    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 *      https://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 */
    017package org.apache.commons.text;
    018
    019import java.text.Format;
    020import java.text.MessageFormat;
    021import java.text.ParsePosition;
    022import java.util.ArrayList;
    023import java.util.Collection;
    024import java.util.Collections;
    025import java.util.HashMap;
    026import java.util.Locale;
    027import java.util.Locale.Category;
    028import java.util.Map;
    029import java.util.Objects;
    030
    031import org.apache.commons.lang3.StringUtils;
    032import org.apache.commons.text.matcher.StringMatcherFactory;
    033
    034/**
    035 * Extends {@link java.text.MessageFormat} to allow pluggable/additional formatting
    036 * options for embedded format elements.  Client code should specify a registry
    037 * of {@code FormatFactory} instances associated with {@code String}
    038 * format names.  This registry will be consulted when the format elements are
    039 * parsed from the message pattern.  In this way custom patterns can be specified,
    040 * and the formats supported by {@link java.text.MessageFormat} can be overridden
    041 * at the format and/or format style level (see MessageFormat).  A "format element"
    042 * embedded in the message pattern is specified (<strong>()?</strong> signifies optionality):<br>
    043 * {@code {}<em>argument-number</em><strong>(</strong>{@code ,}<em>format-name</em><b>
    044 * (</b>{@code ,}<em>format-style</em><strong>)?)?</strong>{@code }}
    045 *
    046 * <p>
    047 * <em>format-name</em> and <em>format-style</em> values are trimmed of surrounding whitespace
    048 * in the manner of {@link java.text.MessageFormat}.  If <em>format-name</em> denotes
    049 * {@code FormatFactory formatFactoryInstance} in {@code registry}, a {@code Format}
    050 * matching <em>format-name</em> and <em>format-style</em> is requested from
    051 * {@code formatFactoryInstance}.  If this is successful, the {@code Format}
    052 * found is used for this format element.
    053 * </p>
    054 *
    055 * <p><strong>NOTICE:</strong> The various subformat mutator methods are considered unnecessary; they exist on the parent
    056 * class to allow the type of customization which it is the job of this class to provide in
    057 * a configurable fashion.  These methods have thus been disabled and will throw
    058 * {@code UnsupportedOperationException} if called.
    059 * </p>
    060 *
    061 * <p>Limitations inherited from {@link java.text.MessageFormat}:</p>
    062 * <ul>
    063 * <li>When using "choice" subformats, support for nested formatting instructions is limited
    064 *     to that provided by the base class.</li>
    065 * <li>Thread-safety of {@code Format}s, including {@code MessageFormat} and thus
    066 *     {@code ExtendedMessageFormat}, is not guaranteed.</li>
    067 * </ul>
    068 *
    069 * @since 1.0
    070 */
    071public class ExtendedMessageFormat extends MessageFormat {
    072
    073    /**
    074     * Serializable Object.
    075     */
    076    private static final long serialVersionUID = -2362048321261811743L;
    077
    078    /**
    079     * The empty string.
    080     */
    081    private static final String EMPTY_PATTERN = StringUtils.EMPTY;
    082
    083    /**
    084     * A comma.
    085     */
    086    private static final char START_FMT = ',';
    087
    088    /**
    089     * A right curly bracket.
    090     */
    091    private static final char END_FE = '}';
    092
    093    /**
    094     * A left curly bracket.
    095     */
    096    private static final char START_FE = '{';
    097
    098    /**
    099     * A properly escaped character representing a single quote.
    100     */
    101    private static final char QUOTE = '\'';
    102
    103    /**
    104     * To pattern string.
    105     */
    106    private String toPattern;
    107
    108    /**
    109     * Our registry of FormatFactory.
    110     */
    111    private final Map<String, ? extends FormatFactory> registry;
    112
    113    /**
    114     * Constructs a new ExtendedMessageFormat for the default locale.
    115     *
    116     * @param pattern  the pattern to use, not null.
    117     * @throws IllegalArgumentException in case of a bad pattern.
    118     */
    119    public ExtendedMessageFormat(final String pattern) {
    120        this(pattern, Locale.getDefault(Category.FORMAT));
    121    }
    122
    123    /**
    124     * Constructs a new ExtendedMessageFormat.
    125     *
    126     * @param pattern  the pattern to use, not null.
    127     * @param locale  the locale to use, not null.
    128     * @throws IllegalArgumentException in case of a bad pattern.
    129     */
    130    public ExtendedMessageFormat(final String pattern, final Locale locale) {
    131        this(pattern, locale, null);
    132    }
    133
    134    /**
    135     * Constructs a new ExtendedMessageFormat.
    136     *
    137     * @param pattern  the pattern to use, not null.
    138     * @param locale   the locale to use, not null.
    139     * @param registry the registry of format factories, may be null.
    140     * @throws IllegalArgumentException in case of a bad pattern.
    141     */
    142    public ExtendedMessageFormat(final String pattern, final Locale locale, final Map<String, ? extends FormatFactory> registry) {
    143        super(EMPTY_PATTERN);
    144        setLocale(locale);
    145        this.registry = registry != null ? Collections.unmodifiableMap(new HashMap<>(registry)) : null;
    146        applyPattern(pattern);
    147    }
    148
    149    /**
    150     * Constructs a new ExtendedMessageFormat for the default locale.
    151     *
    152     * @param pattern  the pattern to use, not null.
    153     * @param registry the registry of format factories, may be null.
    154     * @throws IllegalArgumentException in case of a bad pattern.
    155     */
    156    public ExtendedMessageFormat(final String pattern, final Map<String, ? extends FormatFactory> registry) {
    157        this(pattern, Locale.getDefault(Category.FORMAT), registry);
    158    }
    159
    160    /**
    161     * Consumes a quoted string, adding it to {@code appendTo} if specified.
    162     *
    163     * @param pattern  pattern to parse.
    164     * @param pos      current parse position.
    165     * @param appendTo optional StringBuilder to append.
    166     */
    167    private void appendQuotedString(final String pattern, final ParsePosition pos, final StringBuilder appendTo) {
    168        assert pattern.toCharArray()[pos.getIndex()] == QUOTE : "Quoted string must start with quote character";
    169        // handle quote character at the beginning of the string
    170        if (appendTo != null) {
    171            appendTo.append(QUOTE);
    172        }
    173        next(pos);
    174        final int start = pos.getIndex();
    175        final char[] c = pattern.toCharArray();
    176        for (int i = pos.getIndex(); i < pattern.length(); i++) {
    177            switch (c[pos.getIndex()]) {
    178            case QUOTE:
    179                next(pos);
    180                if (appendTo != null) {
    181                    appendTo.append(c, start, pos.getIndex() - start);
    182                }
    183                return;
    184            default:
    185                next(pos);
    186            }
    187        }
    188        throw new IllegalArgumentException("Unterminated quoted string at position " + start);
    189    }
    190
    191    /**
    192     * Applies the specified pattern.
    193     *
    194     * @param pattern String.
    195     */
    196    @Override
    197    public final void applyPattern(final String pattern) {
    198        if (registry == null) {
    199            super.applyPattern(pattern);
    200            toPattern = super.toPattern();
    201            return;
    202        }
    203        final ArrayList<Format> foundFormats = new ArrayList<>();
    204        final ArrayList<String> foundDescriptions = new ArrayList<>();
    205        final StringBuilder stripCustom = new StringBuilder(pattern.length());
    206        final ParsePosition pos = new ParsePosition(0);
    207        final char[] c = pattern.toCharArray();
    208        int fmtCount = 0;
    209        while (pos.getIndex() < pattern.length()) {
    210            switch (c[pos.getIndex()]) {
    211            case QUOTE:
    212                appendQuotedString(pattern, pos, stripCustom);
    213                break;
    214            case START_FE:
    215                fmtCount++;
    216                seekNonWs(pattern, pos);
    217                final int start = pos.getIndex();
    218                final int index = readArgumentIndex(pattern, next(pos));
    219                stripCustom.append(START_FE).append(index);
    220                seekNonWs(pattern, pos);
    221                Format format = null;
    222                String formatDescription = null;
    223                if (c[pos.getIndex()] == START_FMT) {
    224                    formatDescription = parseFormatDescription(pattern, next(pos));
    225                    format = getFormat(formatDescription);
    226                    if (format == null) {
    227                        stripCustom.append(START_FMT).append(formatDescription);
    228                    }
    229                }
    230                foundFormats.add(format);
    231                foundDescriptions.add(format == null ? null : formatDescription);
    232                if (foundFormats.size() != fmtCount) {
    233                    throw new IllegalArgumentException("The validated expression is false");
    234                }
    235                if (foundDescriptions.size() != fmtCount) {
    236                    throw new IllegalArgumentException("The validated expression is false");
    237                }
    238                if (c[pos.getIndex()] != END_FE) {
    239                    throw new IllegalArgumentException("Unreadable format element at position " + start);
    240                }
    241                //$FALL-THROUGH$
    242            default:
    243                stripCustom.append(c[pos.getIndex()]);
    244                next(pos);
    245            }
    246        }
    247        super.applyPattern(stripCustom.toString());
    248        toPattern = insertFormats(super.toPattern(), foundDescriptions);
    249        if (containsElements(foundFormats)) {
    250            final Format[] origFormats = getFormats();
    251            // only loop over what we know we have, as MessageFormat on Java 1.3
    252            // seems to provide an extra format element:
    253            int i = 0;
    254            for (final Format f : foundFormats) {
    255                if (f != null) {
    256                    origFormats[i] = f;
    257                }
    258                i++;
    259            }
    260            super.setFormats(origFormats);
    261        }
    262    }
    263
    264    /**
    265     * Tests whether the specified Collection contains non-null elements.
    266     *
    267     * @param coll to check.
    268     * @return {@code true} if some Object was found, {@code false} otherwise.
    269     */
    270    private boolean containsElements(final Collection<?> coll) {
    271        if (coll == null || coll.isEmpty()) {
    272            return false;
    273        }
    274        return coll.stream().anyMatch(Objects::nonNull);
    275    }
    276
    277    @Override
    278    public boolean equals(final Object obj) {
    279        if (this == obj) {
    280            return true;
    281        }
    282        if (!super.equals(obj)) {
    283            return false;
    284        }
    285        if (!(obj instanceof ExtendedMessageFormat)) {
    286            return false;
    287        }
    288        final ExtendedMessageFormat other = (ExtendedMessageFormat) obj;
    289        return Objects.equals(registry, other.registry) && Objects.equals(toPattern, other.toPattern);
    290    }
    291
    292    /**
    293     * Gets a custom format from a format description.
    294     *
    295     * @param desc String.
    296     * @return Format.
    297     */
    298    private Format getFormat(final String desc) {
    299        if (registry != null) {
    300            String name = desc;
    301            String args = null;
    302            final int i = desc.indexOf(START_FMT);
    303            if (i > 0) {
    304                name = desc.substring(0, i).trim();
    305                args = desc.substring(i + 1).trim();
    306            }
    307            final FormatFactory factory = registry.get(name);
    308            if (factory != null) {
    309                return factory.getFormat(name, args, getLocale());
    310            }
    311        }
    312        return null;
    313    }
    314
    315    /**
    316     * Consumes quoted string only.
    317     *
    318     * @param pattern pattern to parse.
    319     * @param pos current parse position.
    320     */
    321    private void getQuotedString(final String pattern, final ParsePosition pos) {
    322        appendQuotedString(pattern, pos, null);
    323    }
    324
    325    @Override
    326    public int hashCode() {
    327        final int prime = 31;
    328        final int result = super.hashCode();
    329        return prime * result + Objects.hash(registry, toPattern);
    330    }
    331
    332    /**
    333     * Inserts formats back into the pattern for toPattern() support.
    334     *
    335     * @param pattern source.
    336     * @param customPatterns The custom patterns to re-insert, if any.
    337     * @return full pattern.
    338     */
    339    private String insertFormats(final String pattern, final ArrayList<String> customPatterns) {
    340        if (!containsElements(customPatterns)) {
    341            return pattern;
    342        }
    343        final StringBuilder sb = new StringBuilder(pattern.length() * 2);
    344        final ParsePosition pos = new ParsePosition(0);
    345        int fe = -1;
    346        int depth = 0;
    347        while (pos.getIndex() < pattern.length()) {
    348            final char c = pattern.charAt(pos.getIndex());
    349            switch (c) {
    350            case QUOTE:
    351                appendQuotedString(pattern, pos, sb);
    352                break;
    353            case START_FE:
    354                depth++;
    355                sb.append(START_FE).append(readArgumentIndex(pattern, next(pos)));
    356                // do not look for custom patterns when they are embedded, e.g. in a choice
    357                if (depth == 1) {
    358                    fe++;
    359                    final String customPattern = customPatterns.get(fe);
    360                    if (customPattern != null) {
    361                        sb.append(START_FMT).append(customPattern);
    362                    }
    363                }
    364                break;
    365            case END_FE:
    366                depth--;
    367                //$FALL-THROUGH$
    368            default:
    369                sb.append(c);
    370                next(pos);
    371            }
    372        }
    373        return sb.toString();
    374    }
    375
    376    /**
    377     * Advances parse position by 1.
    378     *
    379     * @param pos ParsePosition.
    380     * @return {@code pos}.
    381     */
    382    private ParsePosition next(final ParsePosition pos) {
    383        pos.setIndex(pos.getIndex() + 1);
    384        return pos;
    385    }
    386
    387    /**
    388     * Parses the format component of a format element.
    389     *
    390     * @param pattern string to parse.
    391     * @param pos current parse position.
    392     * @return Format description String.
    393     */
    394    private String parseFormatDescription(final String pattern, final ParsePosition pos) {
    395        final int start = pos.getIndex();
    396        seekNonWs(pattern, pos);
    397        final int text = pos.getIndex();
    398        int depth = 1;
    399        while (pos.getIndex() < pattern.length()) {
    400            switch (pattern.charAt(pos.getIndex())) {
    401            case START_FE:
    402                depth++;
    403                next(pos);
    404                break;
    405            case END_FE:
    406                depth--;
    407                if (depth == 0) {
    408                    return pattern.substring(text, pos.getIndex());
    409                }
    410                next(pos);
    411                break;
    412            case QUOTE:
    413                getQuotedString(pattern, pos);
    414                break;
    415            default:
    416                next(pos);
    417                break;
    418            }
    419        }
    420        throw new IllegalArgumentException(
    421                "Unterminated format element at position " + start);
    422    }
    423
    424    /**
    425     * Reads the argument index from the current format element.
    426     *
    427     * @param pattern pattern to parse.
    428     * @param pos current parse position.
    429     * @return argument index.
    430     */
    431    private int readArgumentIndex(final String pattern, final ParsePosition pos) {
    432        final int start = pos.getIndex();
    433        seekNonWs(pattern, pos);
    434        final StringBuilder result = new StringBuilder();
    435        boolean error = false;
    436        for (; !error && pos.getIndex() < pattern.length(); next(pos)) {
    437            char c = pattern.charAt(pos.getIndex());
    438            if (Character.isWhitespace(c)) {
    439                seekNonWs(pattern, pos);
    440                c = pattern.charAt(pos.getIndex());
    441                if (c != START_FMT && c != END_FE) {
    442                    error = true;
    443                    continue;
    444                }
    445            }
    446            if ((c == START_FMT || c == END_FE) && result.length() > 0) {
    447                try {
    448                    return Integer.parseInt(result.toString());
    449                } catch (final NumberFormatException e) { // NOPMD
    450                    // we've already ensured only digits, so unless something
    451                    // outlandishly large was specified we should be okay.
    452                }
    453            }
    454            error = !Character.isDigit(c);
    455            result.append(c);
    456        }
    457        if (error) {
    458            throw new IllegalArgumentException(
    459                    "Invalid format argument index at position " + start + ": "
    460                            + pattern.substring(start, pos.getIndex()));
    461        }
    462        throw new IllegalArgumentException(
    463                "Unterminated format element at position " + start);
    464    }
    465
    466    /**
    467     * Consumes whitespace from the current parse position.
    468     *
    469     * @param pattern String to read.
    470     * @param pos current position.
    471     */
    472    private void seekNonWs(final String pattern, final ParsePosition pos) {
    473        int len = 0;
    474        final char[] buffer = pattern.toCharArray();
    475        do {
    476            len = StringMatcherFactory.INSTANCE.splitMatcher().isMatch(buffer, pos.getIndex(), 0, buffer.length);
    477            pos.setIndex(pos.getIndex() + len);
    478        } while (len > 0 && pos.getIndex() < pattern.length());
    479    }
    480
    481    /**
    482     * Throws UnsupportedOperationException, see class Javadoc for details.
    483     *
    484     * @param formatElementIndex format element index.
    485     * @param newFormat          the new format.
    486     * @throws UnsupportedOperationException always thrown since this isn't supported by {@link ExtendedMessageFormat}.
    487     */
    488    @Override
    489    public void setFormat(final int formatElementIndex, final Format newFormat) {
    490        throw new UnsupportedOperationException();
    491    }
    492
    493    /**
    494     * Throws UnsupportedOperationException, see class Javadoc for details.
    495     *
    496     * @param argumentIndex argument index.
    497     * @param newFormat     the new format.
    498     * @throws UnsupportedOperationException always thrown since this isn't supported by {@link ExtendedMessageFormat}.
    499     */
    500    @Override
    501    public void setFormatByArgumentIndex(final int argumentIndex,
    502                                         final Format newFormat) {
    503        throw new UnsupportedOperationException();
    504    }
    505
    506    /**
    507     * Throws UnsupportedOperationException - see class Javadoc for details.
    508     *
    509     * @param newFormats new formats.
    510     * @throws UnsupportedOperationException always thrown since this isn't supported by {@link ExtendedMessageFormat}.
    511     */
    512    @Override
    513    public void setFormats(final Format[] newFormats) {
    514        throw new UnsupportedOperationException();
    515    }
    516
    517    /**
    518     * Throws UnsupportedOperationException - see class Javadoc for details.
    519     *
    520     * @param newFormats new formats
    521     * @throws UnsupportedOperationException always thrown since this isn't supported by {@link ExtendedMessageFormat}
    522     */
    523    @Override
    524    public void setFormatsByArgumentIndex(final Format[] newFormats) {
    525        throw new UnsupportedOperationException();
    526    }
    527
    528    /**
    529     * {@inheritDoc}
    530     */
    531    @Override
    532    public String toPattern() {
    533        return toPattern;
    534    }
    535}