src/java.base/share/classes/java/text/ChoiceFormat.java
changeset 47216 71c04702a3d5
parent 46893 4c5a4cd5b092
child 49510 a7777856ae98
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/java.base/share/classes/java/text/ChoiceFormat.java	Tue Sep 12 19:03:39 2017 +0200
@@ -0,0 +1,654 @@
+/*
+ * Copyright (c) 1996, 2017, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.  Oracle designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Oracle in the LICENSE file that accompanied this code.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+/*
+ * (C) Copyright Taligent, Inc. 1996, 1997 - All Rights Reserved
+ * (C) Copyright IBM Corp. 1996 - 1998 - All Rights Reserved
+ *
+ *   The original version of this source code and documentation is copyrighted
+ * and owned by Taligent, Inc., a wholly-owned subsidiary of IBM. These
+ * materials are provided under terms of a License Agreement between Taligent
+ * and Sun. This technology is protected by multiple US and International
+ * patents. This notice and attribution to Taligent may not be removed.
+ *   Taligent is a registered trademark of Taligent, Inc.
+ *
+ */
+
+package java.text;
+
+import java.io.InvalidObjectException;
+import java.io.IOException;
+import java.io.ObjectInputStream;
+import java.util.Arrays;
+
+/**
+ * A <code>ChoiceFormat</code> allows you to attach a format to a range of numbers.
+ * It is generally used in a <code>MessageFormat</code> for handling plurals.
+ * The choice is specified with an ascending list of doubles, where each item
+ * specifies a half-open interval up to the next item:
+ * <blockquote>
+ * <pre>
+ * X matches j if and only if limit[j] &le; X &lt; limit[j+1]
+ * </pre>
+ * </blockquote>
+ * If there is no match, then either the first or last index is used, depending
+ * on whether the number (X) is too low or too high.  If the limit array is not
+ * in ascending order, the results of formatting will be incorrect.  ChoiceFormat
+ * also accepts <code>&#92;u221E</code> as equivalent to infinity(INF).
+ *
+ * <p>
+ * <strong>Note:</strong>
+ * <code>ChoiceFormat</code> differs from the other <code>Format</code>
+ * classes in that you create a <code>ChoiceFormat</code> object with a
+ * constructor (not with a <code>getInstance</code> style factory
+ * method). The factory methods aren't necessary because <code>ChoiceFormat</code>
+ * doesn't require any complex setup for a given locale. In fact,
+ * <code>ChoiceFormat</code> doesn't implement any locale specific behavior.
+ *
+ * <p>
+ * When creating a <code>ChoiceFormat</code>, you must specify an array of formats
+ * and an array of limits. The length of these arrays must be the same.
+ * For example,
+ * <ul>
+ * <li>
+ *     <em>limits</em> = {1,2,3,4,5,6,7}<br>
+ *     <em>formats</em> = {"Sun","Mon","Tue","Wed","Thur","Fri","Sat"}
+ * <li>
+ *     <em>limits</em> = {0, 1, ChoiceFormat.nextDouble(1)}<br>
+ *     <em>formats</em> = {"no files", "one file", "many files"}<br>
+ *     (<code>nextDouble</code> can be used to get the next higher double, to
+ *     make the half-open interval.)
+ * </ul>
+ *
+ * <p>
+ * Here is a simple example that shows formatting and parsing:
+ * <blockquote>
+ * <pre>{@code
+ * double[] limits = {1,2,3,4,5,6,7};
+ * String[] dayOfWeekNames = {"Sun","Mon","Tue","Wed","Thur","Fri","Sat"};
+ * ChoiceFormat form = new ChoiceFormat(limits, dayOfWeekNames);
+ * ParsePosition status = new ParsePosition(0);
+ * for (double i = 0.0; i <= 8.0; ++i) {
+ *     status.setIndex(0);
+ *     System.out.println(i + " -> " + form.format(i) + " -> "
+ *                              + form.parse(form.format(i),status));
+ * }
+ * }</pre>
+ * </blockquote>
+ * Here is a more complex example, with a pattern format:
+ * <blockquote>
+ * <pre>{@code
+ * double[] filelimits = {0,1,2};
+ * String[] filepart = {"are no files","is one file","are {2} files"};
+ * ChoiceFormat fileform = new ChoiceFormat(filelimits, filepart);
+ * Format[] testFormats = {fileform, null, NumberFormat.getInstance()};
+ * MessageFormat pattform = new MessageFormat("There {0} on {1}");
+ * pattform.setFormats(testFormats);
+ * Object[] testArgs = {null, "ADisk", null};
+ * for (int i = 0; i < 4; ++i) {
+ *     testArgs[0] = new Integer(i);
+ *     testArgs[2] = testArgs[0];
+ *     System.out.println(pattform.format(testArgs));
+ * }
+ * }</pre>
+ * </blockquote>
+ * <p>
+ * Specifying a pattern for ChoiceFormat objects is fairly straightforward.
+ * For example:
+ * <blockquote>
+ * <pre>{@code
+ * ChoiceFormat fmt = new ChoiceFormat(
+ *      "-1#is negative| 0#is zero or fraction | 1#is one |1.0<is 1+ |2#is two |2<is more than 2.");
+ * System.out.println("Formatter Pattern : " + fmt.toPattern());
+ *
+ * System.out.println("Format with -INF : " + fmt.format(Double.NEGATIVE_INFINITY));
+ * System.out.println("Format with -1.0 : " + fmt.format(-1.0));
+ * System.out.println("Format with 0 : " + fmt.format(0));
+ * System.out.println("Format with 0.9 : " + fmt.format(0.9));
+ * System.out.println("Format with 1.0 : " + fmt.format(1));
+ * System.out.println("Format with 1.5 : " + fmt.format(1.5));
+ * System.out.println("Format with 2 : " + fmt.format(2));
+ * System.out.println("Format with 2.1 : " + fmt.format(2.1));
+ * System.out.println("Format with NaN : " + fmt.format(Double.NaN));
+ * System.out.println("Format with +INF : " + fmt.format(Double.POSITIVE_INFINITY));
+ * }</pre>
+ * </blockquote>
+ * And the output result would be like the following:
+ * <blockquote>
+ * <pre>{@code
+ * Format with -INF : is negative
+ * Format with -1.0 : is negative
+ * Format with 0 : is zero or fraction
+ * Format with 0.9 : is zero or fraction
+ * Format with 1.0 : is one
+ * Format with 1.5 : is 1+
+ * Format with 2 : is two
+ * Format with 2.1 : is more than 2.
+ * Format with NaN : is negative
+ * Format with +INF : is more than 2.
+ * }</pre>
+ * </blockquote>
+ *
+ * <h3><a id="synchronization">Synchronization</a></h3>
+ *
+ * <p>
+ * Choice formats are not synchronized.
+ * It is recommended to create separate format instances for each thread.
+ * If multiple threads access a format concurrently, it must be synchronized
+ * externally.
+ *
+ *
+ * @see          DecimalFormat
+ * @see          MessageFormat
+ * @author       Mark Davis
+ * @since 1.1
+ */
+public class ChoiceFormat extends NumberFormat {
+
+    // Proclaim serial compatibility with 1.1 FCS
+    private static final long serialVersionUID = 1795184449645032964L;
+
+    /**
+     * Sets the pattern.
+     * @param newPattern See the class description.
+     * @exception NullPointerException if {@code newPattern}
+     *            is {@code null}
+     */
+    public void applyPattern(String newPattern) {
+        StringBuffer[] segments = new StringBuffer[2];
+        for (int i = 0; i < segments.length; ++i) {
+            segments[i] = new StringBuffer();
+        }
+        double[] newChoiceLimits = new double[30];
+        String[] newChoiceFormats = new String[30];
+        int count = 0;
+        int part = 0;
+        double startValue = 0;
+        double oldStartValue = Double.NaN;
+        boolean inQuote = false;
+        for (int i = 0; i < newPattern.length(); ++i) {
+            char ch = newPattern.charAt(i);
+            if (ch=='\'') {
+                // Check for "''" indicating a literal quote
+                if ((i+1)<newPattern.length() && newPattern.charAt(i+1)==ch) {
+                    segments[part].append(ch);
+                    ++i;
+                } else {
+                    inQuote = !inQuote;
+                }
+            } else if (inQuote) {
+                segments[part].append(ch);
+            } else if (ch == '<' || ch == '#' || ch == '\u2264') {
+                if (segments[0].length() == 0) {
+                    throw new IllegalArgumentException("Each interval must"
+                            + " contain a number before a format");
+                }
+
+                String tempBuffer = segments[0].toString();
+                if (tempBuffer.equals("\u221E")) {
+                    startValue = Double.POSITIVE_INFINITY;
+                } else if (tempBuffer.equals("-\u221E")) {
+                    startValue = Double.NEGATIVE_INFINITY;
+                } else {
+                    startValue = Double.valueOf(tempBuffer);
+                }
+
+                if (ch == '<' && startValue != Double.POSITIVE_INFINITY &&
+                        startValue != Double.NEGATIVE_INFINITY) {
+                    startValue = nextDouble(startValue);
+                }
+                if (startValue <= oldStartValue) {
+                    throw new IllegalArgumentException("Incorrect order of"
+                            + " intervals, must be in ascending order");
+                }
+                segments[0].setLength(0);
+                part = 1;
+            } else if (ch == '|') {
+                if (count == newChoiceLimits.length) {
+                    newChoiceLimits = doubleArraySize(newChoiceLimits);
+                    newChoiceFormats = doubleArraySize(newChoiceFormats);
+                }
+                newChoiceLimits[count] = startValue;
+                newChoiceFormats[count] = segments[1].toString();
+                ++count;
+                oldStartValue = startValue;
+                segments[1].setLength(0);
+                part = 0;
+            } else {
+                segments[part].append(ch);
+            }
+        }
+        // clean up last one
+        if (part == 1) {
+            if (count == newChoiceLimits.length) {
+                newChoiceLimits = doubleArraySize(newChoiceLimits);
+                newChoiceFormats = doubleArraySize(newChoiceFormats);
+            }
+            newChoiceLimits[count] = startValue;
+            newChoiceFormats[count] = segments[1].toString();
+            ++count;
+        }
+        choiceLimits = new double[count];
+        System.arraycopy(newChoiceLimits, 0, choiceLimits, 0, count);
+        choiceFormats = new String[count];
+        System.arraycopy(newChoiceFormats, 0, choiceFormats, 0, count);
+    }
+
+    /**
+     * Gets the pattern.
+     *
+     * @return the pattern string
+     */
+    public String toPattern() {
+        StringBuilder result = new StringBuilder();
+        for (int i = 0; i < choiceLimits.length; ++i) {
+            if (i != 0) {
+                result.append('|');
+            }
+            // choose based upon which has less precision
+            // approximate that by choosing the closest one to an integer.
+            // could do better, but it's not worth it.
+            double less = previousDouble(choiceLimits[i]);
+            double tryLessOrEqual = Math.abs(Math.IEEEremainder(choiceLimits[i], 1.0d));
+            double tryLess = Math.abs(Math.IEEEremainder(less, 1.0d));
+
+            if (tryLessOrEqual < tryLess) {
+                result.append(choiceLimits[i]);
+                result.append('#');
+            } else {
+                if (choiceLimits[i] == Double.POSITIVE_INFINITY) {
+                    result.append("\u221E");
+                } else if (choiceLimits[i] == Double.NEGATIVE_INFINITY) {
+                    result.append("-\u221E");
+                } else {
+                    result.append(less);
+                }
+                result.append('<');
+            }
+            // Append choiceFormats[i], using quotes if there are special characters.
+            // Single quotes themselves must be escaped in either case.
+            String text = choiceFormats[i];
+            boolean needQuote = text.indexOf('<') >= 0
+                || text.indexOf('#') >= 0
+                || text.indexOf('\u2264') >= 0
+                || text.indexOf('|') >= 0;
+            if (needQuote) result.append('\'');
+            if (text.indexOf('\'') < 0) result.append(text);
+            else {
+                for (int j=0; j<text.length(); ++j) {
+                    char c = text.charAt(j);
+                    result.append(c);
+                    if (c == '\'') result.append(c);
+                }
+            }
+            if (needQuote) result.append('\'');
+        }
+        return result.toString();
+    }
+
+    /**
+     * Constructs with limits and corresponding formats based on the pattern.
+     *
+     * @param newPattern the new pattern string
+     * @exception NullPointerExcpetion if {@code newPattern} is
+     *            {@code null}
+     * @see #applyPattern
+     */
+    public ChoiceFormat(String newPattern)  {
+        applyPattern(newPattern);
+    }
+
+    /**
+     * Constructs with the limits and the corresponding formats.
+     *
+     * @param limits limits in ascending order
+     * @param formats corresponding format strings
+     * @exception NullPointerException if {@code limits} or {@code formats}
+     *            is {@code null}
+     * @see #setChoices
+     */
+    public ChoiceFormat(double[] limits, String[] formats) {
+        setChoices(limits, formats);
+    }
+
+    /**
+     * Set the choices to be used in formatting.
+     * @param limits contains the top value that you want
+     * parsed with that format, and should be in ascending sorted order. When
+     * formatting X, the choice will be the i, where
+     * limit[i] &le; X {@literal <} limit[i+1].
+     * If the limit array is not in ascending order, the results of formatting
+     * will be incorrect.
+     * @param formats are the formats you want to use for each limit.
+     * They can be either Format objects or Strings.
+     * When formatting with object Y,
+     * if the object is a NumberFormat, then ((NumberFormat) Y).format(X)
+     * is called. Otherwise Y.toString() is called.
+     * @exception NullPointerException if {@code limits} or
+     *            {@code formats} is {@code null}
+     */
+    public void setChoices(double[] limits, String formats[]) {
+        if (limits.length != formats.length) {
+            throw new IllegalArgumentException(
+                "Array and limit arrays must be of the same length.");
+        }
+        choiceLimits = Arrays.copyOf(limits, limits.length);
+        choiceFormats = Arrays.copyOf(formats, formats.length);
+    }
+
+    /**
+     * Get the limits passed in the constructor.
+     * @return the limits.
+     */
+    public double[] getLimits() {
+        double[] newLimits = Arrays.copyOf(choiceLimits, choiceLimits.length);
+        return newLimits;
+    }
+
+    /**
+     * Get the formats passed in the constructor.
+     * @return the formats.
+     */
+    public Object[] getFormats() {
+        Object[] newFormats = Arrays.copyOf(choiceFormats, choiceFormats.length);
+        return newFormats;
+    }
+
+    // Overrides
+
+    /**
+     * Specialization of format. This method really calls
+     * <code>format(double, StringBuffer, FieldPosition)</code>
+     * thus the range of longs that are supported is only equal to
+     * the range that can be stored by double. This will never be
+     * a practical limitation.
+     */
+    public StringBuffer format(long number, StringBuffer toAppendTo,
+                               FieldPosition status) {
+        return format((double)number, toAppendTo, status);
+    }
+
+    /**
+     * Returns pattern with formatted double.
+     * @param number number to be formatted and substituted.
+     * @param toAppendTo where text is appended.
+     * @param status ignore no useful status is returned.
+     * @exception NullPointerException if {@code toAppendTo}
+     *            is {@code null}
+     */
+   public StringBuffer format(double number, StringBuffer toAppendTo,
+                               FieldPosition status) {
+        // find the number
+        int i;
+        for (i = 0; i < choiceLimits.length; ++i) {
+            if (!(number >= choiceLimits[i])) {
+                // same as number < choiceLimits, except catchs NaN
+                break;
+            }
+        }
+        --i;
+        if (i < 0) i = 0;
+        // return either a formatted number, or a string
+        return toAppendTo.append(choiceFormats[i]);
+    }
+
+    /**
+     * Parses a Number from the input text.
+     * @param text the source text.
+     * @param status an input-output parameter.  On input, the
+     * status.index field indicates the first character of the
+     * source text that should be parsed.  On exit, if no error
+     * occurred, status.index is set to the first unparsed character
+     * in the source text.  On exit, if an error did occur,
+     * status.index is unchanged and status.errorIndex is set to the
+     * first index of the character that caused the parse to fail.
+     * @return A Number representing the value of the number parsed.
+     * @exception NullPointerException if {@code status} is {@code null}
+     *            or if {@code text} is {@code null} and the list of
+     *            choice strings is not empty.
+     */
+    public Number parse(String text, ParsePosition status) {
+        // find the best number (defined as the one with the longest parse)
+        int start = status.index;
+        int furthest = start;
+        double bestNumber = Double.NaN;
+        double tempNumber = 0.0;
+        for (int i = 0; i < choiceFormats.length; ++i) {
+            String tempString = choiceFormats[i];
+            if (text.regionMatches(start, tempString, 0, tempString.length())) {
+                status.index = start + tempString.length();
+                tempNumber = choiceLimits[i];
+                if (status.index > furthest) {
+                    furthest = status.index;
+                    bestNumber = tempNumber;
+                    if (furthest == text.length()) break;
+                }
+            }
+        }
+        status.index = furthest;
+        if (status.index == start) {
+            status.errorIndex = furthest;
+        }
+        return Double.valueOf(bestNumber);
+    }
+
+    /**
+     * Finds the least double greater than {@code d}.
+     * If {@code NaN}, returns same value.
+     * <p>Used to make half-open intervals.
+     *
+     * @param d the reference value
+     * @return the least double value greather than {@code d}
+     * @see #previousDouble
+     */
+    public static final double nextDouble (double d) {
+        return nextDouble(d,true);
+    }
+
+    /**
+     * Finds the greatest double less than {@code d}.
+     * If {@code NaN}, returns same value.
+     *
+     * @param d the reference value
+     * @return the greatest double value less than {@code d}
+     * @see #nextDouble
+     */
+    public static final double previousDouble (double d) {
+        return nextDouble(d,false);
+    }
+
+    /**
+     * Overrides Cloneable
+     */
+    public Object clone()
+    {
+        ChoiceFormat other = (ChoiceFormat) super.clone();
+        // for primitives or immutables, shallow clone is enough
+        other.choiceLimits = choiceLimits.clone();
+        other.choiceFormats = choiceFormats.clone();
+        return other;
+    }
+
+    /**
+     * Generates a hash code for the message format object.
+     */
+    public int hashCode() {
+        int result = choiceLimits.length;
+        if (choiceFormats.length > 0) {
+            // enough for reasonable distribution
+            result ^= choiceFormats[choiceFormats.length-1].hashCode();
+        }
+        return result;
+    }
+
+    /**
+     * Equality comparison between two
+     */
+    public boolean equals(Object obj) {
+        if (obj == null) return false;
+        if (this == obj)                      // quick check
+            return true;
+        if (getClass() != obj.getClass())
+            return false;
+        ChoiceFormat other = (ChoiceFormat) obj;
+        return (Arrays.equals(choiceLimits, other.choiceLimits)
+             && Arrays.equals(choiceFormats, other.choiceFormats));
+    }
+
+    /**
+     * After reading an object from the input stream, do a simple verification
+     * to maintain class invariants.
+     * @throws InvalidObjectException if the objects read from the stream is invalid.
+     */
+    private void readObject(ObjectInputStream in) throws IOException, ClassNotFoundException {
+        in.defaultReadObject();
+        if (choiceLimits.length != choiceFormats.length) {
+            throw new InvalidObjectException(
+                    "limits and format arrays of different length.");
+        }
+    }
+
+    // ===============privates===========================
+
+    /**
+     * A list of lower bounds for the choices.  The formatter will return
+     * <code>choiceFormats[i]</code> if the number being formatted is greater than or equal to
+     * <code>choiceLimits[i]</code> and less than <code>choiceLimits[i+1]</code>.
+     * @serial
+     */
+    private double[] choiceLimits;
+
+    /**
+     * A list of choice strings.  The formatter will return
+     * <code>choiceFormats[i]</code> if the number being formatted is greater than or equal to
+     * <code>choiceLimits[i]</code> and less than <code>choiceLimits[i+1]</code>.
+     * @serial
+     */
+    private String[] choiceFormats;
+
+    /*
+    static final long SIGN          = 0x8000000000000000L;
+    static final long EXPONENT      = 0x7FF0000000000000L;
+    static final long SIGNIFICAND   = 0x000FFFFFFFFFFFFFL;
+
+    private static double nextDouble (double d, boolean positive) {
+        if (Double.isNaN(d) || Double.isInfinite(d)) {
+                return d;
+            }
+        long bits = Double.doubleToLongBits(d);
+        long significand = bits & SIGNIFICAND;
+        if (bits < 0) {
+            significand |= (SIGN | EXPONENT);
+        }
+        long exponent = bits & EXPONENT;
+        if (positive) {
+            significand += 1;
+            // FIXME fix overflow & underflow
+        } else {
+            significand -= 1;
+            // FIXME fix overflow & underflow
+        }
+        bits = exponent | (significand & ~EXPONENT);
+        return Double.longBitsToDouble(bits);
+    }
+    */
+
+    static final long SIGN                = 0x8000000000000000L;
+    static final long EXPONENT            = 0x7FF0000000000000L;
+    static final long POSITIVEINFINITY    = 0x7FF0000000000000L;
+
+    /**
+     * Finds the least double greater than {@code d} (if {@code positive} is
+     * {@code true}), or the greatest double less than {@code d} (if
+     * {@code positive} is {@code false}).
+     * If {@code NaN}, returns same value.
+     *
+     * Does not affect floating-point flags,
+     * provided these member functions do not:
+     *          Double.longBitsToDouble(long)
+     *          Double.doubleToLongBits(double)
+     *          Double.isNaN(double)
+     *
+     * @param d        the reference value
+     * @param positive {@code true} if the least double is desired;
+     *                 {@code false} otherwise
+     * @return the least or greater double value
+     */
+    public static double nextDouble (double d, boolean positive) {
+
+        /* filter out NaN's */
+        if (Double.isNaN(d)) {
+            return d;
+        }
+
+        /* zero's are also a special case */
+        if (d == 0.0) {
+            double smallestPositiveDouble = Double.longBitsToDouble(1L);
+            if (positive) {
+                return smallestPositiveDouble;
+            } else {
+                return -smallestPositiveDouble;
+            }
+        }
+
+        /* if entering here, d is a nonzero value */
+
+        /* hold all bits in a long for later use */
+        long bits = Double.doubleToLongBits(d);
+
+        /* strip off the sign bit */
+        long magnitude = bits & ~SIGN;
+
+        /* if next double away from zero, increase magnitude */
+        if ((bits > 0) == positive) {
+            if (magnitude != POSITIVEINFINITY) {
+                magnitude += 1;
+            }
+        }
+        /* else decrease magnitude */
+        else {
+            magnitude -= 1;
+        }
+
+        /* restore sign bit and return */
+        long signbit = bits & SIGN;
+        return Double.longBitsToDouble (magnitude | signbit);
+    }
+
+    private static double[] doubleArraySize(double[] array) {
+        int oldSize = array.length;
+        double[] newArray = new double[oldSize * 2];
+        System.arraycopy(array, 0, newArray, 0, oldSize);
+        return newArray;
+    }
+
+    private String[] doubleArraySize(String[] array) {
+        int oldSize = array.length;
+        String[] newArray = new String[oldSize * 2];
+        System.arraycopy(array, 0, newArray, 0, oldSize);
+        return newArray;
+    }
+
+}