src/java.base/share/classes/java/util/concurrent/TimeUnit.java

*** 33,42 ****
--- 33,45 ----
   * http://creativecommons.org/publicdomain/zero/1.0/
   */
  
  package java.util.concurrent;
  
+ import java.time.temporal.ChronoUnit;
+ import java.util.Objects;
+ 
  /**
   * A {@code TimeUnit} represents time durations at a given unit of
   * granularity and provides utility methods to convert across units,
   * and to perform timing and delay operations in these units.  A
   * {@code TimeUnit} does not maintain time information, but only
*** 388,393 ****
--- 391,456 ----
              int ns = excessNanos(timeout, ms);
              Thread.sleep(ms, ns);
          }
      }
  
+     /**
+      * Converts a {@code TimeUnit} to an equivalent {@code ChronoUnit}.
+      *
+      * @param  timeUnit the timeUnit to convert, not null
+      * @return the converted equivalent chronoUnit
+      * @throws IllegalArgumentException if the unit cannot be converted
+      * @since 9
+      */
+     public static ChronoUnit toChronoUnit(TimeUnit timeUnit) {
+         Objects.requireNonNull(timeUnit, "timeUnit");
+         switch (timeUnit) {
+             case NANOSECONDS:
+                 return ChronoUnit.NANOS;
+             case MICROSECONDS:
+                 return ChronoUnit.MICROS;
+             case MILLISECONDS:
+                 return ChronoUnit.MILLIS;
+             case SECONDS:
+                 return ChronoUnit.SECONDS;
+             case MINUTES:
+                 return ChronoUnit.MINUTES;
+             case HOURS:
+                 return ChronoUnit.HOURS;
+             case DAYS:
+                 return ChronoUnit.DAYS;
+             default:
+                 throw new IllegalArgumentException("Unknown TimeUnit");
+         }
+     }
+ 
+     /**
+      * Converts a {@code ChronoUnit} to an equivalent {@code TimeUnit}.
+      *
+      * @param chronoUnit  the unit to convert, not null
+      * @return the converted equivalent timeUnit
+      * @throws IllegalArgumentException if the unit cannot be converted
+      * @since 9
+      */
+     public static TimeUnit of(ChronoUnit chronoUnit) {
+         Objects.requireNonNull(chronoUnit, "chronoUnit");
+         switch (chronoUnit) {
+             case NANOS:
+                 return TimeUnit.NANOSECONDS;
+             case MICROS:
+                 return TimeUnit.MICROSECONDS;
+             case MILLIS:
+                 return TimeUnit.MILLISECONDS;
+             case SECONDS:
+                 return TimeUnit.SECONDS;
+             case MINUTES:
+                 return TimeUnit.MINUTES;
+             case HOURS:
+                 return TimeUnit.HOURS;
+             case DAYS:
+                 return TimeUnit.DAYS;
+             default:
+                 throw new IllegalArgumentException("No TimeUnit equivalent for " + chronoUnit);
+         }
+     }
+ 
  }