Source for gnu.javax.net.ssl.provider.Util

   1: /* Util.java -- Miscellaneous utility methods.
   2:    Copyright (C) 2006  Free Software Foundation, Inc.
   3: 
   4: This file is a part of GNU Classpath.
   5: 
   6: GNU Classpath is free software; you can redistribute it and/or modify
   7: it under the terms of the GNU General Public License as published by
   8: the Free Software Foundation; either version 2 of the License, or (at
   9: your option) any later version.
  10: 
  11: GNU Classpath is distributed in the hope that it will be useful, but
  12: WITHOUT ANY WARRANTY; without even the implied warranty of
  13: MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14: General Public License for more details.
  15: 
  16: You should have received a copy of the GNU General Public License
  17: along with GNU Classpath; if not, write to the Free Software
  18: Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301
  19: USA
  20: 
  21: Linking this library statically or dynamically with other modules is
  22: making a combined work based on this library.  Thus, the terms and
  23: conditions of the GNU General Public License cover the whole
  24: combination.
  25: 
  26: As a special exception, the copyright holders of this library give you
  27: permission to link this library with independent modules to produce an
  28: executable, regardless of the license terms of these independent
  29: modules, and to copy and distribute the resulting executable under
  30: terms of your choice, provided that you also meet, for each linked
  31: independent module, the terms and conditions of the license of that
  32: module.  An independent module is a module which is not derived from
  33: or based on this library.  If you modify this library, you may extend
  34: this exception to your version of the library, but you are not
  35: obligated to do so.  If you do not wish to do so, delete this
  36: exception statement from your version.  */
  37: 
  38: 
  39: package gnu.javax.net.ssl.provider;
  40: 
  41: import java.io.PrintWriter;
  42: import java.io.StringWriter;
  43: 
  44: import java.lang.reflect.Array;
  45: import java.lang.reflect.InvocationTargetException;
  46: import java.lang.reflect.Method;
  47: import java.math.BigInteger;
  48: 
  49: import java.nio.ByteBuffer;
  50: 
  51: import java.security.AccessController;
  52: import java.security.PrivilegedAction;
  53: import java.security.Security;
  54: 
  55: /**
  56:  * A collection of useful class methods.
  57:  *
  58:  * @author Casey Marshall (rsdio@metastatic.org)
  59:  */
  60: public final class Util
  61: {
  62: 
  63:   // Constants.
  64:   // -------------------------------------------------------------------------
  65: 
  66:   static final String HEX = "0123456789abcdef";
  67: 
  68:   // Static methods only.
  69:   private Util() { }
  70: 
  71:   // Class methods.
  72:   // -------------------------------------------------------------------------
  73: 
  74:   public static Object wrapBuffer(ByteBuffer buffer)
  75:   {
  76:     return wrapBuffer(buffer, "");
  77:   }
  78:   
  79:   public static Object wrapBuffer(ByteBuffer buffer, String prefix)
  80:   {
  81:     return new WrappedBuffer(buffer, prefix);
  82:   }
  83:   
  84:   private static class WrappedBuffer
  85:   {
  86:     private final ByteBuffer buffer;
  87:     private final String prefix;
  88:     
  89:     WrappedBuffer(ByteBuffer buffer, String prefix)
  90:     {
  91:       this.buffer = buffer;
  92:       this.prefix = prefix;
  93:     }
  94:     
  95:     public String toString()
  96:     {
  97:       return hexDump(buffer, prefix);
  98:     }
  99:   }
 100:   
 101:   /**
 102:    * Convert a hexadecimal string into its byte representation.
 103:    *
 104:    * @param hex The hexadecimal string.
 105:    * @return The converted bytes.
 106:    */
 107:   public static byte[] toByteArray(String hex)
 108:   {
 109:     hex = hex.toLowerCase();
 110:     byte[] buf = new byte[hex.length() / 2];
 111:     int j = 0;
 112:     for (int i = 0; i < buf.length; i++)
 113:       {
 114:         buf[i] = (byte) ((Character.digit(hex.charAt(j++), 16) << 4) |
 115:                           Character.digit(hex.charAt(j++), 16));
 116:       }
 117:     return buf;
 118:   }
 119: 
 120:   /**
 121:    * Convert a byte array to a hexadecimal string, as though it were a
 122:    * big-endian arbitrarily-sized integer.
 123:    *
 124:    * @param buf The bytes to format.
 125:    * @param off The offset to start at.
 126:    * @param len The number of bytes to format.
 127:    * @return A hexadecimal representation of the specified bytes.
 128:    */
 129:   public static String toHexString(byte[] buf, int off, int len)
 130:   {
 131:     StringBuffer str = new StringBuffer();
 132:     for (int i = 0; i < len; i++)
 133:       {
 134:         str.append(HEX.charAt(buf[i+off] >>> 4 & 0x0F));
 135:         str.append(HEX.charAt(buf[i+off] & 0x0F));
 136:       }
 137:     return str.toString();
 138:   }
 139: 
 140:   /**
 141:    * See {@link #toHexString(byte[],int,int)}.
 142:    */
 143:   public static String toHexString(byte[] buf)
 144:   {
 145:     return Util.toHexString(buf, 0, buf.length);
 146:   }
 147: 
 148:   /**
 149:    * Convert a byte array to a hexadecimal string, separating octets
 150:    * with the given character.
 151:    *
 152:    * @param buf The bytes to format.
 153:    * @param off The offset to start at.
 154:    * @param len The number of bytes to format.
 155:    * @param sep The character to insert between octets.
 156:    * @return A hexadecimal representation of the specified bytes.
 157:    */
 158:   public static String toHexString(byte[] buf, int off, int len, char sep)
 159:   {
 160:     StringBuffer str = new StringBuffer();
 161:     for (int i = 0; i < len; i++)
 162:       {
 163:         str.append(HEX.charAt(buf[i+off] >>> 4 & 0x0F));
 164:         str.append(HEX.charAt(buf[i+off] & 0x0F));
 165:         if (i < len - 1)
 166:           str.append(sep);
 167:       }
 168:     return str.toString();
 169:   }
 170: 
 171:   /**
 172:    * See {@link #toHexString(byte[],int,int,char)}.
 173:    */
 174:   public static String toHexString(byte[] buf, char sep)
 175:   {
 176:     return Util.toHexString(buf, 0, buf.length, sep);
 177:   }
 178: 
 179:   /**
 180:    * Create a representation of the given byte array similar to the
 181:    * output of <code>`hexdump -C'</code>, which is
 182:    *
 183:    * <p><pre>OFFSET  SIXTEEN-BYTES-IN-HEX  PRINTABLE-BYTES</pre>
 184:    *
 185:    * <p>The printable bytes show up as-is if they are printable and
 186:    * not a newline character, otherwise showing as '.'.
 187:    *
 188:    * @param buf The bytes to format.
 189:    * @param off The offset to start at.
 190:    * @param len The number of bytes to encode.
 191:    * @param prefix A string to prepend to every line.
 192:    * @return The formatted string.
 193:    */
 194:   public static String hexDump(byte[] buf, int off, int len, String prefix)
 195:   {
 196:     String nl = getProperty("line.separator");
 197:     StringBuffer str = new StringBuffer();
 198:     int i = 0;
 199:     while (i < len)
 200:       {
 201:         if (prefix != null)
 202:           str.append(prefix);
 203:         str.append(Util.formatInt(i+off, 16, 8));
 204:         str.append("  ");
 205:         String s = Util.toHexString(buf, i+off, Math.min(16, len-i), ' ');
 206:         str.append(s);
 207:         for (int j = s.length(); j < 49; j++)
 208:           str.append(" ");
 209:         for (int j = 0; j < Math.min(16, len - i); j++)
 210:           {
 211:             if ((buf[i+off+j] & 0xFF) < 0x20 || (buf[i+off+j] & 0xFF) > 0x7E)
 212:               str.append('.');
 213:             else
 214:               str.append((char) (buf[i+off+j] & 0xFF));
 215:           }
 216:         str.append(nl);
 217:         i += 16;
 218:       }
 219:     return str.toString();
 220:   }
 221: 
 222:   public static String hexDump (ByteBuffer buf)
 223:   {
 224:     return hexDump (buf, null);
 225:   }
 226: 
 227:   public static String hexDump (ByteBuffer buf, String prefix)
 228:   {
 229:     buf = buf.duplicate();
 230:     StringWriter str = new StringWriter ();
 231:     PrintWriter out = new PrintWriter (str);
 232:     int i = 0;
 233:     int len = buf.remaining();
 234:     byte[] line = new byte[16];
 235:     while (i < len)
 236:       {
 237:         if (prefix != null)
 238:           out.print(prefix);
 239:         out.print(Util.formatInt (i, 16, 8));
 240:         out.print("  ");
 241:         int l = Math.min(16, len - i);
 242:         buf.get(line, 0, l);
 243:         String s = Util.toHexString(line, 0, l, ' ');
 244:         out.print(s);
 245:         for (int j = s.length(); j < 49; j++)
 246:           out.print(' ');
 247:         for (int j = 0; j < l; j++)
 248:           {
 249:             int c = line[j] & 0xFF;
 250:             if (c < 0x20 || c > 0x7E)
 251:               out.print('.');
 252:             else
 253:               out.print((char) c);
 254:           }
 255:         out.println();
 256:         i += 16;
 257:       }
 258:     return str.toString();
 259:   }
 260: 
 261:   /**
 262:    * See {@link #hexDump(byte[],int,int,String)}.
 263:    */
 264:   public static String hexDump(byte[] buf, int off, int len)
 265:   {
 266:     return hexDump(buf, off, len, "");
 267:   }
 268: 
 269:   /**
 270:    * See {@link #hexDump(byte[],int,int,String)}.
 271:    */
 272:   public static String hexDump(byte[] buf, String prefix)
 273:   {
 274:     return hexDump(buf, 0, buf.length, prefix);
 275:   }
 276: 
 277:   /**
 278:    * See {@link #hexDump(byte[],int,int,String)}.
 279:    */
 280:   public static String hexDump(byte[] buf)
 281:   {
 282:     return hexDump(buf, 0, buf.length);
 283:   }
 284: 
 285:   /**
 286:    * Format an integer into the specified radix, zero-filled.
 287:    *
 288:    * @param i The integer to format.
 289:    * @param radix The radix to encode to.
 290:    * @param len The target length of the string. The string is
 291:    *   zero-padded to this length, but may be longer.
 292:    * @return The formatted integer.
 293:    */
 294:   public static String formatInt(int i, int radix, int len)
 295:   {
 296:     String s = Integer.toString(i, radix);
 297:     StringBuffer buf = new StringBuffer();
 298:     for (int j = 0; j < len - s.length(); j++)
 299:       buf.append("0");
 300:     buf.append(s);
 301:     return buf.toString();
 302:   }
 303: 
 304:   /**
 305:    * Concatenate two byte arrays into one.
 306:    *
 307:    * @param b1 The first byte array.
 308:    * @param b2 The second byte array.
 309:    * @return The concatenation of b1 and b2.
 310:    */
 311:   public static byte[] concat(byte[] b1, byte[] b2)
 312:   {
 313:     byte[] b3 = new byte[b1.length+b2.length];
 314:     System.arraycopy(b1, 0, b3, 0, b1.length);
 315:     System.arraycopy(b2, 0, b3, b1.length, b2.length);
 316:     return b3;
 317:   }
 318: 
 319:   /**
 320:    * See {@link #trim(byte[],int,int)}.
 321:    */
 322:   public static byte[] trim(byte[] buffer, int len)
 323:   {
 324:     return trim(buffer, 0, len);
 325:   }
 326: 
 327:   /**
 328:    * Returns a portion of a byte array, possibly zero-filled.
 329:    *
 330:    * @param buffer The byte array to trim.
 331:    * @param off The offset to begin reading at.
 332:    * @param len The number of bytes to return. This value can be larger
 333:    *        than <i>buffer.length - off</i>, in which case the rest of the
 334:    *        returned byte array will be filled with zeros.
 335:    * @throws IndexOutOfBoundsException If <i>off</i> or <i>len</i> is
 336:    *         negative, or if <i>off</i> is larger than the byte array's
 337:    *         length.
 338:    * @return The trimmed byte array.
 339:    */
 340:   public static byte[] trim(byte[] buffer, int off, int len)
 341:   {
 342:     if (off < 0 || len < 0 || off > buffer.length)
 343:       throw new IndexOutOfBoundsException("max=" + buffer.length +
 344:                                           " off=" + off + " len=" + len);
 345:     if (off == 0 && len == buffer.length)
 346:       return buffer;
 347:     byte[] b = new byte[len];
 348:     System.arraycopy(buffer, off, b, 0, Math.min(len, buffer.length - off));
 349:     return b;
 350:   }
 351: 
 352:   /**
 353:    * Returns the byte array representation of the given big integer with
 354:    * the leading zero byte (if any) trimmed off.
 355:    *
 356:    * @param bi The integer to trim.
 357:    * @return The byte representation of the big integer, with any leading
 358:    *   zero removed.
 359:    */
 360:   public static byte[] trim(BigInteger bi)
 361:   {
 362:     byte[] buf = bi.toByteArray();
 363:     if (buf[0] == 0x00 && !bi.equals(BigInteger.ZERO))
 364:       {
 365:         return trim(buf, 1, buf.length - 1);
 366:       }
 367:     else
 368:       {
 369:         return buf;
 370:       }
 371:   }
 372: 
 373:   /**
 374:    * Returns the integer value of <code>{@link
 375:    * java.lang.System#currentTimeMillis()} / 1000</code>.
 376:    *
 377:    * @return The current time, in seconds.
 378:    */
 379:   public static int unixTime()
 380:   {
 381:     return (int) (System.currentTimeMillis() / 1000L);
 382:   }
 383: 
 384:   /**
 385:    * Transform an Object array into another by calling the given method
 386:    * on each object. The returned object array will have the runtime
 387:    * type of <i>returnType</i>. For example, the following will transform
 388:    * array of objects into their String representations, returning a String
 389:    * array. For example:
 390:    *
 391:    * <blockquote><p><code>
 392:    * String[] strings = (String[]) Util.transform(array, String.class,
 393:    * "toString", null);
 394:    * </code></p></blockquote>
 395:    *
 396:    * <p>If any element of the given array is <tt>null</tt>, then that
 397:    * entry in the returned array will also be <tt>null</tt>.
 398:    *
 399:    * @param array The array to transform. It does not need to be of
 400:    *        uniform type.
 401:    * @param returnType The desired return type of the returned array.
 402:    *        This must by the <i>component</i> type, not the array type.
 403:    * @param method The name of the method to invoke from each object.
 404:    * @param args The arguments to pass to the method, or <tt>null</tt>
 405:    *        if the method takes no arguments.
 406:    * @throws InvocationTargetException If an exception occurs while
 407:    *         calling <i>method</i> of any object.
 408:    * @throws NoSuchMethodException If <i>method</i> is not the name of
 409:    *         a valid method of any component of the array.
 410:    * @throws ClassCastException If the returned object from the method
 411:    *         is not assignable to the return type.
 412:    * @throws IllegalArgumentException If <i>args</i> is not appropriate
 413:    *         for <i>method</i>
 414:    * @throws IllegalAccessException If <i>method</i> is not accessible.
 415:    * @throws SecurityException If <i>method</i> is not accessible.
 416:    * @return An array containing the output of <i>method</i> called on
 417:    *         each element of <i>array</i> with <i>args</i>. The return type
 418:    *         of the array will be an array of <i>returnType</i>.
 419:    */
 420:   static Object[] transform(Object[] array, Class returnType,
 421:                             String method, Object[] args)
 422:     throws InvocationTargetException, NoSuchMethodException,
 423:            IllegalAccessException
 424:   {
 425:     if (args == null)
 426:       args = new Object[0];
 427:     Object[] result = (Object[]) Array.newInstance(returnType, array.length);
 428:     Class[] argsClasses = new Class[args.length];
 429:     for (int i = 0; i < args.length; i++)
 430:       {
 431:         argsClasses[i] = args[i].getClass();
 432:       }
 433:     for (int i = 0; i < array.length; i++)
 434:       {
 435:         if (array[i] == null)
 436:           {
 437:             result[i] = null;
 438:             continue;
 439:           }
 440:         Class objClass = array[i].getClass();
 441:         Method objMethod = objClass.getMethod(method, argsClasses);
 442:         Object o = objMethod.invoke(array[i], args);
 443:         if (!returnType.isAssignableFrom(o.getClass()))
 444:           throw new ClassCastException();
 445:         result[i] = o;
 446:       }
 447:     return result;
 448:   }
 449: 
 450:   /**
 451:    * Get a system property as a privileged action.
 452:    *
 453:    * @param name The name of the property to get.
 454:    * @return The property named <i>name</i>, or null if the property is
 455:    *   not set.
 456:    * @throws SecurityException If the Jessie code still does not have
 457:    *   permission to read the property.
 458:    */
 459:   @Deprecated static String getProperty(final String name)
 460:   {
 461:     return (String) AccessController.doPrivileged(
 462:       new PrivilegedAction()
 463:       {
 464:         public Object run()
 465:         {
 466:           return System.getProperty(name);
 467:         }
 468:       }
 469:     );
 470:   }
 471: 
 472:   /**
 473:    * Get a security property as a privileged action.
 474:    *
 475:    * @param name The name of the property to get.
 476:    * @return The property named <i>name</i>, or null if the property is
 477:    *   not set.
 478:    * @throws SecurityException If the Jessie code still does not have
 479:    *   permission to read the property.
 480:    */
 481:   @Deprecated static String getSecurityProperty(final String name)
 482:   {
 483:     return (String) AccessController.doPrivileged(
 484:       new PrivilegedAction()
 485:       {
 486:         public Object run()
 487:         {
 488:           return Security.getProperty(name);
 489:         }
 490:       }
 491:     );
 492:   }
 493: }