--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/jdk/src/share/classes/java/util/Formattable.java Sat Dec 01 00:00:00 2007 +0000
@@ -0,0 +1,164 @@
+/*
+ * Copyright 2003-2004 Sun Microsystems, Inc. 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. Sun designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Sun 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
+ * CA 95054 USA or visit www.sun.com if you need additional information or
+ * have any questions.
+ */
+
+package java.util;
+
+import java.io.IOException;
+
+/**
+ * The <tt>Formattable</tt> interface must be implemented by any class that
+ * needs to perform custom formatting using the <tt>'s'</tt> conversion
+ * specifier of {@link java.util.Formatter}. This interface allows basic
+ * control for formatting arbitrary objects.
+ *
+ * For example, the following class prints out different representations of a
+ * stock's name depending on the flags and length constraints:
+ *
+ * <blockquote><pre>
+ * import java.nio.CharBuffer;
+ * import java.util.Formatter;
+ * import java.util.Formattable;
+ * import java.util.Locale;
+ * import static java.util.FormattableFlags.*;
+ *
+ * ...
+ *
+ * public class StockName implements Formattable {
+ * private String symbol, companyName, frenchCompanyName;
+ * public StockName(String symbol, String companyName,
+ * String frenchCompanyName) {
+ * ...
+ * }
+ *
+ * ...
+ *
+ * public void formatTo(Formatter fmt, int f, int width, int precision) {
+ * StringBuilder sb = new StringBuilder();
+ *
+ * // decide form of name
+ * String name = companyName;
+ * if (fmt.locale().equals(Locale.FRANCE))
+ * name = frenchCompanyName;
+ * boolean alternate = (f & ALTERNATE) == ALTERNATE;
+ * boolean usesymbol = alternate || (precision != -1 && precision < 10);
+ * String out = (usesymbol ? symbol : name);
+ *
+ * // apply precision
+ * if (precision == -1 || out.length() < precision) {
+ * // write it all
+ * sb.append(out);
+ * } else {
+ * sb.append(out.substring(0, precision - 1)).append('*');
+ * }
+ *
+ * // apply width and justification
+ * int len = sb.length();
+ * if (len < width)
+ * for (int i = 0; i < width - len; i++)
+ * if ((f & LEFT_JUSTIFY) == LEFT_JUSTIFY)
+ * sb.append(' ');
+ * else
+ * sb.insert(0, ' ');
+ *
+ * fmt.format(sb.toString());
+ * }
+ *
+ * public String toString() {
+ * return String.format("%s - %s", symbol, companyName);
+ * }
+ * }
+ * </pre></blockquote>
+ *
+ * <p> When used in conjunction with the {@link java.util.Formatter}, the above
+ * class produces the following output for various format strings.
+ *
+ * <blockquote><pre>
+ * Formatter fmt = new Formatter();
+ * StockName sn = new StockName("HUGE", "Huge Fruit, Inc.",
+ * "Fruit Titanesque, Inc.");
+ * fmt.format("%s", sn); // -> "Huge Fruit, Inc."
+ * fmt.format("%s", sn.toString()); // -> "HUGE - Huge Fruit, Inc."
+ * fmt.format("%#s", sn); // -> "HUGE"
+ * fmt.format("%-10.8s", sn); // -> "HUGE "
+ * fmt.format("%.12s", sn); // -> "Huge Fruit,*"
+ * fmt.format(Locale.FRANCE, "%25s", sn); // -> " Fruit Titanesque, Inc."
+ * </pre></blockquote>
+ *
+ * <p> Formattables are not necessarily safe for multithreaded access. Thread
+ * safety is optional and may be enforced by classes that extend and implement
+ * this interface.
+ *
+ * <p> Unless otherwise specified, passing a <tt>null</tt> argument to
+ * any method in this interface will cause a {@link
+ * NullPointerException} to be thrown.
+ *
+ * @since 1.5
+ */
+public interface Formattable {
+
+ /**
+ * Formats the object using the provided {@link Formatter formatter}.
+ *
+ * @param formatter
+ * The {@link Formatter formatter}. Implementing classes may call
+ * {@link Formatter#out() formatter.out()} or {@link
+ * Formatter#locale() formatter.locale()} to obtain the {@link
+ * Appendable} or {@link Locale} used by this
+ * <tt>formatter</tt> respectively.
+ *
+ * @param flags
+ * The flags modify the output format. The value is interpreted as
+ * a bitmask. Any combination of the following flags may be set:
+ * {@link FormattableFlags#LEFT_JUSTIFY}, {@link
+ * FormattableFlags#UPPERCASE}, and {@link
+ * FormattableFlags#ALTERNATE}. If no flags are set, the default
+ * formatting of the implementing class will apply.
+ *
+ * @param width
+ * The minimum number of characters to be written to the output.
+ * If the length of the converted value is less than the
+ * <tt>width</tt> then the output will be padded by
+ * <tt>' '</tt> until the total number of characters
+ * equals width. The padding is at the beginning by default. If
+ * the {@link FormattableFlags#LEFT_JUSTIFY} flag is set then the
+ * padding will be at the end. If <tt>width</tt> is <tt>-1</tt>
+ * then there is no minimum.
+ *
+ * @param precision
+ * The maximum number of characters to be written to the output.
+ * The precision is applied before the width, thus the output will
+ * be truncated to <tt>precision</tt> characters even if the
+ * <tt>width</tt> is greater than the <tt>precision</tt>. If
+ * <tt>precision</tt> is <tt>-1</tt> then there is no explicit
+ * limit on the number of characters.
+ *
+ * @throws IllegalFormatException
+ * If any of the parameters are invalid. For specification of all
+ * possible formatting errors, see the <a
+ * href="../util/Formatter.html#detail">Details</a> section of the
+ * formatter class specification.
+ */
+ void formatTo(Formatter formatter, int flags, int width, int precision);
+}