I am trying to parse the JSON result from the Wordpress plugins API using Retrofit2 and GSON. I have generated my POJO using the well known website and modified it into the following model:
PluginsApiResponse.java
public class PluginsApiResponse {
#SerializedName("plugins")
#Expose
private List<Plugin> plugins = null;
public List<Plugin> getPlugins() {
return plugins;
}
public void setPlugins(List<Plugin> plugins) {
this.plugins = plugins;
}
}
Plugin.java
public class Plugin {
#SerializedName("name")
#Expose
private String name;
#SerializedName("homepage")
#Expose
private String homepage;
#SerializedName("screenshots")
#Expose
private Screenshots screenshots;
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String getHomepage() {
return homepage;
}
public void setHomepage(String homepage) {
this.homepage = homepage;
}
public Screenshots getScreenshots() {
return screenshots;
}
public void setScreenshots(Screenshots screenshots) {
this.screenshots = screenshots;
}
}
Screenshots.java
public class Screenshots {
#SerializedName("1")
#Expose
private com.dkalsan.retrofitwordpress._1 _1;
#SerializedName("2")
#Expose
private com.dkalsan.retrofitwordpress._2 _2;
#SerializedName("3")
#Expose
private com.dkalsan.retrofitwordpress._3 _3;
public com.dkalsan.retrofitwordpress._1 get1() {
return _1;
}
public void set1(com.dkalsan.retrofitwordpress._1 _1) {
this._1 = _1;
}
public com.dkalsan.retrofitwordpress._2 get2() {
return _2;
}
public void set2(com.dkalsan.retrofitwordpress._2 _2) {
this._2 = _2;
}
public com.dkalsan.retrofitwordpress._3 get3() {
return _3;
}
public void set3(com.dkalsan.retrofitwordpress._3 _3) {
this._3 = _3;
}
}
_1.java (_2.java and _3.java are identical)
public class _1 {
#SerializedName("src")
#Expose
private String src;
#SerializedName("caption")
#Expose
private String caption;
public String getSrc() {
return src;
}
public void setSrc(String src) {
this.src = src;
}
public String getCaption() {
return caption;
}
public void setCaption(String caption) {
this.caption = caption;
}
}
The problem occurs in case the screenshots field contains no entries. I've set up the HttpLoggingInterceptor, which logs the response code 200 and the json in its entirety. I've also excluded the possibility of it being the internet connectivity issue according to the following article. If I remove the screenshots field from the model there is no trouble parsing. Is it possible that the error persists due to GSON trying to deserialize the nonexistent fields 1, 2, and 3 and if so, how to deal with it?
Turn out the problem was in the JSON response formatting. If there were no screenshots it was formatted as a JSON array, otherwise it was formatted as a JSON object containing objects 1, 2, 3, etc. I've managed to fix it by following the answer on this stackoverflow question.
Here is the problem, when I send my object to server using retrofit I got it null. I'm doing this to create the json object:
HashMap<String, UserModel> map = new HashMap<>();
map.put("user", user);
But, when the json arrives in the server I got something like this:
{"user":null}
Then I printed ny json file with this line:
Log.d("TAG", new JSONObject(map).toString());
And I saw the same null object.
So, here is my question, Why is this happening? And how can I fix that?
Here goes some information about my project:
Retrofit version: 2.0.0
Retrofit serializer: jackson version 2.0.0
using also jackson to convert JodaTime version 2.4.0
here goes how I get retrofit instance:
public T buildServiceInstance(Class<T> clazz){
return new Retrofit.Builder().baseUrl(BuildConfig.API_HOST)
.addConverterFactory(JacksonConverterFactory.create())
.build().create(clazz);
}
I call that method here:
public static final IUserApi serviceInstance = new ApiBuildRequester<IUserApi>()
.buildServiceInstance(IUserApi.class);
Method declaration on interface IUserApi:
#POST("User.svc/Save")
Call<ResponseSaveUserApiModel> save(#Body HashMap<String, UserModel> map);
And at last, but I guess, not less important:
public class UserModel implements Parcelable {
private String idUser;
private String name;
private String email;
#JsonProperty("password")
private String safePassword;
private String salt;
private String phoneNumber;
private String facebookProfilePictureUrl;
private String facebookUserId;
public UserModel() {
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String getIdUser() {
return idUser;
}
public void setIdUser(String idUser) {
this.idUser = idUser;
}
public String getEmail() {
return email;
}
public void setEmail(String email) {
this.email = email;
}
public String getSafePassword() {
return safePassword;
}
public void setSafePassword(String safePassword) {
this.safePassword = safePassword;
}
public String getPhoneNumber() {
return phoneNumber;
}
public void setPhoneNumber(String phoneNumber) {
this.phoneNumber = phoneNumber;
}
public String getFacebookProfilePictureUrl() {
return facebookProfilePictureUrl;
}
public void setFacebookProfilePictureUrl(String facebookProfilePictureUrl) {
this.facebookProfilePictureUrl = facebookProfilePictureUrl;
}
public String getFacebookUserId() {
return facebookUserId;
}
public void setFacebookUserId(String facebookUserId) {
this.facebookUserId = facebookUserId;
}
#Override
public int describeContents() {
return 0;
}
public UserModel(Parcel in) { // Deve estar na mesma ordem do "writeToParcel"
setIdUser(in.readString());
setName(in.readString());
setEmail(in.readString());
setSafePassword(in.readString());
setPhoneNumber(in.readString());
setFacebookProfilePictureUrl(in.readString());
setFacebookUserId(in.readString());
}
#Override
public void writeToParcel(Parcel dest, int flags) { //Deve estar na mesma ordem do construtor que recebe parcel
dest.writeString(idUser);
dest.writeString(name);
dest.writeString(email);
dest.writeString(safePassword);
dest.writeString(phoneNumber);
dest.writeString(facebookProfilePictureUrl);
dest.writeString(facebookUserId);
}
public static final Parcelable.Creator<UserModel> CREATOR = new Parcelable.Creator<UserModel>(){
#Override
public UserModel createFromParcel(Parcel source) {
return new UserModel(source);
}
#Override
public UserModel[] newArray(int size) {
return new UserModel[size];
}
};
public String getSalt() {
return salt;
}
public void setSalt(String salt) {
this.salt = salt;
}
}
Debug screen:
#Selvin and #cricket_007 You are the best!
I got this using your hint that my printing was wrong, and I found the solution.
I have two types of users in my app, facebook users or native users, two forms, but just one object, and here was the problem, when I sent facebook objects (complete) it worked fine, but when I tried to send native users, with some null properties, it crashed my serialization.
So I had to check every property before send it, it's just a workaround, but for now it's enough, thank you a lot folks!
I am trying to assign the value returned by some function to a field in the deserialized class of json.
FileInfo.java
public class FileInfo {
#SerializedName("Name")
private String mName;
#SerializedName("Url")
private String mUri;
#SerializedName("Size")
private Integer mSize;
#SerializedName("ModTime")
private Long mModifiedTime;
private FileType mType;
#SerializedName("Children")
private ArrayList<FileInfo> mChildren = new ArrayList<>();
public ArrayList<FileInfo> getChildren() {
return mChildren;
}
public long getModifiedTime() {
return mModifiedTime;
}
public String getName() {
return mName;
}
public Integer getSize() {
return mSize;
}
public String getUrl() {
return mUri;
}
public FileType getType() {
return mType;
}
public void setChildren(ArrayList<FileInfo> mChildren) {
this.mChildren = mChildren;
}
public void setModifiedTime(long mModifiedTime) {
this.mModifiedTime = mModifiedTime;
}
public void setName(String mName) {
this.mName = mName;
}
public void setSize(Integer mSize) {
this.mSize = mSize;
}
public void setType(FileType mType) {
this.mType = mType;
}
public void setUri(String mUri) {
this.mUri = mUri;
}
#Override
public String toString() {
return FileInfo.class.toString();
}
public FileInfo() {
}
}
The mType needs to be assigned to foo(mName). I looked up custom deserializers and instance creators but none of those helped. I also thought of TypeAdapters which i feel defeats the purpose of keeping deserialization(using GSON) simple.
This is a sample JSON string that will be deserialized.
[
{
"Name":"Airport",
"Url":"http://192.168.2.2/api/sites/Baltimore%20Airport/Airport",
"Size":0,
"ModTime":"2015-12-02T14:19:17.29824-05:00",
"Children":null
}
]
P.S. I'm not sure if this should be done during deserialization but trying anyways. Also please let me know of alternative ways to achieve this.
I need to parse a JSON response that I receive from a web service but I am receiving following error message, I puzzled with the this. I tried it without Results class as well to no avail. Any help would be appreciated.
The request sent by the client was syntactically incorrect.
Code
RestTemplate restTemplate = new RestTemplate();
restTemplate.getMessageConverters().add(new
MappingJackson2HttpMessageConverter());
ResponseEntity<Results> responseEntity = restTemplate
.getForEntity(
"http://primesport.sieenasoftware.com/QryApi
/GetEvents?
username=username&
password=password&
userid=23",
Results.class);
System.err.println(">>" + responseEntity.getBody().getEvents().size());
Classes
Results
public class Results {
private List<Events> events;
getter and setter
}
Events
public class Event {
private long eventId;
private String name;
private String subTitle;
private String description;
private String localDate;
private String localDateFrom;
private String imageUrl;
private int venueId;
private String venue;
private int availableTickets;
private long performerId;
private String performer;
private String performerType;
private int subcategoryId;
private String urlCategoryName;
private String metaTitle;
private String metaDescription;
private String primeSportUrl;
private String sectionWiseView;
private String venueCity;
private String venueState;
private String snippetDate;
private int eiProductionId;
private boolean requireBillingAsShipping;
public long getEventId() {
return eventId;
}
public void setEventId(long eventId) {
this.eventId = eventId;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String getSubTitle() {
return subTitle;
}
public void setSubTitle(String subTitle) {
this.subTitle = subTitle;
}
public String getDescription() {
return description;
}
public void setDescription(String description) {
this.description = description;
}
public String getLocalDate() {
return localDate;
}
public void setLocalDate(String localDate) {
this.localDate = localDate;
}
public String getLocalDateFrom() {
return localDateFrom;
}
public void setLocalDateFrom(String localDateFrom) {
this.localDateFrom = localDateFrom;
}
public String getImageUrl() {
return imageUrl;
}
public void setImageUrl(String imageUrl) {
this.imageUrl = imageUrl;
}
public int getVenueId() {
return venueId;
}
public void setVenueId(int venueId) {
this.venueId = venueId;
}
public String getVenue() {
return venue;
}
public void setVenue(String venue) {
this.venue = venue;
}
public int getAvailableTickets() {
return availableTickets;
}
public void setAvailableTickets(int availableTickets) {
this.availableTickets = availableTickets;
}
public long getPerformerId() {
return performerId;
}
public void setPerformerId(long performerId) {
this.performerId = performerId;
}
public String getPerformer() {
return performer;
}
public void setPerformer(String performer) {
this.performer = performer;
}
public String getPerformerType() {
return performerType;
}
public void setPerformerType(String performerType) {
this.performerType = performerType;
}
public int getSubcategoryId() {
return subcategoryId;
}
public void setSubcategoryId(int subcategoryId) {
this.subcategoryId = subcategoryId;
}
public String getUrlCategoryName() {
return urlCategoryName;
}
public void setUrlCategoryName(String urlCategoryName) {
this.urlCategoryName = urlCategoryName;
}
public String getMetaTitle() {
return metaTitle;
}
public void setMetaTitle(String metaTitle) {
this.metaTitle = metaTitle;
}
public String getMetaDescription() {
return metaDescription;
}
public void setMetaDescription(String metaDescription) {
this.metaDescription = metaDescription;
}
public String getPrimeSportUrl() {
return primeSportUrl;
}
public void setPrimeSportUrl(String primeSportUrl) {
this.primeSportUrl = primeSportUrl;
}
public String getSectionWiseView() {
return sectionWiseView;
}
public void setSectionWiseView(String sectionWiseView) {
this.sectionWiseView = sectionWiseView;
}
public String getVenueCity() {
return venueCity;
}
public void setVenueCity(String venueCity) {
this.venueCity = venueCity;
}
public String getVenueState() {
return venueState;
}
public void setVenueState(String venueState) {
this.venueState = venueState;
}
public String getSnippetDate() {
return snippetDate;
}
public void setSnippetDate(String snippetDate) {
this.snippetDate = snippetDate;
}
public int getEiProductionId() {
return eiProductionId;
}
public void setEiProductionId(int eiProductionId) {
this.eiProductionId = eiProductionId;
}
public boolean isRequireBillingAsShipping() {
return requireBillingAsShipping;
}
public void setRequireBillingAsShipping(boolean requireBillingAsShipping) {
this.requireBillingAsShipping = requireBillingAsShipping;
}
}
Partial Response
[{
"EventId":1000250537,
"Name":"US Open Golf",
"SubTitle":null,
"Description":"US Open Golf Tickets",
"Date":"\/Date(1434873560000)\/",
"LocalDate":"6/20/2015 11:59 PM",
"LocalDateFrom":null,
"ImageUrl":null,
"VenueId":146566,
"Venue":"Chambers Bay Golf Course",
"AvailableTickets":33,
"PerformerId":151551,
"Performer":"US Open Golf",
"PerformerType":"Golf",
"SubcategoryId":55,
"UrlCategoryName":"Sports",
"MetaTitle":null,
"MetaDescription":null,
"PrimeSportUrl":"http://primesport.sieenasoftware.com/e/sports/us-open-golf/chambers-bay-golf-course/",
"SectionWiseView":null,
"VenueCity":"UNIVERSITY PLACE",
"VenueState":"WA",
"SnippetDate":null,
"EIProductionId":99985,
"RequireBillingAsShipping":false},
{
"EventId":1000253479,
"Name":"Womens College World Series",
"SubTitle":null,
"Description": .....
UPDATE
I know JAXB can be used for both JSON and XML, I am trying to use it to see if it would help to solve the issue.
UPDATE
The code is returning following exception:
org.springframework.http.converter.HttpMessageNotReadableException: Could not read JSON: Can not deserialize instance of com.myproject.myevent.Results out of START_ARRAY token
at [Source: java.io.PushbackInputStream#dedcd10; line: 1, column: 1]; nested exception is com.fasterxml.jackson.databind.JsonMappingException: Can not deserialize instance of com.myproject.myevent.Results out of START_ARRAY token
at [Source: java.io.PushbackInputStream#dedcd10; line: 1, column: 1]
at org.springframework.http.converter.json.AbstractJackson2HttpMessageConverter.readJavaType(AbstractJackson2HttpMessageConverter.java:208)
at org.springframework.http.converter.json.AbstractJackson2HttpMessageConverter.read(AbstractJackson2HttpMessageConverter.java:200)
at org.springframework.web.client.HttpMessageConverterExtractor.extractData(HttpMessageConverterExtractor.java:97)
at org.springframework.web.client.RestTemplate$ResponseEntityResponseExtractor.extractData(RestTemplate.java:809)
at org.springframework.web.client.RestTemplate$ResponseEntityResponseExtractor.extractData(RestTemplate.java:793)
at org.springframework.web.client.RestTemplate.doExecute(RestTemplate.java:576)
at org.springframework.web.client.RestTemplate.execute(RestTemplate.java:529)
at org.springframework.web.client.RestTemplate.getForEntity(RestTemplate.java:261)
at com.myproject.service.TicketSeviceImpl.primeSport(TicketSeviceImpl.java:217)
at com.myproject.service.TicketSeviceImpl.findTicket(TicketSeviceImpl.java:45)
at com.myproject.web.TicketController.findTicket(TicketController.java:29)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:606)
UPDATE
following code returns
Code
try {
System.err.println(">>> primeSport");
RestTemplate restTemplate = new RestTemplate();
restTemplate.getMessageConverters().add(
new MappingJackson2HttpMessageConverter());
ResponseEntity<Event[]> responseEntity = restTemplate
.getForEntity(
"http://primesport.sieenasoftware.com/QryApi/GetEvents?username=username&password=password&userid=23",
Event[].class);
System.err.println(">>" + responseEntity.getBody().length);
System.err.println(">>" + responseEntity.getBody()[0].getEventId());
System.err.println(">>" + responseEntity.getBody()[1].getEventId());
} catch (Exception e) {
e.printStackTrace();
}
Output
>1532
>0
>0
Can you try the following and see whether helps:
ResponseEntity<Events[]> responseEntity = restTemplate
.getForEntity(
"http://primesport.sieenasoftware.com/QryApi
/GetEvents?
username=username&
password=password&
userid=23",
Events[].class);
System.err.println(">>" + responseEntity.getBody().length);
For mapping the fields to the JSON members you can use Jackson annotation JSONProperty("EventId") can be used for the eventId field. Similarly for others.
#JsonProperty("EventId")
private long eventId;
#JsonProperty("Name")
private String name;
Have you tried to see the exact request getting generated? Let's say in a proxy software like fiddler/charles?
Sometimes I have experienced, the framework adds additional constructs(encoding, etc), before the requests actually really gets to the wire(or reaching the server endpoint).
Try this, to create the request. Even the documentation for RestTemplate suggests to avoid double encoding for URL. It may not be very apparent when looking in the IDE.
String url = "http://primesport.sieenasoftware.com/QryApi/GetEvents?";
MultiValueMap<String, String> params = new LinkedMultiValueMap<String, String>();
params.add("username", "username");
params.add("password", "password");
params.add("userid", "23");
UriComponents uriComponents = UriComponentsBuilder.fromHttpUrl(url).queryParams(params).build();
System.out.println(uriComponents.toUri());
Please let me know, how it works out.
Also, please let know, if you cant find steps to setup fiddler proxy. It quite a handy tool, while coding the service clients.
According to the json format, all you need is using the Event class instead of the Result class.
Or change the JSON result to this :
["events": {
"EventId":1000250537,
"Name":"US Open Golf",
"SubTitle":null,
"Description":"US Open Golf Tickets",
"Date":"\/Date(1434873560000)\/",
"LocalDate":"6/20/2015 11:59 PM",
"LocalDateFrom":null,
"ImageUrl":null,
"VenueId":146566,
"Venue":"Chambers Bay Golf Course",
"AvailableTickets":33,
"PerformerId":151551,
"Performer":"US Open Golf",
"PerformerType":"Golf",
"SubcategoryId":55,
"UrlCategoryName":"Sports",
"MetaTitle":null,
"MetaDescription":null,
"PrimeSportUrl":"http://primesport.sieenasoftware.com/e/sports/us-open-golf/chambers-bay-golf-course/",
"SectionWiseView":null,
"VenueCity":"UNIVERSITY PLACE",
"VenueState":"WA",
"SnippetDate":null,
"EIProductionId":99985,
"RequireBillingAsShipping":false},
{
"EventId":1000253479,
"Name":"Womens College World Series",
"SubTitle":null,
"Description": .....
You can try importing Jackson Jar or add dependency in pom.xml if you are using Maven.
ObjectMapper mapper = new ObjectMapper();
try
{
mapper.writeValue(new File("c://temp/employee.json"), Results);
}
I am new to implement Azure Mobile Service. I have refer the demo of ToDoItem given by Azure.
In same manner i have make class User for my own app. Then I am inserting the data in to the MobileServiceTable but it gives me error like below:
{"message":"The operation failed with the following error: 'A null store-generated value was returned for a non-nullable member 'CreatedAt' of type 'CrazyLabApp.Models.User'.'."}
I have not created any field like this as it is not created in ToDoItem demo as well. I have seen that there are 4 fields that are by Default created by the MobileServiceTable. createdAt is one of the field of that.
I am wonder about whats wrong i am doing.
Check my below Userclass:
public class User {
#com.google.gson.annotations.SerializedName("id")
private String ServiceUserId;
#com.google.gson.annotations.SerializedName("email")
private String Email;
#com.google.gson.annotations.SerializedName("firstname")
private String FirstName;
#com.google.gson.annotations.SerializedName("lastname")
private String LastName;
#com.google.gson.annotations.SerializedName("profilepic")
private String ProfilePic;
#com.google.gson.annotations.SerializedName("introduction")
private String Introduction;
#com.google.gson.annotations.SerializedName("website")
private String Website;
#com.google.gson.annotations.SerializedName("title")
private String Title;
#com.google.gson.annotations.SerializedName("_createdAt")
private Date CreatedAt;
#com.google.gson.annotations.SerializedName("coverimage")
private ArrayList<CoverImage> CoverImages;
/*public Date getCreatedAt() {
return CreatedAt;
}
public void setCreatedAt(Date createdAt) {
CreatedAt = createdAt;
}*/
#com.google.gson.annotations.SerializedName("followers")
private ArrayList<User> Followers;
#com.google.gson.annotations.SerializedName("likes")
private ArrayList<Likes> Likes;
#com.google.gson.annotations.SerializedName("collections")
private ArrayList<Collections> Collections;
#com.google.gson.annotations.SerializedName("comments")
private ArrayList<Comments> Comments;
#com.google.gson.annotations.SerializedName("stories")
private ArrayList<Story> Stories ;
//-------------- Methods
public ArrayList<Story> getStories() {
return Stories;
}
public void setStories(ArrayList<Story> stories) {
Stories = stories;
}
public ArrayList<com.promact.crazylab.model.Comments> getComments() {
return Comments;
}
public void setComments(ArrayList<com.promact.crazylab.model.Comments> comments) {
Comments = comments;
}
public ArrayList<com.promact.crazylab.model.Collections> getCollections() {
return Collections;
}
public void setCollections(ArrayList<com.promact.crazylab.model.Collections> collections) {
Collections = collections;
}
public ArrayList<com.promact.crazylab.model.Likes> getLikes() {
return Likes;
}
public void setLikes(ArrayList<com.promact.crazylab.model.Likes> likes) {
Likes = likes;
}
public ArrayList<User> getFollowers() {
return Followers;
}
public void setFollowers(ArrayList<User> followers) {
Followers = followers;
}
public ArrayList<CoverImage> getCoverImages() {
return CoverImages;
}
public void setCoverImages(ArrayList<CoverImage> coverImages) {
CoverImages = coverImages;
}
public String getTitle() {
return Title;
}
public void setTitle(String title) {
Title = title;
}
public String getWebsite() {
return Website;
}
public void setWebsite(String website) {
Website = website;
}
public String getIntroduction() {
return Introduction;
}
public void setIntroduction(String introduction) {
Introduction = introduction;
}
public String getLastName() {
return LastName;
}
public void setLastName(String lastName) {
LastName = lastName;
}
public String getProfilePic() {
return ProfilePic;
}
public void setProfilePic(String profilePic) {
ProfilePic = profilePic;
}
public String getEmail() {
return Email;
}
public void setEmail(String email) {
Email = email;
}
public String getFirstName() {
return FirstName;
}
public void setFirstName(String firstName) {
FirstName = firstName;
}
public String getServiceUserId() {
return ServiceUserId;
}
public void setServiceUserId(String serviceUserId) {
ServiceUserId = serviceUserId;
}
#Override
public boolean equals(Object o) {
return o instanceof User && ((User) o).ServiceUserId == ServiceUserId;
}
}
Also check below code the way i am inserting it:
final User u = new User();
u.setFirstName(mName);
u.setEmail(mEmail);
u.setProfilePic(mUrl);
mUserTable = mClient.getTable(User.class);
// Insert the new item
new AsyncTask<Void, Void, Void>(){
#Override
protected Void doInBackground(Void... params) {
try {
final User entity = mUserTable.insert(u).get();
} catch (Exception e){
//createAndShowDialog(e, "Error");
System.out.println("Error: "+e.toString());
}
return null;
}
}.execute();
Please help me in this.
The "_createdat" column will be populated automatically by Azure Mobile Services so there is no need to include it in your model. Delete this property from the User class. Its presence is probably overwriting the auto-populated value with a null.
you can solve this problem by just deleting createdAt column from your user table in azure.
Why this error is coming :
I am not sure But I guess this error is coming because createdAt is a non-nullable member and you cannot left it null.
EDIT :
Another aspect of the system columns is that they cannot be sent by the client. For new tables (i.e., those with string ids), if an insert of update request contains a property which starts with ‘__’ (two underscore characters), the request will be rejected. The ‘__createdAt’ property can, however, be set in the server script (although if you really don’t want that column to represent the creation time of the object, you may want to use another column for that) – one way where this (rather bizarre) scenario can be accomplished. If you try to update the ‘__updatedAt’ property, it won’t fail, but by default that column is updated by a SQL trigger, so any updates you make to it will be overridden anyway.
for more info take a look here :-http://blogs.msdn.com/b/carlosfigueira/archive/2013/11/23/new-tables-in-azure-mobile-services-string-id-system-properties-and-optimistic-concurrency.aspx