java.util.FormattableFlags#ALTERNATE源码实例Demo

/**
 * Returns a string representation of the user supplied formattable, accounting for any possible
 * runtime exceptions.
 *
 * @param value the value to be formatted.
 * @return a best-effort string representation of the given value, even if exceptions were thrown.
 */
private static void safeFormatTo(Formattable value, StringBuilder out, FormatOptions options) {
  // Only care about 3 specific flags for Formattable.
  int formatFlags = options.getFlags() & (FLAG_LEFT_ALIGN | FLAG_UPPER_CASE | FLAG_SHOW_ALT_FORM);
  if (formatFlags != 0) {
    // TODO: Maybe re-order the options flags to make this step easier or use a lookup table.
    // Note that reordering flags would require a rethink of how they are parsed.
    formatFlags = ((formatFlags & FLAG_LEFT_ALIGN) != 0 ? FormattableFlags.LEFT_JUSTIFY : 0)
        | ((formatFlags & FLAG_UPPER_CASE) != 0 ? FormattableFlags.UPPERCASE : 0)
        | ((formatFlags & FLAG_SHOW_ALT_FORM) != 0 ? FormattableFlags.ALTERNATE : 0);
  }
  // We may need to undo an arbitrary amount of appending if there is an error.
  int originalLength = out.length();
  Formatter formatter = new Formatter(out, FORMAT_LOCALE);
  try {
    value.formatTo(formatter, formatFlags, options.getWidth(), options.getPrecision());
  } catch (RuntimeException e) {
    out.setLength(originalLength);
    // We only use a StringBuilder to create the Formatter instance.
    try {
      formatter.out().append(getErrorString(value, e));
    } catch (IOException impossible) { }
  }
}
 

@Override
public void formatTo(Formatter formatter, int flags, int width, int precision) {
    final boolean alt = (flags & FormattableFlags.ALTERNATE) == FormattableFlags.ALTERNATE;
    final boolean upper = (flags & FormattableFlags.UPPERCASE) == FormattableFlags.UPPERCASE;
    final boolean leftJustified = (flags & FormattableFlags.LEFT_JUSTIFY) == FormattableFlags.LEFT_JUSTIFY;

    String out;
    if (!alt) {
        out = getAsMention();
    } else if (upper) {
        out = getAsTag().toUpperCase();
    } else {
        out = getAsTag();
    }

    MiscUtil.appendTo(formatter, width, precision, leftJustified, out);
}
 

@Override
public void formatTo(Formatter formatter, int flags, int width, int precision)
{
    boolean alt = (flags & FormattableFlags.ALTERNATE) == FormattableFlags.ALTERNATE;
    boolean upper = (flags & FormattableFlags.UPPERCASE) == FormattableFlags.UPPERCASE;
    boolean leftJustified = (flags & FormattableFlags.LEFT_JUSTIFY) == FormattableFlags.LEFT_JUSTIFY;

    String out;
    if (!alt)
        out = getAsMention();
    else if (upper)
        out = getAsTag().toUpperCase();
    else
        out = getAsTag();

    MiscUtil.appendTo(formatter, width, precision, leftJustified, out);
}
 

@Override
default void formatTo(Formatter formatter, int flags, int width, int precision) {
    boolean alternate = (flags & FormattableFlags.ALTERNATE) != 0;
    String representation = alternate ? this.toString() : this.getName();
    boolean uppercase = (flags & FormattableFlags.UPPERCASE) != 0;
    boolean leftAlign = (flags & FormattableFlags.LEFT_JUSTIFY) != 0;
    boolean doPad = representation.length() < width;
    String padString = null;

    if (doPad) {
        char[] spaces = new char[width - representation.length()];
        Arrays.fill(spaces, ' ');
        padString = new String(spaces);
    }

    try {
        if (doPad && !leftAlign) {
            formatter.out().append(padString);
        }

        formatter.out().append(uppercase ? representation.toUpperCase() : representation);

        if (doPad && leftAlign) {
            formatter.out().append(padString);
        }
    } catch (IOException e) {
        ExceptionLogger.getConsumer().accept(e);
    }
}
 

@Override
default void formatTo(Formatter formatter, int flags, int width, int precision) {
    boolean alternate = (flags & FormattableFlags.ALTERNATE) != 0;
    String representation = alternate ? this.toString() : this.getName();
    boolean uppercase = (flags & FormattableFlags.UPPERCASE) != 0;
    boolean leftAlign = (flags & FormattableFlags.LEFT_JUSTIFY) != 0;
    boolean doPad = representation.length() < width;
    String padString = null;

    if (doPad) {
        char[] spaces = new char[width - representation.length()];
        Arrays.fill(spaces, ' ');
        padString = new String(spaces);
    }

    try {
        if (doPad && !leftAlign) {
            formatter.out().append(padString);
        }

        formatter.out().append(uppercase ? representation.toUpperCase() : representation);

        if (doPad && leftAlign) {
            formatter.out().append(padString);
        }
    } catch (IOException e) {
        ExceptionLogger.getConsumer().accept(e);
    }
}
 

@Override
default void formatTo(Formatter formatter, int flags, int width, int precision)
{
    boolean leftJustified = (flags & FormattableFlags.LEFT_JUSTIFY) == FormattableFlags.LEFT_JUSTIFY;
    boolean upper = (flags & FormattableFlags.UPPERCASE) == FormattableFlags.UPPERCASE;
    boolean alt = (flags & FormattableFlags.ALTERNATE) == FormattableFlags.ALTERNATE;
    String out;

    if (alt)
        out = "#" + (upper ? getName().toUpperCase(formatter.locale()) : getName());
    else
        out = getAsMention();

    MiscUtil.appendTo(formatter, width, precision, leftJustified, out);
}
 

/**
 * Returns a {@link Formattable} object that can be used with {@link String#format(String, Object...)}.
 * <p>
 * When used as the argument for a {@literal %s} format string element, the {@literal bytes} value
 * will be formatted using the current {@link ByteSizeStrings} values, or if the alternative
 * flag is set (using the {@literal %#s} format string) it will use the {@link ByteSizeStrings#metric()}
 * formatter. Finally, the precision of the formatted value can be adjusted using format string
 * argumenbts like {@literal %.6s}.
 *
 * @see http://docs.oracle.com/javase/7/docs/api/java/util/Formatter.html#syntax
 */
public Formattable formatted(final long bytes) {
    return new Formattable() {
        @Override
        public void formatTo(Formatter formatter, int flags, int width, int precision) {
            boolean alternate = (flags & FormattableFlags.ALTERNATE) == FormattableFlags.ALTERNATE;
            ByteSizeStrings strings = alternate ? ByteSizeStrings.metric() : ByteSizeStrings.this;
            if (precision != -1) {
                formatter.format("%s", strings.makeSizeString(bytes, precision));
            } else {
                formatter.format("%s", strings.makeSizeString(bytes));
            }
        }
    };
}
 

/**
 * Formats the name or identifier of this object using the provider formatter.
 * This method is invoked when an {@code IdentifiedObject} object is formatted
 * using the {@code "%s"} conversion specifier of {@link java.util.Formatter}.
 * Users don't need to invoke this method explicitly.
 *
 * <p>If the alternate flags is present (as in {@code "%#s"}), then this method
 * will format the identifier (if present) instead than the object name.</p>
 *
 * @param  formatter  the formatter in which to format this identified object.
 * @param  flags      whether to apply left alignment, use upper-case letters and/or use alternate form.
 * @param  width      minimal number of characters to write, padding with {@code ' '} if necessary.
 * @param  precision  maximal number of characters to write, or -1 if no limit.
 *
 * @see IdentifiedObjects#getName(IdentifiedObject, Citation)
 * @see IdentifiedObjects#getIdentifierOrName(IdentifiedObject)
 *
 * @since 1.1
 */
@Override
public void formatTo(final java.util.Formatter formatter, final int flags, final int width, final int precision) {
    final String value;
    if ((flags & FormattableFlags.ALTERNATE) != 0) {
        value = IdentifiedObjects.getIdentifierOrName(this);
    } else {
        value = IdentifiedObjects.getName(this, null);
    }
    Strings.formatTo(formatter, flags, width, precision, value);
}