Transform you JSON into java object, and insert it in the session before calling fireAllRules : Object obj = your_JSON_2_Object_convert_method(....); session.insert(obj); session.fireAllRules(); ----- Mail original ----- De: "ihabo01" <ihabo01(a)gmail.com&gt; À: rules-users(a)lists.jboss.org Envoyé: Jeudi 8 Décembre 2011 18:07:30 Objet: [rules-users] Inserting Facts from Json Format Hello to all, I have the following simple rule: declare FlatData param1 : String param2 : String end rule "Test" when a:FlatData(param1=="something") then a.setParam2("hi"); end And I have the following code to load the rule: KnowledgeBuilder kBuilder = KnowledgeBuilderFactory.newKnowledgeBuilder(); kBuilder.add(ResourceFactory.newFileResource("myRule.drl"),ResourceType.DRL); KnowledgeBaseConfiguration kBaseConfig = KnowledgeBaseFactory .newKnowledgeBaseConfiguration(); KnowledgeBase kBase = KnowledgeBaseFactory.newKnowledgeBase(kBaseConfig); kBase.addKnowledgePackages(kBuilder.getKnowledgePackages()); StatefulKnowledgeSession session = kBase.newStatefulKnowledgeSession(); session.fireAllRules(); And I have also the following object (in Json) that I would like to insert as a fact just before firing the rules: {"object":{" FlatData ":{"param1":"value1","param2":”value2”}}}} How can I achieve that? Many thanks in advance for your help Ihab -- View this message in context: http://drools.46999.n3.nabble.com/Inserting-Facts-from-Json-Format-tp3570... Sent from the Drools: User forum mailing list archive at Nabble.com. _______________________________________________ rules-users mailing list rules-users(a)lists.jboss.org https://lists.jboss.org/mailman/listinfo/rules-users

Do you mean that the class is defined in DRL using "declare"? (You cannot "define an object in a rule".) A declared type is a Java type, even if it is only available in DRL code. So, write a rule that's triggered by whatever fits into your application logic (*) and on the RHS proceed with the code to read and unmarshal JSON, and insert the resulting objects. (*) For one firing at startup use rule "load facts from JSON" salience 1000 when then //... end -W On 09/12/2011, ihabo01 <ihabo01(a)gmail.com&gt; wrote:

That's what I ended up doing, many thanks. I will put my code below in case it can help somebody else. P.S: for people looking to do the same thing, I still think the batch executor helper is the best way to tackle this need, as we would not need to rewrite the part that converts objects to/from Json. Please check the other part of the thread with Mark to see if we manage to find the right syntax. best regards, private static String retreiveFacts(ArrayList facts, KnowledgeBase kBase, StatefulKnowledgeSession session) throws JSONException { JSONObject resultArray = new JSONObject(); JSONArray objects = new JSONArray(); resultArray.put("objects", objects); for (Iterator iterator = facts.iterator(); iterator.hasNext();) { Object fact = iterator.next(); JSONObject object = new JSONObject(); object.put("object", fact.getClass().getCanonicalName()); JSONObject fields = new JSONObject(); FactType objectType = kBase.getFactType(fact.getClass() .getPackage().getName(), fact.getClass().getSimpleName()); for (FactField field : objectType.getFields()) { fields.put(field.getName(), objectType.get(fact, field.getName().toString())); } object.put("fields", fields); objects.put(object); } return resultArray.toString(); } private static ArrayList insertFacts(JSONObject json, KnowledgeBase kBase, StatefulKnowledgeSession session) throws IOException, JSONException, InstantiationException, IllegalAccessException { ArrayList handlers = new ArrayList(); JSONArray objects = (JSONArray) json.get("objects"); for (int i = 0; i < objects.length(); i++) { JSONObject object = objects.getJSONObject(i); String objectCanonicalName = object.getString("object"); System.out.println(objectCanonicalName); int classNameSeparatorIndex = objectCanonicalName.lastIndexOf("."); String packageName = objectCanonicalName.substring(0, classNameSeparatorIndex); String className = objectCanonicalName .substring(classNameSeparatorIndex + 1); FactType objectType = kBase.getFactType(packageName, className); Object factObject = objectType.newInstance(); JSONObject fields = object.getJSONObject("fields"); for (Iterator iterator = fields.keys(); iterator.hasNext();) { String key = (String) iterator.next(); System.out.println("field " + key + " value " + fields.get(key)); objectType.set(factObject, key, fields.get(key)); } session.insert(factObject); handlers.add(factObject); } return handlers; } -- View this message in context: http://drools.46999.n3.nabble.com/Inserting-Facts-from-Json-Format-tp3570... Sent from the Drools: User forum mailing list archive at Nabble.com.

1) Expose global object to drools with methods that can serialize and deserialize JSON. Maybe you could use http://jackson.codehaus.org/. 2) Insert a "wrapper object" into knowledge space that contains a reference to JSON object as text, stream or whatever. 3) Use (1) to deserialize the JSON data in contained in (2). 4) retract (2) 5) insert (3) Obviously the declared object and the JSON object needs to have the same structure. Good luck! // Olle On 12/8/11 6:07 PM, "ihabo01" <ihabo01(a)gmail.com&gt; wrote:

Many thanks mark, Actually in one of the emails in this thread I have mentioned that I have found the BatchExecutionHelper but all my attempts to use it failed. If you can point me to an example, I would appreciate it as I have looked all around but to no avail (this part of drools does not seem that popular) To be more specific, I have tried to do something such as: Object insertCMD = BatchExecutionHelper.newJSonMarshaller().fromXML(fileToString("batchCommands/batchCommandInsert.json")); Where my Jason file contains something like: {"batch-execution":{"lookup":"ksession1","commands":[{"insert":{"object":{"decision1.FlatData":{"name":"john","relatipshipType":"parent"}}}},{"fire-all-rules":""}]}} Problem is how can the BatchExecutionHelper get the definition of my object? (object definition is declared in the DRL file itself) When you look at JAXB integration, this is achieved like this: JAXBContext jaxbContext = KnowledgeBuilderHelper.newJAXBContext(classesName.toArray(new String[classesName.size()]), kbase); But I don't see how this can be done with JSON. Any indications will be much appreciated. Best regards, Ihab -- View this message in context: http://drools.46999.n3.nabble.com/Inserting-Facts-from-Json-Format-tp3570... Sent from the Drools: User forum mailing list archive at Nabble.com.