added ability to skip null properties

pom.xml

@@ -6,7 +6,7 @@
 
     <groupId>black.door</groupId>
     <artifactId>hate</artifactId>
-    <version>v1r0t2</version>
+    <version>v1r0t3</version>
 
     <dependencies>
         <dependency>

src/main/java/black/door/hate/HalRepresentation.java

@@ -131,6 +131,7 @@ public static class HalRepresentationBuilder{
 		private Map<String, HalRepresentation> embedded;
 		private Map<String, List<HalRepresentation>> multiEmbedded;
 		private Map<String, Object> properties;
+		private boolean ignoreNullProperties = false;
 
 		public HalRepresentationBuilder() {
 			links = new HashMap<>();
@@ -140,8 +141,21 @@ public HalRepresentationBuilder() {
 			properties = new HashMap<>();
 		}
 
+		/**
+		 * Causes any properties with null values added to this builder after this call to be ignored.
+		 * Properties with null values added before this call will still be included.
+		 * Null properties are included by default.
+		 * @param active
+		 * @return this builder
+		 */
+		public HalRepresentationBuilder ignoreNullProperties(boolean active){
+			this.ignoreNullProperties = active;
+			return this;
+		}
+
 		public HalRepresentationBuilder addProperty(String name, Object prop){
-			properties.put(name, prop);
+			if(!ignoreNullProperties || prop != null)
+				properties.put(name, prop);
 			return this;
 		}
 

src/test/java/black/door/hate/HalRepresentationTest.java

@@ -96,6 +96,25 @@ public void testNulls() throws Exception{
         System.out.println(orderz.serialize());
     }
 
+    @Test
+    public void testIgnoreNullProp(){
+        HalRepresentation rep = HalRepresentation.builder()
+                .ignoreNullProperties(true)
+                .addProperty("thing", "value")
+                .addProperty("nullthing", null)
+                .build();
+        assertFalse(rep.getProperties().containsKey("nullthing"));
+        assertTrue(rep.getProperties().containsKey("thing"));
+
+        HalRepresentation rep2 = HalRepresentation.builder()
+                .addProperty("thing", "value")
+                .addProperty("nullthing", null)
+                .build();
+        assertTrue(rep2.getProperties().containsKey("nullthing"));
+        assertTrue(rep2.getProperties().containsKey("thing"));
+    }
+
+
     @Test
     public void testSerialize() throws Exception {
         val basket1 = new Basket(98712);