diff -r c588664d547e -r 55b829ca2334 jdk/src/share/classes/java/time/chrono/JapaneseEra.java
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/jdk/src/share/classes/java/time/chrono/JapaneseEra.java	Tue Feb 12 09:25:43 2013 -0800
@@ -0,0 +1,334 @@
+/*
+ * Copyright (c) 2012, 2013, 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.
+ */
+
+/*
+ * Copyright (c) 2012, Stephen Colebourne & Michael Nascimento Santos
+ *
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ *  * Redistributions of source code must retain the above copyright notice,
+ *    this list of conditions and the following disclaimer.
+ *
+ *  * Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ *
+ *  * Neither the name of JSR-310 nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
+ * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+ * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+ * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
+ * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
+ * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+package java.time.chrono;
+
+import java.io.DataInput;
+import java.io.DataOutput;
+import java.io.IOException;
+import java.io.InvalidObjectException;
+import java.io.ObjectStreamException;
+import java.io.Serializable;
+import java.time.DateTimeException;
+import java.time.LocalDate;
+import java.util.Arrays;
+
+import sun.util.calendar.CalendarDate;
+
+/**
+ * An era in the Japanese Imperial calendar system.
+ * <p>
+ * This class defines the valid eras for the Japanese chronology.
+ * Only Meiji (1868-09-08 - 1912-07-29) and later eras are supported.
+ * Japan introduced the Gregorian calendar since Meiji 6. The dates
+ * between Meiji 1 - 5 are not historically correct.
+ * The older eras are recognized as Seireki (Western calendar) era,
+ * and the year of era of Seireki is proleptic Gregorian year.
+ * (The Julian to Gregorian transition is not supported.)
+ *
+ * <h3>Specification for implementors</h3>
+ * This class is immutable and thread-safe.
+ *
+ * @since 1.8
+ */
+final class JapaneseEra
+        implements Era, Serializable {
+
+    // The offset value to 0-based index from the era value.
+    // i.e., getValue() + ERA_OFFSET == 0-based index; except that -999 is mapped to zero
+    static final int ERA_OFFSET = 2;
+
+    static final sun.util.calendar.Era[] ERA_CONFIG;
+
+    /**
+     * The singleton instance for the before Meiji era ( - 1868-09-07)
+     * which has the value -999.
+     */
+    public static final JapaneseEra SEIREKI = new JapaneseEra(-999, LocalDate.MIN);
+    /**
+     * The singleton instance for the 'Meiji' era (1868-09-08 - 1912-07-29)
+     * which has the value -1.
+     */
+    public static final JapaneseEra MEIJI = new JapaneseEra(-1, LocalDate.of(1868, 9, 8));
+    /**
+     * The singleton instance for the 'Taisho' era (1912-07-30 - 1926-12-24)
+     * which has the value 0.
+     */
+    public static final JapaneseEra TAISHO = new JapaneseEra(0, LocalDate.of(1912, 7, 30));
+    /**
+     * The singleton instance for the 'Showa' era (1926-12-25 - 1989-01-07)
+     * which has the value 1.
+     */
+    public static final JapaneseEra SHOWA = new JapaneseEra(1, LocalDate.of(1926, 12, 25));
+    /**
+     * The singleton instance for the 'Heisei' era (1989-01-08 - current)
+     * which has the value 2.
+     */
+    public static final JapaneseEra HEISEI = new JapaneseEra(2, LocalDate.of(1989, 1, 8));
+
+    // the number of defined JapaneseEra constants.
+    // There could be an extra era defined in its configuration.
+    private static final int N_ERA_CONSTANTS = HEISEI.getValue() + ERA_OFFSET + 1;
+
+    /**
+     * Serialization version.
+     */
+    private static final long serialVersionUID = 1466499369062886794L;
+
+    // array for the singleton JapaneseEra instances
+    private static final JapaneseEra[] KNOWN_ERAS;
+
+    static {
+        sun.util.calendar.Era[] sunEras = JapaneseChronology.JCAL.getEras();
+        ERA_CONFIG = new sun.util.calendar.Era[sunEras.length + 1];
+        for (int i = 1; i < ERA_CONFIG.length; i++) {
+            ERA_CONFIG[i] = sunEras[i - 1];
+        }
+        KNOWN_ERAS = new JapaneseEra[ERA_CONFIG.length];
+        KNOWN_ERAS[0] = SEIREKI;
+        KNOWN_ERAS[1] = MEIJI;
+        KNOWN_ERAS[2] = TAISHO;
+        KNOWN_ERAS[3] = SHOWA;
+        KNOWN_ERAS[4] = HEISEI;
+        for (int i = N_ERA_CONSTANTS; i < ERA_CONFIG.length; i++) {
+            CalendarDate date = ERA_CONFIG[i].getSinceDate();
+            LocalDate isoDate = LocalDate.of(date.getYear(), date.getMonth(), date.getDayOfMonth());
+            KNOWN_ERAS[i] = new JapaneseEra(i - ERA_OFFSET, isoDate);
+        }
+    };
+
+    /**
+     * The era value.
+     * @serial
+     */
+    private final int eraValue;
+
+    // the first day of the era
+    private final transient LocalDate since;
+
+    /**
+     * Creates an instance.
+     *
+     * @param eraValue  the era value, validated
+     * @param since  the date representing the first date of the era, validated not null
+     */
+    private JapaneseEra(int eraValue, LocalDate since) {
+        this.eraValue = eraValue;
+        this.since = since;
+    }
+
+    /**
+     * Returns the singleton {@code JapaneseEra} corresponding to this object.
+     * It's possible that this version of {@code JapaneseEra} doesn't support the latest era value.
+     * In that case, this method throws an {@code ObjectStreamException}.
+     *
+     * @return the singleton {@code JapaneseEra} for this object
+     * @throws ObjectStreamException if the deserialized object has any unknown numeric era value.
+     */
+    private Object readResolve() throws ObjectStreamException {
+        try {
+            return of(eraValue);
+        } catch (DateTimeException e) {
+            InvalidObjectException ex = new InvalidObjectException("Invalid era");
+            ex.initCause(e);
+            throw ex;
+        }
+    }
+
+    //-----------------------------------------------------------------------
+    /**
+     * Returns the Sun private Era instance corresponding to this {@code JapaneseEra}.
+     * SEIREKI doesn't have its corresponding one.
+     *
+     * @return the Sun private Era instance for this {@code JapaneseEra},
+     *         or null for SEIREKI.
+     */
+    sun.util.calendar.Era getPrivateEra() {
+        return ERA_CONFIG[ordinal(eraValue)];
+    }
+
+    //-----------------------------------------------------------------------
+    /**
+     * Obtains an instance of {@code JapaneseEra} from a value.
+     * <p>
+     * The {@link #SHOWA} era that contains 1970-01-01 (ISO calendar system) has the value 1
+     * Later era is numbered 2 ({@link #HEISEI}). Earlier eras are numbered 0 ({@link #TAISHO}),
+     * -1 ({@link #MEIJI}), only Meiji and later eras are supported. The prior to Meiji,
+     * {@link #SEIREKI} is used.
+     *
+     * @param japaneseEra  the era to represent
+     * @return the {@code JapaneseEra} singleton, never null
+     * @throws DateTimeException if {@code japaneseEra} is invalid
+     */
+    public static JapaneseEra of(int japaneseEra) {
+        if (japaneseEra != SEIREKI.eraValue &&
+            (japaneseEra < MEIJI.eraValue || japaneseEra > HEISEI.eraValue)) {
+            throw new DateTimeException("japaneseEra is invalid");
+        }
+        return KNOWN_ERAS[ordinal(japaneseEra)];
+    }
+
+    /**
+     * Returns an array of JapaneseEras.
+     * @return an array of JapaneseEras
+     */
+    static JapaneseEra[] values() {
+        return Arrays.copyOf(KNOWN_ERAS, KNOWN_ERAS.length);
+    }
+
+    //-----------------------------------------------------------------------
+    /**
+     * Obtains an instance of {@code JapaneseEra} from a date.
+     *
+     * @param date  the date, not null
+     * @return the Era singleton, never null
+     */
+    static JapaneseEra from(LocalDate date) {
+        for (int i = KNOWN_ERAS.length - 1; i > 0; i--) {
+            JapaneseEra era = KNOWN_ERAS[i];
+            if (date.compareTo(era.since) >= 0) {
+                return era;
+            }
+        }
+        return SEIREKI;
+    }
+
+    static JapaneseEra toJapaneseEra(sun.util.calendar.Era privateEra) {
+        for (int i = ERA_CONFIG.length - 1; i > 0; i--) {
+            if (ERA_CONFIG[i].equals(privateEra)) {
+                return KNOWN_ERAS[i];
+            }
+        }
+        return SEIREKI;
+    }
+
+    static sun.util.calendar.Era privateEraFrom(LocalDate isoDate) {
+        for (int i = KNOWN_ERAS.length - 1; i > 0; i--) {
+            JapaneseEra era = KNOWN_ERAS[i];
+            if (isoDate.compareTo(era.since) >= 0) {
+                return ERA_CONFIG[i];
+            }
+        }
+        return null;
+    }
+
+    /**
+     * Returns the index into the arrays from the Era value.
+     * the eraValue is a valid Era number, -999, -1..2.
+     * @param eravalue the era value to convert to the index
+     * @return the index of the current Era
+     */
+    private static int ordinal(int eravalue) {
+        return (eravalue == SEIREKI.eraValue) ? 0 : eravalue + ERA_OFFSET;
+    }
+
+    //-----------------------------------------------------------------------
+    /**
+     * Returns the numeric value of this {@code JapaneseEra}.
+     * <p>
+     * The {@link #SHOWA} era that contains 1970-01-01 (ISO calendar system) has the value 1.
+     * Later eras are numbered from 2 ({@link #HEISEI}).
+     * Earlier eras are numbered 0 ({@link #TAISHO}), -1 ({@link #MEIJI}), and -999 ({@link #SEIREKI}).
+     *
+     * @return the era value
+     */
+    @Override
+    public int getValue() {
+        return eraValue;
+    }
+
+    @Override
+    public JapaneseChronology getChronology() {
+        return JapaneseChronology.INSTANCE;
+    }
+
+    //-----------------------------------------------------------------------
+    String getAbbreviation() {
+        int index = ordinal(getValue());
+        if (index == 0) {
+            return "";
+        }
+        return ERA_CONFIG[index].getAbbreviation();
+    }
+
+    String getName() {
+        int index = ordinal(getValue());
+        if (index == 0) {
+            return "Seireki";
+        }
+        return ERA_CONFIG[index].getName();
+    }
+
+    @Override
+    public String toString() {
+        return getName();
+    }
+
+    //-----------------------------------------------------------------------
+    private Object writeReplace() {
+        return new Ser(Ser.JAPANESE_ERA_TYPE, this);
+    }
+
+    void writeExternal(DataOutput out) throws IOException {
+        out.writeByte(this.getValue());
+    }
+
+    static JapaneseEra readExternal(DataInput in) throws IOException {
+        byte eraValue = in.readByte();
+        return JapaneseEra.of(eraValue);
+    }
+
+}