[rules-users] collection question

I'm trying to write a rule to add an object to a collection if the collection already contained a certain object with a specific attribute. I developed a small example so maybe that will make more sense: Use Case: In a product shipping applicaiton, anytime a product with the name "cd1" is in the shipping order, a bonus product named "bonus_cd" needs to be added to the shipping order. The bonus cd should not be added if it's already in the shipping order. Shipping Order: public class ShippingOrder { private Set<Product> products; public ShippingOrder() {} public Set<Product> getProducts() { return products; } public void setProducts(Set<Product> products) { this.products = products; } } Product: public class Product { private String name; public Product(){} public String getName() { return name; } public void setName(String name) { this.name = name; } } Rule: rule "AddBonusCd" when $so : ShippingOrder() $productList : ArrayList(size == 1) from collect( Product(name matches "cd1|bonus_cd") from $so.products) then System.out.println("Adding Bonus Cd"); Set<Product> productSet = new HashSet<Product>($so.getProducts()); Product bonusCd = new Product(); bonusCd.setName("bonus_cd"); productSet.add(bonusCd); modify($so) { setProducts(productSet); } end The Shipping Order object is inserted as the fact. The rule is valid if only cd1 or cd_bonus is in the shipping order. I only want the rule to run when cd1 is in the product set but cd_bonus is not. Makes sense? Thanks, J -- View this message in context: http://drools-java-rules-engine.46999.n3.nabble.com/collection-question-t... Sent from the Drools - User mailing list archive at Nabble.com.