What are the significant diffs between:
org.json.JSONObject and javax.json.JsonObject?
Most importantly are they interchangeable from client to Webservice?
ie. can I send JSONObject to Webservice and have the Webservice believe the type is JsonObject (and vice versa)?
(JSONObject found in the json-20080701.jar of ACRA)
(JsonObject found in C:\glassfish4\glassfish\modules\javax.json.jar)
What are the significant diffs between org.json.JSONObject and
javax.json.JsonObject?
javax.json.JsonObject is included in Java EE 7
javax.json.JsonObject is immutable
org.json.JSONObject has siginificantly more convenience methods
Most importantly are they interchangeable from client to Webservice?
ie. can I send JSONObject to Webservice and have the Webservice
believe the type is JsonObject (and vice versa)?
Of course this should work. It is not the class instance which gets transferred to the webservice, but the JSON data, which is generated from the class instance. On the other side, the JSON data can be parsed back into any kind of object.
Example:
If you have a simple class named Person:
public class Person {
private String name = "Hans";
private int age = 26;
}
This could be transformed into JSON similar to: {"name":"Hans", "age":25}
The generated JSON string is sent to the webservice.
Now, on the other end of your application, or in any other application, this JSON string can be parsed into any class, if you have an appropriate parser. You don't even need Java to parse it.
Related
When posting JSON to Web API, not only does it get deserialized automatically, one can also use model validation like
// ItemPostRequest
class ItemPostRequest {
[Required] // this will automatically be validated and errors created if it is missing
public string Description { get; set; }
}
However in my case, I only have a string containing JSON. I can deserialize it using JsonSerializer.Deserialize<ItemPostRequest>(myJsonString); but that's missing the validation.
How to use the validation / how to manually deserialize and validate JSON like Web API does it internally?
In my case the JSON string is part of form-data with keys like file and json, but the form-data formatter only cares about splitting the form-data into key-value pairs, it doesn't care about deserializing the json and the model validation for it. So I have to do this manually - but how?
Deserialize the JSON in a model binder, like written here: https://stackoverflow.com/a/49471892
Then the validation will be done automatically :-)
Perhaps something like below. I have not tested it, but you should be able to use TryValidateModel() to manually validate your ItemPostRequest based on your class annotations (e.g. [Required]).
// Deserialize
var itemPostRequest = JsonSerializer.Deserialize<ItemPostRequest>(myJsonString);
// Reset just in case
ModelState.Clear();
// Manually validate the model using the annotations on the model class
TryValidateModel(itemPostRequest);
// If it fails, return error
if (!ModelState.IsValid)
{
return BadRequest(ModelState);
}
// Otherwise we're good, keep going...
I'm developing a Rest Client using Spring Boot and Spring Framework (spring-boot-starter-parent 2.1.6.RELEASE)
I have a class representing a response object as shown below:
public class ValidateResponse {
private String ResponseCode;
private String ResponseDesc;
//getters and setters
//constructors using fields
//empty constructor
}
I'm creating a web-hook for an external api and I need to return a JSON object to for a specific endpoint (the JSON object properties must start with uppercase(s)). I'm calling returning the object from a PostMapping method nested in a RequestMapping root path:
#PostMapping("hooks/validate")
public ValidateResponse responseObj(#RequestHeader Map<String, String> headersObj) {
ValidateResponse response = new ValidateResponse("000000", "Success");
logger.info("Endpoint = hooks/validate | Request Headers = {}", headersObj);
return response;
}
However, when I hit the endpoint from postman I'm getting duplicate varialbes
{
"ResponseCode": "000000",
"ResponseDesc": "Success",
"responseCode": "000000",
"responseDesc": "Success"
}
I understand that the pojo-json conversion is handled by spring but I don't understand why the conversion is yielding duplicate variables.
Note: I know the ResponseDesc and the ResponseCode are not declared using the best standards for naming variables (camelCasing).
I've done some digging and according to the Java Language Specification
An identifier is an unlimited-length sequence of Java letters and Java digits, the first of which must be a Java letter.
and
The "Java letters" include uppercase and lowercase ASCII Latin letters A-Z (\u0041-\u005a), and a-z (\u0061-\u007a), and, for historical reasons, the ASCII underscore (_, or \u005f) and dollar sign ($, or \u0024). The $ character should be used only in mechanically generated source code or, rarely, to access pre-existing names on legacy systems.
So, I'm assuming its syntactically correct to define a variable using the Camelcase format [Need clarification on this].
I'm considering having to create the JSON object manually but I'd like to know the cause of this behaviour first. Any pointers are appreciated.
Jackson deserializes all the public fields that it comes across. However if you want Jackson to return the response in your expected element names (in your case elements starting with capital letters), make the fields private and annotate them with the #JsonProperty(expected_name_here). Your class file will typically looks as shown below
public class ValidateResponse {
#JsonProperty("ResponseDesc")
private String responseCode;
#JsonProperty("ResponseDesc")
private String responseDesc;
//getters and setters
//constructors using fields
//empty constructor
}
Note: The getters and setters for these fields should be public, otherwise Jackson won't see anything to deserialize in the class.
public class ValidateResponse {
#JsonProperty("ResponseDesc")
public String responseCode;
#JsonProperty("ResponseDesc")
public String responseDesc;
//getters and setters
//constructors using fields
//empty constructor
}
This must fix your problem, however I do not know the reason as it requires deep Jackson investigation.
EDIT
I found out the reason.
The field got duplicated because in you case you had:
2 public fields named in upper case -> they are to be processed by jackson
2 getters getResponseCode and getResponseDesc -> they are to be resolved
as accessors for properties responseCode and responseDesc accordingly.
Summing this up - you have 4 properties resolved by Jackson. Simply making your fields private will resolve your issue, however I still advise using JsonProperty approach.
I added a com.google.code.gson dependency in the projects pom.xml file to configure Spring Boot to use Gson (instead of the default jackson).
The Json object returned from the hooks/validate endpoint must have its property names starting with a capital letter. Using a java class to generate the response object was resulting to camelCased property names so I resolved to create the JSON response object manually. Here's the code for creating the custom JSON object:
public ResponseEntity<String> responseObj(#RequestHeader Map<String, String> headersObj) {
HttpHeaders responseHeaders = new HttpHeaders();
responseHeaders.setContentType(MediaType.APPLICATION_JSON);
JsonObject response = new JsonObject();
response.addProperty("ResponseCode", "00000000");
response.addProperty("ResponseDesc" , "Success");
logger.info("Endpoint = hooks/validate | Request Headers = {}", headersObj);
return ResponseEntity.ok().headers(responseHeaders).body(response.toString());
}
Note The JSON object is returned as a String so the response from the endpoint must have an additional header to define MediaType to inform the calling system that the response is in JSON format:
responseHeaders.setContentType(MediaType.APPLICATION_JSON);
then add the header to the response:
return ResponseEntity.ok().headers(responseHeaders).body(response.toString());
I have this Data Object with an Int64 column:
[TableAttribute(Name="dbo.vw_RelationLineOfBusiness")]
[DataServiceKey("ProviderRelationLobId")]
public partial class RelationLineOfBusiness
{
#region Column Mappings
private System.Guid _Lineofbusiness;
private System.String _ContractNumber;
private System.Nullable<System.Int32> _ProviderType;
private System.String _InsuredProviderType;
private System.Guid _ProviderRelationLobId;
private System.String _LineOfBusinessDesc;
private System.String _CultureCode;
private System.String _ContractDesc;
private System.Nullable<System.Guid> _ProviderRelationKey;
private System.String _ProviderRelationNbr;
**private System.Int64 _AssignedNbr;**
When I post/Put object through my OData controller using HttpClient and NewtsonSoft:
partial class RelationLineOfBusinessController : ODataController
{
public HttpResponseMessage PutRelationLineOfBusiness([FromODataUri] System.Guid key, Invidasys.VidaPro.Model.RelationLineOfBusiness entity)
the entity object is null and the error in my modelstate :
"Cannot convert a primitive value to the expected type 'Edm.Int64'. See the inner exception for more details."
I noticed when I do a get on my object using the below URL:
Invidasys.Rest.Service/VidaPro/RelationLineOfBusiness(guid'c6824edc-23b4-4f76-a777-108d482c0fee')
my json looks like the following - I noticed that the AssignedNbr is treated as a string.
{
"odata.metadata":"Invidasys.Rest.Service/VIDAPro/$metadata#RelationLineOfBusiness/#Element",
"Lineofbusiness":"ba129c95-c5bb-4e40-993e-c28ca86fffe4","ContractNumber":null,"ProviderType":null,
"InsuredProviderType":"PCP","ProviderRelationLobId":"c6824edc-23b4-4f76-a777-108d482c0fee",
"LineOfBusinessDesc":"MEDICAID","CultureCode":"en-US","ContractDesc":null,
"ProviderRelationKey":"a2d3b61f-3d76-46f4-9887-f2b0c8966914","ProviderRelationNbr":"4565454645",
"AssignedNbr":"1000000045","Ispar":true,"ProviderTypeDesc":null,"InsuredProviderTypeDesc":"Primary Care Physician",
"StartDate":"2012-01-01T00:00:00","EndDate":"2014-01-01T00:00:00","Created":"2014-06-13T10:59:33.567",
"CreatedBy":"Michael","Updated":"2014-06-13T10:59:33.567","UpdatedBy":"Michael"
}
When I do a PUT with httpclient the JSON is showing up in my restful services as the following and the json for the AssignedNbr column is not in quotes which results in the restful services failing to build the JSON back to an object. I played with the JSON and put the AssignedNbr in quotes and the request goes through correctly.
{"AssignedNbr":1000000045,"ContractDesc":null,"ContractNumber":null,"Created":"/Date(1402682373567-0700)/",
"CreatedBy":"Michael","CultureCode":"en-US","EndDate":"/Date(1388559600000-0700)/","InsuredProviderType":"PCP",
"InsuredProviderTypeDesc":"Primary Care Physician","Ispar":true,"LineOfBusinessDesc":"MEDICAID",
"Lineofbusiness":"ba129c95-c5bb-4e40-993e-c28ca86fffe4","ProviderRelationKey":"a2d3b61f-3d76-46f4-9887-f2b0c8966914",
"ProviderRelationLobId":"c6824edc-23b4-4f76-a777-108d482c0fee","ProviderRelationNbr":"4565454645","ProviderType":null,
"ProviderTypeDesc":null,"StartDate":"/Date(1325401200000-0700)/","Updated":"/Date(1408374995760-0700)/","UpdatedBy":"ED"}
The reason we wanted to expose our business model as restful services was to hide any data validation and expose all our databases in format that is easy to develop against. I looked at the DataServiceContext to see if it would work and it does but it uses XML to communicate between the restful services and the client. Which would work but DataServiceContext does not give the level of messaging that HttpRequestMessage/HttpResponseMessage gives me for informing users on the errors/missing information with their post.
We are planning on supporting multiple devices from our restful services platform but that requires that I can use NewtonSoft Json as well as Microsoft's DataContractJsonSerializer if need be.
My question is for a restful service standpoint - is there a way I can configure/code the restful services to take in the AssignedNbr as in JSON as without the quotes.
Or from a JSON standpoint is their a way I can get the JSON built without getting into the serializing business nor do I want our clients to have deal with custom serializers if they want to write their own apps against our restful services.
Any suggestions?
Thanks.
I think you can migrate to Web API 2.2 for OData V4. Here's the information:
Announcing the Release of ASP.NET MVC 5.2, Web API 2.2 and Web Pages 3.2
OData V4 Spec says:
3.2 Controlling the Representation of Numbers
The IEEE754Compatible=true format parameter indicates that the service MUST serialize Edm.Int64 and Edm.Decimal numbers (including the odata.count, if requested) as strings. If not specified, or specified as IEEE754Compatible=false, all numbers MUST be serialized as JSON numbers.
This enables support for JavaScript numbers that are defined to be 64-bit binary format IEEE 754 values [ECMAScript] (see section 4.3.1.9) resulting in integers losing precision past 15 digits, and decimals losing precision due to the conversion from base 10 to base 2.
OData JSON payloads that format Edm.Int64 and Edm.Decimal values as strings MUST specify this format parameter in the media type returned in the Content-Type header.
So, for payload as:
#"{
""Lineofbusiness"": ""ba129c95-c5bb-4e40-993e-c28ca86fffe4"",
""AssignedNbr"": ""1000000045""
}";
you should set:
request.Content.Headers.ContentType = MediaTypeHeaderValue.Parse("application/json;IEEE754Compatible=true");
Otherwise, you shouldn't.
Sam Xu is exactly right and should be marked as the answer.
However, I wanted to add exactly what you need to do to add this to the pipeline.
First, you can set this global, per route etc. You can find that information here:
http://www.asp.net/web-api/overview/advanced/http-message-handlers
Below you'll find an example that will work.
public static void Configuration(IAppBuilder builder)
{
HttpConfiguration config = new HttpConfiguration();
config.MessageHandlers.Add(new MethodOverrideHandler());
}
public class MethodOverrideHandler : DelegatingHandler
{
protected override Task<HttpResponseMessage> SendAsync(
HttpRequestMessage request, CancellationToken cancellationToken)
{
request.Content.Headers.ContentType = MediaTypeHeaderValue.Parse("application/json;IEEE754Compatible=true");
return base.SendAsync(request, cancellationToken);
}
}
Alternatively, try changing the type you send to your web api to Number instead of string
Also, check the Type of the decimal that you are sending. If it's type 'string' you can change it to type number. For my service, making this change no longer throws the error.
//Gnuget Package Manager Install-Package numeral
if (typeof newValue === 'string')
{
newValue = numeral().unformat(newValue);
}
odatajs.oData.request(
{
requestUri: xxx,
method: "PATCH",
data: { PriceNull: newValue }
}
Is it possible to configure jackson to always add the type of the serialized object to the generated json output.
For example:
package org.acme;
class ClassA
{
String a;
String b;
}
and I want the generated json to be:
["org.acme.ClassA",{"a":"str1","b":"str2"}]
You can do that with enableDefaultTyping() of the ObjectMapper
e.g.
mapper.enableDefaultTyping(DefaultTyping.OBJECT_AND_NON_CONCRETE);
See ObjectMapper API
If your are free to change from Jackson and do not especially need the format to match the one your are showing you can try Genson http://code.google.com/p/genson.
For example if your requirement is to be able to deserialize interfaces or abstract classes based on the original type of the object you serialized you can do:
interface Entity {}
static class Person implements Entity {}
Genson genson = new Genson.Builder().setWithClassMetadata(true).create();
// json will be equal to {"#class":"my.package.Person"}
String json = genson.serialize(new Person());
// and now Genson is able to deserialize it back to Person using the information
// in the Json Object
Person person = (Person) genson.deserialize(json, Entity.class);
Another nice feature is the ability to define aliases for your classes, so you show less information in the json stream but also this allows you to do refactoring without worring of existing json streams (for example if you store it in a database).
Genson genson = new Genson.Builder().addAlias("person", Person.class).create();
// json value is {"#class": "person"}
String json = genson.serialize(new Person());
Have a look at the wiki.
For some reason, I haven't found any normal way to do the following:
I want to Post a json object, and add additional parameters to the call (in this case, an authentication token).
This is a simple RESTful server in myUrl/server, which should give access to different resources of a "person" in the url myUrl/server/person/personCode/resourceName.
GET is easy, and requires no object, only parameters.
The problem arrises when I get to POST - how do I attach the JSON, and keep the other parameters as well?
The class (much has been removed for clarity and proprietary reasons...):
//Handles the person's resources
#Path("/person/{personCode}/{resourceName}")
public class PersonResourceProvider {
#GET
#Produces("application/json")
public String getPersonResource(#PathParam("personCode") String personCode, #PathParam("resourceName") String resourceName, #DefaultValue("") #QueryParam("auth_token") String auth_token) throws UnhandledResourceException, UnauthorizedAccessException {
//Authenticates the user in some way, throwing an exception when needed...
authenticate(personCode, auth_token, resourceName);
//Returns the resource somehow...
}
#POST
#Produces("application/json")
public String postPersonResource(#PathParam("personCode") String personCode, #PathParam("resourceName") String resourceName, #DefaultValue("") #QueryParam("resourceData") String resourceData, #DefaultValue("") #QueryParam("auth_token") String auth_token) throws UnhandledResourceException, UnauthorizedAccessException {
//Again, authenticating
authenticate(personCode, auth_token, resourceName);
//Post the given resource
}
}
Now, the GET method works perfectly, when you go to
myUrl/person/personCode/resourceName, it gives me the correct resource.
The auth_token is used with every single call to the server (for now, authentication is done by comparing with a predefined string), so it's needed. All the other parameters are provided through the path, except for the authentication token, which should not be in the path as it does not relate to the identity of the required resource.
When I get to POST, it's a problem.
I know there's a way to tell the method it consumes a JSON, but in that case, what will happen to the other parameters (auth_token is one of them)?
Should I use Multipart?
Another related question, this is the first time I've designed such a server, is this design correct?
Thanks!
I am not sure I understand what you are trying to achieve. Let me try explain a few things - hope it will be relevant to your question:
#QueryParam injects parameters which are part of your path - i.e. the part of the URL that goes after "?".
E.g. if you have a URL like this:
http://yourserver.com/person/personCode/resourceName?resourceData=abc&token=1234
Then there would be 2 query params - one named resourceData with value "abc" and the other one named token with value "1234".
If you are passing an entity in the POST request, and that entity is of application/json type, you can simply annotate your post method using #Consumes("application/json") annotation and add another parameter to your method, which does not need to be annotated at all.
That parameter can be either a String (in that case Jersey would pass a raw JSON string and you would have to parse it yourself) or it can be a java bean annotated with #XmlRootElement annotation - in that case (if you also include jersey-json module on your classpath) Jersey will try to unmarshall the json string into that object using JAXB. You can also use Jackson or Jettison libraries to do that - see this section of Jersey User Guide for more info: http://jersey.java.net/nonav/documentation/latest/json.html
Found!
Client side:
Client c = Client.create();
WebResource service = c.resource("www.yourserver.com/");
String s = service.path("test/personCode/resourceName")
.queryParam("auth_token", "auth")
.type("text/plain")
.post(String.class, jsonString);
Server side:
import com.sun.jersey.api.client.Client;
import com.sun.jersey.api.client.WebResource;
#Path("/test/{personCode}/{resourceName}")
public class TestResourceProvider {
#POST
#Consumes("text/plain")
#Produces("application/json")
public String postUserResource(String jsonString,
#PathParam("personCode") String personCode,
#PathParam("resourceName") String resourceName,
#QueryParam("auth_token") String auth_token)
throws UnhandledResourceException {
//Do whatever...
}
}
In my case, I will parse the json I get in the server depending on the resource name, but you can also pass the object itself, and make the server consume an "application/json".