
return _STANDARD_DECODABET;
}
} // end getAlphabet
/** Defeats instantiation. */
private Base64() {
}
/* ******** E N C O D I N G M E T H O D S ******** */
/**
* Encodes up to the first three bytes of array <var>threeBytes</var> and returns a four-byte array in Base64
* notation. The actual number of significant bytes in your array is given by <var>numSigBytes</var>. The array
* <var>threeBytes</var> needs only be as big as <var>numSigBytes</var>. Code can reuse a byte array by passing a
* four-byte array as <var>b4</var>.
*
* @param b4
* A reusable byte array to reduce array instantiation
* @param threeBytes
* the array to convert
* @param numSigBytes
* the number of significant bytes in your array
* @return four byte array in Base64 notation.
* @since 1.5.1
*/
private static byte[] encode3to4(byte[] b4, byte[] threeBytes, int numSigBytes, int options) {
encode3to4(threeBytes, 0, numSigBytes, b4, 0, options);
return b4;
} // end encode3to4
/**
* <p>
* Encodes up to three bytes of the array <var>source</var> and writes the resulting four Base64 bytes to
* <var>destination</var>. The source and destination arrays can be manipulated anywhere along their length by
* specifying <var>srcOffset</var> and <var>destOffset</var>. This method does not check to make sure your arrays
* are large enough to accomodate <var>srcOffset</var> + 3 for the <var>source</var> array or <var>destOffset</var>
* + 4 for the <var>destination</var> array. The actual number of significant bytes in your array is given by
* <var>numSigBytes</var>.
* </p>
* <p>
* This is the lowest level of the encoding methods with all possible parameters.
* </p>
*
* @param source
* the array to convert
* @param srcOffset
* the index where conversion begins
* @param numSigBytes
* the number of significant bytes in your array
* @param destination
* the array to hold the conversion
* @param destOffset
* the index where output will be put
* @return the <var>destination</var> array
* @since 1.3
*/
private static byte[] encode3to4(byte[] source, int srcOffset, int numSigBytes, byte[] destination, int destOffset,
int options) {
byte[] ALPHABET = getAlphabet(options);
// 1 2 3
// 01234567890123456789012345678901 Bit position
// --------000000001111111122222222 Array position from threeBytes
// --------| || || || | Six bit groups to index ALPHABET
// >>18 >>12 >> 6 >> 0 Right shift necessary
// 0x3f 0x3f 0x3f Additional AND
// Create buffer with zero-padding if there are only one or two
// significant bytes passed in the array.
// We have to shift left 24 in order to flush out the 1"s that appear
// when Java treats a value as negative that is cast from a byte to an int.
int inBuff = (numSigBytes > 0 ? ((source[srcOffset] << 24) >>> 8) : 0)
| (numSigBytes > 1 ? ((source[srcOffset + 1] << 24) >>> 16) : 0)
| (numSigBytes > 2 ? ((source[srcOffset + 2] << 24) >>> 24) : 0);
switch (numSigBytes) {
case 3 :
destination[destOffset] = ALPHABET[(inBuff >>> 18)];
destination[destOffset + 1] = ALPHABET[(inBuff >>> 12) & 0x3f];
destination[destOffset + 2] = ALPHABET[(inBuff >>> 6) & 0x3f];
destination[destOffset + 3] = ALPHABET[(inBuff) & 0x3f];
return destination;
case 2 :
destination[destOffset] = ALPHABET[(inBuff >>> 18)];
destination[destOffset + 1] = ALPHABET[(inBuff >>> 12) & 0x3f];
destination[destOffset + 2] = ALPHABET[(inBuff >>> 6) & 0x3f];
destination[destOffset + 3] = EQUALS_SIGN;
return destination;
case 1 :
destination[destOffset] = ALPHABET[(inBuff >>> 18)];
destination[destOffset + 1] = ALPHABET[(inBuff >>> 12) & 0x3f];
destination[destOffset + 2] = EQUALS_SIGN;
destination[destOffset + 3] = EQUALS_SIGN;
return destination;
default :
return destination;
} // end switch
} // end encode3to4
/**
* Performs Base64 encoding on the <code>raw</code> ByteBuffer, writing it to the <code>encoded</code> ByteBuffer.
* This is an experimental feature. Currently it does not pass along any options (such as {@link #DO_BREAK_LINES} or
* {@link #GZIP}.
*
* @param raw
* input buffer
* @param encoded
* output buffer
* @since 2.3
*/
public static void encode(java.nio.ByteBuffer raw, java.nio.ByteBuffer encoded) {
byte[] raw3 = new byte[3];
byte[] enc4 = new byte[4];
while (raw.hasRemaining()) {
int rem = Math.min(3, raw.remaining());
raw.get(raw3, 0, rem);
Base64.encode3to4(enc4, raw3, rem, Base64.NO_OPTIONS);
encoded.put(enc4);
} // end input remaining
}
/**
* Performs Base64 encoding on the <code>raw</code> ByteBuffer, writing it to the <code>encoded</code> CharBuffer.
* This is an experimental feature. Currently it does not pass along any options (such as {@link #DO_BREAK_LINES} or
* {@link #GZIP}.
*
* @param raw
* input buffer
* @param encoded
* output buffer
* @since 2.3
*/
public static void encode(java.nio.ByteBuffer raw, java.nio.CharBuffer encoded) {
byte[] raw3 = new byte[3];
byte[] enc4 = new byte[4];
while (raw.hasRemaining()) {
int rem = Math.min(3, raw.remaining());
raw.get(raw3, 0, rem);
Base64.encode3to4(enc4, raw3, rem, Base64.NO_OPTIONS);
for (int i = 0; i < 4; i++) {
encoded.put((char) (enc4[i] & 0xFF));
}
} // end input remaining
}
/**
* Serializes an object and returns the Base64-encoded version of that serialized object.
*
* <p>
* As of v 2.3, if the object cannot be serialized or there is another error, the method will throw an
* java.io.IOException. <b>This is new to v2.3!</b> In earlier versions, it just returned a null value, but in
* retrospect that"s a pretty poor way to handle it.
* </p>
*
* The object is not GZip-compressed before being encoded.
*
* @param serializableObject
* The object to encode
* @return The Base64-encoded object
* @throws java.io.IOException
* if there is an error
* @throws NullPointerException
* if serializedObject is null
* @since 1.4
*/
public static String encodeObject(java.io.Serializable serializableObject) throws java.io.IOException {
return encodeObject(serializableObject, NO_OPTIONS);
} // end encodeObject
/**
* Serializes an object and returns the Base64-encoded version of that serialized object.
*
* <p>
* As of v 2.3, if the object cannot be serialized or there is another error, the method will throw an
* java.io.IOException. <b>This is new to v2.3!</b> In earlier versions, it just returned a null value, but in
* retrospect that"s a pretty poor way to handle it.
* </p>
*
* The object is not GZip-compressed before being encoded.
* <p>
* Example options:
*
* <pre>
* GZIP: gzip-compresses object before encoding it.
* DO_BREAK_LINES: break lines at 76 characters
* </pre>
* <p>
* Example: <code>encodeObject( myObj, Base64.GZIP )</code> or
* <p>
* Example: <code>encodeObject( myObj, Base64.GZIP | Base64.DO_BREAK_LINES )</code>
*
* @param serializableObject
* The object to encode
* @param options
* Specified options
* @return The Base64-encoded object
* @see Base64#GZIP
* @see Base64#DO_BREAK_LINES
* @throws java.io.IOException
* if there is an error
* @since 2.0
*/
public static String encodeObject(java.io.Serializable serializableObject, int options) throws java.io.IOException {
if (serializableObject == null) {
throw new NullPointerException("Cannot serialize a null object.");
} // end if: null
// Streams
java.io.ByteArrayOutputStream baos = null;
java.io.OutputStream b64os = null;
java.util.zip.GZIPOutputStream gzos = null;
java.io.ObjectOutputStream oos = null;
try {
// ObjectOutputStream -> (GZIP) -> Base64 -> ByteArrayOutputStream
baos = new java.io.ByteArrayOutputStream();
b64os = new Base64.OutputStream(baos, ENCODE | options);
if ((options & GZIP) != 0) {
// Gzip
gzos = new java.util.zip.GZIPOutputStream(b64os);
oos = new java.io.ObjectOutputStream(gzos);
} else {
// Not gzipped
oos = new java.io.ObjectOutputStream(b64os);
}
oos.writeObject(serializableObject);
} // end try
catch (java.io.IOException e) {
// Catch it and then throw it immediately so that
// the finally{} block is called for cleanup.
throw e;
} // end catch
finally {
try {
oos.close();
} catch (Exception e) {
}
try {
gzos.close();
} catch (Exception e) {
}
try {
b64os.close();
} catch (Exception e) {
}
try {
baos.close();
} catch (Exception e) {
}
} // end finally
// Return value according to relevant encoding.
try {
return new String(baos.toByteArray(), PREFERRED_ENCODING);
} // end try
catch (java.io.UnsupportedEncodingException uue) {
// Fall back to some Java default
return new String(baos.toByteArray());
} // end catch
} // end encode
/**
* Encodes a byte array into Base64 notation. Does not GZip-compress data.
*
* @param source
* The data to convert
* @return The data in Base64-encoded form
* @throws NullPointerException
* if source array is null
* @since 1.4
*/
public static String encodeBytes(byte[] source) {
// Since we"re not going to have the GZIP encoding turned on,
// we"re not going to have an java.io.IOException thrown, so
// we should not force the user to have to catch it.
String encoded = null;
try {
encoded = encodeBytes(source, 0, source.length, NO_OPTIONS);
} catch (java.io.IOException ex) {
assert false : ex.getMessage();
} // end catch
assert encoded != null;
return encoded;
} // end encodeBytes
/**
* Encodes a byte array into Base64 notation.
* <p>
* Example options:
*
* <pre>
* GZIP: gzip-compresses object before encoding it.
* DO_BREAK_LINES: break lines at 76 characters
* <i>Note: Technically, this makes your encoding non-compliant.</i>
* </pre>
* <p>
* Example: <code>encodeBytes( myData, Base64.GZIP )</code> or
* <p>
* Example: <code>encodeBytes( myData, Base64.GZIP | Base64.DO_BREAK_LINES )</code>
*
*
* <p>
* As of v 2.3, if there is an error with the GZIP stream, the method will throw an java.io.IOException. <b>This is
* new to v2.3!</b> In earlier versions, it just returned a null value, but in retrospect that"s a pretty poor way
* to handle it.
* </p>
*
*
* @param source
* The data to convert
* @param options
* Specified options
* @return The Base64-encoded data as a String
* @see Base64#GZIP
* @see Base64#DO_BREAK_LINES
* @throws java.io.IOException
* if there is an error
* @throws NullPointerException
* if source array is null
* @since 2.0
*/
public static String encodeBytes(byte[] source, int options) throws java.io.IOException {
return encodeBytes(source, 0, source.length, options);
} // end encodeBytes
/**
* Encodes a byte array into Base64 notation. Does not GZip-compress data.
*
* <p>
* As of v 2.3, if there is an error, the method will throw an java.io.IOException. <b>This is new to v2.3!</b> In
* earlier versions, it just returned a null value, but in retrospect that"s a pretty poor way to handle it.
* </p>
*
*
* @param source
* The data to convert
* @param off
* Offset in array where conversion should begin
* @param len
* Length of data to convert
* @return The Base64-encoded data as a String
* @throws NullPointerException
* if source array is null
* @throws IllegalArgumentException
* if source array, offset, or length are invalid
* @since 1.4
*/
public static String encodeBytes(byte[] source, int off, int len) {
// Since we"re not going to have the GZIP encoding turned on,
// we"re not going to have an java.io.IOException thrown, so
// we should not force the user to have to catch it.
String encoded = null;
try {
encoded = encodeBytes(source, off, len, NO_OPTIONS);
} catch (java.io.IOException ex) {
assert false : ex.getMessage();
} // end catch
assert encoded != null;
return encoded;
} // end encodeBytes
/**
* Encodes a byte array into Base64 notation.
* <p>
* Example options:
*
* <pre>
* GZIP: gzip-compresses object before encoding it.
* DO_BREAK_LINES: break lines at 76 characters
* <i>Note: Technically, this makes your encoding non-compliant.</i>
* </pre>
* <p>
* Example: <code>encodeBytes( myData, Base64.GZIP )</code> or
* <p>
* Example: <code>encodeBytes( myData, Base64.GZIP | Base64.DO_BREAK_LINES )</code>
*
*
* <p>
* As of v 2.3, if there is an error with the GZIP stream, the method will throw an java.io.IOException. <b>This is
* new to v2.3!</b> In earlier versions, it just returned a null value, but in retrospect that"s a pretty poor way
* to handle it.
* </p>
*
*
* @param source
* The data to convert
* @param off
* Offset in array where conversion should begin
* @param len
* Length of data to convert
* @param options
* Specified options
* @return The Base64-encoded data as a String
* @see Base64#GZIP
* @see Base64#DO_BREAK_LINES
* @throws java.io.IOException
* if there is an error
* @throws NullPointerException
* if source array is null
* @throws IllegalArgumentException
* if source array, offset, or length are invalid
* @since 2.0
*/
public static String encodeBytes(byte[] source, int off, int len, int options) throws java.io.IOException {
byte[] encoded = encodeBytesToBytes(source, off, len, options);
// Return value according to relevant encoding.
try {
return new String(encoded, PREFERRED_ENCODING);
} // end try
catch (java.io.UnsupportedEncodingException uue) {
return new String(encoded);
} // end catch
} // end encodeBytes
/**
* Similar to {@link #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.
*
*
* @param source
* The data to convert
* @return The Base64-encoded data as a byte[] (of ASCII characters)
* @throws NullPointerException
* if source array is null
* @since 2.3.1
*/
public static byte[] encodeBytesToBytes(byte[] source) {
byte[] encoded = null;
try {
encoded = encodeBytesToBytes(source, 0, source.length, Base64.NO_OPTIONS);
} catch (java.io.IOException ex) {
assert false : "IOExceptions only come from GZipping, which is turned off: " + ex.getMessage();
}
return encoded;
}
/**
* Similar to {@link #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.
*
*
* @param source
* The data to convert
* @param off
* Offset in array where conversion should begin
* @param len
* Length of data to convert
* @param options
* Specified options
* @return The Base64-encoded data as a String
* @see Base64#GZIP
* @see Base64#DO_BREAK_LINES
* @throws java.io.IOException
* if there is an error
* @throws NullPointerException
* if source array is null
* @throws IllegalArgumentException
* if source array, offset, or length are invalid
* @since 2.3.1
*/
public static byte[] encodeBytesToBytes(byte[] source, int off, int len, int options) throws java.io.IOException {
if (source == null) {
throw new NullPointerException("Cannot serialize a null array.");
} // end if: null
if (off < 0) {
throw new IllegalArgumentException("Cannot have negative offset: " + off);
} // end if: off < 0
if (len < 0) {
throw new IllegalArgumentException("Cannot have length offset: " + len);
} // end if: len < 0
if (off + len > source.length) {
throw new IllegalArgumentException(String.format(
"Cannot have offset of %d and length of %d with array of length %d", off, len, source.length));
} // end if: off < 0
// Compress?
if ((options & GZIP) != 0) {
java.io.ByteArrayOutputStream baos = null;
java.util.zip.GZIPOutputStream gzos = null;
Base64.OutputStream b64os = null;
try {
// GZip -> Base64 -> ByteArray
baos = new java.io.ByteArrayOutputStream();
b64os = new Base64.OutputStream(baos, ENCODE | options);
gzos = new java.util.zip.GZIPOutputStream(b64os);
gzos.write(source, off, len);
gzos.close();
} // end try
catch (java.io.IOException e) {
// Catch it and then throw it immediately so that
// the finally{} block is called for cleanup.
throw e;
} // end catch
finally {
try {
gzos.close();
} catch (Exception e) {
}
try {
b64os.close();
} catch (Exception e) {
}
try {
baos.close();
} catch (Exception e) {
}
} // end finally
return baos.toByteArray();
} // end if: compress
// Else, don"t compress. Better not to use streams at all then.
else {
boolean breakLines = (options & DO_BREAK_LINES) != 0;
// int len43 = len * 4 / 3;
// byte[] outBuff = new byte[ ( len43 ) // Main 4:3
// + ( (len % 3) > 0 ? 4 : 0 ) // Account for padding
// + (breakLines ? ( len43 / MAX_LINE_LENGTH ) : 0) ]; // New lines
// Try to determine more precisely how big the array needs to be.
// If we get it right, we don"t have to do an array copy, and
// we save a bunch of memory.
int encLen = (len / 3) * 4 + (len % 3 > 0 ? 4 : 0); // Bytes needed for actual encoding
if (breakLines) {
encLen += encLen / MAX_LINE_LENGTH; // Plus extra newline characters
}
byte[] outBuff = new byte[encLen];
int d = 0;
int e = 0;
int len2 = len - 2;
int lineLength = 0;
for (; d < len2; d += 3, e += 4) {
encode3to4(source, d + off, 3, outBuff, e, options);
lineLength += 4;
if (breakLines && lineLength >= MAX_LINE_LENGTH) {
outBuff[e + 4] = NEW_LINE;
e++;
lineLength = 0;
} // end if: end of line
} // en dfor: each piece of array
if (d < len) {
encode3to4(source, d + off, len - d, outBuff, e, options);
e += 4;
} // end if: some padding needed
// Only resize array if we didn"t guess it right.
if (e <= outBuff.length - 1) {
// If breaking lines and the last byte falls right at
// the line length (76 bytes per line), there will be
// one extra byte, and the array will need to be resized.
// Not too bad of an estimate on array size, I"d say.
byte[] finalOut = new byte[e];
System.arraycopy(outBuff, 0, finalOut, 0, e);
// System.err.println("Having to resize array from " + outBuff.length + " to " + e );
return finalOut;
} else {
// System.err.println("No need to resize array.");
return outBuff;
}
} // end else: don"t compress
} // end encodeBytesToBytes
/* ******** D E C O D I N G M E T H O D S ******** */
/**
* Decodes four bytes from array <var>source</var> and writes the resulting bytes (up to three of them) to
* <var>destination</var>. The source and destination arrays can be manipulated anywhere along their length by
* specifying <var>srcOffset</var> and <var>destOffset</var>. This method does not check to make sure your arrays
* are large enough to accomodate <var>srcOffset</var> + 4 for the <var>source</var> array or <var>destOffset</var>
* + 3 for the <var>destination</var> array. This method returns the actual number of bytes that were converted from
* the Base64 encoding.
* <p>
* This is the lowest level of the decoding methods with all possible parameters.
* </p>
*
*
* @param source
* the array to convert
* @param srcOffset
* the index where conversion begins
* @param destination
* the array to hold the conversion
* @param destOffset
* the index where output will be put
* @param options
* alphabet type is pulled from this (standard, url-safe, ordered)
* @return the number of decoded bytes converted
* @throws NullPointerException
* if source or destination arrays are null
* @throws IllegalArgumentException
* if srcOffset or destOffset are invalid or there is not enough room in the array.
* @since 1.3
*/
private static int decode4to3(byte[] source, int srcOffset, byte[] destination, int destOffset, int options) {
// Lots of error checking and exception throwing
if (source == null) {
throw new NullPointerException("Source array was null.");
} // end if
if (destination == null) {
throw new NullPointerException("Destination array was null.");
} // end if
if (srcOffset < 0 || srcOffset + 3 >= source.length) {
throw new IllegalArgumentException(String.format(
"Source array with length %d cannot have offset of %d and still process four bytes.",
source.length, srcOffset));
} // end if
if (destOffset < 0 || destOffset + 2 >= destination.length) {
throw new IllegalArgumentException(String.format(
"Destination array with length %d cannot have offset of %d and still store three bytes.",
destination.length, destOffset));
} // end if
byte[] DECODABET = getDecodabet(options);
// Example: Dk==
if (source[srcOffset + 2] == EQUALS_SIGN) {
// Two ways to do the same thing. Don"t know which way I like best.
// int outBuff = ( ( DECODABET[ source[ srcOffset ] ] << 24 ) >>> 6 )
// | ( ( DECODABET[ source[ srcOffset + 1] ] << 24 ) >>> 12 );
int outBuff = ((DECODABET[source[srcOffset]] & 0xFF) << 18)
| ((DECODABET[source[srcOffset + 1]] & 0xFF) << 12);
destination[destOffset] = (byte) (outBuff >>> 16);
return 1;
}
// Example: DkL=
else if (source[srcOffset + 3] == EQUALS_SIGN) {
// Two ways to do the same thing. Don"t know which way I like best.
// int outBuff = ( ( DECODABET[ source[ srcOffset ] ] << 24 ) >>> 6 )
// | ( ( DECODABET[ source[ srcOffset + 1 ] ] << 24 ) >>> 12 )
// | ( ( DECODABET[ source[ srcOffset + 2 ] ] << 24 ) >>> 18 );
int outBuff = ((DECODABET[source[srcOffset]] & 0xFF) << 18)
| ((DECODABET[source[srcOffset + 1]] & 0xFF) << 12)
| ((DECODABET[source[srcOffset + 2]] & 0xFF) << 6);
destination[destOffset] = (byte) (outBuff >>> 16);
destination[destOffset + 1] = (byte) (outBuff >>> 8);
return 2;
}
// Example: DkLE
else {
// Two ways to do the same thing. Don"t know which way I like best.
// int outBuff = ( ( DECODABET[ source[ srcOffset ] ] << 24 ) >>> 6 )
// | ( ( DECODABET[ source[ srcOffset + 1 ] ] << 24 ) >>> 12 )
// | ( ( DECODABET[ source[ srcOffset + 2 ] ] << 24 ) >>> 18 )
// | ( ( DECODABET[ source[ srcOffset + 3 ] ] << 24 ) >>> 24 );
int outBuff = ((DECODABET[source[srcOffset]] & 0xFF) << 18)
| ((DECODABET[source[srcOffset + 1]] & 0xFF) << 12)
| ((DECODABET[source[srcOffset + 2]] & 0xFF) << 6) | ((DECODABET[source[srcOffset + 3]] & 0xFF));
destination[destOffset] = (byte) (outBuff >> 16);
destination[destOffset + 1] = (byte) (outBuff >> 8);
destination[destOffset + 2] = (byte) (outBuff);
return 3;
}
} // end decodeToBytes
/**
* Low-level access to decoding ASCII characters in the form of a byte array. <strong>Ignores GUNZIP option, if it"s
* set.</strong> 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.
*
* @param source
* The Base64 encoded data
* @return decoded data
* @since 2.3.1
*/
public static byte[] decode(byte[] source) throws java.io.IOException {
byte[] decoded = null;
// try {
decoded = decode(source, 0, source.length, Base64.NO_OPTIONS);
// } catch( java.io.IOException ex ) {
// assert false : "IOExceptions only come from GZipping, which is turned off: " + ex.getMessage();
// }
return decoded;
}
/**
* Low-level access to decoding ASCII characters in the form of a byte array. <strong>Ignores GUNZIP option, if it"s
* set.</strong> 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.
*
* @param source
* The Base64 encoded data
* @param off
* The offset of where to begin decoding
* @param len
* The length of characters to decode
* @param options
* Can specify options such as alphabet type to use
* @return decoded data
* @throws java.io.IOException
* If bogus characters exist in source data
* @since 1.3
*/
public static byte[] decode(byte[] source, int off, int len, int options) throws java.io.IOException {
// Lots of error checking and exception throwing
if (source == null声明：该文观点仅代表作者本人，牛骨文系教育信息发布平台，牛骨文仅提供信息存储空间服务。
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