I'm able to return JSON response in my Dropwizard resource without any problem. But when I tried to return a JSONPObject, the response still returns a JSON, instead of a JSON wrapped in the callback function requested.
#Path("/results")
#Produces(MediaType.APPLICATION_JSON)
public class ExperimentResultResource {
...
#Path("results/{experimentId}")
#GET
#Timed
public Object getResults(
#PathParam("experimentId") #NotEmpty long experimentId,
#QueryParam("callback") String callback) {
....
ExperimentResultRepresentation representation = dataSource.queryResults(query);
if (callback != null) {
JSONPObject obj = new JSONPObject(callback, representation);
return obj;
}
return representation;
}
The good thing is that, instead of spitting out the original JSON, it did include the serializationType and function element in the JSON body:
{
"value": { // the original JSON body }
"serializationType": null,
"function": "jQuery17209002291325014085_1450240336024"
}
I also tried including the #JSONP annotation above the method as well. No luck either.
Any idea?
Solved.
Use com.fasterxml.jackson.databind.util.JSONPObject instead of org.codehaus.jackson.map.util.JSONPObject.
Related
Input JSON:
{ "name": "gerry" }
Action method:
{ public ActionResult GenerateQrCode([FromBody] string name }
Problem:
The simple-type args are null
ModelState: Invalid
The built-in json deserializer can't handle the input in this form
I've tried:
ConfigureServices() -> services.AddControllersWithViews().AddNewtonsoftJson(); to switch to NewtonSoft, which I know/love
I've set a break-point into the non-NewtonSoft built-in MS SystemTextJsonInputFormatter.ctor() just to check, if it's still used: yes, it is, I'm not sure why, when I'm calling the above .AddNewtonsoftJson()
The situation:
The client POSTs all the input params as one JSON string document, which is UTF8 w/out BOM
The string comes in at the server-side and is nicely readable with new System.IO.StreamReader(Request.Body).ReadToEnd() from inside the immediate window
I need a way ASP.NET Core deserializes this, as it was able under the .NET4.X for many years w/out any issue
I wouldn't like to add [FromBody] and similar opt-in signatures all over the server actions/args
You pass the name as json but accept as a string so it will be null, you can use an InputFormatter like:
public class RawJsonBodyInputFormatter : InputFormatter
{
public RawJsonBodyInputFormatter()
{
this.SupportedMediaTypes.Add("application/json");
}
public override async Task<InputFormatterResult> ReadRequestBodyAsync(InputFormatterContext context)
{
var request = context.HttpContext.Request;
using (var reader = new StreamReader(request.Body))
{
var content = await reader.ReadToEndAsync();
return await InputFormatterResult.SuccessAsync(content);
}
}
protected override bool CanReadType(Type type)
{
return type == typeof(string);
}
}
In startup.cs:
services
.AddMvc(options =>
{
options.InputFormatters.Insert(0, new RawJsonBodyInputFormatter());
});
And then you can get the row string
To deserilize it, you can check this, use Newtonsoft and make the string to a Model
[HttpPost]
public IActionResult GenerateQrCode([FromBody] string name)
{
object o = JsonConvert.DeserializeObject(name);
MyModel my = JsonConvert.DeserializeObject<MyModel>(o.ToString());
return View();
}
I am working on/extending TOH. I have an add method that wants to push the new Hero onto the array then return user to the list.
the result of the call to addHero is coming back as a JSON hero inside double ticks, so as a string.
i have read many articles which seem to point to
angular.toJson
or
.map(response=> response.JSON())
These are not working.
Here is the excerpt from my heroes.component.ts
add(name: string): void {
name = name.trim();
if (!name) { return; }
this.heroService.addHero({ name } as Hero)
.subscribe(hero =>
{
this.heroes.push(hero);
this.location.go('/Heroes');
}
);
}
and hero.service.ts
This clearly returns a Hero object...
addHero (hero: Hero): Observable<Hero> {
return this.http.post<Hero>(this.heroesUrl, hero, httpOptions).pipe(
tap((hero: Hero) => console.log(`added hero w/ id=${hero.id}`)),
catchError(this.handleError<Hero>('addHero'))
);
}
Upon return, the result is successfully pushed to the array, but enclosed in quotes.
The UI evidence of this is that the list has a blank entry at the bottom because there is no .Name property on that final array element.
If i refresh the page, everyone gets loaded as json.
Simple question but I can not seem to find an answer. Have been through many S/O questions involving ng2, php, etc. but none seem to address ng6, or provide a clue I can take away. if they do, Im missing it.
If you want to parse a json into a javascript object you can use JSON.parse(response.JSON())
I'm guessing response.JSON() is returning the response as json, which then needs to be parsed
Edit: you can probably just remove the map => response.JSON() . As angular httpClient already parses it
The issue was the return type of the routine in the service.
#youris question got me to look harder at the service.
The issue is that the default response is not coded correctly as utf8 and 'text/html'
Here is the corrected code.
Public Function add(mh As mHero) As CustomJsonStringResult
Dim h As New TOHbos.Hero()
h.name.Value = mh.name
h.Save()
Return JsonStringResultExtension.JSONString(Me, h.JSON, HttpStatusCode.OK)
End Function
the referenced JsonStringResultExtension is credited to #NKosi in this post. (Code included for ease of referece)
Web Api: recommended way to return json string
public static class JsonStringResultExtension {
public static CustomJsonStringResult JsonString(this ApiController controller, string jsonContent, HttpStatusCode statusCode = HttpStatusCode.OK) {
var result = new CustomJsonStringResult(controller.Request, statusCode, jsonContent);
return result;
}
public class CustomJsonStringResult : IHttpActionResult {
private string json;
private HttpStatusCode statusCode;
private HttpRequestMessage request;
public CustomJsonStringResult(HttpRequestMessage httpRequestMessage, HttpStatusCode statusCode = HttpStatusCode.OK, string json = "") {
this.request = httpRequestMessage;
this.json = json;
this.statusCode = statusCode;
}
public Task<HttpResponseMessage> ExecuteAsync(CancellationToken cancellationToken) {
return Task.FromResult(Execute());
}
private HttpResponseMessage Execute() {
var response = request.CreateResponse(statusCode);
response.Content = new StringContent(json, Encoding.UTF8, "application/json");
return response;
}
}
}
Making these changes, the result is json, its pushed to the array correctly, and shows up in the Heroes list correctly.
First off my question is very similar to below however I'm not sure if the answers are applicable to my specific problem or whether I just need clarification about how to approach it:
Convert LinkedHashMap<String,String> to an object in Java
I am using struts2 json rest plugin to convert a json array into a java array. The array is sent through an ajax post request and the java receives this data. However instead of being the object type I expect it is received as a LinkedHashmap. Which is identical to the json request in structure.
[
{advance_Or_Premium=10000, available=true},
{advance_Or_Premium=10000, available=true},
{advance_Or_Premium=10000, available=true}
]
The data is all present and correct but just in the wrong type. Ideally I want to send the data in my object type or if this is not possible convert the LinkedHashMap from a list of keys and values into the object array. Here is the class I am using, incoming data is received in the create() method:
#Namespace(value = "/rest")
public class OptionRequestAction extends MadeAbstractAction implements ModelDriven<ArrayList<OptionRequestRest>>
{
private String id;
ArrayList<OptionRequestRest> model = new ArrayList<OptionRequestRest>();
public HttpHeaders create()
{
// TODO - need to use model here but it's a LinkedHashmap
return new DefaultHttpHeaders("create");
}
public String getId()
{
return this.id;
}
public ArrayList<OptionRequestRest> getModel()
{
return this.model;
}
public ArrayList<OptionRequestRest> getOptionRequests()
{
#SuppressWarnings("unchecked")
ArrayList<OptionRequestRest> lReturn = (ArrayList<OptionRequestRest>) this.getSession().get("optionRequest");
return lReturn;
}
// Handles /option-request GET requests
public HttpHeaders index()
{
this.model = this.getOptionRequests();
return new DefaultHttpHeaders("index").lastModified(new Date());
}
public void setId(String pId)
{
this.id = pId;
}
public void setModel(ArrayList<OptionRequestRest> pModel)
{
this.model = pModel;
}
// Handles /option-request/{id} GET requests
public HttpHeaders show()
{
this.model = this.getOptionRequests();
return new DefaultHttpHeaders("show").lastModified(new Date());
}
}
One of the things which is confusing me is that this code works fine and returns the correct object type if the model is not an array. Please let me know if my question is not clear enough and needs additional information. Thanks.
Following this example.
GET response is:
{
"singer":"Metallica",
"title":"Enter Sandman"
}
If more objects were included output should be like this:
[{
"singer":"Metallica",
"title":"Enter Sandman"
}, {
"singer":"Elvis",
"title":"Rock"
}]
I want to get the 'classname' written too. Something like this:
{"Track":[ {
"singer":"Metallica",
"title":"Enter Sandman"
}, {
"singer":"Elvis",
"title":"Rock"
}]}
Any simple ways to achieve this?
Looking forward to get data directly into Datatables from a JAX-RS Resteasy (Jackson) Server. Also trying to avoid DTO.
class TrackList
{
private List<Track> Track = new ArrayList<Track>();
// setter, getter
}
GET method
public TrackList getTrackInJSON() {
EDIT
GET method
public String getTrackInJSON() {
// ... create list of objects
return convertToString(objects);
}
utility method
static <T> String convertToString(List<T> list) throws IOException
{
final String json = new ObjectMapper().writeValueAsString(list);
return new StringBuilder()
.append("{\"")
.append(list.get(0).getClass().getSimpleName())
.append("\":")
.append(json)
.append("}")
.toString();
}
I'm working on a little app and using GWT to build it.
I just tried making a request to a remote server which will return a response as JSON.
I've tried using the overlay types concept but I couldn't get it working. I've been changing the code around so its a bit off from where the Google GWT tutorials left.
JavaScriptObject json;
public JavaScriptObject executeQuery(String query) {
String url = "http://api.domain.com?client_id=xxxx&query=";
RequestBuilder builder = new RequestBuilder(RequestBuilder.GET,
URL.encode(url + query));
try {
#SuppressWarnings("unused")
Request request = builder.sendRequest(null, new RequestCallback() {
public void onError(Request request, Throwable exception) {
// violation, etc.)
}
public void onResponseReceived(Request request,
Response response) {
if (200 == response.getStatusCode()) {
// Process the response in response.getText()
json =parseJson(response.getText());
} else {
}
}
});
} catch (RequestException e) {
// Couldn't connect to server
}
return json;
}
public static native JavaScriptObject parseJson(String jsonStr) /*-{
return eval(jsonStr );
;
}-*/;
In the chrome's debugger I get umbrellaexception, unable to see the stack trace and GWT debugger dies with NoSuchMethodError... Any ideas, pointers?
You may have a look to GWT AutoBean framework.
AutoBean allow you to serialize and deserialize JSON string from and to Plain Old Java Object.
For me this framework became essential :
Code is cleaner than with JSNI objects (JavaScript Native Interface)
No dependancy with Framework not supported by Google (like RestyGWT)
You just define interfaces with getters and setters :
// Declare any bean-like interface with matching getters and setters,
// no base type is necessary
interface Person {
Address getAddress();
String getName();
void setName(String name):
void setAddress(Address a);
}
interface Address {
String getZipcode();
void setZipcode(String zipCode);
}
Later you can serialize or deserialize JSON String using a factory (See documentation) :
// (...)
String serializeToJson(Person person) {
// Retrieve the AutoBean controller
AutoBean<Person> bean = AutoBeanUtils.getAutoBean(person);
return AutoBeanCodex.encode(bean).getPayload();
}
Person deserializeFromJson(String json) {
AutoBean<Person> bean = AutoBeanCodex.decode(myFactory, Person.class, json);
return bean.as();
}
// (...)
First post on Stack Overflow (!) : I hope this help :)
Use JsonUtils#safeEval() to evaluate the JSON string instead of calling eval() directly.
More importantly, don't try to pass the result of an asynchronous call (like RequestBuilder#sendRequest() back to a caller using return - use a callback:
public void executeQuery(String query,
final AsyncCallback<JavaScriptObject> callback)
{
...
try {
builder.sendRequest(null, new RequestCallback() {
public void onError(Request request, Throwable caught) {
callback.onFailure(caught);
}
public void onResponseReceived(Request request, Response response) {
if (Response.SC_OK == response.getStatusCode()) {
try {
callback.onSuccess(JsonUtils.safeEval(response.getText()));
} catch (IllegalArgumentException iax) {
callback.onFailure(iax);
}
} else {
// Better to use a typed exception here to indicate the specific
// cause of the failure.
callback.onFailure(new Exception("Bad return code."));
}
}
});
} catch (RequestException e) {
callback.onFailure(e);
}
}
Generally, the workflow you're describing consists of four steps:
Make the request
Receive the JSON text
Parse the JSON in JavaScript objects
Describe these JavaScript objects using an overlay type
It sounds like you've already got steps 1 and 2 working properly.
Parse the JSON
JSONParser.parseStrict will do nicely. You'll be returned a JSONValue object.
This will allow you to avoid using your custom native method and will also make sure that it prevents arbitrary code execution while parsing the JSON. If your JSON payload is trusted and you want raw speed, use JSONParser.parseLenient. In either case, you need not write your own parser method.
Let's say that you're expecting the following JSON:
{
"name": "Bob Jones",
"occupations": [
"Igloo renovations contractor",
"Cesium clock cleaner"
]
}
Since you know that the JSON describes an object, you can tell the JSONValue that you're expecting to get a JavaScriptObject.
String jsonText = makeRequestAndGetJsonText(); // assume you've already made request
JSONValue jsonValue = JSONParser.parseStrict(jsonText);
JSONObject jsonObject = jsonValue.isObject(); // assert that this is an object
if (jsonObject == null) {
// uh oh, it wasn't an object after
// do error handling here
throw new RuntimeException("JSON payload did not describe an object");
}
Describe as an overlay type
Now that you know that your JSON describes an object, you can get that object and describe it in terms of a JavaScript class. Say you have this overlay type:
class Person {
String getName() /*-{
return this.name;
}-*/;
JsArray getOccupations() /*-{
return this.occupations;
}-*/;
}
You can make your new JavaScript object conform to this Java class by doing a cast:
Person person = jsonObject.getJavaScriptObject().cast();
String name = person.getName(); // name is "Bob Jones"
Using eval is generally dangerous, and can result in all kinds of strange behavior, if the server returns invalid JSON (note, that it's necessary, that the JSON top element is an array, if you simply use eval(jsonStr)!). So I'd make the server return a very simple result like
[ "hello" ]
and see, if the error still occurs, or if you can get a better stack trace.
Note: I assume, that the server is reachable under the same URL + port + protocol as your GWT host page (otherwise, RequestBuilder wouldn't work anyway due to Same Origin Policy.)
You actually don't need to parse the JSON, you can use native JSNI objects (JavaScript Native Interface).
Here's an example I pulled from a recent project doing basically the same thing you're doing:
public class Person extends JavaScriptObject{
// Overlay types always have protected, zero argument constructors.
protected Person(){}
// JSNI methods to get stock data
public final native String getName() /*-{ return this.name; }-*/;
public final native String getOccupation() /*-{ return this.occupation; }-*/;
// Non-JSNI methods below
}
and then to retrieve it like so:
/**
* Convert the string of JSON into JavaScript object.
*
*/
private final native JsArray<Person> asArrayOfPollData(String json) /*-{
return eval(json);
}-*/;
private void retrievePeopleList(){
errorMsgLabel.setVisible(false);
String url = JSON_URL;
url = URL.encode(url);
RequestBuilder builder = new RequestBuilder(RequestBuilder.POST, url);
try{
#SuppressWarnings("unused")
Request request = builder.sendRequest(null, new RequestCallback() {
#Override
public void onResponseReceived(Request req, Response resp) {
if(resp.getStatusCode() == 200){
JsArray<Person> jsonPeople = asArrayOfPeopleData(resp.getText());
populatePeopleTable(people);
}
else{
displayError("Couldn't retrieve JSON (" + resp.getStatusText() + ")");
}
}
#Override
public void onError(Request req, Throwable arg1) {
System.out.println("couldn't retrieve JSON");
displayError("Couldn't retrieve JSON");
}
});
} catch(RequestException e) {
System.out.println("couldn't retrieve JSON");
displayError("Couldn't retrieve JSON");
}
}
So essentially you're casting the response as an array of JSON Objects. Good stuff.
More info here: http://code.google.com/webtoolkit/doc/latest/DevGuideCodingBasicsJSNI.html