Bind complex component (JSON) automatically generates data

Question

My JSON data is in request().body().asFormUrlEncoded().get("records")

 [{"string":"foo","termId":"793340"},{"string":"bar","termId":"460288"}] 

My definition of form:

 public static class MyForm { @Constraints.Required public List<Map<String,String>> records; public String someField; } 

It does not bind records automatically. Then I tried with POJO:

 public static class Record { public String string; public String termId; public void setString(String string) { this.string = string; } public void setTermId(String termId) { this.termId = termId; } } 

And adapted the form:

 public static class MyForm { @Constraints.Required public List<Record> records; public String someField; } 

It also does not automatically bind data. Do I really need to use low level APIs like jackson for this simple use? Any pointer? Could not find copy / paste example, and from jackson I have org.codehaus.jackson and com.fasterxml.jackson in my classpath.

UPDATE 2013-05-10: The secondary someField field has been someField to clarify that records are just one field, not the entire data structure. The answer below (I don’t see the answers on these editing screens, so it doesn’t matter if there is only one) works, but only with entries. Here is an example:

 private List<Record> recordsFromRequest() { String[] jsonData = request().body().asFormUrlEncoded().get("records"); Form<Record> recordDummyForm = Form.form(Record.class); Iterator<JsonNode> it = Json.parse(jsonData[0]).iterator(); List<Record> records = new ArrayList<>(); while (it.hasNext()) { records.add(recordDummyForm.bind(it.next()).get()); } return records; } 

For other form fields, as usual:

 Form<MyForm> form = play.data.Form.form(MyForm.class).bindFromRequest(); 

So, now I get to all the published form data, and my problem is solved this way (thanks!). However, this is a little ugly. I still can not figure out how to get all the data for publication in one object. If someone answers this, I will update the question and delete this part. Otherwise, I will accept one answer in a couple of days.

Answer 1

In my opinion, you should use the jackson API as described in the official documentation here .

I assume you get JSON with request().body().asFormUrlEncoded().get() , so it returns a String[] containing your JSON string. You can do something like this (maybe a little complicated and skip Exception ):

 String[] jsonData = request().body().asFormUrlEncoded().get("records") MyForm myForm = new MyForm(); // Record should act as form, because each JSON string data contain this type Form<Record> form = Form.form(Record.class); // parse the JSON string and assign iterator Iterator<JsonNode> it = Json.parse(jsonData[0]).iterator(); // assign to the MyForm instance while (it.hasNext()) { formData.records.add(form.bind(it.next()).get()); // bind the JSON and add } 

So, at the end of the above code ((MyForm) formData).records should contain a List<Record> object from your JSON.

Answer 2

I tried to reproduce your error. Therefore, I created the model as follows:

 public class EasyContact { public String someField; @Required public List<Record> records; public static class Record { public String string; public String termId; @Override public String toString() { return "Record [string=" + string + ", termId=" + termId + "]"; } } @Override public String toString() { return "EasyContact [someField=" + someField + ", records=" + records+ "]"; } } 

Then a simple controller like this:

  public static Result submit() { Form<EasyContact> filledForm = form(EasyContact.class).bindFromRequest(); Logger.info("Posted binding: " + filledForm.get().toString()); return ok(); } 

Now is the time to check:

 curl -X POST -H 'Content-Type: application/json' -d '{"someField":"didac", "records": [{"string": "string1", "termId": "111"},{"string": "string2", "termId": "222"}]}' localhost:9000/contacts 

On the playback command line, I see the correct output:

 [info] application - Posted binding: EasyContact [someField=didac, records=[Record [string=string1, termId=111], Record [string=string2, termId=222]]] 

The only error I found is when the Content-Type is not set in the request (-H ...). In this case, the structure throws an IllegalState exception.