Http 204 error in REST web service (Jersey) - web-services

I am using Jersey/Java to develop my REST services. I need to return an XML representation for my CarStore :
#XmlRootElement
public class CarStore {
private List<Car> cars;
public List<Car> getCars() {
return cars;
}
public void setCars(List<Car> cars) {
this.cars = cars;
}
Here is my Car object :
#XmlRootElement
> public class Car {
private String carName;
private Specs carSpecs;
private Category carCategory;
public String getCarName() {
return carName;
}
public void setCarName(String carName) {
this.carName = carName;
}
public Specs getCarSpecs() {
return carSpecs;
}
public void setCarSpecs(Specs carSpecs) {
this.carSpecs = carSpecs;
}
public Category getCarCategory() {
return carCategory;
}
public void setCarCategory(Category carCategory) {
this.carCategory = carCategory;
}
}
Specs and Category are enums like this :
#XmlRootElement
> public enum Category {
SEDANS, COMPACTS, WAGONS, HATCH_HYBRIDS, SUVS, CONVERTIBLES, COMPARABLE;
}
My resource class is :
#GET
#Produces({MediaType.APPLICATION_XML})
public CarStore getCars()
{
return CarStoreModel.instance.getAllCars();
}
My jersey client is :
WebResource service = client.resource(getBaseURI());
System.out.println(service.path("rest").path("cars").accept(
MediaType.APPLICATION_XML).get(String.class));
I am getting Http 204 error on access alongwith client exception :
com.sun.jersey.api.client.UniformInterfaceException
Any ideas ? Thanks !
EDIT : I have yet not developed the model class...I just initialized some car objects as dummy data and put them in carstore. Showing all the classes here would be very clumsy.
BTW, sorry for writing 204 Error..it is just that I am getting an Exception that led me think so.

I'm guessing the exception is not related to the response code (204) because 204 is a success condition that indicates "No Content."

I believe you are getting a UniformInterfaceException because your getCars() function is not returning an HTTP response body. The root problem is that your Car List isn't being converted into XML by JAXB because it is missing the #XmlElement annotation.
Your getCars() function should be:
#GET
#Produces(MediaType.APPLICATION_XML)
public CarStore getCars() {
// myCarStore is an instance of CarStore
return myCarStore.getCars();
}
and your Car List in CarStore should be defined:
#XmlElement(name="car")
private List<Car> cars;

Is what you're returning in xml format? I'm not sure what getAllCars does but you can use something like Fiddler to help you view the traffic and see what is being returned to the client and whether its in proper format etc

In your client code, is the resource path correct? Make sure getBaseURI is returning a value.
Perhaps try:
Client client = new Client();
WebResource resource = client.resource(getBaseURI());
CarStore carStore = resource.path("/rest/cars").accept(MediaType.APPLICATION_XML).get(CarStore.class);

Aren't you missing a #Path annotation on your resource class?
#GET
#Path("cars")
#Produces({ MediaType.APPLICATION_XML })
public CarStore getCars() {
return CarStoreModel.instance.getAllCars();
}
Check if the URL at which your REST WS is mounted the one you expect by putting a breakpoint in your getCars() method (or putting a System.out.println) to make sure it actually gets called.

It seems there is a hard coded check in Jersey to throw a UniformInterfaceException when a HTTP 204 is returned.
The best solution will be to 'fix' the rest server so it never returns a null. e.g. return an Empty list or a Class with not values set.
Else you will need to catch UniformInterfaceException which is really ugly
if (getStatus() == 204) {
throw new UniformInterfaceException(this);
}
More info here :
http://grepcode.com/file/repo1.maven.org/maven2/com.sun.jersey/jersey-client/1.17.1/com/sun/jersey/api/client/ClientResponse.java#ClientResponse.getEntity%28java.lang.Class%2Cjava.lang.reflect.Type%29

Related

How to send a property as a string in RestEasy response?

I have a class called Product which has a property called id of type long. Below is the class
public class Product {
private long id;
}
The value of id is beyond the value which javascript can handle. I realized this after seeing the below link
Parse json in javascript - long numbers get rounded
I dont want to declare the field as String in the domain class. But I want to say to RestEasy that it has to send the value as a string in the json response.
How can I do this? I dont want to use any third party api. Is it possible in RestEasy. I have gone through the documentation but did not find any such annotation or may be I did not go through the documentation properly.
Can anyone please help. Thanks all in advance.
If you are using Jackson as JSON Serializer you can extend the JacksonJsonProvider:
#Provider
public class JsonProvider extends org.codehaus.jackson.JacksonJsonProvider {
public JsonProvider() {
ObjectMapper objectMapper = locateMapper(ObjectMapper.class, MediaType.APPLICATION_JSON_TYPE);
objectMapper.configure(org.codehaus.jackson.JsonGenerator.Feature.WRITE_NUMBERS_AS_STRINGS, true);
}
}
If you are using Jettison you can register a custom XmlAdapter:
public class LongAdapter extends XmlAdapter<String, Long> {
#Override
public String marshal(Long id) throws Exception {
if (id == null) {
return "";
}
return id.toString();
}
#Override
public Long unmarshal(String id) throws Exception {
return Long.parseLong(id);
}
}

ConstraintViolationException in Java RESTful Webservice

I'm relatively new to JavaEE and web services, however, I'm using netbeans to generate my client and webservice resources. I have a resource "CustomerData" that represents a mysql database table and a value "rewardsPoints" representing a column in that table, however, I am unable to update the value due to a ConstraintViolationException, specifically:
javax.validation.ConstraintViolationException: Bean Validation constraint(s) violated while executing Automatic Bean Validation on callback event:'preUpdate'. Please refer to embedded ConstraintViolations for details.
I'm not familiar with the 'preUpdate' callback event, is it something I need to override? I can't seem to figure out exactly why this exception is being thrown, but, as I said, i'm very new to web service programming. Here are my classes:
#Stateless
#Path("customers")
public class CustomerDataFacadeREST extends AbstractFacade<CustomerData> {
#PersistenceContext(unitName = "CustomerPortalPU")
private EntityManager em;
public CustomerDataFacadeREST() {
super(CustomerData.class);
}
#PUT
#Path("{id}")
#Consumes({"application/xml", "application/json"})
public void edit(#PathParam("id") Integer id, CustomerData entity) {
super.edit(entity);
}
#GET
#Path("{id}")
#Produces({"application/xml", "application/json"})
public CustomerData find(#PathParam("id") Integer id) {
return super.find(id);
}
#GET
#Path("addPoints/{id}/{amount}")
#Produces({"text/plain"})
public String addPoints(#PathParam("id") Integer id, #PathParam("amount") int amount) {
CustomerData customer = find(id);
customer.getRewardsPoints(customer.getRewardsPoints() + amount);
em.persist(customer);
edit(customer);
return customer.getRewardsPoints();
}
#Override
protected EntityManager getEntityManager() {
return em;
}
}
And the CustomerData entity class:
#Entity
#Table(name = "tbl_customer_data")
#XmlRootElement
public class CustomerData implements Serializable {
private static final long serialVersionUID = 1L;
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
#Basic(optional = false)
#Column(name = "id")
private Integer id;
#Basic(optional = false)
#NotNull
#Column(name = "rewards_points")
private int rewardsPoints;
public CustomerData(Integer id, int rewardsPoints) {
this.id = id;
this.rewardsPoints = rewardsPoints;
}
public Integer getId() {
return id;
}
public void setId(Integer id) {
this.id = id;
}
public int getRewardsPoints() {
return rewardsPoints;
}
public void setRewardsPoints(int rewardsPoints) {
this.rewardsPoints = rewardsPoints;
}
}
When I try to access the URI:
http://localhost:8080/CustomerPortal/ws/customers/addPoints/1/5
to add 5 points to user with id 1 i get an HTTP 500 error and in the glassfish logs it says
[2013-11-05T03:28:11.733-0500] [glassfish 4.0] [WARNING] [ejb.system_exception] [javax.enterprise.system.container.ejb.com.sun.ejb.containers] [tid: _ThreadID=21 _ThreadName=http-listener-1(3)] [timeMillis: 1383640091733] [levelValue: 900] [[
EJB5184:A system exception occurred during an invocation on EJB CustomerDataFacadeREST, method: public java.lang.String com.webservice.entities.CustomerDataFacadeREST.addPoints(java.lang.Integer,int)]]
[2013-11-05T03:28:11.741-0500] [glassfish 4.0] [WARNING] [] [javax.enterprise.web] [tid: _ThreadID=21 _ThreadName=http-listener-1(3)] [timeMillis: 1383640091741] [levelValue: 900] [[
StandardWrapperValve[com.webservice.entities.ApplicationConfig]: Servlet.service() for servlet com.webservice.entities.ApplicationConfig threw exception
javax.validation.ConstraintViolationException: Bean Validation constraint(s) violated while executing Automatic Bean Validation on callback event:'preUpdate'. Please refer to embedded ConstraintViolations for details.
Any resources, insight or information regarding this issue would be extremely helpful.
The exception has little to do with web services: it has to do with Bean Validation instead.
In this case, since the Validation fails inside method addPoints (look at the stack trace) the only line that can cause it is when persisting or editing an Entity of type CustomerData. The only constraint you have in that class is that rewardsPoints should not be null. So, that's the cause of the exception.
However there some things that won't work in addPoints method:
You should check that find() method doesn't return a null object.
customer.getRewardsPoints(customer.getRewardsPoints() + amount) never sets the property (does it compile?)
EntityManager.persist() throws exception if the entity already exists. You probably want to remove that line if you only want to edit (update) the entity.
Note: I am not sure that the code you have posted is really compiling and causing that exception. That's probably caused by another version.

Why is AutoFixture Customization causing inherited properties to not be filled?

I wrote the following customization and have it applied as part of a composite on most of my tests. My entities have a read-only Id, but I'm using their SetId method in this customization to make sure all entities have some Id if they are transient (don't have an Id already).
public class SetEntityIdCustomization : ICustomization {
public void Customize(IFixture fixture) {
var engine = ((Fixture)fixture).Engine;
fixture.Customizations.Add(new Postprocessor(
engine, o => {
var entity = o as BaseEntity;
if (entity == null || !entity.IsTransient()) {
return;
}
entity.SetId(fixture.CreateAnonymous<Guid>());
}));
}
}
This has been working great, until I discovered a very odd thing today. If I feed a test one of my entities that directly inherits from BaseEntity, all is well and it's writeable properties are auto-filled. However, if I ask for an entity that inherits from something further down from BaseEntity, my customization prevents the properties from auto-filling.
The User entity in this test method is filled properly:
public class User : BaseEntity {
public string Email { get; set; }
public int CoolThings { get; set; }
}
...
[Theory, AutoDomainData]
public void SomeTest(User user, ...) {
// user.Email and user.CoolThings have auto-filled values, as expected.
...
}
However, the AwesomeUser entity in the following test does not get any of the same properties auto-filled.
public class AwesomeUser : User {
...
}
...
[Theory, AutoDomainData]
public void SomeOtherTest(AwesomeUser user, ...) {
// user.Email nor user.CoolThings have auto-filled values. What gives?
...
}
In both test cases, the Id property is auto-filled because of my customization. If I remove my customization, the SomeOtherTest's AwesomeUser instance gets its inherited properties auto-filled just fine. I must assume that my customization is what is messing things up.
Is there a better way to get all my BaseEntity instances to set their Id, or is there something else I'm missing with AutoFixture? I've applied my customization first, in the middle, and last, to no avail.
The solution provided above is a pretty clever attempt, but not something I've seen before. A more idiomatic solution would be something like this:
public void Customize(IFixture fixture)
{
fixture.Customizations.Add(
new FilteringSpecimenBuilder(
new Postprocessor(
new BaseEntityBuilder(
new ConstructorInvoker(
new ModestConstructorQuery())),
new AutoPropertiesCommand().Execute),
new BaseEntitySpecification()));
}
private class BaseEntityBuilder : ISpecimenBuilder
{
private readonly ISpecimenBuilder builder;
private readonly IRequestSpecification specification;
public BaseEntityBuilder(ISpecimenBuilder builder)
{
this.builder = builder;
this.specification = new BaseEntitySpecification();
}
public object Create(object request, ISpecimenContext context)
{
if (!this.specification.IsSatisfiedBy(request))
return new NoSpecimen(request);
var b = (BaseEntity)this.builder.Create(request, context);
b.SetId((Guid)context.Resolve(typeof(Guid)));
return b;
}
}
private class BaseEntitySpecification : IRequestSpecification
{
public bool IsSatisfiedBy(object request)
{
var t = request as Type;
if (t == null)
return false;
if (!typeof(BaseEntity).IsAssignableFrom(t))
return false;
return true;
}
}
As you can see, this isn't a simple one-liner, which is indicative of AutoFixture being a rather opinionated library. In this case, AutoFixture's opinion is:
Favor object composition over class inheritance.
-Design Patterns, p. 20
AutoFixture is first and foremost a TDD tool, and one of the main advantages of TDD is that it provides feedback about class design. In this case, the feedback is: Inheritance is awkward and troublesome. Reconsider the design.

How to make AfterBeanDiscovery get triggered in JUnit

I have the following four classes: DataConsumer, DataProducer, SomeQualifier, a META-INF/beans.xml and a test. The class files are coded as follows:
public class DataConsumer {
private boolean loaded = false;
#Inject
#SomeQualifier
private String someString;
public void afterBeanDiscovery(
#Observes final AfterBeanDiscovery afterBeanDiscovery,
final BeanManager manager) {
loaded = true;
}
public boolean getLoaded() {
return loaded;
}
public String sayHello() {
return someString;
}
}
public class DataProducer {
#Produces
#SomeQualifier
private final String sample = "sample";
}
public #interface SomeQualifier {
}
The unit test looks like this.
public class WeldTest {
#Test
public void testHelloWorld() {
final WeldContainer weld = new Weld().initialize();
final DataConsumer consumer = weld.instance()
.select(DataConsumer.class).get();
Assert.assertEquals("sample", consumer.sayHello());
Assert.assertTrue(consumer.getLoaded());
}
}
However, it is failing on the assertTrue with getLoaded() it appears that the #Observes does not get fired.
Take a look at arquillian: www.arquillian.org. It'll take care of all of this for you.
I found a similar question that had answered my question
CDI - Observing Container Events
Although I am unable to use DataConsumer as both an Extension and a CDI managed bean. So it needs a third class just to be the Extension. However, because Extension have no access to managed beans since they are not created yet, I conclude that is no possible solution to use an #Observes AfterBeanDiscovery to modify the bean data. Even the BeanManager that gets passed in cannot find any of the beans.

Error when using Code First in web service "System.Data.ProviderIncompatibleException: The provider did not return a ProviderManifestToken string."

I'm using Code First. Everything works just fine (inserts, updates, selects) everything is tested. The problem comes when I try to use the web services. I get the error "System.Data.ProviderIncompatibleException: The provider did not return a ProviderManifestToken string.". Looking at the inner exception I get this message "Could not determine storage version; a valid storage connection or a version hint is required.".
The web service Code:
/// <summary>
/// Summary description for UserServices
/// </summary>
[WebService(Namespace = "http://localhost:3955/WebServices/UserServices")]
//[WebServiceBinding(ConformsTo = WsiProfiles.BasicProfile1_1)]
//[System.ComponentModel.ToolboxItem(false)]
// To allow this Web Service to be called from script, using ASP.NET AJAX, uncomment the following line.
[System.Web.Script.Services.ScriptService]
public class UserServices : System.Web.Services.WebService
{
[WebMethod]
public bool LoginControlPanelUser(string user, string password)
{
if(Membership.ValidateUser(user, password))
{
return DbUsersDAO.HasAuthenticationType(user, password);
}
return false;
}
}
The DAO code:
public static bool HasAuthenticationType(string user, string authenticationTypeCode)
{
try
{
using (VirtusCloudCoreContext ctx = new VirtusCloudCoreContext())
{
DBUser User = ctx.DBUsers.SingleOrDefault(u => u.Login.Equals(user) && u.Active.Equals(true));
if (User != null)
{
return DBAuthenticationTypesDAO.GetById(User.DBAuthenticationTypeId).Name.Equals("Admin");
}
}
return false;
}
catch (Exception ex)
{
ErrorsHelper.InsertError(ex);
throw ex;
}
}
The Context class:
public VirtusCloudCoreContext()
{
Database.SetInitializer<VirtusCloudCoreContext>(new VirtusCloudCoreContextInitializer());
this.Database.Connection.ConnectionString = "Data Source=localhost\SQLEXPRESS;Database=DatabaseName;User Id=******;Password=*******;" ;
}
I get the exception when I try to get the user.... Any ideas?
This error occurs often when the connection string is wrong but I think in your case it's because you're trying to manually set the connection string.
Try making your context inherit from DbContext and take a connection string in your constructor which it passes through to the base constructor, like this:
public class VirtualCloudCoreContext : DbContext {
public VirtualCloudCoreContext(string connectionString)
: base (connectionString) {
}
}
I'm using a new DB-generated EDMX in VS2012 Web Project with a separate class file - both projects have EF 6.1.1 installed. Even though I'm using SQL 2012, I had to edit the EDMX file directly and change it to ProviderManifestToken="2008" from 2012.
Not sure if related to Telerik Grid/EntityDataSource or not. More mention of this issue here but related to VS2013.