1   /**
2    * Copyright (c) 2000-2010 Liferay, Inc. All rights reserved.
3    *
4    * The contents of this file are subject to the terms of the Liferay Enterprise
5    * Subscription License ("License"). You may not use this file except in
6    * compliance with the License. You can obtain a copy of the License by
7    * contacting Liferay, Inc. See the License for the specific language governing
8    * permissions and limitations under the License, including but not limited to
9    * distribution rights of the Software.
10   *
11   *
12   *
13   */
14  
15  package com.liferay.portal.kernel.util;
16  
17  import com.liferay.portal.kernel.io.unsync.UnsyncByteArrayInputStream;
18  import com.liferay.portal.kernel.io.unsync.UnsyncByteArrayOutputStream;
19  import com.liferay.portal.kernel.log.Log;
20  import com.liferay.portal.kernel.log.LogFactoryUtil;
21  
22  import java.io.IOException;
23  import java.io.ObjectInputStream;
24  import java.io.ObjectOutputStream;
25  
26  /**
27   * <a href="Base64.java.html"><b><i>View Source</i></b></a>
28   *
29   * @author Brian Wing Shun Chan
30   */
31  public class Base64 {
32  
33      protected static char getChar(int sixbit) {
34          if (sixbit >= 0 && sixbit <= 25) {
35              return (char)(65 + sixbit);
36          }
37  
38          if (sixbit >= 26 && sixbit <= 51) {
39              return (char)(97 + (sixbit - 26));
40          }
41  
42          if (sixbit >= 52 && sixbit <= 61) {
43              return (char)(48 + (sixbit - 52));
44          }
45  
46          if (sixbit == 62) {
47              return CharPool.PLUS;
48          }
49  
50          return sixbit != 63 ? CharPool.QUESTION : CharPool.SLASH;
51      }
52  
53      protected static int getValue(char c) {
54          if ((c >= CharPool.UPPER_CASE_A) && (c <= CharPool.UPPER_CASE_Z)) {
55              return c - 65;
56          }
57  
58          if ((c >= CharPool.LOWER_CASE_A) && (c <= CharPool.LOWER_CASE_Z)) {
59              return (c - 97) + 26;
60          }
61  
62          if (c >= CharPool.NUMBER_0 && c <= CharPool.NUMBER_9) {
63              return (c - 48) + 52;
64          }
65  
66          if (c == CharPool.PLUS) {
67              return 62;
68          }
69  
70          if (c == CharPool.SLASH) {
71              return 63;
72          }
73  
74          return c != CharPool.EQUAL ? -1 : 0;
75      }
76  
77      public static String encode(byte raw[]) {
78          return encode(raw, 0, raw.length);
79      }
80  
81      public static String encode(byte raw[], int offset, int length) {
82          int lastIndex = Math.min(raw.length, offset + length);
83  
84          StringBuilder sb = new StringBuilder(
85              ((lastIndex - offset) / 3 + 1) * 4);
86  
87          for (int i = offset; i < lastIndex; i += 3) {
88              sb.append(encodeBlock(raw, i, lastIndex));
89          }
90  
91          return sb.toString();
92      }
93  
94      protected static char[] encodeBlock(byte raw[], int offset, int lastIndex) {
95          int block = 0;
96          int slack = lastIndex - offset - 1;
97          int end = slack < 2 ? slack : 2;
98  
99          for (int i = 0; i <= end; i++) {
100             byte b = raw[offset + i];
101 
102             int neuter = b >= 0 ? ((int) (b)) : b + 256;
103             block += neuter << 8 * (2 - i);
104         }
105 
106         char base64[] = new char[4];
107 
108         for (int i = 0; i < 4; i++) {
109             int sixbit = block >>> 6 * (3 - i) & 0x3f;
110             base64[i] = getChar(sixbit);
111         }
112 
113         if (slack < 1) {
114             base64[2] = CharPool.EQUAL;
115         }
116 
117         if (slack < 2) {
118             base64[3] = CharPool.EQUAL;
119         }
120 
121         return base64;
122     }
123 
124     public static byte[] decode(String base64) {
125         if (Validator.isNull(base64)) {
126             return new byte[0];
127         }
128 
129         int pad = 0;
130 
131         for (int i = base64.length() - 1; base64.charAt(i) == CharPool.EQUAL;
132                 i--) {
133 
134             pad++;
135         }
136 
137         int length = (base64.length() * 6) / 8 - pad;
138         byte raw[] = new byte[length];
139         int rawindex = 0;
140 
141         for (int i = 0; i < base64.length(); i += 4) {
142             int block = (getValue(base64.charAt(i)) << 18) +
143                         (getValue(base64.charAt(i + 1)) << 12) +
144                         (getValue(base64.charAt(i + 2)) << 6) +
145                         getValue(base64.charAt(i + 3));
146 
147             for (int j = 0; j < 3 && rawindex + j < raw.length; j++) {
148                 raw[rawindex + j] = (byte)(block >> 8 * (2 - j) & 0xff);
149             }
150 
151             rawindex += 3;
152         }
153 
154         return raw;
155     }
156 
157     public static String objectToString(Object o) {
158         if (o == null) {
159             return null;
160         }
161 
162         UnsyncByteArrayOutputStream ubaos = new UnsyncByteArrayOutputStream(
163             32000);
164 
165         try {
166             ObjectOutputStream os = new ObjectOutputStream(ubaos);
167 
168             os.flush();
169             os.writeObject(o);
170             os.flush();
171         }
172         catch (IOException e) {
173             _log.error(e, e);
174         }
175 
176         return encode(ubaos.unsafeGetByteArray(), 0, ubaos.size());
177     }
178 
179     public static Object stringToObject(String s) {
180         return stringToObject(s, null);
181     }
182 
183     public static Object stringToObject(String s, ClassLoader classLoader) {
184         if (s == null) {
185             return null;
186         }
187 
188         byte bytes[] = decode(s);
189 
190         UnsyncByteArrayInputStream ubais = new UnsyncByteArrayInputStream(
191             bytes);
192 
193         try {
194             ObjectInputStream is = null;
195 
196             if (classLoader == null) {
197                 is = new ObjectInputStream(ubais);
198             }
199             else {
200                 is = new ClassLoaderObjectInputStream(ubais, classLoader);
201             }
202 
203             return is.readObject();
204         }
205         catch (Exception e) {
206             _log.error(e, e);
207         }
208 
209         return null;
210     }
211 
212     private static Log _log = LogFactoryUtil.getLog(Base64.class);
213 
214 }