messageformat.java

来自「《移动Agent技术》一书的所有章节源代码。」· Java 代码 · 共 850 行 · 第 1/3 页

                    }
                } else {
                    switch (ch) {
                    case ',':
                        if (part < 3)
                            part += 1;
                        else
                            segments[part].append(ch);
                        break;
                    case '{':
                        ++braceStack;
                        segments[part].append(ch);
                        break;
                    case '}':
                        if (braceStack == 0) {
                            part = 0;
                            makeFormat(i, formatNumber, segments);
                            formatNumber++;
                        } else {
                            --braceStack;
                            segments[part].append(ch);
                        }
                        break;
                    case '\'':
                        inQuote = true;
                        // fall through, so we keep quotes in other parts
                    default:
                        segments[part].append(ch);
                        break;
                    }
                }
            }
            pattern = segments[0].toString();
    }


    /**
     * Gets the pattern. See the class description.
     */

    public String toPattern() {
        // later, make this more extensible
        int lastOffset = 0;
        StringBuffer result = new StringBuffer();
        for (int i = 0; i <= maxOffset; ++i) {
            copyAndFixQuotes(pattern, lastOffset, offsets[i],result);
            lastOffset = offsets[i];
            result.append('{');
            result.append(argumentNumbers[i]);
            if (formats[i] == null) {
                // do nothing, string format
            } else if (formats[i] instanceof DecimalFormat) {
                if (formats[i].equals(NumberFormat.getInstance(locale))) {
                    result.append(",number");
                } else if (formats[i].equals(
                                             NumberFormat.getCurrencyInstance(locale))) {
                    result.append(",number,currency");
                } else if (formats[i].equals(
                                             NumberFormat.getPercentInstance(locale))) {
                    result.append(",number,percent");
                } else if (formats[i].equals(getIntegerFormat(locale))) {
                    result.append(",number,integer");
                } else {
                    result.append(",number," +
                                  ((DecimalFormat)formats[i]).toPattern());
                }
            } else if (formats[i] instanceof SimpleDateFormat) {
                if (formats[i].equals(DateFormat.getDateInstance(
                                                               DateFormat.DEFAULT,locale))) {
                    result.append(",date");
                } else if (formats[i].equals(DateFormat.getDateInstance(
                                                                      DateFormat.SHORT,locale))) {
                    result.append(",date,short");
                } else if (formats[i].equals(DateFormat.getDateInstance(
                                                                      DateFormat.DEFAULT,locale))) {
                    result.append(",date,medium");
                } else if (formats[i].equals(DateFormat.getDateInstance(
                                                                      DateFormat.LONG,locale))) {
                    result.append(",date,long");
                } else if (formats[i].equals(DateFormat.getDateInstance(
                                                                      DateFormat.FULL,locale))) {
                    result.append(",date,full");
                } else if (formats[i].equals(DateFormat.getTimeInstance(
                                                                      DateFormat.DEFAULT,locale))) {
                    result.append(",time");
                } else if (formats[i].equals(DateFormat.getTimeInstance(
                                                                      DateFormat.SHORT,locale))) {
                    result.append(",time,short");
                } else if (formats[i].equals(DateFormat.getTimeInstance(
                                                                      DateFormat.DEFAULT,locale))) {
                    result.append(",time,medium");
                } else if (formats[i].equals(DateFormat.getTimeInstance(
                                                                      DateFormat.LONG,locale))) {
                    result.append(",time,long");
                } else if (formats[i].equals(DateFormat.getTimeInstance(
                                                                      DateFormat.FULL,locale))) {
                    result.append(",time,full");
                } else {
                    result.append(",date,"
                                  + ((SimpleDateFormat)formats[i]).toPattern());
                }
            } else if (formats[i] instanceof ChoiceFormat) {
                result.append(",choice,"
                              + ((ChoiceFormat)formats[i]).toPattern());
            } else {
                //result.append(", unknown");
            }
            result.append('}');
        }
        copyAndFixQuotes(pattern, lastOffset, pattern.length(), result);
        return result.toString();
    }

    /**
     * Sets formats to use on parameters.
     * See the class description about format numbering.
     */
    public void setFormats(Format[] newFormats) {
        try {
            formats = (Format[]) newFormats.clone();
        } catch (Exception e) {
            return; // should never occur!
        }
    }

    /**
     * Sets formats individually to use on parameters.
     * See the class description about format numbering.
     */
    public void setFormat(int variable, Format newFormat) {
        formats[variable] = newFormat;
    }

    /**
     * Gets formats that were set with setFormats.
     * See the class description about format numbering.
     */
    public Format[] getFormats() {
        try {
            return (Format[]) formats.clone();
        } catch (Exception e) {
            return formats; // should never occur!
        }
    }

    /**
     * Returns pattern with formatted objects.
     * @param source an array of objects to be formatted & substituted.
     * @param result where text is appended.
     * @param ignore no useful status is returned.
     */
    public final StringBuffer format(Object[] source, StringBuffer result,
                                     FieldPosition ignore)
    {
        return format(source,result,ignore, 0);
    }

    /**
     * Convenience routine.
     * Avoids explicit creation of MessageFormat,
     * but doesn't allow future optimizations.
     */
    public static String format(String pattern, Object[] arguments) {
            MessageFormat temp = new MessageFormat(pattern);
            return temp.format(arguments);
    }

    // Overrides
    public final StringBuffer format(Object source, StringBuffer result,
                                     FieldPosition ignore)
    {
        return format((Object[])source,result,ignore, 0);
    }

    /**
     * Parses the string.
     *
     * <p>Caveats: The parse may fail in a number of circumstances.
     * For example:
     * <ul>
     * <li>If one of the arguments does not occur in the pattern.
     * <li>If the format of an argument is loses information, such as
     *     with a choice format where a large number formats to "many".
     * <li>Does not yet handle recursion (where
     *     the substituted strings contain {n} references.)
     * <li>Will not always find a match (or the correct match)
     *     if some part of the parse is ambiguous.
     *     For example, if the pattern "{1},{2}" is used with the
     *     string arguments {"a,b", "c"}, it will format as "a,b,c".
     *     When the result is parsed, it will return {"a", "b,c"}.
     * <li>If a single argument is formatted twice in the string,
     *     then the later parse wins.
     * </ul>
     */
    public Object[] parse(String source, ParsePosition status) {
        Object[] resultArray = new Object[10];
        int patternOffset = 0;
        int sourceOffset = status.index;
        ParsePosition tempStatus = new ParsePosition(0);
        for (int i = 0; i <= maxOffset; ++i) {
            // match up to format
            int len = offsets[i] - patternOffset;
            if (len == 0 || pattern.regionMatches(patternOffset,
                                                  source, sourceOffset, len)) {
                sourceOffset += len;
                patternOffset += len;
            } else {
                return null; // leave index as is to signal error
            }

            // now use format
            if (formats[i] == null) {   // string format
                // if at end, use longest possible match
                // otherwise uses first match to intervening string
                // does NOT recursively try all possibilities
                int tempLength = (i != maxOffset) ? offsets[i+1] : pattern.length();

                int next;
                if (patternOffset >= tempLength) {
                    next = source.length();
                }else{
                    next = source.indexOf( pattern.substring(patternOffset,tempLength), sourceOffset);
                }

                if (next < 0) {
                    return null; // leave index as is to signal error
                } else {
                    resultArray[argumentNumbers[i]]
                        = source.substring(sourceOffset,next);
                    sourceOffset = next;
                }
            } else {
                tempStatus.index = sourceOffset;
                resultArray[argumentNumbers[i]]
                    = formats[i].parseObject(source,tempStatus);
                if (tempStatus.index == sourceOffset) {
                    return null; // leave index as is to signal error
                }
                sourceOffset = tempStatus.index; // update
            }
        }
        int len = pattern.length() - patternOffset;
        if (len == 0 || pattern.regionMatches(patternOffset,
                                              source, sourceOffset, len)) {
            status.index = sourceOffset + len;
        } else {
            return null; // leave index as is to signal error
        }
        return resultArray;
    }

    /**
     * Parses the string. Does not yet handle recursion (where
     * the substituted strings contain {n} references.)
     * @exception ParseException if the string can't be parsed.
     */
    public Object[] parse(String source) throws ParseException {
        ParsePosition status  = new ParsePosition(0);
        Object[] result = parse(source, status);
        if (status.index == 0)  // unchanged, returned object is null
            throw new ParseException("MessageFormat parse error!", 0);

        return result;
    }

    /**
     * Parses the string. Does not yet handle recursion (where
     * the substituted strings contain %n references.)
     */
    public Object parseObject (String text, ParsePosition status) {
        return parse(text, status);
    }

    /**
     * Overrides Cloneable
     */
    public Object clone()
    {
        MessageFormat other = (MessageFormat) super.clone();

        // clone arrays. Can't do with utility because of bug in Cloneable
        other.formats = (Format[]) formats.clone(); // shallow clone
        for (int i = 0; i < formats.length; ++i) {
            if (formats[i] != null)