/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* https://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.commons.text;
import java.text.Format;
import java.text.MessageFormat;
import java.text.ParsePosition;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Collections;
import java.util.HashMap;
import java.util.Locale;
import java.util.Locale.Category;
import java.util.Map;
import java.util.Objects;
import org.apache.commons.lang3.StringUtils;
import org.apache.commons.text.matcher.StringMatcherFactory;
/**
* Extends {@link java.text.MessageFormat} to allow pluggable/additional formatting
* options for embedded format elements.
* <p>
* Client code should specify a registry
* of {@code FormatFactory} instances associated with {@code String}
* format names. This registry will be consulted when the format elements are
* parsed from the message pattern. In this way custom patterns can be specified,
* and the formats supported by {@link java.text.MessageFormat} can be overridden
* at the format and/or format style level (see MessageFormat). A "format element"
* embedded in the message pattern is specified (<strong>()?</strong> signifies optionality):
* </p>
* <p>
* {@code {}<em>argument-number</em><strong>(</strong>{@code ,}<em>format-name</em><b>
* (</b>{@code ,}<em>format-style</em><strong>)?)?</strong>{@code }}
* </p>
*
* <p>
* <em>format-name</em> and <em>format-style</em> values are trimmed of surrounding whitespace
* in the manner of {@link java.text.MessageFormat}. If <em>format-name</em> denotes
* {@code FormatFactory formatFactoryInstance} in {@code registry}, a {@code Format}
* matching <em>format-name</em> and <em>format-style</em> is requested from
* {@code formatFactoryInstance}. If this is successful, the {@code Format}
* found is used for this format element.
* </p>
*
* <p><strong>NOTICE:</strong> The various subformat mutator methods are considered unnecessary; they exist on the parent
* class to allow the type of customization which it is the job of this class to provide in
* a configurable fashion. These methods have thus been disabled and will throw
* {@code UnsupportedOperationException} if called.
* </p>
*
* <p>Limitations inherited from {@link java.text.MessageFormat}:</p>
* <ul>
* <li>When using "choice" subformats, support for nested formatting instructions is limited
* to that provided by the base class.</li>
* <li>Thread-safety of {@code Format}s, including {@code MessageFormat} and thus
* {@code ExtendedMessageFormat}, is not guaranteed.</li>
* </ul>
*
* @since 1.0
*/
public class ExtendedMessageFormat extends MessageFormat {
/**
* Serializable Object.
*/
private static final long serialVersionUID = -2362048321261811743L;
/**
* The empty string.
*/
private static final String EMPTY_PATTERN = StringUtils.EMPTY;
/**
* A comma.
*/
private static final char START_FMT = ',';
/**
* A right curly bracket.
*/
private static final char END_FE = '}';
/**
* A left curly bracket.
*/
private static final char START_FE = '{';
/**
* A properly escaped character representing a single quote.
*/
private static final char QUOTE = '\'';
/**
* To pattern string.
*/
private String toPattern;
/**
* Our registry of FormatFactory.
*/
private final Map<String, ? extends FormatFactory> registry;
/**
* Constructs a new ExtendedMessageFormat for the default locale.
*
* @param pattern the pattern to use, not null.
* @throws IllegalArgumentException in case of a bad pattern.
*/
public ExtendedMessageFormat(final String pattern) {
this(pattern, Locale.getDefault(Category.FORMAT)); }
/**
* Constructs a new ExtendedMessageFormat.
*
* @param pattern the pattern to use, not null.
* @param locale the locale to use, not null.
* @throws IllegalArgumentException in case of a bad pattern.
*/
public ExtendedMessageFormat(final String pattern, final Locale locale) {
this(pattern, locale, null); }
/**
* Constructs a new ExtendedMessageFormat.
*
* @param pattern the pattern to use, not null.
* @param locale the locale to use, not null.
* @param registry the registry of format factories, may be null.
* @throws IllegalArgumentException in case of a bad pattern.
*/
public ExtendedMessageFormat(final String pattern, final Locale locale, final Map<String, ? extends FormatFactory> registry) {
super(EMPTY_PATTERN); setLocale(locale); this.registry = registry != null ? Collections.unmodifiableMap(new HashMap<>(registry)) : null; applyPattern(pattern); }
/**
* Constructs a new ExtendedMessageFormat for the default locale.
*
* @param pattern the pattern to use, not null.
* @param registry the registry of format factories, may be null.
* @throws IllegalArgumentException in case of a bad pattern.
*/
public ExtendedMessageFormat(final String pattern, final Map<String, ? extends FormatFactory> registry) {
this(pattern, Locale.getDefault(Category.FORMAT), registry); }
/**
* Consumes a quoted string, adding it to {@code appendTo} if specified.
*
* @param pattern pattern to parse.
* @param pos current parse position.
* @param appendTo optional StringBuilder to append.
*/
private void appendQuotedString(final String pattern, final ParsePosition pos, final StringBuilder appendTo) {
assert pattern.toCharArray()[pos.getIndex()] == QUOTE : "Quoted string must start with quote character";
// handle quote character at the beginning of the string
if (appendTo != null) { appendTo.append(QUOTE);
}
next(pos); final int start = pos.getIndex(); final char[] c = pattern.toCharArray(); for (int i = pos.getIndex(); i < pattern.length(); i++) { switch (c[pos.getIndex()]) {
case QUOTE:
next(pos); if (appendTo != null) { appendTo.append(c, start, pos.getIndex() - start);
}
return;
default:
next(pos);
}
}
throw new IllegalArgumentException("Unterminated quoted string at position " + start);
}
/**
* Applies the specified pattern.
*
* @param pattern String.
*/
@Override
public final void applyPattern(final String pattern) {
if (registry == null) { super.applyPattern(pattern); toPattern = super.toPattern(); return;
}
final ArrayList<Format> foundFormats = new ArrayList<>(); final ArrayList<String> foundDescriptions = new ArrayList<>(); final StringBuilder stripCustom = new StringBuilder(pattern.length()); final ParsePosition pos = new ParsePosition(0); final char[] c = pattern.toCharArray(); int fmtCount = 0; while (pos.getIndex() < pattern.length()) { switch (c[pos.getIndex()]) {
case QUOTE:
appendQuotedString(pattern, pos, stripCustom); break;
case START_FE:
fmtCount++; seekNonWs(pattern, pos); final int start = pos.getIndex(); final int index = readArgumentIndex(pattern, next(pos)); stripCustom.append(START_FE).append(index); seekNonWs(pattern, pos); Format format = null; String formatDescription = null; if (c[pos.getIndex()] == START_FMT) { formatDescription = parseFormatDescription(pattern, next(pos)); format = getFormat(formatDescription); if (format == null) { stripCustom.append(START_FMT).append(formatDescription);
}
}
foundFormats.add(format); foundDescriptions.add(format == null ? null : formatDescription); if (foundFormats.size() != fmtCount) { throw new IllegalArgumentException("The validated expression is false");
}
if (foundDescriptions.size() != fmtCount) { throw new IllegalArgumentException("The validated expression is false");
}
if (c[pos.getIndex()] != END_FE) { throw new IllegalArgumentException("Unreadable format element at position " + start);
}
//$FALL-THROUGH$
default:
stripCustom.append(c[pos.getIndex()]); next(pos);
}
}
super.applyPattern(stripCustom.toString()); toPattern = insertFormats(super.toPattern(), foundDescriptions); if (containsElements(foundFormats)) { final Format[] origFormats = getFormats();
// only loop over what we know we have, as MessageFormat on Java 1.3
// seems to provide an extra format element:
int i = 0; for (final Format f : foundFormats) { if (f != null) { origFormats[i] = f;
}
i++; } super.setFormats(origFormats);
}
}
/**
* Tests whether the specified Collection contains non-null elements.
*
* @param coll to check.
* @return {@code true} if some Object was found, {@code false} otherwise.
*/
private boolean containsElements(final Collection<?> coll) {
if (coll == null || coll.isEmpty()) { return false;
}
return coll.stream().anyMatch(Objects::nonNull);
}
@Override
public boolean equals(final Object obj) {
if (this == obj) { return true;
}
if (!super.equals(obj)) { return false;
}
if (!(obj instanceof ExtendedMessageFormat)) { return false;
}
final ExtendedMessageFormat other = (ExtendedMessageFormat) obj; return Objects.equals(registry, other.registry) && Objects.equals(toPattern, other.toPattern);
}
/**
* Gets a custom format from a format description.
*
* @param desc String.
* @return Format.
*/
private Format getFormat(final String desc) {
if (registry != null) { String name = desc; String args = null; final int i = desc.indexOf(START_FMT); if (i > 0) { name = desc.substring(0, i).trim(); args = desc.substring(i + 1).trim();
}
final FormatFactory factory = registry.get(name); if (factory != null) { return factory.getFormat(name, args, getLocale());
}
}
return null;
}
/**
* Consumes quoted string only.
*
* @param pattern pattern to parse.
* @param pos current parse position.
*/
private void getQuotedString(final String pattern, final ParsePosition pos) {
appendQuotedString(pattern, pos, null); }
@Override
public int hashCode() {
final int prime = 31; final int result = super.hashCode(); return prime * result + Objects.hash(registry, toPattern);
}
/**
* Inserts formats back into the pattern for toPattern() support.
*
* @param pattern source.
* @param customPatterns The custom patterns to re-insert, if any.
* @return full pattern.
*/
private String insertFormats(final String pattern, final ArrayList<String> customPatterns) {
if (!containsElements(customPatterns)) { return pattern;
}
final StringBuilder sb = new StringBuilder(pattern.length() * 2); final ParsePosition pos = new ParsePosition(0); int fe = -1; int depth = 0; while (pos.getIndex() < pattern.length()) { final char c = pattern.charAt(pos.getIndex()); switch (c) {
case QUOTE:
appendQuotedString(pattern, pos, sb); break;
case START_FE:
depth++; sb.append(START_FE).append(readArgumentIndex(pattern, next(pos)));
// do not look for custom patterns when they are embedded, e.g. in a choice
if (depth == 1) { fe++; final String customPattern = customPatterns.get(fe); if (customPattern != null) { sb.append(START_FMT).append(customPattern);
}
}
break;
case END_FE:
depth--;
//$FALL-THROUGH$
default:
sb.append(c); next(pos);
}
} return sb.toString();
}
/**
* Advances parse position by 1.
*
* @param pos ParsePosition.
* @return {@code pos}.
*/
private ParsePosition next(final ParsePosition pos) {
pos.setIndex(pos.getIndex() + 1); return pos;
}
/**
* Parses the format component of a format element.
*
* @param pattern string to parse.
* @param pos current parse position.
* @return Format description String.
*/
private String parseFormatDescription(final String pattern, final ParsePosition pos) {
final int start = pos.getIndex(); seekNonWs(pattern, pos); final int text = pos.getIndex(); int depth = 1; while (pos.getIndex() < pattern.length()) { switch (pattern.charAt(pos.getIndex())) {
case START_FE:
depth++; next(pos); break;
case END_FE:
depth--; if (depth == 0) { return pattern.substring(text, pos.getIndex());
}
next(pos); break;
case QUOTE:
getQuotedString(pattern, pos); break;
default:
next(pos); break;
}
}
throw new IllegalArgumentException(
"Unterminated format element at position " + start);
}
/**
* Reads the argument index from the current format element.
*
* @param pattern pattern to parse.
* @param pos current parse position.
* @return argument index.
*/
private int readArgumentIndex(final String pattern, final ParsePosition pos) {
final int start = pos.getIndex(); seekNonWs(pattern, pos); final StringBuilder result = new StringBuilder(); boolean error = false; for (; !error && pos.getIndex() < pattern.length(); next(pos)) { char c = pattern.charAt(pos.getIndex()); if (Character.isWhitespace(c)) { seekNonWs(pattern, pos); c = pattern.charAt(pos.getIndex()); if (c != START_FMT && c != END_FE) { error = true; continue;
}
}
if ((c == START_FMT || c == END_FE) && result.length() > 0) {
try {
return Integer.parseInt(result.toString()); } catch (final NumberFormatException e) { // NOPMD
// we've already ensured only digits, so unless something
// outlandishly large was specified we should be okay.
}
}
error = !Character.isDigit(c); result.append(c);
}
if (error) { throw new IllegalArgumentException(
"Invalid format argument index at position " + start + ": "
+ pattern.substring(start, pos.getIndex()));
}
throw new IllegalArgumentException(
"Unterminated format element at position " + start);
}
/**
* Consumes whitespace from the current parse position.
*
* @param pattern String to read.
* @param pos current position.
*/
private void seekNonWs(final String pattern, final ParsePosition pos) {
int len = 0; final char[] buffer = pattern.toCharArray();
do {
len = StringMatcherFactory.INSTANCE.splitMatcher().isMatch(buffer, pos.getIndex(), 0, buffer.length); pos.setIndex(pos.getIndex() + len); } while (len > 0 && pos.getIndex() < pattern.length()); }
/**
* Throws UnsupportedOperationException, see class Javadoc for details.
*
* @param formatElementIndex format element index.
* @param newFormat the new format.
* @throws UnsupportedOperationException always thrown since this isn't supported by {@link ExtendedMessageFormat}.
*/
@Override
public void setFormat(final int formatElementIndex, final Format newFormat) {
throw new UnsupportedOperationException();
}
/**
* Throws UnsupportedOperationException, see class Javadoc for details.
*
* @param argumentIndex argument index.
* @param newFormat the new format.
* @throws UnsupportedOperationException always thrown since this isn't supported by {@link ExtendedMessageFormat}.
*/
@Override
public void setFormatByArgumentIndex(final int argumentIndex,
final Format newFormat) {
throw new UnsupportedOperationException();
}
/**
* Throws UnsupportedOperationException - see class Javadoc for details.
*
* @param newFormats new formats.
* @throws UnsupportedOperationException always thrown since this isn't supported by {@link ExtendedMessageFormat}.
*/
@Override
public void setFormats(final Format[] newFormats) {
throw new UnsupportedOperationException();
}
/**
* Throws UnsupportedOperationException - see class Javadoc for details.
*
* @param newFormats new formats
* @throws UnsupportedOperationException always thrown since this isn't supported by {@link ExtendedMessageFormat}
*/
@Override
public void setFormatsByArgumentIndex(final Format[] newFormats) {
throw new UnsupportedOperationException();
}
/**
* {@inheritDoc}
*/
@Override
public String toPattern() {
return toPattern;
}
}
