Error getting JSON Map<String, Object> with SpringMVC and Jackson2 - json

Question

I'm trying to get a Map where there are a 'number' with the number of actions and 'actions' with a list of actions.
I've checked the list of actions in java and it works just fine.
I have 4 actions and in json file I'm getting right just the first one.
Controller in java
#RequestMapping(value = "/getactions/{idTask}", method = RequestMethod.GET, produces = "application/json")
#ResponseBody
public Map<String, Object> getActions(Principal principal,
#PathVariable Long idTask) {
logger.info("Task controller get actions...");
List<TaskAction> actions = null;
if (principal == null) {
actions = new ArrayList<TaskAction>();
} else {
actions = taskActionService.getAllTaskActions(idTask);
}
System.out.println(">>>>>>>>Task Controller - Actions>>>>>>>>>>>>> "
+ actions.size());
for (TaskAction ta : actions) {
System.out.println(">>>>>>>>ta: " + ta.getActionname());
}
System.out.println(">>>>>>>>END getAllActions()>>>>>>>>>>>>> ");
Map<String, Object> data = new HashMap<String, Object>();
data.put("actions", actions);
data.put("number", actions.size());
return data;
}
Sysout
>>>>>>>>Task Controller - Actions>>>>>>>>>>>>> 4
>>>>>>>>ta: tacometer
>>>>>>>>ta: hola
>>>>>>>>ta: hi there
>>>>>>>>ta: other action
>>>>>>>>END getAllActions()>>>>>>>>>>>>>
I'm not getting any error, but the json result only gets the first element in the action list and the id of the rest of actions.
json that I get from http...getactions/8
{
"number":4,
"actions":[
{ ... },
3,
4,
5
]
}
The ... is the first action that is well recovered. (I've avoided to write the code for clearity)
Any ideas about what could it be?
Thanks in advance.
Example of json with 2 actions
{
"number": 2,
"actions": [{
"idTaskAction": 4,
"task": {
"idTask": 8,
"taskname": "abbbbbbbbbbbbbb",
"description": "fffffffffffffffqqqqq",
"date": 1389569940000,
"deadline": -23918633280000,
"category": {
"idTaskCategory": 1,
"sortOrder": 0,
"categoryname": "cat1",
"timestamp": 1402437394000
},
"priority": {
"idTaskPriority": 1,
"sortOrder": 0,
"aka": "none",
"priorityname": "low",
"timestamp": 1402437527000
},
"state": {
"idTaskState": 1,
"statename": "pending"
},
"user": {
"idUser": 1,
"username": "joe"
},
"userResponsible": {
"idUser": 1,
"username": "joe"
},
"evaluation": "12345678saad",
"pending": 0,
"actions": [{
"idTaskAction": 2,
"task": 8,
"date": 1402652358000,
"actionname": "tacometer",
"description": "asfdafa",
"duration": 12,
"user": {
"idUser": 1,
"username": "joe"
},
"timestamp": 1411493866000
},
{
"idTaskAction": 3,
"task": 8,
"date": 1404207558000,
"actionname": "hola",
"description": "un dos tres",
"duration": 20,
"user": {
"idUser": 1,
"username": "joe"
},
"timestamp": 1405022827000
},
4,
{
"idTaskAction": 5,
"task": 8,
"date": 1412164741000,
"actionname": "other action",
"description": "ya me my",
"duration": 22,
"user": {
"idUser": 1,
"username": "joe"
},
"timestamp": 1411733131000
}],
"timestamp": 1411733131000
},
"date": 1412074440000,
"actionname": "hi there",
"description": "lkjñlkj ya",
"duration": 25,
"user": {
"idUser": 1,
"username": "joe"
},
"timestamp": 1411733090000
},
5]
}

Answer 1

The problem was that the classes Task, User... has #JsonIdentityInfo with ObjectIdGenerator.PropertyGenerator.class option so when Jackson try to serialize the object into json, if the object it is already in the file, then it is not added again. This way avoid to serialize json file with infinite recursions.
To solve this we need to change ObjectIdGenerator.PropertyGenerator.class for ObjectIdGenerator.None.class so that the objects are serialized even if they are already part of other objects.
Change
#JsonIdentityInfo(generator = ObjectIdGenerators.PropertyGenerator.class, property = "#id")
for
#JsonIdentityInfo(generator = ObjectIdGenerators.None.class, property = "#id")