    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 * @version $Id: Utility.java 1808131 2017-09-12 16:36:55Z britter $
    044 */
    045// @since 6.0 methods are no longer final
    046public abstract class Utility {
    047
    048    private static int unwrap( final ThreadLocal<Integer> tl ) {
    049        return tl.get().intValue();
    050    }
    051
    052
    053    private static void wrap( final ThreadLocal<Integer> tl, final int value ) {
    054        tl.set(Integer.valueOf(value));
    055    }
    056
    057    private static ThreadLocal<Integer> consumed_chars = new ThreadLocal<Integer>() {
    058
    059        @Override
    060        protected Integer initialValue() {
    061            return Integer.valueOf(0);
    062        }
    063    };/* How many chars have been consumed
    064     * during parsing in signatureToString().
    065     * Read by methodSignatureToString().
    066     * Set by side effect,but only internally.
    067     */
    068    private static boolean wide = false; /* The `WIDE' instruction is used in the
    069     * byte code to allow 16-bit wide indices
    070     * for local variables. This opcode
    071     * precedes an `ILOAD', e.g.. The opcode
    072     * immediately following takes an extra
    073     * byte which is combined with the
    074     * following byte to form a
    075     * 16-bit value.
    076     */
    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++) { // 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 name <em>str</em>, i.e., chop off the <em>prefix</em>,
    470     * if the
    471     * class name starts with this string and the flag <em>chopit</em> is true.
    472     * Slashes <em>/</em> are converted to dots <em>.</em>.
    473     *
    474     * @param str The long class name
    475     * @param prefix The prefix the get rid off
    476     * @param chopit Flag that determines whether chopping is executed or not
    477     * @return Compacted class name
    478     */
    479    public static String compactClassName( String str, final String prefix, final boolean chopit ) {
    480        final int len = prefix.length();
    481        str = str.replace('/', '.'); // Is `/' on all systems, even DOS
    482        if (chopit) {
    483            // If string starts with `prefix' and contains no further dots
    484            if (str.startsWith(prefix) && (str.substring(len).indexOf('.') == -1)) {
    485                str = str.substring(len);
    486            }
    487        }
    488        return str;
    489    }
    490
    491
    492    /**
    493     * Shorten long class names, <em>java/lang/String</em> becomes
    494     * <em>java.lang.String</em>,
    495     * e.g.. If <em>chopit</em> is <em>true</em> the prefix <em>java.lang</em>
    496     * is also removed.
    497     *
    498     * @param str The long class name
    499     * @param chopit Flag that determines whether chopping is executed or not
    500     * @return Compacted class name
    501     */
    502    public static String compactClassName( final String str, final boolean chopit ) {
    503        return compactClassName(str, "java.lang.", chopit);
    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     * @param  signature    Method signature
    563     * @return Array of argument types
    564     * @throws  ClassFormatException
    565     */
    566    public static String[] methodSignatureArgumentTypes( final String signature )
    567            throws ClassFormatException {
    568        return methodSignatureArgumentTypes(signature, true);
    569    }
    570
    571
    572    /**
    573     * @param  signature    Method signature
    574     * @param chopit Shorten class names ?
    575     * @return Array of argument types
    576     * @throws  ClassFormatException
    577     */
    578    public static String[] methodSignatureArgumentTypes( final String signature, final boolean chopit )
    579            throws ClassFormatException {
    580        final List<String> vec = new ArrayList<>();
    581        int index;
    582        try { // Read all declarations between for `(' and `)'
    583            if (signature.charAt(0) != '(') {
    584                throw new ClassFormatException("Invalid method signature: " + signature);
    585            }
    586            index = 1; // current string position
    587            while (signature.charAt(index) != ')') {
    588                vec.add(signatureToString(signature.substring(index), chopit));
    589                //corrected concurrent private static field acess
    590                index += unwrap(consumed_chars); // update position
    591            }
    592        } catch (final StringIndexOutOfBoundsException e) { // Should never occur
    593            throw new ClassFormatException("Invalid method signature: " + signature, e);
    594        }
    595        return vec.toArray(new String[vec.size()]);
    596    }
    597
    598
    599    /**
    600     * @param  signature    Method signature
    601     * @return return type of method
    602     * @throws  ClassFormatException
    603     */
    604    public static String methodSignatureReturnType( final String signature ) throws ClassFormatException {
    605        return methodSignatureReturnType(signature, true);
    606    }
    607
    608
    609    /**
    610     * @param  signature    Method signature
    611     * @param chopit Shorten class names ?
    612     * @return return type of method
    613     * @throws  ClassFormatException
    614     */
    615    public static String methodSignatureReturnType( final String signature, final boolean chopit ) throws ClassFormatException {
    616        int index;
    617        String type;
    618        try {
    619            // Read return type after `)'
    620            index = signature.lastIndexOf(')') + 1;
    621            type = signatureToString(signature.substring(index), chopit);
    622        } catch (final StringIndexOutOfBoundsException e) { // Should never occur
    623            throw new ClassFormatException("Invalid method signature: " + signature, e);
    624        }
    625        return type;
    626    }
    627
    628
    629    /**
    630     * Converts method signature to string with all class names compacted.
    631     *
    632     * @param signature to convert
    633     * @param name of method
    634     * @param access flags of method
    635     * @return Human readable signature
    636     */
    637    public static String methodSignatureToString( final String signature, final String name, final String access ) {
    638        return methodSignatureToString(signature, name, access, true);
    639    }
    640
    641
    642    public static String methodSignatureToString( final String signature, final String name, final String access, final boolean chopit ) {
    643        return methodSignatureToString(signature, name, access, chopit, null);
    644    }
    645
    646
    647    /**
    648     * A returntype signature represents the return value from a method.
    649     * It is a series of bytes in the following grammar:
    650     *
    651     * <pre>
    652     * &lt;return_signature&gt; ::= &lt;field_type&gt; | V
    653     * </pre>
    654     *
    655     * The character V indicates that the method returns no value. Otherwise, the
    656     * signature indicates the type of the return value.
    657     * An argument signature represents an argument passed to a method:
    658     *
    659     * <pre>
    660     * &lt;argument_signature&gt; ::= &lt;field_type&gt;
    661     * </pre>
    662     *
    663     * A method signature represents the arguments that the method expects, and
    664     * the value that it returns.
    665     * <pre>
    666     * &lt;method_signature&gt; ::= (&lt;arguments_signature&gt;) &lt;return_signature&gt;
    667     * &lt;arguments_signature&gt;::= &lt;argument_signature&gt;*
    668     * </pre>
    669     *
    670     * This method converts such a string into a Java type declaration like
    671     * `void main(String[])' and throws a `ClassFormatException' when the parsed
    672     * type is invalid.
    673     *
    674     * @param  signature    Method signature
    675     * @param  name         Method name
    676     * @param  access       Method access rights
    677     * @param chopit
    678     * @param vars
    679     * @return Java type declaration
    680     * @throws  ClassFormatException
    681     */
    682    public static String methodSignatureToString( final String signature, final String name,
    683            final String access, final boolean chopit, final LocalVariableTable vars ) throws ClassFormatException {
    684        final StringBuilder buf = new StringBuilder("(");
    685        String type;
    686        int index;
    687        int var_index = access.contains("static") ? 0 : 1;
    688        try { // Read all declarations between for `(' and `)'
    689            if (signature.charAt(0) != '(') {
    690                throw new ClassFormatException("Invalid method signature: " + signature);
    691            }
    692            index = 1; // current string position
    693            while (signature.charAt(index) != ')') {
    694                final String param_type = signatureToString(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 = signatureToString(signature.substring(index), chopit);
    716        } catch (final StringIndexOutOfBoundsException e) { // Should never occur
    717            throw new ClassFormatException("Invalid method signature: " + signature, e);
    718        }
    719        if (buf.length() > 1) {
    720            buf.setLength(buf.length() - 2);
    721        }
    722        buf.append(")");
    723        return access + ((access.length() > 0) ? " " : "") + // May be an empty string
    724                type + " " + name + buf.toString();
    725    }
    726
    727
    728    // Guess what this does
    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     * Converts signature to string with all class names compacted.
    767     *
    768     * @param signature to convert
    769     * @return Human readable signature
    770     */
    771    public static String signatureToString( final String signature ) {
    772        return signatureToString(signature, true);
    773    }
    774
    775
    776    /**
    777     * The field signature represents the value of an argument to a function or
    778     * the value of a variable. It is a series of bytes generated by the
    779     * following grammar:
    780     *
    781     * <PRE>
    782     * &lt;field_signature&gt; ::= &lt;field_type&gt;
    783     * &lt;field_type&gt;      ::= &lt;base_type&gt;|&lt;object_type&gt;|&lt;array_type&gt;
    784     * &lt;base_type&gt;       ::= B|C|D|F|I|J|S|Z
    785     * &lt;object_type&gt;     ::= L&lt;fullclassname&gt;;
    786     * &lt;array_type&gt;      ::= [&lt;field_type&gt;
    787     *
    788     * The meaning of the base types is as follows:
    789     * B byte signed byte
    790     * C char character
    791     * D double double precision IEEE float
    792     * F float single precision IEEE float
    793     * I int integer
    794     * J long long integer
    795     * L&lt;fullclassname&gt;; ... an object of the given class
    796     * S short signed short
    797     * Z boolean true or false
    798     * [&lt;field sig&gt; ... array
    799     * </PRE>
    800     *
    801     * This method converts this string into a Java type declaration such as
    802     * `String[]' and throws a `ClassFormatException' when the parsed type is
    803     * invalid.
    804     *
    805     * @param  signature  Class signature
    806     * @param chopit Flag that determines whether chopping is executed or not
    807     * @return Java type declaration
    808     * @throws ClassFormatException
    809     */
    810    public static String signatureToString( final String signature, final boolean chopit ) {
    811        //corrected concurrent private static field acess
    812        wrap(consumed_chars, 1); // This is the default, read just one char like `B'
    813        try {
    814            switch (signature.charAt(0)) {
    815                case 'B':
    816                    return "byte";
    817                case 'C':
    818                    return "char";
    819                case 'D':
    820                    return "double";
    821                case 'F':
    822                    return "float";
    823                case 'I':
    824                    return "int";
    825                case 'J':
    826                    return "long";
    827                case 'T': { // TypeVariableSignature
    828                    final int index = signature.indexOf(';'); // Look for closing `;'
    829                    if (index < 0) {
    830                        throw new ClassFormatException("Invalid signature: " + signature);
    831                    }
    832                    //corrected concurrent private static field acess
    833                    wrap(consumed_chars, index + 1); // "Tblabla;" `T' and `;' are removed
    834                    return compactClassName(signature.substring(1, index), chopit);
    835                }
    836                case 'L': { // Full class name
    837                    // should this be a while loop? can there be more than
    838                    // one generic clause?  (markro)
    839                    int fromIndex = signature.indexOf('<'); // generic type?
    840                    if (fromIndex < 0) {
    841                        fromIndex = 0;
    842                    } else {
    843                        fromIndex = signature.indexOf('>', fromIndex);
    844                        if (fromIndex < 0) {
    845                            throw new ClassFormatException("Invalid signature: " + signature);
    846                        }
    847                    }
    848                    final int index = signature.indexOf(';', fromIndex); // Look for closing `;'
    849                    if (index < 0) {
    850                        throw new ClassFormatException("Invalid signature: " + signature);
    851                    }
    852
    853                    // check to see if there are any TypeArguments
    854                    final int bracketIndex = signature.substring(0, index).indexOf('<');
    855                    if (bracketIndex < 0) {
    856                        // just a class identifier
    857                        wrap(consumed_chars, index + 1); // "Lblabla;" `L' and `;' are removed
    858                        return compactClassName(signature.substring(1, index), chopit);
    859                    }
    860                    // but make sure we are not looking past the end of the current item
    861                    fromIndex = signature.indexOf(';');
    862                    if (fromIndex < 0) {
    863                        throw new ClassFormatException("Invalid signature: " + signature);
    864                    }
    865                    if (fromIndex < bracketIndex) {
    866                        // just a class identifier
    867                        wrap(consumed_chars, fromIndex + 1); // "Lblabla;" `L' and `;' are removed
    868                        return compactClassName(signature.substring(1, fromIndex), chopit);
    869                    }
    870
    871                    // we have TypeArguments; build up partial result
    872                    // as we recurse for each TypeArgument
    873                    final StringBuilder type = new StringBuilder(compactClassName(signature.substring(1, bracketIndex), chopit)).append("<");
    874                    int consumed_chars = bracketIndex + 1; // Shadows global var
    875
    876                    // check for wildcards
    877                    if (signature.charAt(consumed_chars) == '+') {
    878                        type.append("? extends ");
    879                        consumed_chars++;
    880                    } else if (signature.charAt(consumed_chars) == '-') {
    881                        type.append("? super ");
    882                        consumed_chars++;
    883                    }
    884
    885                    // get the first TypeArgument
    886                    if (signature.charAt(consumed_chars) == '*') {
    887                        type.append("?");
    888                        consumed_chars++;
    889                    } else {
    890                        type.append(signatureToString(signature.substring(consumed_chars), chopit));
    891                        // update our consumed count by the number of characters the for type argument
    892                        consumed_chars = unwrap(Utility.consumed_chars) + consumed_chars;
    893                        wrap(Utility.consumed_chars, consumed_chars);
    894                    }
    895
    896                    // are there more TypeArguments?
    897                    while (signature.charAt(consumed_chars) != '>') {
    898                        type.append(", ");
    899                        // check for wildcards
    900                        if (signature.charAt(consumed_chars) == '+') {
    901                            type.append("? extends ");
    902                            consumed_chars++;
    903                        } else if (signature.charAt(consumed_chars) == '-') {
    904                            type.append("? super ");
    905                            consumed_chars++;
    906                        }
    907                        if (signature.charAt(consumed_chars) == '*') {
    908                            type.append("?");
    909                            consumed_chars++;
    910                        } else {
    911                            type.append(signatureToString(signature.substring(consumed_chars), chopit));
    912                            // update our consumed count by the number of characters the for type argument
    913                            consumed_chars = unwrap(Utility.consumed_chars) + consumed_chars;
    914                            wrap(Utility.consumed_chars, consumed_chars);
    915                        }
    916                    }
    917
    918                    // process the closing ">"
    919                    consumed_chars++;
    920                    type.append(">");
    921
    922                    if (signature.charAt(consumed_chars) == '.') {
    923                        // we have a ClassTypeSignatureSuffix
    924                        type.append(".");
    925                        // convert SimpleClassTypeSignature to fake ClassTypeSignature
    926                        // and then recurse to parse it
    927                        type.append(signatureToString("L" + signature.substring(consumed_chars+1), chopit));
    928                        // update our consumed count by the number of characters the for type argument
    929                        // note that this count includes the "L" we added, but that is ok
    930                        // as it accounts for the "." we didn't consume
    931                        consumed_chars = unwrap(Utility.consumed_chars) + consumed_chars;
    932                        wrap(Utility.consumed_chars, consumed_chars);
    933                        return type.toString();
    934                    }
    935                    if (signature.charAt(consumed_chars) != ';') {
    936                        throw new ClassFormatException("Invalid signature: " + signature);
    937                    }
    938                    wrap(Utility.consumed_chars, consumed_chars + 1); // remove final ";"
    939                    return type.toString();
    940                }
    941                case 'S':
    942                    return "short";
    943                case 'Z':
    944                    return "boolean";
    945                case '[': { // Array declaration
    946                    int n;
    947                    StringBuilder brackets;
    948                    String type;
    949                    int consumed_chars; // Shadows global var
    950                    brackets = new StringBuilder(); // Accumulate []'s
    951                    // Count opening brackets and look for optional size argument
    952                    for (n = 0; signature.charAt(n) == '['; n++) {
    953                        brackets.append("[]");
    954                    }
    955                    consumed_chars = n; // Remember value
    956                    // The rest of the string denotes a `<field_type>'
    957                    type = signatureToString(signature.substring(n), chopit);
    958                    //corrected concurrent private static field acess
    959                    //Utility.consumed_chars += consumed_chars; is replaced by:
    960                    final int _temp = unwrap(Utility.consumed_chars) + consumed_chars;
    961                    wrap(Utility.consumed_chars, _temp);
    962                    return type + brackets.toString();
    963                }
    964                case 'V':
    965                    return "void";
    966                default:
    967                    throw new ClassFormatException("Invalid signature: `" + signature + "'");
    968            }
    969        } catch (final StringIndexOutOfBoundsException e) { // Should never occur
    970            throw new ClassFormatException("Invalid signature: " + signature, e);
    971        }
    972    }
    973
    974
    975    /** Parse Java type such as "char", or "java.lang.String[]" and return the
    976     * signature in byte code format, e.g. "C" or "[Ljava/lang/String;" respectively.
    977     *
    978     * @param  type Java type
    979     * @return byte code signature
    980     */
    981    public static String getSignature( String type ) {
    982        final StringBuilder buf = new StringBuilder();
    983        final char[] chars = type.toCharArray();
    984        boolean char_found = false;
    985        boolean delim = false;
    986        int index = -1;
    987        loop: for (int i = 0; i < chars.length; i++) {
    988            switch (chars[i]) {
    989                case ' ':
    990                case '\t':
    991                case '\n':
    992                case '\r':
    993                case '\f':
    994                    if (char_found) {
    995                        delim = true;
    996                    }
    997                    break;
    998                case '[':
    999                    if (!char_found) {
    1000                        throw new RuntimeException("Illegal type: " + type);
    1001                    }
    1002                    index = i;
    1003                    break loop;
    1004                default:
    1005                    char_found = true;
    1006                    if (!delim) {
    1007                        buf.append(chars[i]);
    1008                    }
    1009            }
    1010        }
    1011        int brackets = 0;
    1012        if (index > 0) {
    1013            brackets = countBrackets(type.substring(index));
    1014        }
    1015        type = buf.toString();
    1016        buf.setLength(0);
    1017        for (int i = 0; i < brackets; i++) {
    1018            buf.append('[');
    1019        }
    1020        boolean found = false;
    1021        for (int i = Const.T_BOOLEAN; (i <= Const.T_VOID) && !found; i++) {
    1022            if (Const.getTypeName(i).equals(type)) {
    1023                found = true;
    1024                buf.append(Const.getShortTypeName(i));
    1025            }
    1026        }
    1027        if (!found) {
    1028            buf.append('L').append(type.replace('.', '/')).append(';');
    1029        }
    1030        return buf.toString();
    1031    }
    1032
    1033
    1034    private static int countBrackets( final String brackets ) {
    1035        final char[] chars = brackets.toCharArray();
    1036        int count = 0;
    1037        boolean open = false;
    1038        for (final char c : chars) {
    1039            switch (c) {
    1040                case '[':
    1041                    if (open) {
    1042                        throw new RuntimeException("Illegally nested brackets:" + brackets);
    1043                    }
    1044                    open = true;
    1045                    break;
    1046                case ']':
    1047                    if (!open) {
    1048                        throw new RuntimeException("Illegally nested brackets:" + brackets);
    1049                    }
    1050                    open = false;
    1051                    count++;
    1052                    break;
    1053                default:
    1054                    // Don't care
    1055                    break;
    1056            }
    1057        }
    1058        if (open) {
    1059            throw new RuntimeException("Illegally nested brackets:" + brackets);
    1060        }
    1061        return count;
    1062    }
    1063
    1064
    1065    /**
    1066     * Return type of method signature as a byte value as defined in <em>Constants</em>
    1067     *
    1068     * @param  signature in format described above
    1069     * @return type of method signature
    1070     * @see    Const
    1071     *
    1072     * @throws ClassFormatException if signature is not a method signature
    1073     */
    1074    public static byte typeOfMethodSignature( final String signature ) throws ClassFormatException {
    1075        int index;
    1076        try {
    1077            if (signature.charAt(0) != '(') {
    1078                throw new ClassFormatException("Invalid method signature: " + signature);
    1079            }
    1080            index = signature.lastIndexOf(')') + 1;
    1081            return typeOfSignature(signature.substring(index));
    1082        } catch (final StringIndexOutOfBoundsException e) {
    1083            throw new ClassFormatException("Invalid method signature: " + signature, e);
    1084        }
    1085    }
    1086
    1087
    1088    /**
    1089     * Return type of signature as a byte value as defined in <em>Constants</em>
    1090     *
    1091     * @param  signature in format described above
    1092     * @return type of signature
    1093     * @see    Const
    1094     *
    1095     * @throws ClassFormatException if signature isn't a known type
    1096     */
    1097    public static byte typeOfSignature( final String signature ) throws ClassFormatException {
    1098        try {
    1099            switch (signature.charAt(0)) {
    1100                case 'B':
    1101                    return Const.T_BYTE;
    1102                case 'C':
    1103                    return Const.T_CHAR;
    1104                case 'D':
    1105                    return Const.T_DOUBLE;
    1106                case 'F':
    1107                    return Const.T_FLOAT;
    1108                case 'I':
    1109                    return Const.T_INT;
    1110                case 'J':
    1111                    return Const.T_LONG;
    1112                case 'L':
    1113                case 'T':
    1114                    return Const.T_REFERENCE;
    1115                case '[':
    1116                    return Const.T_ARRAY;
    1117                case 'V':
    1118                    return Const.T_VOID;
    1119                case 'Z':
    1120                    return Const.T_BOOLEAN;
    1121                case 'S':
    1122                    return Const.T_SHORT;
    1123                case '!':
    1124                case '+':
    1125                case '*':
    1126                    return typeOfSignature(signature.substring(1));
    1127                default:
    1128                    throw new ClassFormatException("Invalid method signature: " + signature);
    1129            }
    1130        } catch (final StringIndexOutOfBoundsException e) {
    1131            throw new ClassFormatException("Invalid method signature: " + signature, e);
    1132        }
    1133    }
    1134
    1135
    1136    /** Map opcode names to opcode numbers. E.g., return Constants.ALOAD for "aload"
    1137     */
    1138    public static short searchOpcode( String name ) {
    1139        name = name.toLowerCase(Locale.ENGLISH);
    1140        for (short i = 0; i < Const.OPCODE_NAMES_LENGTH; i++) {
    1141            if (Const.getOpcodeName(i).equals(name)) {
    1142                return i;
    1143            }
    1144        }
    1145        return -1;
    1146    }
    1147
    1148
    1149    /**
    1150     * Convert (signed) byte to (unsigned) short value, i.e., all negative
    1151     * values become positive.
    1152     */
    1153    private static short byteToShort( final byte b ) {
    1154        return (b < 0) ? (short) (256 + b) : (short) b;
    1155    }
    1156
    1157
    1158    /** Convert bytes into hexadecimal string
    1159     *
    1160     * @param bytes an array of bytes to convert to hexadecimal
    1161     *
    1162     * @return bytes as hexadecimal string, e.g. 00 fa 12 ...
    1163     */
    1164    public static String toHexString( final byte[] bytes ) {
    1165        final StringBuilder buf = new StringBuilder();
    1166        for (int i = 0; i < bytes.length; i++) {
    1167            final short b = byteToShort(bytes[i]);
    1168            final String hex = Integer.toHexString(b);
    1169            if (b < 0x10) {
    1170                buf.append('0');
    1171            }
    1172            buf.append(hex);
    1173            if (i < bytes.length - 1) {
    1174                buf.append(' ');
    1175            }
    1176        }
    1177        return buf.toString();
    1178    }
    1179
    1180
    1181    /**
    1182     * Return a string for an integer justified left or right and filled up with
    1183     * `fill' characters if necessary.
    1184     *
    1185     * @param i integer to format
    1186     * @param length length of desired string
    1187     * @param left_justify format left or right
    1188     * @param fill fill character
    1189     * @return formatted int
    1190     */
    1191    public static String format( final int i, final int length, final boolean left_justify, final char fill ) {
    1192        return fillup(Integer.toString(i), length, left_justify, fill);
    1193    }
    1194
    1195
    1196    /**
    1197     * Fillup char with up to length characters with char `fill' and justify it left or right.
    1198     *
    1199     * @param str string to format
    1200     * @param length length of desired string
    1201     * @param left_justify format left or right
    1202     * @param fill fill character
    1203     * @return formatted string
    1204     */
    1205    public static String fillup( final String str, final int length, final boolean left_justify, final char fill ) {
    1206        final int len = length - str.length();
    1207        final char[] buf = new char[(len < 0) ? 0 : len];
    1208        for (int j = 0; j < buf.length; j++) {
    1209            buf[j] = fill;
    1210        }
    1211        if (left_justify) {
    1212            return str + new String(buf);
    1213        }
    1214        return new String(buf) + str;
    1215    }
    1216
    1217
    1218    static boolean equals( final byte[] a, final byte[] b ) {
    1219        int size;
    1220        if ((size = a.length) != b.length) {
    1221            return false;
    1222        }
    1223        for (int i = 0; i < size; i++) {
    1224            if (a[i] != b[i]) {
    1225                return false;
    1226            }
    1227        }
    1228        return true;
    1229    }
    1230
    1231
    1232    public static void printArray( final PrintStream out, final Object[] obj ) {
    1233        out.println(printArray(obj, true));
    1234    }
    1235
    1236
    1237    public static void printArray( final PrintWriter out, final Object[] obj ) {
    1238        out.println(printArray(obj, true));
    1239    }
    1240
    1241
    1242    public static String printArray( final Object[] obj ) {
    1243        return printArray(obj, true);
    1244    }
    1245
    1246
    1247    public static String printArray( final Object[] obj, final boolean braces ) {
    1248        return printArray(obj, braces, false);
    1249    }
    1250
    1251
    1252    public static String printArray( final Object[] obj, final boolean braces, final boolean quote ) {
    1253        if (obj == null) {
    1254            return null;
    1255        }
    1256        final StringBuilder buf = new StringBuilder();
    1257        if (braces) {
    1258            buf.append('{');
    1259        }
    1260        for (int i = 0; i < obj.length; i++) {
    1261            if (obj[i] != null) {
    1262                buf.append(quote ? "\"" : "").append(obj[i]).append(quote ? "\"" : "");
    1263            } else {
    1264                buf.append("null");
    1265            }
    1266            if (i < obj.length - 1) {
    1267                buf.append(", ");
    1268            }
    1269        }
    1270        if (braces) {
    1271            buf.append('}');
    1272        }
    1273        return buf.toString();
    1274    }
    1275
    1276
    1277    /**
    1278     * @param ch the character to test if it's part of an identifier
    1279     *
    1280     * @return true, if character is one of (a, ... z, A, ... Z, 0, ... 9, _)
    1281     */
    1282    public static boolean isJavaIdentifierPart( final char ch ) {
    1283        return ((ch >= 'a') && (ch <= 'z')) || ((ch >= 'A') && (ch <= 'Z'))
    1284                || ((ch >= '0') && (ch <= '9')) || (ch == '_');
    1285    }
    1286
    1287
    1288    /**
    1289     * Encode byte array it into Java identifier string, i.e., a string
    1290     * that only contains the following characters: (a, ... z, A, ... Z,
    1291     * 0, ... 9, _, $).  The encoding algorithm itself is not too
    1292     * clever: if the current byte's ASCII value already is a valid Java
    1293     * identifier part, leave it as it is. Otherwise it writes the
    1294     * escape character($) followed by:
    1295     *
    1296     * <ul>
    1297     *   <li> the ASCII value as a hexadecimal string, if the value is not in the range 200..247</li>
    1298     *   <li>a Java identifier char not used in a lowercase hexadecimal string, if the value is in the range 200..247</li>
    1299     * </ul>
    1300     *
    1301     * <p>This operation inflates the original byte array by roughly 40-50%</p>
    1302     *
    1303     * @param bytes the byte array to convert
    1304     * @param compress use gzip to minimize string
    1305     *
    1306     * @throws IOException if there's a gzip exception
    1307     */
    1308    public static String encode(byte[] bytes, final boolean compress) throws IOException {
    1309        if (compress) {
    1310            try (ByteArrayOutputStream baos = new ByteArrayOutputStream();
    1311                    GZIPOutputStream gos = new GZIPOutputStream(baos)) {
    1312                gos.write(bytes, 0, bytes.length);
    1313                bytes = baos.toByteArray();
    1314            }
    1315        }
    1316        final CharArrayWriter caw = new CharArrayWriter();
    1317        try (JavaWriter jw = new JavaWriter(caw)) {
    1318            for (final byte b : bytes) {
    1319                final int in = b & 0x000000ff; // Normalize to unsigned
    1320                jw.write(in);
    1321            }
    1322        }
    1323        return caw.toString();
    1324    }
    1325
    1326
    1327    /**
    1328     * Decode a string back to a byte array.
    1329     *
    1330     * @param s the string to convert
    1331     * @param uncompress use gzip to uncompress the stream of bytes
    1332     *
    1333     * @throws IOException if there's a gzip exception
    1334     */
    1335    public static byte[] decode(final String s, final boolean uncompress) throws IOException {
    1336        byte[] bytes;
    1337        try (JavaReader jr = new JavaReader(new CharArrayReader(s.toCharArray()));
    1338                ByteArrayOutputStream bos = new ByteArrayOutputStream()) {
    1339            int ch;
    1340            while ((ch = jr.read()) >= 0) {
    1341                bos.write(ch);
    1342            }
    1343            bytes = bos.toByteArray();
    1344        }
    1345        if (uncompress) {
    1346            final GZIPInputStream gis = new GZIPInputStream(new ByteArrayInputStream(bytes));
    1347            final byte[] tmp = new byte[bytes.length * 3]; // Rough estimate
    1348            int count = 0;
    1349            int b;
    1350            while ((b = gis.read()) >= 0) {
    1351                tmp[count++] = (byte) b;
    1352            }
    1353            bytes = new byte[count];
    1354            System.arraycopy(tmp, 0, bytes, 0, count);
    1355        }
    1356        return bytes;
    1357    }
    1358
    1359    // A-Z, g-z, _, $
    1360    private static final int FREE_CHARS = 48;
    1361    private static int[] CHAR_MAP = new int[FREE_CHARS];
    1362    private static int[] MAP_CHAR = new int[256]; // Reverse map
    1363    private static final char ESCAPE_CHAR = '$';
    1364    static {
    1365        int j = 0;
    1366        for (int i = 'A'; i <= 'Z'; i++) {
    1367            CHAR_MAP[j] = i;
    1368            MAP_CHAR[i] = j;
    1369            j++;
    1370        }
    1371        for (int i = 'g'; i <= 'z'; i++) {
    1372            CHAR_MAP[j] = i;
    1373            MAP_CHAR[i] = j;
    1374            j++;
    1375        }
    1376        CHAR_MAP[j] = '$';
    1377        MAP_CHAR['$'] = j;
    1378        j++;
    1379        CHAR_MAP[j] = '_';
    1380        MAP_CHAR['_'] = j;
    1381    }
    1382
    1383    /**
    1384     * Decode characters into bytes.
    1385     * Used by <a href="Utility.html#decode(java.lang.String, boolean)">decode()</a>
    1386     */
    1387    private static class JavaReader extends FilterReader {
    1388
    1389        public JavaReader(final Reader in) {
    1390            super(in);
    1391        }
    1392
    1393
    1394        @Override
    1395        public int read() throws IOException {
    1396            final int b = in.read();
    1397            if (b != ESCAPE_CHAR) {
    1398                return b;
    1399            }
    1400            final int i = in.read();
    1401            if (i < 0) {
    1402                return -1;
    1403            }
    1404            if (((i >= '0') && (i <= '9')) || ((i >= 'a') && (i <= 'f'))) { // Normal escape
    1405                final int j = in.read();
    1406                if (j < 0) {
    1407                    return -1;
    1408                }
    1409                final char[] tmp = {
    1410                        (char) i, (char) j
    1411                };
    1412                final int s = Integer.parseInt(new String(tmp), 16);
    1413                return s;
    1414            }
    1415            return MAP_CHAR[i];
    1416        }
    1417
    1418
    1419        @Override
    1420        public int read( final char[] cbuf, final int off, final int len ) throws IOException {
    1421            for (int i = 0; i < len; i++) {
    1422                cbuf[off + i] = (char) read();
    1423            }
    1424            return len;
    1425        }
    1426    }
    1427
    1428    /**
    1429     * Encode bytes into valid java identifier characters.
    1430     * Used by <a href="Utility.html#encode(byte[], boolean)">encode()</a>
    1431     */
    1432    private static class JavaWriter extends FilterWriter {
    1433
    1434        public JavaWriter(final Writer out) {
    1435            super(out);
    1436        }
    1437
    1438
    1439        @Override
    1440        public void write( final int b ) throws IOException {
    1441            if (isJavaIdentifierPart((char) b) && (b != ESCAPE_CHAR)) {
    1442                out.write(b);
    1443            } else {
    1444                out.write(ESCAPE_CHAR); // Escape character
    1445                // Special escape
    1446                if (b >= 0 && b < FREE_CHARS) {
    1447                    out.write(CHAR_MAP[b]);
    1448                } else { // Normal escape
    1449                    final char[] tmp = Integer.toHexString(b).toCharArray();
    1450                    if (tmp.length == 1) {
    1451                        out.write('0');
    1452                        out.write(tmp[0]);
    1453                    } else {
    1454                        out.write(tmp[0]);
    1455                        out.write(tmp[1]);
    1456                    }
    1457                }
    1458            }
    1459        }
    1460
    1461
    1462        @Override
    1463        public void write( final char[] cbuf, final int off, final int len ) throws IOException {
    1464            for (int i = 0; i < len; i++) {
    1465                write(cbuf[off + i]);
    1466            }
    1467        }
    1468
    1469
    1470        @Override
    1471        public void write( final String str, final int off, final int len ) throws IOException {
    1472            write(str.toCharArray(), off, len);
    1473        }
    1474    }
    1475
    1476
    1477    /**
    1478     * Escape all occurences of newline chars '\n', quotes \", etc.
    1479     */
    1480    public static String convertString( final String label ) {
    1481        final char[] ch = label.toCharArray();
    1482        final StringBuilder buf = new StringBuilder();
    1483        for (final char element : ch) {
    1484            switch (element) {
    1485                case '\n':
    1486                    buf.append("\\n");
    1487                    break;
    1488                case '\r':
    1489                    buf.append("\\r");
    1490                    break;
    1491                case '\"':
    1492                    buf.append("\\\"");
    1493                    break;
    1494                case '\'':
    1495                    buf.append("\\'");
    1496                    break;
    1497                case '\\':
    1498                    buf.append("\\\\");
    1499                    break;
    1500                default:
    1501                    buf.append(element);
    1502                    break;
    1503            }
    1504        }
    1505        return buf.toString();
    1506    }
    1507
    1508}