001/* 002 * Licensed to the Apache Software Foundation (ASF) under one or more 003 * contributor license agreements. See the NOTICE file distributed with 004 * this work for additional information regarding copyright ownership. 005 * The ASF licenses this file to You under the Apache License, Version 2.0 006 * (the "License"); you may not use this file except in compliance with 007 * the License. You may obtain a copy of the License at 008 * 009 * http://www.apache.org/licenses/LICENSE-2.0 010 * 011 * Unless required by applicable law or agreed to in writing, software 012 * distributed under the License is distributed on an "AS IS" BASIS, 013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 014 * See the License for the specific language governing permissions and 015 * limitations under the License. 016 */ 017 018package org.apache.bcel.classfile; 019 020import java.io.ByteArrayInputStream; 021import java.io.ByteArrayOutputStream; 022import java.io.CharArrayReader; 023import java.io.CharArrayWriter; 024import java.io.FilterReader; 025import java.io.FilterWriter; 026import java.io.IOException; 027import java.io.PrintStream; 028import java.io.PrintWriter; 029import java.io.Reader; 030import java.io.Writer; 031import java.util.ArrayList; 032import java.util.List; 033import java.util.Locale; 034import java.util.zip.GZIPInputStream; 035import java.util.zip.GZIPOutputStream; 036 037import org.apache.bcel.Const; 038import org.apache.bcel.util.ByteSequence; 039 040/** 041 * Utility functions that do not really belong to any class in particular. 042 * 043 */ 044// @since 6.0 methods are no longer final 045public abstract class Utility { 046 047 private static int unwrap( final ThreadLocal<Integer> tl ) { 048 return tl.get().intValue(); 049 } 050 051 private static void wrap( final ThreadLocal<Integer> tl, final int value ) { 052 tl.set(Integer.valueOf(value)); 053 } 054 055 /* How many chars have been consumed 056 * during parsing in typeSignatureToString(). 057 * Read by methodSignatureToString(). 058 * Set by side effect, but only internally. 059 */ 060 private static ThreadLocal<Integer> consumed_chars = new ThreadLocal<Integer>() { 061 @Override 062 protected Integer initialValue() { 063 return Integer.valueOf(0); 064 } 065 }; 066 067 /* The `WIDE' instruction is used in the 068 * byte code to allow 16-bit wide indices 069 * for local variables. This opcode 070 * precedes an `ILOAD', e.g.. The opcode 071 * immediately following takes an extra 072 * byte which is combined with the 073 * following byte to form a 074 * 16-bit value. 075 */ 076 private static boolean wide = false; 077 078 079 /** 080 * Convert bit field of flags into string such as `static final'. 081 * 082 * @param access_flags Access flags 083 * @return String representation of flags 084 */ 085 public static String accessToString( final int access_flags ) { 086 return accessToString(access_flags, false); 087 } 088 089 090 /** 091 * Convert bit field of flags into string such as `static final'. 092 * 093 * Special case: Classes compiled with new compilers and with the 094 * `ACC_SUPER' flag would be said to be "synchronized". This is 095 * because SUN used the same value for the flags `ACC_SUPER' and 096 * `ACC_SYNCHRONIZED'. 097 * 098 * @param access_flags Access flags 099 * @param for_class access flags are for class qualifiers ? 100 * @return String representation of flags 101 */ 102 public static String accessToString( final int access_flags, final boolean for_class ) { 103 final StringBuilder buf = new StringBuilder(); 104 int p = 0; 105 for (int i = 0; p < Const.MAX_ACC_FLAG_I; i++) { // Loop through known flags 106 p = pow2(i); 107 if ((access_flags & p) != 0) { 108 /* Special case: Classes compiled with new compilers and with the 109 * `ACC_SUPER' flag would be said to be "synchronized". This is 110 * because SUN used the same value for the flags `ACC_SUPER' and 111 * `ACC_SYNCHRONIZED'. 112 */ 113 if (for_class && ((p == Const.ACC_SUPER) || (p == Const.ACC_INTERFACE))) { 114 continue; 115 } 116 buf.append(Const.getAccessName(i)).append(" "); 117 } 118 } 119 return buf.toString().trim(); 120 } 121 122 123 /** 124 * @param access_flags the class flags 125 * 126 * @return "class" or "interface", depending on the ACC_INTERFACE flag 127 */ 128 public static String classOrInterface( final int access_flags ) { 129 return ((access_flags & Const.ACC_INTERFACE) != 0) ? "interface" : "class"; 130 } 131 132 133 /** 134 * Disassemble a byte array of JVM byte codes starting from code line 135 * `index' and return the disassembled string representation. Decode only 136 * `num' opcodes (including their operands), use -1 if you want to 137 * decompile everything. 138 * 139 * @param code byte code array 140 * @param constant_pool Array of constants 141 * @param index offset in `code' array 142 * <EM>(number of opcodes, not bytes!)</EM> 143 * @param length number of opcodes to decompile, -1 for all 144 * @param verbose be verbose, e.g. print constant pool index 145 * @return String representation of byte codes 146 */ 147 public static String codeToString( final byte[] code, final ConstantPool constant_pool, final int index, 148 final int length, final boolean verbose ) { 149 final StringBuilder buf = new StringBuilder(code.length * 20); // Should be sufficient // CHECKSTYLE IGNORE MagicNumber 150 try (ByteSequence stream = new ByteSequence(code)) { 151 for (int i = 0; i < index; i++) { 152 codeToString(stream, constant_pool, verbose); 153 } 154 for (int i = 0; stream.available() > 0; i++) { 155 if ((length < 0) || (i < length)) { 156 final String indices = fillup(stream.getIndex() + ":", 6, true, ' '); 157 buf.append(indices).append(codeToString(stream, constant_pool, verbose)).append('\n'); 158 } 159 } 160 } catch (final IOException e) { 161 throw new ClassFormatException("Byte code error: " + buf.toString(), e); 162 } 163 return buf.toString(); 164 } 165 166 167 public static String codeToString( final byte[] code, final ConstantPool constant_pool, final int index, final int length ) { 168 return codeToString(code, constant_pool, index, length, true); 169 } 170 171 172 /** 173 * Disassemble a stream of byte codes and return the 174 * string representation. 175 * 176 * @param bytes stream of bytes 177 * @param constant_pool Array of constants 178 * @param verbose be verbose, e.g. print constant pool index 179 * @return String representation of byte code 180 * 181 * @throws IOException if a failure from reading from the bytes argument occurs 182 */ 183 public static String codeToString( final ByteSequence bytes, final ConstantPool constant_pool, 184 final boolean verbose ) throws IOException { 185 final short opcode = (short) bytes.readUnsignedByte(); 186 int default_offset = 0; 187 int low; 188 int high; 189 int npairs; 190 int index; 191 int vindex; 192 int constant; 193 int[] match; 194 int[] jump_table; 195 int no_pad_bytes = 0; 196 int offset; 197 final StringBuilder buf = new StringBuilder(Const.getOpcodeName(opcode)); 198 /* Special case: Skip (0-3) padding bytes, i.e., the 199 * following bytes are 4-byte-aligned 200 */ 201 if ((opcode == Const.TABLESWITCH) || (opcode == Const.LOOKUPSWITCH)) { 202 final int remainder = bytes.getIndex() % 4; 203 no_pad_bytes = (remainder == 0) ? 0 : 4 - remainder; 204 for (int i = 0; i < no_pad_bytes; i++) { 205 byte b; 206 if ((b = bytes.readByte()) != 0) { 207 System.err.println("Warning: Padding byte != 0 in " 208 + Const.getOpcodeName(opcode) + ":" + b); 209 } 210 } 211 // Both cases have a field default_offset in common 212 default_offset = bytes.readInt(); 213 } 214 switch (opcode) { 215 /* Table switch has variable length arguments. 216 */ 217 case Const.TABLESWITCH: 218 low = bytes.readInt(); 219 high = bytes.readInt(); 220 offset = bytes.getIndex() - 12 - no_pad_bytes - 1; 221 default_offset += offset; 222 buf.append("\tdefault = ").append(default_offset).append(", low = ").append(low) 223 .append(", high = ").append(high).append("("); 224 jump_table = new int[high - low + 1]; 225 for (int i = 0; i < jump_table.length; i++) { 226 jump_table[i] = offset + bytes.readInt(); 227 buf.append(jump_table[i]); 228 if (i < jump_table.length - 1) { 229 buf.append(", "); 230 } 231 } 232 buf.append(")"); 233 break; 234 /* Lookup switch has variable length arguments. 235 */ 236 case Const.LOOKUPSWITCH: { 237 npairs = bytes.readInt(); 238 offset = bytes.getIndex() - 8 - no_pad_bytes - 1; 239 match = new int[npairs]; 240 jump_table = new int[npairs]; 241 default_offset += offset; 242 buf.append("\tdefault = ").append(default_offset).append(", npairs = ").append( 243 npairs).append(" ("); 244 for (int i = 0; i < npairs; i++) { 245 match[i] = bytes.readInt(); 246 jump_table[i] = offset + bytes.readInt(); 247 buf.append("(").append(match[i]).append(", ").append(jump_table[i]).append(")"); 248 if (i < npairs - 1) { 249 buf.append(", "); 250 } 251 } 252 buf.append(")"); 253 } 254 break; 255 /* Two address bytes + offset from start of byte stream form the 256 * jump target 257 */ 258 case Const.GOTO: 259 case Const.IFEQ: 260 case Const.IFGE: 261 case Const.IFGT: 262 case Const.IFLE: 263 case Const.IFLT: 264 case Const.JSR: 265 case Const.IFNE: 266 case Const.IFNONNULL: 267 case Const.IFNULL: 268 case Const.IF_ACMPEQ: 269 case Const.IF_ACMPNE: 270 case Const.IF_ICMPEQ: 271 case Const.IF_ICMPGE: 272 case Const.IF_ICMPGT: 273 case Const.IF_ICMPLE: 274 case Const.IF_ICMPLT: 275 case Const.IF_ICMPNE: 276 buf.append("\t\t#").append((bytes.getIndex() - 1) + bytes.readShort()); 277 break; 278 /* 32-bit wide jumps 279 */ 280 case Const.GOTO_W: 281 case Const.JSR_W: 282 buf.append("\t\t#").append((bytes.getIndex() - 1) + bytes.readInt()); 283 break; 284 /* Index byte references local variable (register) 285 */ 286 case Const.ALOAD: 287 case Const.ASTORE: 288 case Const.DLOAD: 289 case Const.DSTORE: 290 case Const.FLOAD: 291 case Const.FSTORE: 292 case Const.ILOAD: 293 case Const.ISTORE: 294 case Const.LLOAD: 295 case Const.LSTORE: 296 case Const.RET: 297 if (wide) { 298 vindex = bytes.readUnsignedShort(); 299 wide = false; // Clear flag 300 } else { 301 vindex = bytes.readUnsignedByte(); 302 } 303 buf.append("\t\t%").append(vindex); 304 break; 305 /* 306 * Remember wide byte which is used to form a 16-bit address in the 307 * following instruction. Relies on that the method is called again with 308 * the following opcode. 309 */ 310 case Const.WIDE: 311 wide = true; 312 buf.append("\t(wide)"); 313 break; 314 /* Array of basic type. 315 */ 316 case Const.NEWARRAY: 317 buf.append("\t\t<").append(Const.getTypeName(bytes.readByte())).append(">"); 318 break; 319 /* Access object/class fields. 320 */ 321 case Const.GETFIELD: 322 case Const.GETSTATIC: 323 case Const.PUTFIELD: 324 case Const.PUTSTATIC: 325 index = bytes.readUnsignedShort(); 326 buf.append("\t\t").append( 327 constant_pool.constantToString(index, Const.CONSTANT_Fieldref)).append( 328 verbose ? " (" + index + ")" : ""); 329 break; 330 /* Operands are references to classes in constant pool 331 */ 332 case Const.NEW: 333 case Const.CHECKCAST: 334 buf.append("\t"); 335 //$FALL-THROUGH$ 336 case Const.INSTANCEOF: 337 index = bytes.readUnsignedShort(); 338 buf.append("\t<").append( 339 constant_pool.constantToString(index, Const.CONSTANT_Class)) 340 .append(">").append(verbose ? " (" + index + ")" : ""); 341 break; 342 /* Operands are references to methods in constant pool 343 */ 344 case Const.INVOKESPECIAL: 345 case Const.INVOKESTATIC: 346 index = bytes.readUnsignedShort(); 347 final Constant c = constant_pool.getConstant(index); 348 // With Java8 operand may be either a CONSTANT_Methodref 349 // or a CONSTANT_InterfaceMethodref. (markro) 350 buf.append("\t").append( 351 constant_pool.constantToString(index, c.getTag())) 352 .append(verbose ? " (" + index + ")" : ""); 353 break; 354 case Const.INVOKEVIRTUAL: 355 index = bytes.readUnsignedShort(); 356 buf.append("\t").append( 357 constant_pool.constantToString(index, Const.CONSTANT_Methodref)) 358 .append(verbose ? " (" + index + ")" : ""); 359 break; 360 case Const.INVOKEINTERFACE: 361 index = bytes.readUnsignedShort(); 362 final int nargs = bytes.readUnsignedByte(); // historical, redundant 363 buf.append("\t").append( 364 constant_pool 365 .constantToString(index, Const.CONSTANT_InterfaceMethodref)) 366 .append(verbose ? " (" + index + ")\t" : "").append(nargs).append("\t") 367 .append(bytes.readUnsignedByte()); // Last byte is a reserved space 368 break; 369 case Const.INVOKEDYNAMIC: 370 index = bytes.readUnsignedShort(); 371 buf.append("\t").append( 372 constant_pool 373 .constantToString(index, Const.CONSTANT_InvokeDynamic)) 374 .append(verbose ? " (" + index + ")\t" : "") 375 .append(bytes.readUnsignedByte()) // Thrid byte is a reserved space 376 .append(bytes.readUnsignedByte()); // Last byte is a reserved space 377 break; 378 /* Operands are references to items in constant pool 379 */ 380 case Const.LDC_W: 381 case Const.LDC2_W: 382 index = bytes.readUnsignedShort(); 383 buf.append("\t\t").append( 384 constant_pool.constantToString(index, constant_pool.getConstant(index) 385 .getTag())).append(verbose ? " (" + index + ")" : ""); 386 break; 387 case Const.LDC: 388 index = bytes.readUnsignedByte(); 389 buf.append("\t\t").append( 390 constant_pool.constantToString(index, constant_pool.getConstant(index) 391 .getTag())).append(verbose ? " (" + index + ")" : ""); 392 break; 393 /* Array of references. 394 */ 395 case Const.ANEWARRAY: 396 index = bytes.readUnsignedShort(); 397 buf.append("\t\t<").append( 398 compactClassName(constant_pool.getConstantString(index, 399 Const.CONSTANT_Class), false)).append(">").append( 400 verbose ? " (" + index + ")" : ""); 401 break; 402 /* Multidimensional array of references. 403 */ 404 case Const.MULTIANEWARRAY: { 405 index = bytes.readUnsignedShort(); 406 final int dimensions = bytes.readUnsignedByte(); 407 buf.append("\t<").append( 408 compactClassName(constant_pool.getConstantString(index, 409 Const.CONSTANT_Class), false)).append(">\t").append(dimensions) 410 .append(verbose ? " (" + index + ")" : ""); 411 } 412 break; 413 /* Increment local variable. 414 */ 415 case Const.IINC: 416 if (wide) { 417 vindex = bytes.readUnsignedShort(); 418 constant = bytes.readShort(); 419 wide = false; 420 } else { 421 vindex = bytes.readUnsignedByte(); 422 constant = bytes.readByte(); 423 } 424 buf.append("\t\t%").append(vindex).append("\t").append(constant); 425 break; 426 default: 427 if (Const.getNoOfOperands(opcode) > 0) { 428 for (int i = 0; i < Const.getOperandTypeCount(opcode); i++) { 429 buf.append("\t\t"); 430 switch (Const.getOperandType(opcode, i)) { 431 case Const.T_BYTE: 432 buf.append(bytes.readByte()); 433 break; 434 case Const.T_SHORT: 435 buf.append(bytes.readShort()); 436 break; 437 case Const.T_INT: 438 buf.append(bytes.readInt()); 439 break; 440 default: // Never reached 441 throw new IllegalStateException("Unreachable default case reached!"); 442 } 443 } 444 } 445 } 446 return buf.toString(); 447 } 448 449 450 public static String codeToString( final ByteSequence bytes, final ConstantPool constant_pool ) 451 throws IOException { 452 return codeToString(bytes, constant_pool, true); 453 } 454 455 456 /** 457 * Shorten long class names, <em>java/lang/String</em> becomes 458 * <em>String</em>. 459 * 460 * @param str The long class name 461 * @return Compacted class name 462 */ 463 public static String compactClassName( final String str ) { 464 return compactClassName(str, true); 465 } 466 467 468 /** 469 * Shorten long class names, <em>java/lang/String</em> becomes 470 * <em>java.lang.String</em>, 471 * e.g.. If <em>chopit</em> is <em>true</em> the prefix <em>java.lang</em> 472 * is also removed. 473 * 474 * @param str The long class name 475 * @param chopit flag that determines whether chopping is executed or not 476 * @return Compacted class name 477 */ 478 public static String compactClassName( final String str, final boolean chopit ) { 479 return compactClassName(str, "java.lang.", chopit); 480 } 481 482 483 /** 484 * Shorten long class name <em>str</em>, i.e., chop off the <em>prefix</em>, 485 * if the 486 * class name starts with this string and the flag <em>chopit</em> is true. 487 * Slashes <em>/</em> are converted to dots <em>.</em>. 488 * 489 * @param str The long class name 490 * @param prefix The prefix the get rid off 491 * @param chopit flag that determines whether chopping is executed or not 492 * @return Compacted class name 493 */ 494 public static String compactClassName( String str, final String prefix, final boolean chopit ) { 495 final int len = prefix.length(); 496 str = str.replace('/', '.'); // Is `/' on all systems, even DOS 497 if (chopit) { 498 // If string starts with `prefix' and contains no further dots 499 if (str.startsWith(prefix) && (str.substring(len).indexOf('.') == -1)) { 500 str = str.substring(len); 501 } 502 } 503 return str; 504 } 505 506 507 /** 508 * @return `flag' with bit `i' set to 1 509 */ 510 public static int setBit( final int flag, final int i ) { 511 return flag | pow2(i); 512 } 513 514 515 /** 516 * @return `flag' with bit `i' set to 0 517 */ 518 public static int clearBit( final int flag, final int i ) { 519 final int bit = pow2(i); 520 return (flag & bit) == 0 ? flag : flag ^ bit; 521 } 522 523 524 /** 525 * @return true, if bit `i' in `flag' is set 526 */ 527 public static boolean isSet( final int flag, final int i ) { 528 return (flag & pow2(i)) != 0; 529 } 530 531 532 /** 533 * Converts string containing the method return and argument types 534 * to a byte code method signature. 535 * 536 * @param ret Return type of method 537 * @param argv Types of method arguments 538 * @return Byte code representation of method signature 539 * 540 * @throws ClassFormatException if the signature is for Void 541 */ 542 public static String methodTypeToSignature( final String ret, final String[] argv ) 543 throws ClassFormatException { 544 final StringBuilder buf = new StringBuilder("("); 545 String str; 546 if (argv != null) { 547 for (final String element : argv) { 548 str = getSignature(element); 549 if (str.endsWith("V")) { 550 throw new ClassFormatException("Invalid type: " + element); 551 } 552 buf.append(str); 553 } 554 } 555 str = getSignature(ret); 556 buf.append(")").append(str); 557 return buf.toString(); 558 } 559 560 561 /** 562 * Converts argument list portion of method signature to string with all class names compacted. 563 * 564 * @param signature Method signature 565 * @return String Array of argument types 566 * @throws ClassFormatException 567 */ 568 public static String[] methodSignatureArgumentTypes( final String signature ) 569 throws ClassFormatException { 570 return methodSignatureArgumentTypes(signature, true); 571 } 572 573 574 /** 575 * Converts argument list portion of method signature to string. 576 * 577 * @param signature Method signature 578 * @param chopit flag that determines whether chopping is executed or not 579 * @return String Array of argument types 580 * @throws ClassFormatException 581 */ 582 public static String[] methodSignatureArgumentTypes( final String signature, final boolean chopit ) 583 throws ClassFormatException { 584 final List<String> vec = new ArrayList<>(); 585 int index; 586 try { 587 // Skip any type arguments to read argument declarations between `(' and `)' 588 index = signature.indexOf('(') + 1; 589 if (index <= 0) { 590 throw new ClassFormatException("Invalid method signature: " + signature); 591 } 592 while (signature.charAt(index) != ')') { 593 vec.add(typeSignatureToString(signature.substring(index), chopit)); 594 //corrected concurrent private static field acess 595 index += unwrap(consumed_chars); // update position 596 } 597 } catch (final StringIndexOutOfBoundsException e) { // Should never occur 598 throw new ClassFormatException("Invalid method signature: " + signature, e); 599 } 600 return vec.toArray(new String[vec.size()]); 601 } 602 603 604 /** 605 * Converts return type portion of method signature to string with all class names compacted. 606 * 607 * @param signature Method signature 608 * @return String representation of method return type 609 * @throws ClassFormatException 610 */ 611 public static String methodSignatureReturnType( final String signature ) throws ClassFormatException { 612 return methodSignatureReturnType(signature, true); 613 } 614 615 616 /** 617 * Converts return type portion of method signature to string. 618 * 619 * @param signature Method signature 620 * @param chopit flag that determines whether chopping is executed or not 621 * @return String representation of method return type 622 * @throws ClassFormatException 623 */ 624 public static String methodSignatureReturnType( final String signature, final boolean chopit ) throws ClassFormatException { 625 int index; 626 String type; 627 try { 628 // Read return type after `)' 629 index = signature.lastIndexOf(')') + 1; 630 if (index <= 0) { 631 throw new ClassFormatException("Invalid method signature: " + signature); 632 } 633 type = typeSignatureToString(signature.substring(index), chopit); 634 } catch (final StringIndexOutOfBoundsException e) { // Should never occur 635 throw new ClassFormatException("Invalid method signature: " + signature, e); 636 } 637 return type; 638 } 639 640 641 /** 642 * Converts method signature to string with all class names compacted. 643 * 644 * @param signature to convert 645 * @param name of method 646 * @param access flags of method 647 * @return Human readable signature 648 */ 649 public static String methodSignatureToString( final String signature, final String name, final String access ) { 650 return methodSignatureToString(signature, name, access, true); 651 } 652 653 654 /** 655 * Converts method signature to string. 656 * 657 * @param signature to convert 658 * @param name of method 659 * @param access flags of method 660 * @param chopit flag that determines whether chopping is executed or not 661 * @return Human readable signature 662 */ 663 public static String methodSignatureToString( final String signature, final String name, final String access, final boolean chopit ) { 664 return methodSignatureToString(signature, name, access, chopit, null); 665 } 666 667 668 /** 669 * This method converts a method signature string into a Java type declaration like 670 * `void main(String[])' and throws a `ClassFormatException' when the parsed 671 * type is invalid. 672 * 673 * @param signature Method signature 674 * @param name Method name 675 * @param access Method access rights 676 * @param chopit flag that determines whether chopping is executed or not 677 * @param vars the LocalVariableTable for the method 678 * @return Java type declaration 679 * @throws ClassFormatException 680 */ 681 public static String methodSignatureToString( final String signature, final String name, 682 final String access, final boolean chopit, final LocalVariableTable vars ) throws ClassFormatException { 683 final StringBuilder buf = new StringBuilder("("); 684 String type; 685 int index; 686 int var_index = access.contains("static") ? 0 : 1; 687 try { 688 // Skip any type arguments to read argument declarations between `(' and `)' 689 index = signature.indexOf('(') + 1; 690 if (index <= 0) { 691 throw new ClassFormatException("Invalid method signature: " + signature); 692 } 693 while (signature.charAt(index) != ')') { 694 final String param_type = typeSignatureToString(signature.substring(index), chopit); 695 buf.append(param_type); 696 if (vars != null) { 697 final LocalVariable l = vars.getLocalVariable(var_index, 0); 698 if (l != null) { 699 buf.append(" ").append(l.getName()); 700 } 701 } else { 702 buf.append(" arg").append(var_index); 703 } 704 if ("double".equals(param_type) || "long".equals(param_type)) { 705 var_index += 2; 706 } else { 707 var_index++; 708 } 709 buf.append(", "); 710 //corrected concurrent private static field acess 711 index += unwrap(consumed_chars); // update position 712 } 713 index++; // update position 714 // Read return type after `)' 715 type = typeSignatureToString(signature.substring(index), chopit); 716 } catch (final StringIndexOutOfBoundsException e) { // Should never occur 717 throw new ClassFormatException("Invalid method signature: " + signature, e); 718 } 719 // ignore any throws information in the signature 720 if (buf.length() > 1) { 721 buf.setLength(buf.length() - 2); 722 } 723 buf.append(")"); 724 return access + ((access.length() > 0) ? " " : "") + // May be an empty string 725 type + " " + name + buf.toString(); 726 } 727 728 729 private static int pow2( final int n ) { 730 return 1 << n; 731 } 732 733 734 /** 735 * Replace all occurrences of <em>old</em> in <em>str</em> with <em>new</em>. 736 * 737 * @param str String to permute 738 * @param old String to be replaced 739 * @param new_ Replacement string 740 * @return new String object 741 */ 742 public static String replace( String str, final String old, final String new_ ) { 743 int index; 744 int old_index; 745 try { 746 if (str.contains(old)) { // `old' found in str 747 final StringBuilder buf = new StringBuilder(); 748 old_index = 0; // String start offset 749 // While we have something to replace 750 while ((index = str.indexOf(old, old_index)) != -1) { 751 buf.append(str.substring(old_index, index)); // append prefix 752 buf.append(new_); // append replacement 753 old_index = index + old.length(); // Skip `old'.length chars 754 } 755 buf.append(str.substring(old_index)); // append rest of string 756 str = buf.toString(); 757 } 758 } catch (final StringIndexOutOfBoundsException e) { // Should not occur 759 System.err.println(e); 760 } 761 return str; 762 } 763 764 765 /** 766 * WARNING: 767 * 768 * There is some nomenclature confusion through much of the BCEL code base with 769 * respect to the terms Descriptor and Signature. For the offical definitions see: 770 * 771 * @see <a href="https://docs.oracle.com/javase/specs/jvms/se8/html/jvms-4.html#jvms-4.3"> 772 * Descriptors in The Java Virtual Machine Specification</a> 773 * 774 * @see <a href="https://docs.oracle.com/javase/specs/jvms/se8/html/jvms-4.html#jvms-4.7.9.1"> 775 * Signatures in The Java Virtual Machine Specification</a> 776 * 777 * In brief, a descriptor is a string representing the type of a field or method. 778 * Signatures are similar, but more complex. Signatures are used to encode declarations 779 * written in the Java programming language that use types outside the type system of the 780 * Java Virtual Machine. They are used to describe the type of any class, interface, 781 * constructor, method or field whose declaration uses type variables or parameterized types. 782 * 783 * To parse a descriptor, call typeSignatureToString. 784 * To parse a signature, call signatureToString. 785 * 786 * Note that if the signature string is a single, non-generic item, the call to 787 * signatureToString reduces to a call to typeSignatureToString. 788 * Also note, that if you only wish to parse the first item in a longer signature 789 * string, you should call typeSignatureToString directly. 790 */ 791 792 793 /** 794 * Converts a signature to a string with all class names compacted. 795 * Class, Method and Type signatures are supported. 796 * Enum and Interface signatures are not supported. 797 * 798 * @param signature signature to convert 799 * @return String containg human readable signature 800 */ 801 public static String signatureToString( final String signature ) { 802 return signatureToString(signature, true); 803 } 804 805 806 /** 807 * Converts a signature to a string. 808 * Class, Method and Type signatures are supported. 809 * Enum and Interface signatures are not supported. 810 * 811 * @param signature signature to convert 812 * @param chopit flag that determines whether chopping is executed or not 813 * @return String containg human readable signature 814 */ 815 public static String signatureToString( final String signature, final boolean chopit ) { 816 String type = ""; 817 String typeParams = ""; 818 int index = 0; 819 if (signature.charAt(0) == '<') { 820 // we have type paramters 821 typeParams = typeParamTypesToString(signature, chopit); 822 index += unwrap(consumed_chars); // update position 823 } 824 if (signature.charAt(index) == '(') { 825 // We have a Method signature. 826 // add types of arguments 827 type = typeParams + typeSignaturesToString(signature.substring(index), chopit, ')'); 828 index += unwrap(consumed_chars); // update position 829 // add return type 830 type = type + typeSignatureToString(signature.substring(index), chopit); 831 index += unwrap(consumed_chars); // update position 832 // ignore any throws information in the signature 833 return type; 834 } 835 // Could be Class or Type... 836 type = typeSignatureToString(signature.substring(index), chopit); 837 index += unwrap(consumed_chars); // update position 838 if ((typeParams.length() == 0) && (index == signature.length())) { 839 // We have a Type signature. 840 return type; 841 } 842 // We have a Class signature. 843 final StringBuilder typeClass = new StringBuilder(typeParams); 844 typeClass.append(" extends "); 845 typeClass.append(type); 846 if (index < signature.length()) { 847 typeClass.append(" implements "); 848 typeClass.append(typeSignatureToString(signature.substring(index), chopit)); 849 index += unwrap(consumed_chars); // update position 850 } 851 while (index < signature.length()) { 852 typeClass.append(", "); 853 typeClass.append(typeSignatureToString(signature.substring(index), chopit)); 854 index += unwrap(consumed_chars); // update position 855 } 856 return typeClass.toString(); 857 } 858 859 860 /** 861 * Converts a type parameter list signature to a string. 862 * 863 * @param signature signature to convert 864 * @param chopit flag that determines whether chopping is executed or not 865 * @return String containg human readable signature 866 */ 867 private static String typeParamTypesToString( final String signature, final boolean chopit ) { 868 // The first character is guranteed to be '<' 869 final StringBuilder typeParams = new StringBuilder("<"); 870 int index = 1; // skip the '<' 871 // get the first TypeParameter 872 typeParams.append(typeParamTypeToString(signature.substring(index), chopit)); 873 index += unwrap(consumed_chars); // update position 874 // are there more TypeParameters? 875 while (signature.charAt(index) != '>') { 876 typeParams.append(", "); 877 typeParams.append(typeParamTypeToString(signature.substring(index), chopit)); 878 index += unwrap(consumed_chars); // update position 879 } 880 wrap(consumed_chars, index + 1); // account for the '>' char 881 return typeParams.append(">").toString(); 882 } 883 884 885 /** 886 * Converts a type parameter signature to a string. 887 * 888 * @param signature signature to convert 889 * @param chopit flag that determines whether chopping is executed or not 890 * @return String containg human readable signature 891 */ 892 private static String typeParamTypeToString( final String signature, final boolean chopit ) { 893 int index = signature.indexOf(':'); 894 if (index <= 0) { 895 throw new ClassFormatException("Invalid type parameter signature: " + signature); 896 } 897 // get the TypeParameter identifier 898 final StringBuilder typeParam = new StringBuilder(signature.substring(0, index)); 899 index++; // account for the ':' 900 if (signature.charAt(index) != ':') { 901 // we have a class bound 902 typeParam.append(" extends "); 903 typeParam.append(typeSignatureToString(signature.substring(index), chopit)); 904 index += unwrap(consumed_chars); // update position 905 } 906 // look for interface bounds 907 while (signature.charAt(index) == ':') { 908 index++; // skip over the ':' 909 typeParam.append(" & "); 910 typeParam.append(typeSignatureToString(signature.substring(index), chopit)); 911 index += unwrap(consumed_chars); // update position 912 } 913 wrap(consumed_chars, index); 914 return typeParam.toString(); 915 } 916 917 918 /** 919 * Converts a list of type signatures to a string. 920 * 921 * @param signature signature to convert 922 * @param chopit flag that determines whether chopping is executed or not 923 * @param term character indicating the end of the list 924 * @return String containg human readable signature 925 */ 926 private static String typeSignaturesToString( final String signature, final boolean chopit, final char term ) { 927 // The first character will be an 'open' that matches the 'close' contained in term. 928 final StringBuilder typeList = new StringBuilder(signature.substring(0, 1)); 929 int index = 1; // skip the 'open' character 930 // get the first Type in the list 931 if (signature.charAt(index) != term) { 932 typeList.append(typeSignatureToString(signature.substring(index), chopit)); 933 index += unwrap(consumed_chars); // update position 934 } 935 // are there more types in the list? 936 while (signature.charAt(index) != term) { 937 typeList.append(", "); 938 typeList.append(typeSignatureToString(signature.substring(index), chopit)); 939 index += unwrap(consumed_chars); // update position 940 } 941 wrap(consumed_chars, index + 1); // account for the term char 942 return typeList.append(term).toString(); 943 } 944 945 946 /** 947 * 948 * This method converts a type signature string into a Java type declaration such as 949 * `String[]' and throws a `ClassFormatException' when the parsed type is invalid. 950 * 951 * @param signature type signature 952 * @param chopit flag that determines whether chopping is executed or not 953 * @return string containing human readable type signature 954 * @throws ClassFormatException 955 * @since 6.4.0 956 */ 957 public static String typeSignatureToString( final String signature, final boolean chopit ) throws ClassFormatException { 958 //corrected concurrent private static field acess 959 wrap(consumed_chars, 1); // This is the default, read just one char like `B' 960 try { 961 switch (signature.charAt(0)) { 962 case 'B': 963 return "byte"; 964 case 'C': 965 return "char"; 966 case 'D': 967 return "double"; 968 case 'F': 969 return "float"; 970 case 'I': 971 return "int"; 972 case 'J': 973 return "long"; 974 case 'T': { // TypeVariableSignature 975 final int index = signature.indexOf(';'); // Look for closing `;' 976 if (index < 0) { 977 throw new ClassFormatException("Invalid type variable signature: " + signature); 978 } 979 //corrected concurrent private static field acess 980 wrap(consumed_chars, index + 1); // "Tblabla;" `T' and `;' are removed 981 return compactClassName(signature.substring(1, index), chopit); 982 } 983 case 'L': { // Full class name 984 // should this be a while loop? can there be more than 985 // one generic clause? (markro) 986 int fromIndex = signature.indexOf('<'); // generic type? 987 if (fromIndex < 0) { 988 fromIndex = 0; 989 } else { 990 fromIndex = signature.indexOf('>', fromIndex); 991 if (fromIndex < 0) { 992 throw new ClassFormatException("Invalid signature: " + signature); 993 } 994 } 995 final int index = signature.indexOf(';', fromIndex); // Look for closing `;' 996 if (index < 0) { 997 throw new ClassFormatException("Invalid signature: " + signature); 998 } 999 1000 // check to see if there are any TypeArguments 1001 final int bracketIndex = signature.substring(0, index).indexOf('<'); 1002 if (bracketIndex < 0) { 1003 // just a class identifier 1004 wrap(consumed_chars, index + 1); // "Lblabla;" `L' and `;' are removed 1005 return compactClassName(signature.substring(1, index), chopit); 1006 } 1007 // but make sure we are not looking past the end of the current item 1008 fromIndex = signature.indexOf(';'); 1009 if (fromIndex < 0) { 1010 throw new ClassFormatException("Invalid signature: " + signature); 1011 } 1012 if (fromIndex < bracketIndex) { 1013 // just a class identifier 1014 wrap(consumed_chars, fromIndex + 1); // "Lblabla;" `L' and `;' are removed 1015 return compactClassName(signature.substring(1, fromIndex), chopit); 1016 } 1017 1018 // we have TypeArguments; build up partial result 1019 // as we recurse for each TypeArgument 1020 final StringBuilder type = new StringBuilder(compactClassName(signature.substring(1, bracketIndex), chopit)).append("<"); 1021 int consumed_chars = bracketIndex + 1; // Shadows global var 1022 1023 // check for wildcards 1024 if (signature.charAt(consumed_chars) == '+') { 1025 type.append("? extends "); 1026 consumed_chars++; 1027 } else if (signature.charAt(consumed_chars) == '-') { 1028 type.append("? super "); 1029 consumed_chars++; 1030 } 1031 1032 // get the first TypeArgument 1033 if (signature.charAt(consumed_chars) == '*') { 1034 type.append("?"); 1035 consumed_chars++; 1036 } else { 1037 type.append(typeSignatureToString(signature.substring(consumed_chars), chopit)); 1038 // update our consumed count by the number of characters the for type argument 1039 consumed_chars = unwrap(Utility.consumed_chars) + consumed_chars; 1040 wrap(Utility.consumed_chars, consumed_chars); 1041 } 1042 1043 // are there more TypeArguments? 1044 while (signature.charAt(consumed_chars) != '>') { 1045 type.append(", "); 1046 // check for wildcards 1047 if (signature.charAt(consumed_chars) == '+') { 1048 type.append("? extends "); 1049 consumed_chars++; 1050 } else if (signature.charAt(consumed_chars) == '-') { 1051 type.append("? super "); 1052 consumed_chars++; 1053 } 1054 if (signature.charAt(consumed_chars) == '*') { 1055 type.append("?"); 1056 consumed_chars++; 1057 } else { 1058 type.append(typeSignatureToString(signature.substring(consumed_chars), chopit)); 1059 // update our consumed count by the number of characters the for type argument 1060 consumed_chars = unwrap(Utility.consumed_chars) + consumed_chars; 1061 wrap(Utility.consumed_chars, consumed_chars); 1062 } 1063 } 1064 1065 // process the closing ">" 1066 consumed_chars++; 1067 type.append(">"); 1068 1069 if (signature.charAt(consumed_chars) == '.') { 1070 // we have a ClassTypeSignatureSuffix 1071 type.append("."); 1072 // convert SimpleClassTypeSignature to fake ClassTypeSignature 1073 // and then recurse to parse it 1074 type.append(typeSignatureToString("L" + signature.substring(consumed_chars+1), chopit)); 1075 // update our consumed count by the number of characters the for type argument 1076 // note that this count includes the "L" we added, but that is ok 1077 // as it accounts for the "." we didn't consume 1078 consumed_chars = unwrap(Utility.consumed_chars) + consumed_chars; 1079 wrap(Utility.consumed_chars, consumed_chars); 1080 return type.toString(); 1081 } 1082 if (signature.charAt(consumed_chars) != ';') { 1083 throw new ClassFormatException("Invalid signature: " + signature); 1084 } 1085 wrap(Utility.consumed_chars, consumed_chars + 1); // remove final ";" 1086 return type.toString(); 1087 } 1088 case 'S': 1089 return "short"; 1090 case 'Z': 1091 return "boolean"; 1092 case '[': { // Array declaration 1093 int n; 1094 StringBuilder brackets; 1095 String type; 1096 int consumed_chars; // Shadows global var 1097 brackets = new StringBuilder(); // Accumulate []'s 1098 // Count opening brackets and look for optional size argument 1099 for (n = 0; signature.charAt(n) == '['; n++) { 1100 brackets.append("[]"); 1101 } 1102 consumed_chars = n; // Remember value 1103 // The rest of the string denotes a `<field_type>' 1104 type = typeSignatureToString(signature.substring(n), chopit); 1105 //corrected concurrent private static field acess 1106 //Utility.consumed_chars += consumed_chars; is replaced by: 1107 final int _temp = unwrap(Utility.consumed_chars) + consumed_chars; 1108 wrap(Utility.consumed_chars, _temp); 1109 return type + brackets.toString(); 1110 } 1111 case 'V': 1112 return "void"; 1113 default: 1114 throw new ClassFormatException("Invalid signature: `" + signature + "'"); 1115 } 1116 } catch (final StringIndexOutOfBoundsException e) { // Should never occur 1117 throw new ClassFormatException("Invalid signature: " + signature, e); 1118 } 1119 } 1120 1121 1122 /** Parse Java type such as "char", or "java.lang.String[]" and return the 1123 * signature in byte code format, e.g. "C" or "[Ljava/lang/String;" respectively. 1124 * 1125 * @param type Java type 1126 * @return byte code signature 1127 */ 1128 public static String getSignature( String type ) { 1129 final StringBuilder buf = new StringBuilder(); 1130 final char[] chars = type.toCharArray(); 1131 boolean char_found = false; 1132 boolean delim = false; 1133 int index = -1; 1134 loop: for (int i = 0; i < chars.length; i++) { 1135 switch (chars[i]) { 1136 case ' ': 1137 case '\t': 1138 case '\n': 1139 case '\r': 1140 case '\f': 1141 if (char_found) { 1142 delim = true; 1143 } 1144 break; 1145 case '[': 1146 if (!char_found) { 1147 throw new IllegalArgumentException("Illegal type: " + type); 1148 } 1149 index = i; 1150 break loop; 1151 default: 1152 char_found = true; 1153 if (!delim) { 1154 buf.append(chars[i]); 1155 } 1156 } 1157 } 1158 int brackets = 0; 1159 if (index > 0) { 1160 brackets = countBrackets(type.substring(index)); 1161 } 1162 type = buf.toString(); 1163 buf.setLength(0); 1164 for (int i = 0; i < brackets; i++) { 1165 buf.append('['); 1166 } 1167 boolean found = false; 1168 for (int i = Const.T_BOOLEAN; (i <= Const.T_VOID) && !found; i++) { 1169 if (Const.getTypeName(i).equals(type)) { 1170 found = true; 1171 buf.append(Const.getShortTypeName(i)); 1172 } 1173 } 1174 if (!found) { 1175 buf.append('L').append(type.replace('.', '/')).append(';'); 1176 } 1177 return buf.toString(); 1178 } 1179 1180 1181 private static int countBrackets( final String brackets ) { 1182 final char[] chars = brackets.toCharArray(); 1183 int count = 0; 1184 boolean open = false; 1185 for (final char c : chars) { 1186 switch (c) { 1187 case '[': 1188 if (open) { 1189 throw new IllegalArgumentException("Illegally nested brackets:" + brackets); 1190 } 1191 open = true; 1192 break; 1193 case ']': 1194 if (!open) { 1195 throw new IllegalArgumentException("Illegally nested brackets:" + brackets); 1196 } 1197 open = false; 1198 count++; 1199 break; 1200 default: 1201 // Don't care 1202 break; 1203 } 1204 } 1205 if (open) { 1206 throw new IllegalArgumentException("Illegally nested brackets:" + brackets); 1207 } 1208 return count; 1209 } 1210 1211 1212 /** 1213 * Return type of method signature as a byte value as defined in <em>Constants</em> 1214 * 1215 * @param signature in format described above 1216 * @return type of method signature 1217 * @see Const 1218 * 1219 * @throws ClassFormatException if signature is not a method signature 1220 */ 1221 public static byte typeOfMethodSignature( final String signature ) throws ClassFormatException { 1222 int index; 1223 try { 1224 if (signature.charAt(0) != '(') { 1225 throw new ClassFormatException("Invalid method signature: " + signature); 1226 } 1227 index = signature.lastIndexOf(')') + 1; 1228 return typeOfSignature(signature.substring(index)); 1229 } catch (final StringIndexOutOfBoundsException e) { 1230 throw new ClassFormatException("Invalid method signature: " + signature, e); 1231 } 1232 } 1233 1234 1235 /** 1236 * Return type of signature as a byte value as defined in <em>Constants</em> 1237 * 1238 * @param signature in format described above 1239 * @return type of signature 1240 * @see Const 1241 * 1242 * @throws ClassFormatException if signature isn't a known type 1243 */ 1244 public static byte typeOfSignature( final String signature ) throws ClassFormatException { 1245 try { 1246 switch (signature.charAt(0)) { 1247 case 'B': 1248 return Const.T_BYTE; 1249 case 'C': 1250 return Const.T_CHAR; 1251 case 'D': 1252 return Const.T_DOUBLE; 1253 case 'F': 1254 return Const.T_FLOAT; 1255 case 'I': 1256 return Const.T_INT; 1257 case 'J': 1258 return Const.T_LONG; 1259 case 'L': 1260 case 'T': 1261 return Const.T_REFERENCE; 1262 case '[': 1263 return Const.T_ARRAY; 1264 case 'V': 1265 return Const.T_VOID; 1266 case 'Z': 1267 return Const.T_BOOLEAN; 1268 case 'S': 1269 return Const.T_SHORT; 1270 case '!': 1271 case '+': 1272 case '*': 1273 return typeOfSignature(signature.substring(1)); 1274 default: 1275 throw new ClassFormatException("Invalid method signature: " + signature); 1276 } 1277 } catch (final StringIndexOutOfBoundsException e) { 1278 throw new ClassFormatException("Invalid method signature: " + signature, e); 1279 } 1280 } 1281 1282 1283 /** Map opcode names to opcode numbers. E.g., return Constants.ALOAD for "aload" 1284 */ 1285 public static short searchOpcode( String name ) { 1286 name = name.toLowerCase(Locale.ENGLISH); 1287 for (short i = 0; i < Const.OPCODE_NAMES_LENGTH; i++) { 1288 if (Const.getOpcodeName(i).equals(name)) { 1289 return i; 1290 } 1291 } 1292 return -1; 1293 } 1294 1295 1296 /** 1297 * Convert (signed) byte to (unsigned) short value, i.e., all negative 1298 * values become positive. 1299 */ 1300 private static short byteToShort( final byte b ) { 1301 return (b < 0) ? (short) (256 + b) : (short) b; 1302 } 1303 1304 1305 /** Convert bytes into hexadecimal string 1306 * 1307 * @param bytes an array of bytes to convert to hexadecimal 1308 * 1309 * @return bytes as hexadecimal string, e.g. 00 fa 12 ... 1310 */ 1311 public static String toHexString( final byte[] bytes ) { 1312 final StringBuilder buf = new StringBuilder(); 1313 for (int i = 0; i < bytes.length; i++) { 1314 final short b = byteToShort(bytes[i]); 1315 final String hex = Integer.toHexString(b); 1316 if (b < 0x10) { 1317 buf.append('0'); 1318 } 1319 buf.append(hex); 1320 if (i < bytes.length - 1) { 1321 buf.append(' '); 1322 } 1323 } 1324 return buf.toString(); 1325 } 1326 1327 1328 /** 1329 * Return a string for an integer justified left or right and filled up with 1330 * `fill' characters if necessary. 1331 * 1332 * @param i integer to format 1333 * @param length length of desired string 1334 * @param left_justify format left or right 1335 * @param fill fill character 1336 * @return formatted int 1337 */ 1338 public static String format( final int i, final int length, final boolean left_justify, final char fill ) { 1339 return fillup(Integer.toString(i), length, left_justify, fill); 1340 } 1341 1342 1343 /** 1344 * Fillup char with up to length characters with char `fill' and justify it left or right. 1345 * 1346 * @param str string to format 1347 * @param length length of desired string 1348 * @param left_justify format left or right 1349 * @param fill fill character 1350 * @return formatted string 1351 */ 1352 public static String fillup( final String str, final int length, final boolean left_justify, final char fill ) { 1353 final int len = length - str.length(); 1354 final char[] buf = new char[(len < 0) ? 0 : len]; 1355 for (int j = 0; j < buf.length; j++) { 1356 buf[j] = fill; 1357 } 1358 if (left_justify) { 1359 return str + new String(buf); 1360 } 1361 return new String(buf) + str; 1362 } 1363 1364 1365 static boolean equals( final byte[] a, final byte[] b ) { 1366 int size; 1367 if ((size = a.length) != b.length) { 1368 return false; 1369 } 1370 for (int i = 0; i < size; i++) { 1371 if (a[i] != b[i]) { 1372 return false; 1373 } 1374 } 1375 return true; 1376 } 1377 1378 1379 public static void printArray( final PrintStream out, final Object[] obj ) { 1380 out.println(printArray(obj, true)); 1381 } 1382 1383 1384 public static void printArray( final PrintWriter out, final Object[] obj ) { 1385 out.println(printArray(obj, true)); 1386 } 1387 1388 1389 public static String printArray( final Object[] obj ) { 1390 return printArray(obj, true); 1391 } 1392 1393 1394 public static String printArray( final Object[] obj, final boolean braces ) { 1395 return printArray(obj, braces, false); 1396 } 1397 1398 1399 public static String printArray( final Object[] obj, final boolean braces, final boolean quote ) { 1400 if (obj == null) { 1401 return null; 1402 } 1403 final StringBuilder buf = new StringBuilder(); 1404 if (braces) { 1405 buf.append('{'); 1406 } 1407 for (int i = 0; i < obj.length; i++) { 1408 if (obj[i] != null) { 1409 buf.append(quote ? "\"" : "").append(obj[i]).append(quote ? "\"" : ""); 1410 } else { 1411 buf.append("null"); 1412 } 1413 if (i < obj.length - 1) { 1414 buf.append(", "); 1415 } 1416 } 1417 if (braces) { 1418 buf.append('}'); 1419 } 1420 return buf.toString(); 1421 } 1422 1423 1424 /** 1425 * @param ch the character to test if it's part of an identifier 1426 * 1427 * @return true, if character is one of (a, ... z, A, ... Z, 0, ... 9, _) 1428 */ 1429 public static boolean isJavaIdentifierPart( final char ch ) { 1430 return ((ch >= 'a') && (ch <= 'z')) || ((ch >= 'A') && (ch <= 'Z')) 1431 || ((ch >= '0') && (ch <= '9')) || (ch == '_'); 1432 } 1433 1434 1435 /** 1436 * Encode byte array it into Java identifier string, i.e., a string 1437 * that only contains the following characters: (a, ... z, A, ... Z, 1438 * 0, ... 9, _, $). The encoding algorithm itself is not too 1439 * clever: if the current byte's ASCII value already is a valid Java 1440 * identifier part, leave it as it is. Otherwise it writes the 1441 * escape character($) followed by: 1442 * 1443 * <ul> 1444 * <li> the ASCII value as a hexadecimal string, if the value is not in the range 200..247</li> 1445 * <li>a Java identifier char not used in a lowercase hexadecimal string, if the value is in the range 200..247</li> 1446 * </ul> 1447 * 1448 * <p>This operation inflates the original byte array by roughly 40-50%</p> 1449 * 1450 * @param bytes the byte array to convert 1451 * @param compress use gzip to minimize string 1452 * 1453 * @throws IOException if there's a gzip exception 1454 */ 1455 public static String encode(byte[] bytes, final boolean compress) throws IOException { 1456 if (compress) { 1457 try (ByteArrayOutputStream baos = new ByteArrayOutputStream(); 1458 GZIPOutputStream gos = new GZIPOutputStream(baos)) { 1459 gos.write(bytes, 0, bytes.length); 1460 bytes = baos.toByteArray(); 1461 } 1462 } 1463 final CharArrayWriter caw = new CharArrayWriter(); 1464 try (JavaWriter jw = new JavaWriter(caw)) { 1465 for (final byte b : bytes) { 1466 final int in = b & 0x000000ff; // Normalize to unsigned 1467 jw.write(in); 1468 } 1469 } 1470 return caw.toString(); 1471 } 1472 1473 1474 /** 1475 * Decode a string back to a byte array. 1476 * 1477 * @param s the string to convert 1478 * @param uncompress use gzip to uncompress the stream of bytes 1479 * 1480 * @throws IOException if there's a gzip exception 1481 */ 1482 public static byte[] decode(final String s, final boolean uncompress) throws IOException { 1483 byte[] bytes; 1484 try (JavaReader jr = new JavaReader(new CharArrayReader(s.toCharArray())); 1485 ByteArrayOutputStream bos = new ByteArrayOutputStream()) { 1486 int ch; 1487 while ((ch = jr.read()) >= 0) { 1488 bos.write(ch); 1489 } 1490 bytes = bos.toByteArray(); 1491 } 1492 if (uncompress) { 1493 final GZIPInputStream gis = new GZIPInputStream(new ByteArrayInputStream(bytes)); 1494 final byte[] tmp = new byte[bytes.length * 3]; // Rough estimate 1495 int count = 0; 1496 int b; 1497 while ((b = gis.read()) >= 0) { 1498 tmp[count++] = (byte) b; 1499 } 1500 bytes = new byte[count]; 1501 System.arraycopy(tmp, 0, bytes, 0, count); 1502 } 1503 return bytes; 1504 } 1505 1506 // A-Z, g-z, _, $ 1507 private static final int FREE_CHARS = 48; 1508 private static int[] CHAR_MAP = new int[FREE_CHARS]; 1509 private static int[] MAP_CHAR = new int[256]; // Reverse map 1510 private static final char ESCAPE_CHAR = '$'; 1511 static { 1512 int j = 0; 1513 for (int i = 'A'; i <= 'Z'; i++) { 1514 CHAR_MAP[j] = i; 1515 MAP_CHAR[i] = j; 1516 j++; 1517 } 1518 for (int i = 'g'; i <= 'z'; i++) { 1519 CHAR_MAP[j] = i; 1520 MAP_CHAR[i] = j; 1521 j++; 1522 } 1523 CHAR_MAP[j] = '$'; 1524 MAP_CHAR['$'] = j; 1525 j++; 1526 CHAR_MAP[j] = '_'; 1527 MAP_CHAR['_'] = j; 1528 } 1529 1530 /** 1531 * Decode characters into bytes. 1532 * Used by <a href="Utility.html#decode(java.lang.String, boolean)">decode()</a> 1533 */ 1534 private static class JavaReader extends FilterReader { 1535 1536 public JavaReader(final Reader in) { 1537 super(in); 1538 } 1539 1540 1541 @Override 1542 public int read() throws IOException { 1543 final int b = in.read(); 1544 if (b != ESCAPE_CHAR) { 1545 return b; 1546 } 1547 final int i = in.read(); 1548 if (i < 0) { 1549 return -1; 1550 } 1551 if (((i >= '0') && (i <= '9')) || ((i >= 'a') && (i <= 'f'))) { // Normal escape 1552 final int j = in.read(); 1553 if (j < 0) { 1554 return -1; 1555 } 1556 final char[] tmp = { 1557 (char) i, (char) j 1558 }; 1559 final int s = Integer.parseInt(new String(tmp), 16); 1560 return s; 1561 } 1562 return MAP_CHAR[i]; 1563 } 1564 1565 1566 @Override 1567 public int read( final char[] cbuf, final int off, final int len ) throws IOException { 1568 for (int i = 0; i < len; i++) { 1569 cbuf[off + i] = (char) read(); 1570 } 1571 return len; 1572 } 1573 } 1574 1575 /** 1576 * Encode bytes into valid java identifier characters. 1577 * Used by <a href="Utility.html#encode(byte[], boolean)">encode()</a> 1578 */ 1579 private static class JavaWriter extends FilterWriter { 1580 1581 public JavaWriter(final Writer out) { 1582 super(out); 1583 } 1584 1585 1586 @Override 1587 public void write( final int b ) throws IOException { 1588 if (isJavaIdentifierPart((char) b) && (b != ESCAPE_CHAR)) { 1589 out.write(b); 1590 } else { 1591 out.write(ESCAPE_CHAR); // Escape character 1592 // Special escape 1593 if (b >= 0 && b < FREE_CHARS) { 1594 out.write(CHAR_MAP[b]); 1595 } else { // Normal escape 1596 final char[] tmp = Integer.toHexString(b).toCharArray(); 1597 if (tmp.length == 1) { 1598 out.write('0'); 1599 out.write(tmp[0]); 1600 } else { 1601 out.write(tmp[0]); 1602 out.write(tmp[1]); 1603 } 1604 } 1605 } 1606 } 1607 1608 1609 @Override 1610 public void write( final char[] cbuf, final int off, final int len ) throws IOException { 1611 for (int i = 0; i < len; i++) { 1612 write(cbuf[off + i]); 1613 } 1614 } 1615 1616 1617 @Override 1618 public void write( final String str, final int off, final int len ) throws IOException { 1619 write(str.toCharArray(), off, len); 1620 } 1621 } 1622 1623 1624 /** 1625 * Escape all occurences of newline chars '\n', quotes \", etc. 1626 */ 1627 public static String convertString( final String label ) { 1628 final char[] ch = label.toCharArray(); 1629 final StringBuilder buf = new StringBuilder(); 1630 for (final char element : ch) { 1631 switch (element) { 1632 case '\n': 1633 buf.append("\\n"); 1634 break; 1635 case '\r': 1636 buf.append("\\r"); 1637 break; 1638 case '\"': 1639 buf.append("\\\""); 1640 break; 1641 case '\'': 1642 buf.append("\\'"); 1643 break; 1644 case '\\': 1645 buf.append("\\\\"); 1646 break; 1647 default: 1648 buf.append(element); 1649 break; 1650 } 1651 } 1652 return buf.toString(); 1653 } 1654 1655}