Support API backwards compatibility

src/main/java/net/fortuna/ical4j/model/Period.java

@@ -90,6 +90,18 @@ public Period(final DateTime start, final DateTime end) {
         normalise();
     }
 
+    /**
+     * Constructs a new period with the specified start date and duration.
+     *
+     * @param start
+     *            the start date of the period
+     * @param duration
+     *            the duration of the period
+     */
+    public Period(final DateTime start, final Dur duration) {
+        this(start, TemporalAmountAdapter.from(duration));
+    }
+
     /**
      * Constructs a new period with the specified start date and duration.
      * 

src/main/java/net/fortuna/ical4j/model/TemporalAmountAdapter.java

@@ -74,4 +74,14 @@ public static TemporalAmountAdapter fromDateRange(Date start, Date end) {
         }
         return new TemporalAmountAdapter(duration);
     }
+
+    public static TemporalAmount from(Dur duration) {
+        if (duration.getWeeks() > 0) {
+            return Period.ofWeeks(duration.getWeeks());
+        }
+        return Duration.ofDays(duration.getDays())
+                .plusHours(duration.getHours())
+                .plusMinutes(duration.getMinutes())
+                .plusSeconds(duration.getSeconds());
+    }
 }

src/main/java/net/fortuna/ical4j/model/ZoneOffsetAdapter.java

@@ -36,4 +36,12 @@ public String toString() {
         }
         return retVal;
     }
+
+    /**
+     * @param utcOffset
+     * @return a zoneoffset representing the specified utcoffset
+     */
+    public static ZoneOffset from(UtcOffset utcOffset) {
+        return ZoneOffset.of(utcOffset.toString());
+    }
 }

src/main/java/net/fortuna/ical4j/model/property/Duration.java

@@ -127,6 +127,13 @@ public Duration(final ParameterList aList, final String aValue) {
         setValue(aValue);
     }
 
+    /**
+     * @param duration a duration  value
+     */
+    public Duration(final Dur duration) {
+        this(TemporalAmountAdapter.from(duration));
+    }
+
     /**
      * @param duration a duration  value
      */
@@ -135,6 +142,14 @@ public Duration(final TemporalAmount duration) {
         this.duration = new TemporalAmountAdapter(duration);
     }
 
+    /**
+     * @param aList    a list of parameters for this component
+     * @param duration a duration value
+     */
+    public Duration(final ParameterList aList, final Dur duration) {
+        this(aList, TemporalAmountAdapter.from(duration));
+    }
+
     /**
      * @param aList    a list of parameters for this component
      * @param duration a duration value

src/main/java/net/fortuna/ical4j/model/property/Trigger.java

@@ -165,6 +165,13 @@ public Trigger(final ParameterList aList, final String aValue) {
         setValue(aValue);
     }
 
+    /**
+     * @param duration a duration in milliseconds
+     */
+    public Trigger(final Dur duration) {
+        this(TemporalAmountAdapter.from(duration));
+    }
+
     /**
      * @param duration a duration in milliseconds
      */
@@ -173,6 +180,14 @@ public Trigger(final TemporalAmount duration) {
         setDuration(duration);
     }
 
+    /**
+     * @param aList    a list of parameters for this component
+     * @param duration a duration in milliseconds
+     */
+    public Trigger(final ParameterList aList, final Dur duration) {
+        this(aList, TemporalAmountAdapter.from(duration));
+    }
+
     /**
      * @param aList    a list of parameters for this component
      * @param duration a duration in milliseconds

src/main/java/net/fortuna/ical4j/model/property/TzOffsetFrom.java

@@ -52,8 +52,6 @@ public class TzOffsetFrom extends Property {
 
     private static final long serialVersionUID = 450274263165493502L;
 
-    private static final ZoneOffsetFactory ZONEOFFSET_FACTORY = new ZoneOffsetFactory();
-
     private ZoneOffsetAdapter offset;
 
     /**
@@ -84,7 +82,7 @@ public TzOffsetFrom(final ParameterList aList, final String aValue) {
      * @param anOffset a timezone offset in milliseconds
      */
     public TzOffsetFrom(final UtcOffset anOffset) {
-        this(ZONEOFFSET_FACTORY.create(anOffset));
+        this(ZoneOffsetAdapter.from(anOffset));
     }
 
     /**
@@ -100,7 +98,7 @@ public TzOffsetFrom(final ZoneOffset anOffset) {
      * @param anOffset a timezone offset in milliseconds
      */
     public TzOffsetFrom(final ParameterList aList, final UtcOffset anOffset) {
-        this(aList, ZONEOFFSET_FACTORY.create(anOffset));
+        this(aList, ZoneOffsetAdapter.from(anOffset));
     }
 
     /**

src/main/java/net/fortuna/ical4j/model/property/TzOffsetTo.java

@@ -52,8 +52,6 @@ public class TzOffsetTo extends Property {
 
     private static final long serialVersionUID = 8213874575051177732L;
 
-    private static final ZoneOffsetFactory ZONEOFFSET_FACTORY = new ZoneOffsetFactory();
-
     private ZoneOffsetAdapter offset;
 
     /**
@@ -84,7 +82,7 @@ public TzOffsetTo(final ParameterList aList, final String aValue) {
      * @param anOffset a timezone offset in milliseconds
      */
     public TzOffsetTo(final UtcOffset anOffset) {
-        this(ZONEOFFSET_FACTORY.create(anOffset));
+        this(ZoneOffsetAdapter.from(anOffset));
     }
 
     /**
@@ -100,7 +98,7 @@ public TzOffsetTo(final ZoneOffset anOffset) {
      * @param anOffset a timezone offset in milliseconds
      */
     public TzOffsetTo(final ParameterList aList, final UtcOffset anOffset) {
-        this(aList, ZONEOFFSET_FACTORY.create(anOffset));
+        this(aList, ZoneOffsetAdapter.from(anOffset));
     }
 
     /**

src/test/groovy/net/fortuna/ical4j/model/TemporalAmountAdapterTest.groovy

@@ -21,4 +21,14 @@ class TemporalAmountAdapterTest extends Specification {
         java.time.Period.ofYears(1) | "P52W"
         java.time.Period.ofMonths(6) | "P24W"
     }
+
+    def 'verify temporalamount creation'() {
+        expect:
+        TemporalAmountAdapter.from(duration) == expectedTemporalAmount
+
+        where:
+        duration       | expectedTemporalAmount
+        new Dur(1, 2, 3, 4)  | Duration.ofDays(1).plusHours(2).plusMinutes(3).plusSeconds(4)
+        new Dur(5)  | java.time.Period.ofWeeks(5)
+    }
 }

src/test/groovy/net/fortuna/ical4j/model/ZoneOffsetAdapterTest.groovy

@@ -16,4 +16,16 @@ class ZoneOffsetAdapterTest extends Specification {
         ZoneOffset.ofHoursMinutes(5, 30)   | "+0530"
         ZoneOffset.ofHoursMinutesSeconds(-6, -30, -15)   | "-063015"
     }
+
+    def 'verify zoneoffset creation'() {
+        expect:
+        ZoneOffsetAdapter.from(utcOffset) == expectedOffset
+
+        where:
+        utcOffset       | expectedOffset
+        new UtcOffset('+1000')  | ZoneOffset.ofHours(10)
+        new UtcOffset('-0600')  | ZoneOffset.ofHours(-6)
+        new UtcOffset('+0545')  | ZoneOffset.ofHoursMinutes(5, 45)
+    }
+
 }