jdk/src/share/classes/java/time/temporal/JulianFields.java
changeset 15289 3ac550392e43
child 15658 55b829ca2334
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/jdk/src/share/classes/java/time/temporal/JulianFields.java	Tue Jan 22 20:59:21 2013 -0800
@@ -0,0 +1,305 @@
+/*
+ * 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.
+ */
+
+/*
+ * This file is available under and governed by the GNU General Public
+ * License version 2 only, as published by the Free Software Foundation.
+ * However, the following notice accompanied the original version of this
+ * file:
+ *
+ * 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.temporal;
+
+import static java.time.temporal.ChronoField.EPOCH_DAY;
+import static java.time.temporal.ChronoUnit.DAYS;
+import static java.time.temporal.ChronoUnit.FOREVER;
+
+import java.io.InvalidObjectException;
+import java.io.Serializable;
+import java.time.DateTimeException;
+import java.time.LocalDate;
+import java.time.format.DateTimeBuilder;
+
+/**
+ * A set of date fields that provide access to Julian Days.
+ * <p>
+ * The Julian Day is a standard way of expressing date and time commonly used in the scientific community.
+ * It is expressed as a decimal number of whole days where days start at midday.
+ * This class represents variations on Julian Days that count whole days from midnight.
+ *
+ * <h3>Specification for implementors</h3>
+ * This is an immutable and thread-safe class.
+ *
+ * @since 1.8
+ */
+public final class JulianFields {
+
+    /**
+     * The offset from Julian to EPOCH DAY.
+     */
+    private static final long JULIAN_DAY_OFFSET = 2440588L;
+
+    /**
+     * Julian Day field.
+     * <p>
+     * This is an integer-based version of the Julian Day Number.
+     * Julian Day is a well-known system that represents the count of whole days since day 0,
+     * which is defined to be January 1, 4713 BCE in the Julian calendar, and -4713-11-24 Gregorian.
+     * The field  has "JulianDay" as 'name', and 'DAYS' as 'baseUnit'.
+     * The field always refers to the local date-time, ignoring the offset or zone.
+     * <p>
+     * For date-times, 'JULIAN_DAY.doGet()' assumes the same value from
+     * midnight until just before the next midnight.
+     * When 'JULIAN_DAY.doWith()' is applied to a date-time, the time of day portion remains unaltered.
+     * 'JULIAN_DAY.doWith()' and 'JULIAN_DAY.doGet()' only apply to {@code Temporal} objects that
+     * can be converted into {@link ChronoField#EPOCH_DAY}.
+     * A {@link DateTimeException} is thrown for any other type of object.
+     * <p>
+     * <h3>Astronomical and Scientific Notes</h3>
+     * The standard astronomical definition uses a fraction to indicate the time-of-day,
+     * thus 3.25 would represent the time 18:00, since days start at midday.
+     * This implementation uses an integer and days starting at midnight.
+     * The integer value for the Julian Day Number is the astronomical Julian Day value at midday
+     * of the date in question.
+     * This amounts to the astronomical Julian Day, rounded to an integer {@code JDN = floor(JD + 0.5)}.
+     * <p>
+     * <pre>
+     *  | ISO date          |  Julian Day Number | Astronomical Julian Day |
+     *  | 1970-01-01T00:00  |         2,440,588  |         2,440,587.5     |
+     *  | 1970-01-01T06:00  |         2,440,588  |         2,440,587.75    |
+     *  | 1970-01-01T12:00  |         2,440,588  |         2,440,588.0     |
+     *  | 1970-01-01T18:00  |         2,440,588  |         2,440,588.25    |
+     *  | 1970-01-02T00:00  |         2,440,589  |         2,440,588.5     |
+     *  | 1970-01-02T06:00  |         2,440,589  |         2,440,588.75    |
+     *  | 1970-01-02T12:00  |         2,440,589  |         2,440,589.0     |
+     * </pre>
+     * <p>
+     * Julian Days are sometimes taken to imply Universal Time or UTC, but this
+     * implementation always uses the Julian Day number for the local date,
+     * regardless of the offset or time-zone.
+     */
+    public static final TemporalField JULIAN_DAY = new Field("JulianDay", DAYS, FOREVER, JULIAN_DAY_OFFSET);
+
+    /**
+     * Modified Julian Day field.
+     * <p>
+     * This is an integer-based version of the Modified Julian Day Number.
+     * Modified Julian Day (MJD) is a well-known system that counts days continuously.
+     * It is defined relative to astronomical Julian Day as  {@code MJD = JD - 2400000.5}.
+     * Each Modified Julian Day runs from midnight to midnight.
+     * The field always refers to the local date-time, ignoring the offset or zone.
+     * <p>
+     * For date-times, 'MODIFIED_JULIAN_DAY.doGet()' assumes the same value from
+     * midnight until just before the next midnight.
+     * When 'MODIFIED_JULIAN_DAY.doWith()' is applied to a date-time, the time of day portion remains unaltered.
+     * 'MODIFIED_JULIAN_DAY.doWith()' and 'MODIFIED_JULIAN_DAY.doGet()' only apply to {@code Temporal} objects
+     * that can be converted into {@link ChronoField#EPOCH_DAY}.
+     * A {@link DateTimeException} is thrown for any other type of object.
+     * <p>
+     * This implementation is an integer version of MJD with the decimal part rounded to floor.
+     * <p>
+     * <h3>Astronomical and Scientific Notes</h3>
+     * <pre>
+     *  | ISO date          | Modified Julian Day |      Decimal MJD |
+     *  | 1970-01-01T00:00  |             40,587  |       40,587.0   |
+     *  | 1970-01-01T06:00  |             40,587  |       40,587.25  |
+     *  | 1970-01-01T12:00  |             40,587  |       40,587.5   |
+     *  | 1970-01-01T18:00  |             40,587  |       40,587.75  |
+     *  | 1970-01-02T00:00  |             40,588  |       40,588.0   |
+     *  | 1970-01-02T06:00  |             40,588  |       40,588.25  |
+     *  | 1970-01-02T12:00  |             40,588  |       40,588.5   |
+     * </pre>
+     * <p>
+     * Modified Julian Days are sometimes taken to imply Universal Time or UTC, but this
+     * implementation always uses the Modified Julian Day for the local date,
+     * regardless of the offset or time-zone.
+     */
+    public static final TemporalField MODIFIED_JULIAN_DAY = new Field("ModifiedJulianDay", DAYS, FOREVER, 40587L);
+
+    /**
+     * Rata Die field.
+     * <p>
+     * Rata Die counts whole days continuously starting day 1 at midnight at the beginning of 0001-01-01 (ISO).
+     * The field always refers to the local date-time, ignoring the offset or zone.
+     * <p>
+     * For date-times, 'RATA_DIE.doGet()' assumes the same value from
+     * midnight until just before the next midnight.
+     * When 'RATA_DIE.doWith()' is applied to a date-time, the time of day portion remains unaltered.
+     * 'MODIFIED_JULIAN_DAY.doWith()' and 'RATA_DIE.doGet()' only apply to {@code Temporal} objects
+     * that can be converted into {@link ChronoField#EPOCH_DAY}.
+     * A {@link DateTimeException} is thrown for any other type of object.
+     */
+    public static final TemporalField RATA_DIE = new Field("RataDie", DAYS, FOREVER, 719163L);
+
+    /**
+     * Restricted constructor.
+     */
+    private JulianFields() {
+        throw new AssertionError("Not instantiable");
+    }
+
+    /**
+     * implementation of JulianFields.  Each instance is a singleton.
+     */
+    private static class Field implements TemporalField, Serializable {
+
+        private static final long serialVersionUID = -7501623920830201812L;
+
+        private final String name;
+        private final transient TemporalUnit baseUnit;
+        private final transient TemporalUnit rangeUnit;
+        private final transient ValueRange range;
+        private final transient long offset;
+
+        private Field(String name, TemporalUnit baseUnit, TemporalUnit rangeUnit, long offset) {
+            this.name = name;
+            this.baseUnit = baseUnit;
+            this.rangeUnit = rangeUnit;
+            this.range = ValueRange.of(-365243219162L + offset, 365241780471L + offset);
+            this.offset = offset;
+        }
+
+
+        /**
+         * Resolve the object from the stream to the appropriate singleton.
+         * @return one of the singleton objects {@link #JULIAN_DAY},
+         *     {@link #MODIFIED_JULIAN_DAY}, or {@link #RATA_DIE}.
+         * @throws InvalidObjectException if the object in the stream is not one of the singletons.
+         */
+        private Object readResolve() throws InvalidObjectException {
+            if (JULIAN_DAY.getName().equals(name)) {
+                return JULIAN_DAY;
+            } else if (MODIFIED_JULIAN_DAY.getName().equals(name)) {
+                return MODIFIED_JULIAN_DAY;
+            } else if (RATA_DIE.getName().equals(name)) {
+                return RATA_DIE;
+            } else {
+                throw new InvalidObjectException("Not one of the singletons");
+            }
+        }
+
+        //-----------------------------------------------------------------------
+        @Override
+        public String getName() {
+            return name;
+        }
+
+        @Override
+        public TemporalUnit getBaseUnit() {
+            return baseUnit;
+        }
+
+        @Override
+        public TemporalUnit getRangeUnit() {
+            return rangeUnit;
+        }
+
+        @Override
+        public ValueRange range() {
+            return range;
+        }
+
+        //-----------------------------------------------------------------------
+        @Override
+        public boolean doIsSupported(TemporalAccessor temporal) {
+            return temporal.isSupported(EPOCH_DAY);
+        }
+
+        @Override
+        public ValueRange doRange(TemporalAccessor temporal) {
+            if (doIsSupported(temporal) == false) {
+                throw new DateTimeException("Unsupported field: " + this);
+            }
+            return range();
+        }
+
+        @Override
+        public long doGet(TemporalAccessor temporal) {
+            return temporal.getLong(EPOCH_DAY) + offset;
+        }
+
+        @Override
+        public <R extends Temporal> R doWith(R temporal, long newValue) {
+            if (range().isValidValue(newValue) == false) {
+                throw new DateTimeException("Invalid value: " + name + " " + newValue);
+            }
+            return (R) temporal.with(EPOCH_DAY, Math.subtractExact(newValue, offset));
+        }
+
+        //-----------------------------------------------------------------------
+        @Override
+        public boolean resolve(DateTimeBuilder builder, long value) {
+            boolean changed = false;
+            changed = resolve0(JULIAN_DAY, builder, changed);
+            changed = resolve0(MODIFIED_JULIAN_DAY, builder, changed);
+            changed = resolve0(RATA_DIE, builder, changed);
+            return changed;
+        }
+
+        private boolean resolve0(TemporalField field, DateTimeBuilder builder, boolean changed) {
+            if (builder.containsFieldValue(field)) {
+                builder.addCalendrical(LocalDate.ofEpochDay(Math.subtractExact(builder.getFieldValue(JULIAN_DAY), JULIAN_DAY_OFFSET)));
+                builder.removeFieldValue(JULIAN_DAY);
+                changed = true;
+            }
+            return changed;
+        }
+
+        //-----------------------------------------------------------------------
+        @Override
+        public String toString() {
+            return getName();
+        }
+    }
+}