8257845: Integrate JEP 390

8254047: [JEP 390] Revise "value-based class" & apply to wrappers
8252181: [JEP 390] Define & apply annotation jdk.internal.ValueBased
8252183: [JEP 390] Add 'lint' warning for @ValueBased classes
8257027: [JEP 390] Diagnose synchronization on @ValueBased classes
8252180: [JEP 390] Deprecate wrapper class constructors for removal

Co-authored-by: Roger Riggs <rriggs@openjdk.org>
Co-authored-by: Srikanth Adayapalam <sadayapalam@openjdk.org>
Co-authored-by: Lois Foltan <lfoltan@openjdk.org>
Reviewed-by: rriggs, hseigel, mchung, darcy

src/java.base/share/classes/java/time/chrono/HijrahDate.java

@@ -103,12 +103,12 @@ import java.time.temporal.ValueRange;
  * to create new HijrahDate instances.
  * Alternatively, the {@link #withVariant} method can be used to convert
  * to a new HijrahChronology.
- *
  * <p>
  * This is a <a href="{@docRoot}/java.base/java/lang/doc-files/ValueBased.html">value-based</a>
- * class; use of identity-sensitive operations (including reference equality
- * ({@code ==}), identity hash code, or synchronization) on instances of
- * {@code HijrahDate} may have unpredictable results and should be avoided.
+ * class; programmers should treat instances that are
+ * {@linkplain #equals(Object) equal} as interchangeable and should not
+ * use instances for synchronization, or unpredictable behavior may
+ * occur. For example, in a future release, synchronization may fail.
  * The {@code equals} method should be used for comparisons.
  *
  * @implSpec
@@ -116,6 +116,7 @@ import java.time.temporal.ValueRange;
  *
  * @since 1.8
  */
+@jdk.internal.ValueBased
 public final class HijrahDate
         extends ChronoLocalDateImpl<HijrahDate>
         implements ChronoLocalDate, Serializable {

src/java.base/share/classes/java/time/chrono/JapaneseDate.java

@@ -110,12 +110,12 @@ import sun.util.calendar.LocalGregorianCalendar;
  * Calling {@code japaneseDate.get(YEAR)} will return 2012.<br>
  * Calling {@code japaneseDate.get(ERA)} will return 2, corresponding to
  * {@code JapaneseChronology.ERA_HEISEI}.<br>
- *
  * <p>
  * This is a <a href="{@docRoot}/java.base/java/lang/doc-files/ValueBased.html">value-based</a>
- * class; use of identity-sensitive operations (including reference equality
- * ({@code ==}), identity hash code, or synchronization) on instances of
- * {@code JapaneseDate} may have unpredictable results and should be avoided.
+ * class; programmers should treat instances that are
+ * {@linkplain #equals(Object) equal} as interchangeable and should not
+ * use instances for synchronization, or unpredictable behavior may
+ * occur. For example, in a future release, synchronization may fail.
  * The {@code equals} method should be used for comparisons.
  *
  * @implSpec
@@ -123,6 +123,7 @@ import sun.util.calendar.LocalGregorianCalendar;
  *
  * @since 1.8
  */
+@jdk.internal.ValueBased
 public final class JapaneseDate
         extends ChronoLocalDateImpl<JapaneseDate>
         implements ChronoLocalDate, Serializable {
@@ -140,11 +141,11 @@ public final class JapaneseDate
     /**
      * The JapaneseEra of this date.
      */
-    private transient JapaneseEra era;
+    private final transient JapaneseEra era;
     /**
      * The Japanese imperial calendar year of this date.
      */
-    private transient int yearOfEra;
+    private final transient int yearOfEra;
 
     /**
      * The first day supported by the JapaneseChronology is Meiji 6, January 1st.

src/java.base/share/classes/java/time/chrono/MinguoDate.java

@@ -90,12 +90,12 @@ import java.util.Objects;
  * This date operates using the {@linkplain MinguoChronology Minguo calendar}.
  * This calendar system is primarily used in the Republic of China, often known as Taiwan.
  * Dates are aligned such that {@code 0001-01-01 (Minguo)} is {@code 1912-01-01 (ISO)}.
- *
  * <p>
  * This is a <a href="{@docRoot}/java.base/java/lang/doc-files/ValueBased.html">value-based</a>
- * class; use of identity-sensitive operations (including reference equality
- * ({@code ==}), identity hash code, or synchronization) on instances of
- * {@code MinguoDate} may have unpredictable results and should be avoided.
+ * class; programmers should treat instances that are
+ * {@linkplain #equals(Object) equal} as interchangeable and should not
+ * use instances for synchronization, or unpredictable behavior may
+ * occur. For example, in a future release, synchronization may fail.
  * The {@code equals} method should be used for comparisons.
  *
  * @implSpec
@@ -103,6 +103,7 @@ import java.util.Objects;
  *
  * @since 1.8
  */
+@jdk.internal.ValueBased
 public final class MinguoDate
         extends ChronoLocalDateImpl<MinguoDate>
         implements ChronoLocalDate, Serializable {

src/java.base/share/classes/java/time/chrono/ThaiBuddhistChronology.java

@@ -72,7 +72,6 @@ import java.time.temporal.ChronoField;
 import java.time.temporal.TemporalAccessor;
 import java.time.temporal.TemporalField;
 import java.time.temporal.ValueRange;
-import java.util.Arrays;
 import java.util.HashMap;
 import java.util.List;
 import java.util.Locale;

src/java.base/share/classes/java/time/chrono/ThaiBuddhistDate.java

@@ -90,12 +90,12 @@ import java.util.Objects;
  * This date operates using the {@linkplain ThaiBuddhistChronology Thai Buddhist calendar}.
  * This calendar system is primarily used in Thailand.
  * Dates are aligned such that {@code 2484-01-01 (Buddhist)} is {@code 1941-01-01 (ISO)}.
- *
  * <p>
  * This is a <a href="{@docRoot}/java.base/java/lang/doc-files/ValueBased.html">value-based</a>
- * class; use of identity-sensitive operations (including reference equality
- * ({@code ==}), identity hash code, or synchronization) on instances of
- * {@code ThaiBuddhistDate} may have unpredictable results and should be avoided.
+ * class; programmers should treat instances that are
+ * {@linkplain #equals(Object) equal} as interchangeable and should not
+ * use instances for synchronization, or unpredictable behavior may
+ * occur. For example, in a future release, synchronization may fail.
  * The {@code equals} method should be used for comparisons.
  *
  * @implSpec
@@ -103,6 +103,7 @@ import java.util.Objects;
  *
  * @since 1.8
  */
+@jdk.internal.ValueBased
 public final class ThaiBuddhistDate
         extends ChronoLocalDateImpl<ThaiBuddhistDate>
         implements ChronoLocalDate, Serializable {