Replace invalid characters in the javadoc

HTML characters get re-encoded into <,>,&, etc at this point, so we need to turn them back into HTML characters so that Javadoc accepts them as valid

Author: Caitlin Bales (MSFT)

Templates/Java/BaseJavaModel.template.tt

@@ -669,7 +669,7 @@ public {1} {2}{3}{4} {{";
                 property.Name,
                 propertyType,
                 property.Name.SanitizePropertyName(property).ToLowerFirstChar(),
-				property.LongDescription);
+				ReplaceInvalidCharacters(property.LongDescription));
         }
         return sb.ToString();
     }
@@ -693,7 +693,7 @@ public {1} {2}{3}{4} {{";
             sb.AppendFormat(
                 format,
                 ParamName(p).SplitCamelCase(),
-				p.LongDescription,
+				ReplaceInvalidCharacters(p.LongDescription),
                 ParamName(p),
                 ParamType(p),
                 ParamName(p).SanitizePropertyName(p).ToLowerFirstChar()
@@ -834,4 +834,15 @@ public {1} {2}{3}{4} {{";
 		//Specifying a return type of "void" throws an error
 	   return string.Empty;
 	}
+
+	/**
+	* Replaces invalid Javadoc characters with HTML
+	*/
+	public string ReplaceInvalidCharacters(string inputString)
+	{
+		if (inputString != null) {
+			return inputString.Replace("<", "&lt;").Replace(">", "&gt;").Replace("&", "&amp;");
+		}
+		return null;
+	}
 #>