diff --git a/src/main/java/net/fortuna/ical4j/model/component/Available.java b/src/main/java/net/fortuna/ical4j/model/component/Available.java
index 22fb66e1c..193758d94 100644
--- a/src/main/java/net/fortuna/ical4j/model/component/Available.java
+++ b/src/main/java/net/fortuna/ical4j/model/component/Available.java
@@ -37,6 +37,10 @@
 import net.fortuna.ical4j.model.property.DtStart;
 import net.fortuna.ical4j.validate.PropertyValidator;
 import net.fortuna.ical4j.validate.ValidationException;
+import org.apache.commons.collections4.Closure;
+import org.apache.commons.collections4.CollectionUtils;
+
+import java.util.Arrays;
 
 /**
  * $Id$ [05-Apr-2004]
@@ -113,12 +117,12 @@ public final void validate(final boolean recurse)
         /*
          * ; dtstamp / dtstart / uid are required, but MUST NOT occur more than once /
          */
-        PropertyValidator.getInstance().assertOne(Property.DTSTART,
-                getProperties());
-        PropertyValidator.getInstance().assertOne(Property.DTSTAMP,
-                getProperties());
-        PropertyValidator.getInstance().assertOne(Property.UID,
-                getProperties());
+        CollectionUtils.forAllDo(Arrays.asList(Property.DTSTART, Property.DTSTAMP, Property.UID), new Closure<String>() {
+            @Override
+            public void execute(String input) {
+                PropertyValidator.getInstance().assertOne(input, getProperties());
+            }
+        });
 
         /*       If specified, the "DTSTART" and "DTEND" properties in
          *      "VAVAILABILITY" components and "AVAILABLE" sub-components MUST be
@@ -138,16 +142,13 @@ public final void validate(final boolean recurse)
          *               created / last-mod / recurid / rrule /
          *               summary /
          */
-        PropertyValidator.getInstance().assertOneOrLess(Property.CREATED,
-                getProperties());
-        PropertyValidator.getInstance().assertOneOrLess(Property.LAST_MODIFIED,
-                getProperties());
-        PropertyValidator.getInstance().assertOneOrLess(Property.RECURRENCE_ID,
-                getProperties());
-        PropertyValidator.getInstance().assertOneOrLess(Property.RRULE,
-                getProperties());
-        PropertyValidator.getInstance().assertOneOrLess(Property.SUMMARY,
-                getProperties());
+        CollectionUtils.forAllDo(Arrays.asList(Property.CREATED, Property.LAST_MODIFIED, Property.RECURRENCE_ID,
+                Property.RRULE, Property.SUMMARY), new Closure<String>() {
+            @Override
+            public void execute(String input) {
+                PropertyValidator.getInstance().assertOneOrLess(input, getProperties());
+            }
+        });
 
         /*
          ; either a 'dtend' or a 'duration' is required
diff --git a/src/main/java/net/fortuna/ical4j/model/component/VAvailability.java b/src/main/java/net/fortuna/ical4j/model/component/VAvailability.java
index 5d8e2af24..be441be64 100644
--- a/src/main/java/net/fortuna/ical4j/model/component/VAvailability.java
+++ b/src/main/java/net/fortuna/ical4j/model/component/VAvailability.java
@@ -41,6 +41,10 @@
 import net.fortuna.ical4j.validate.PropertyValidator;
 import net.fortuna.ical4j.validate.ValidationException;
 import net.fortuna.ical4j.validate.Validator;
+import org.apache.commons.collections4.Closure;
+import org.apache.commons.collections4.CollectionUtils;
+
+import java.util.Arrays;
 
 /**
  * $Id$ [Apr 5, 2004]
@@ -179,12 +183,12 @@ public final void validate(final boolean recurse)
         /*
          * ; dtstamp / dtstart / uid are required, but MUST NOT occur more than once /
          */
-        PropertyValidator.getInstance().assertOne(Property.DTSTART,
-                getProperties());
-        PropertyValidator.getInstance().assertOne(Property.DTSTAMP,
-                getProperties());
-        PropertyValidator.getInstance().assertOne(Property.UID,
-                getProperties());
+        CollectionUtils.forAllDo(Arrays.asList(Property.DTSTART, Property.DTSTAMP, Property.UID), new Closure<String>() {
+            @Override
+            public void execute(String input) {
+                PropertyValidator.getInstance().assertOne(input, getProperties());
+            }
+        });
 
         /*       If specified, the "DTSTART" and "DTEND" properties in
          *      "VAVAILABILITY" components and "AVAILABLE" sub-components MUST be
@@ -225,20 +229,13 @@ public final void validate(final boolean recurse)
          *                  busytype / created / last-mod /
          *                  organizer / seq / summary / url /
          */
-        PropertyValidator.getInstance().assertOneOrLess(Property.BUSYTYPE,
-                getProperties());
-        PropertyValidator.getInstance().assertOneOrLess(Property.CREATED,
-                getProperties());
-        PropertyValidator.getInstance().assertOneOrLess(Property.LAST_MODIFIED,
-                getProperties());
-        PropertyValidator.getInstance().assertOneOrLess(Property.ORGANIZER,
-                getProperties());
-        PropertyValidator.getInstance().assertOneOrLess(Property.SEQUENCE,
-                getProperties());
-        PropertyValidator.getInstance().assertOneOrLess(Property.SUMMARY,
-                getProperties());
-        PropertyValidator.getInstance().assertOneOrLess(Property.URL,
-                getProperties());
+        CollectionUtils.forAllDo(Arrays.asList(Property.BUSYTYPE, Property.CREATED, Property.LAST_MODIFIED,
+                Property.ORGANIZER, Property.SEQUENCE, Property.SUMMARY, Property.URL), new Closure<String>() {
+            @Override
+            public void execute(String input) {
+                PropertyValidator.getInstance().assertOneOrLess(input, getProperties());
+            }
+        });
 
         /*
          * ; the following are optional, ; and MAY occur more than once
diff --git a/src/main/java/net/fortuna/ical4j/model/component/VEvent.java b/src/main/java/net/fortuna/ical4j/model/component/VEvent.java
index 61ab1725d..50df46a1d 100644
--- a/src/main/java/net/fortuna/ical4j/model/component/VEvent.java
+++ b/src/main/java/net/fortuna/ical4j/model/component/VEvent.java
@@ -41,12 +41,15 @@
 import net.fortuna.ical4j.validate.ValidationException;
 import net.fortuna.ical4j.validate.Validator;
 import net.fortuna.ical4j.validate.component.*;
+import org.apache.commons.collections4.Closure;
+import org.apache.commons.collections4.CollectionUtils;
 import org.apache.commons.lang3.ObjectUtils;
 import org.apache.commons.lang3.builder.HashCodeBuilder;
 
 import java.io.IOException;
 import java.net.URISyntaxException;
 import java.text.ParseException;
+import java.util.Arrays;
 import java.util.HashMap;
 import java.util.Map;
 
@@ -344,40 +347,15 @@ public final void validate(final boolean recurse) throws ValidationException {
          * geo / last-mod / location / organizer / priority / dtstamp / seq / status / summary / transp / uid / url /
          * recurid /
          */
-        PropertyValidator.getInstance().assertOneOrLess(Property.CLASS,
-                getProperties());
-        PropertyValidator.getInstance().assertOneOrLess(Property.CREATED,
-                getProperties());
-        PropertyValidator.getInstance().assertOneOrLess(Property.DESCRIPTION,
-                getProperties());
-        PropertyValidator.getInstance().assertOneOrLess(Property.DTSTART,
-                getProperties());
-        PropertyValidator.getInstance().assertOneOrLess(Property.GEO,
-                getProperties());
-        PropertyValidator.getInstance().assertOneOrLess(Property.LAST_MODIFIED,
-                getProperties());
-        PropertyValidator.getInstance().assertOneOrLess(Property.LOCATION,
-                getProperties());
-        PropertyValidator.getInstance().assertOneOrLess(Property.ORGANIZER,
-                getProperties());
-        PropertyValidator.getInstance().assertOneOrLess(Property.PRIORITY,
-                getProperties());
-        PropertyValidator.getInstance().assertOneOrLess(Property.DTSTAMP,
-                getProperties());
-        PropertyValidator.getInstance().assertOneOrLess(Property.SEQUENCE,
-                getProperties());
-        PropertyValidator.getInstance().assertOneOrLess(Property.STATUS,
-                getProperties());
-        PropertyValidator.getInstance().assertOneOrLess(Property.SUMMARY,
-                getProperties());
-        PropertyValidator.getInstance().assertOneOrLess(Property.TRANSP,
-                getProperties());
-        PropertyValidator.getInstance().assertOneOrLess(Property.UID,
-                getProperties());
-        PropertyValidator.getInstance().assertOneOrLess(Property.URL,
-                getProperties());
-        PropertyValidator.getInstance().assertOneOrLess(Property.RECURRENCE_ID,
-                getProperties());
+        CollectionUtils.forAllDo(Arrays.asList(Property.CLASS, Property.CREATED, Property.DESCRIPTION,
+                Property.DTSTART, Property.GEO, Property.LAST_MODIFIED, Property.LOCATION, Property.ORGANIZER,
+                Property.PRIORITY, Property.DTSTAMP, Property.SEQUENCE, Property.STATUS, Property.SUMMARY,
+                Property.TRANSP, Property.UID, Property.URL, Property.RECURRENCE_ID), new Closure<String>() {
+            @Override
+            public void execute(String input) {
+                PropertyValidator.getInstance().assertOneOrLess(input, getProperties());
+            }
+        });
 
         final Status status = (Status) getProperty(Property.STATUS);
         if (status != null && !Status.VEVENT_TENTATIVE.getValue().equals(status.getValue())
diff --git a/src/main/java/net/fortuna/ical4j/model/component/VFreeBusy.java b/src/main/java/net/fortuna/ical4j/model/component/VFreeBusy.java
index 4505d9656..a58f5c18b 100644
--- a/src/main/java/net/fortuna/ical4j/model/component/VFreeBusy.java
+++ b/src/main/java/net/fortuna/ical4j/model/component/VFreeBusy.java
@@ -41,7 +41,10 @@
 import net.fortuna.ical4j.validate.component.VFreeBusyPublishValidator;
 import net.fortuna.ical4j.validate.component.VFreeBusyReplyValidator;
 import net.fortuna.ical4j.validate.component.VFreeBusyRequestValidator;
+import org.apache.commons.collections4.Closure;
+import org.apache.commons.collections4.CollectionUtils;
 
+import java.util.Arrays;
 import java.util.HashMap;
 import java.util.Iterator;
 import java.util.Map;
@@ -497,20 +500,17 @@ public final void validate(final boolean recurse) throws ValidationException {
                     getProperties());
         }
 
-        final PropertyValidator validator = PropertyValidator.getInstance();
-
         /*
          * ; the following are optional, ; but MUST NOT occur more than once contact / dtstart / dtend / duration /
          * dtstamp / organizer / uid / url /
          */
-        validator.assertOneOrLess(Property.CONTACT, getProperties());
-        validator.assertOneOrLess(Property.DTSTART, getProperties());
-        validator.assertOneOrLess(Property.DTEND, getProperties());
-        validator.assertOneOrLess(Property.DURATION, getProperties());
-        validator.assertOneOrLess(Property.DTSTAMP, getProperties());
-        validator.assertOneOrLess(Property.ORGANIZER, getProperties());
-        validator.assertOneOrLess(Property.UID, getProperties());
-        validator.assertOneOrLess(Property.URL, getProperties());
+        CollectionUtils.forAllDo(Arrays.asList(Property.CONTACT, Property.DTSTART, Property.DTEND, Property.DURATION,
+                Property.DTSTAMP, Property.ORGANIZER, Property.UID, Property.URL), new Closure<String>() {
+            @Override
+            public void execute(String input) {
+                PropertyValidator.getInstance().assertOneOrLess(input, getProperties());
+            }
+        });
 
         /*
          * ; the following are optional, ; and MAY occur more than once attendee / comment / freebusy / rstatus / x-prop
@@ -521,10 +521,12 @@ public final void validate(final boolean recurse) throws ValidationException {
          * calendar component. Any recurring events are resolved into their individual busy time periods using the
          * "FREEBUSY" property.
          */
-        validator.assertNone(Property.RRULE, getProperties());
-        validator.assertNone(Property.EXRULE, getProperties());
-        validator.assertNone(Property.RDATE, getProperties());
-        validator.assertNone(Property.EXDATE, getProperties());
+        CollectionUtils.forAllDo(Arrays.asList(Property.RRULE, Property.EXRULE, Property.RDATE, Property.EXDATE), new Closure<String>() {
+            @Override
+            public void execute(String input) {
+                PropertyValidator.getInstance().assertNone(input, getProperties());
+            }
+        });
 
         // DtEnd value must be later in time that DtStart..
         final DtStart dtStart = (DtStart) getProperty(Property.DTSTART);
diff --git a/src/main/java/net/fortuna/ical4j/model/component/VJournal.java b/src/main/java/net/fortuna/ical4j/model/component/VJournal.java
index 4695f99bb..b11061e57 100644
--- a/src/main/java/net/fortuna/ical4j/model/component/VJournal.java
+++ b/src/main/java/net/fortuna/ical4j/model/component/VJournal.java
@@ -40,7 +40,10 @@
 import net.fortuna.ical4j.validate.component.VJournalAddValidator;
 import net.fortuna.ical4j.validate.component.VJournalCancelValidator;
 import net.fortuna.ical4j.validate.component.VJournalPublishValidator;
+import org.apache.commons.collections4.Closure;
+import org.apache.commons.collections4.CollectionUtils;
 
+import java.util.Arrays;
 import java.util.HashMap;
 import java.util.Map;
 
@@ -173,32 +176,14 @@ public final void validate(final boolean recurse)
          * ; the following are optional, ; but MUST NOT occur more than once class / created / description / dtstart /
          * dtstamp / last-mod / organizer / recurid / seq / status / summary / uid / url /
          */
-        PropertyValidator.getInstance().assertOneOrLess(Property.CLASS,
-                getProperties());
-        PropertyValidator.getInstance().assertOneOrLess(Property.CREATED,
-                getProperties());
-        PropertyValidator.getInstance().assertOneOrLess(Property.DESCRIPTION,
-                getProperties());
-        PropertyValidator.getInstance().assertOneOrLess(Property.DTSTART,
-                getProperties());
-        PropertyValidator.getInstance().assertOneOrLess(Property.DTSTAMP,
-                getProperties());
-        PropertyValidator.getInstance().assertOneOrLess(Property.LAST_MODIFIED,
-                getProperties());
-        PropertyValidator.getInstance().assertOneOrLess(Property.ORGANIZER,
-                getProperties());
-        PropertyValidator.getInstance().assertOneOrLess(Property.RECURRENCE_ID,
-                getProperties());
-        PropertyValidator.getInstance().assertOneOrLess(Property.SEQUENCE,
-                getProperties());
-        PropertyValidator.getInstance().assertOneOrLess(Property.STATUS,
-                getProperties());
-        PropertyValidator.getInstance().assertOneOrLess(Property.SUMMARY,
-                getProperties());
-        PropertyValidator.getInstance().assertOneOrLess(Property.UID,
-                getProperties());
-        PropertyValidator.getInstance().assertOneOrLess(Property.URL,
-                getProperties());
+        CollectionUtils.forAllDo(Arrays.asList(Property.CLASS, Property.CREATED, Property.DESCRIPTION, Property.DTSTART,
+                Property.DTSTAMP, Property.LAST_MODIFIED, Property.ORGANIZER, Property.RECURRENCE_ID, Property.SEQUENCE,
+                Property.STATUS, Property.SUMMARY, Property.UID, Property.URL), new Closure<String>() {
+            @Override
+            public void execute(String input) {
+                PropertyValidator.getInstance().assertOneOrLess(input, getProperties());
+            }
+        });
 
         final Status status = (Status) getProperty(Property.STATUS);
         if (status != null && !Status.VJOURNAL_DRAFT.getValue().equals(status.getValue())
diff --git a/src/main/java/net/fortuna/ical4j/model/component/VToDo.java b/src/main/java/net/fortuna/ical4j/model/component/VToDo.java
index 518d1ad43..7a1a4442b 100644
--- a/src/main/java/net/fortuna/ical4j/model/component/VToDo.java
+++ b/src/main/java/net/fortuna/ical4j/model/component/VToDo.java
@@ -39,12 +39,15 @@
 import net.fortuna.ical4j.validate.ValidationException;
 import net.fortuna.ical4j.validate.Validator;
 import net.fortuna.ical4j.validate.component.*;
+import org.apache.commons.collections4.Closure;
+import org.apache.commons.collections4.CollectionUtils;
 import org.apache.commons.lang3.ObjectUtils;
 import org.apache.commons.lang3.builder.HashCodeBuilder;
 
 import java.io.IOException;
 import java.net.URISyntaxException;
 import java.text.ParseException;
+import java.util.Arrays;
 import java.util.HashMap;
 import java.util.Map;
 
@@ -251,42 +254,15 @@ public final void validate(final boolean recurse)
          * dtstamp / dtstart / geo / last-mod / location / organizer / percent / priority / recurid / seq / status /
          * summary / uid / url /
          */
-        PropertyValidator.getInstance().assertOneOrLess(Property.CLASS,
-                getProperties());
-        PropertyValidator.getInstance().assertOneOrLess(Property.COMPLETED,
-                getProperties());
-        PropertyValidator.getInstance().assertOneOrLess(Property.CREATED,
-                getProperties());
-        PropertyValidator.getInstance().assertOneOrLess(Property.DESCRIPTION,
-                getProperties());
-        PropertyValidator.getInstance().assertOneOrLess(Property.DTSTAMP,
-                getProperties());
-        PropertyValidator.getInstance().assertOneOrLess(Property.DTSTART,
-                getProperties());
-        PropertyValidator.getInstance().assertOneOrLess(Property.GEO,
-                getProperties());
-        PropertyValidator.getInstance().assertOneOrLess(Property.LAST_MODIFIED,
-                getProperties());
-        PropertyValidator.getInstance().assertOneOrLess(Property.LOCATION,
-                getProperties());
-        PropertyValidator.getInstance().assertOneOrLess(Property.ORGANIZER,
-                getProperties());
-        PropertyValidator.getInstance().assertOneOrLess(
-                Property.PERCENT_COMPLETE, getProperties());
-        PropertyValidator.getInstance().assertOneOrLess(Property.PRIORITY,
-                getProperties());
-        PropertyValidator.getInstance().assertOneOrLess(Property.RECURRENCE_ID,
-                getProperties());
-        PropertyValidator.getInstance().assertOneOrLess(Property.SEQUENCE,
-                getProperties());
-        PropertyValidator.getInstance().assertOneOrLess(Property.STATUS,
-                getProperties());
-        PropertyValidator.getInstance().assertOneOrLess(Property.SUMMARY,
-                getProperties());
-        PropertyValidator.getInstance().assertOneOrLess(Property.UID,
-                getProperties());
-        PropertyValidator.getInstance().assertOneOrLess(Property.URL,
-                getProperties());
+        CollectionUtils.forAllDo(Arrays.asList(Property.CLASS, Property.COMPLETED, Property.CREATED, Property.DESCRIPTION,
+                Property.DTSTAMP, Property.DTSTART, Property.GEO, Property.LAST_MODIFIED, Property.LOCATION, Property.ORGANIZER,
+                Property.PERCENT_COMPLETE, Property.PRIORITY, Property.RECURRENCE_ID, Property.SEQUENCE, Property.STATUS,
+                Property.SUMMARY, Property.UID, Property.URL), new Closure<String>() {
+            @Override
+            public void execute(String input) {
+                PropertyValidator.getInstance().assertOneOrLess(input, getProperties());
+            }
+        });
 
         final Status status = (Status) getProperty(Property.STATUS);
         if (status != null && !Status.VTODO_NEEDS_ACTION.getValue().equals(status.getValue())
diff --git a/src/main/java/net/fortuna/ical4j/model/component/VVenue.java b/src/main/java/net/fortuna/ical4j/model/component/VVenue.java
index 403994d02..87b33a9bf 100644
--- a/src/main/java/net/fortuna/ical4j/model/component/VVenue.java
+++ b/src/main/java/net/fortuna/ical4j/model/component/VVenue.java
@@ -37,6 +37,10 @@
 import net.fortuna.ical4j.validate.PropertyValidator;
 import net.fortuna.ical4j.validate.ValidationException;
 import net.fortuna.ical4j.validate.Validator;
+import org.apache.commons.collections4.Closure;
+import org.apache.commons.collections4.CollectionUtils;
+
+import java.util.Arrays;
 
 /**
  * $Id $ [Apr 5, 2004]
@@ -145,36 +149,14 @@ public final void validate(final boolean recurse)
          *                location-type / categories /
          *                dtstamp / created / last-modified
          */
-        PropertyValidator.getInstance().assertOneOrLess(Property.NAME,
-                getProperties());
-        PropertyValidator.getInstance().assertOneOrLess(Property.DESCRIPTION,
-                getProperties());
-        PropertyValidator.getInstance().assertOneOrLess(Property.STREET_ADDRESS,
-                getProperties());
-        PropertyValidator.getInstance().assertOneOrLess(Property.EXTENDED_ADDRESS,
-                getProperties());
-        PropertyValidator.getInstance().assertOneOrLess(Property.LOCALITY,
-                getProperties());
-        PropertyValidator.getInstance().assertOneOrLess(Property.REGION,
-                getProperties());
-        PropertyValidator.getInstance().assertOneOrLess(Property.COUNTRY,
-                getProperties());
-        PropertyValidator.getInstance().assertOneOrLess(Property.POSTALCODE,
-                getProperties());
-        PropertyValidator.getInstance().assertOneOrLess(Property.TZID,
-                getProperties());
-        PropertyValidator.getInstance().assertOneOrLess(Property.GEO,
-                getProperties());
-        PropertyValidator.getInstance().assertOneOrLess(Property.LOCATION_TYPE,
-                getProperties());
-        PropertyValidator.getInstance().assertOneOrLess(Property.CATEGORIES,
-                getProperties());
-        PropertyValidator.getInstance().assertOneOrLess(Property.DTSTAMP,
-                getProperties());
-        PropertyValidator.getInstance().assertOneOrLess(Property.CREATED,
-                getProperties());
-        PropertyValidator.getInstance().assertOneOrLess(Property.LAST_MODIFIED,
-                getProperties());
+        CollectionUtils.forAllDo(Arrays.asList(Property.NAME, Property.DESCRIPTION, Property.STREET_ADDRESS, Property.EXTENDED_ADDRESS,
+                Property.LOCALITY, Property.REGION, Property.COUNTRY, Property.POSTALCODE, Property.TZID, Property.GEO,
+                Property.LOCATION_TYPE, Property.CATEGORIES, Property.DTSTAMP, Property.CREATED, Property.LAST_MODIFIED), new Closure<String>() {
+            @Override
+            public void execute(String input) {
+                PropertyValidator.getInstance().assertOneOrLess(input, getProperties());
+            }
+        });
 
         /*
          * ; the following is optional, ; and MAY occur more than once tel / url / x-prop