I'm using Jersey 1.17 on the server side to process REST requests and JAXB 2 to unmarshall the XML request content.
Context
This is the Jersey method I use. The MyDTO class uses the #XmlRootElement annotation (otherwise, I'd need to define the parameter with the JAXBElement type).
#Path("/myService")
#POST
#Consumes(MediaType.APPLICATION_XML)
public void myService(MyDTO dto) throws Exception
{
// Shouldn't get this far if the XML content in the request was invalid
System.out.println(dto);
}
Requirement
By default, the Sun/Oracle JAXB implementation doesn't throw exceptions when the XML content has errors. For example providing a string value, say ABC, for an Integer attribute simply leaves the value as null instead of throwing an exception.
In JAXB 2 a ValidationEvenHandler can be defined. Using the following handler handler, makes the XML unmarshalling throw an exception the way I need it to.
public class UnmarshallerValidationEventHandler implements ValidationEventHandler {
#Override
public boolean handleEvent(ValidationEvent event) {
// This indicates JAXB that it should continue processing only if the
// severity level is less than error. NOTE: validation event constants
// go in ascending order in level of severity(i.e., 0 WARNING, 1: ERROR, 2 :FATAL_ERROR)
return event.getSeverity() < ValidationEvent.ERROR;
}
}
Question
How can I get Jersey to use a particular JAXBContext instance in order to use an unmarshaller with my custom validation event handler?
Alternatively, given that my application only uses JAXB in Jersey methods, defining a particular JAXBContext globally for the the JVM instance would be a good option. How could that be done?
Jersey Users Guide covers this in Using custom JAXBContext chapter. Basically you need to provide ContextResolver<T> like:
#Provider
public class PlanetJAXBContextProvider implements ContextResolver<JAXBContext> {
private JAXBContext context = null;
public JAXBContext getContext(Class<?> type) {
if(type != Planet.class)
return null; // we don't support nothing else than Planet
if(context == null) {
try {
context = JAXBContext.newInstance(Planet.class);
} catch (JAXBException e) {
// log warning/error; null will be returned which indicates that this
// provider won't/can't be used.
}
}
return context;
}
}
You can see a sample use in storage-service sample project (see JAXBContextResolver).
Note: Instead of ContextResolver<JAXBContext> you can also provide ContextResolver<Marshaller> or/and ContextResolver<Unmarshaller>.
Related
I have a Jersey endpoint which uses a custom OSGi Service ExceptionManager Service.
#Path("service")
public class ServiceFacade {
private volatile ExceptionManager exceptionManager;
public ServiceFacade() {
BundleContext bC = FrameworkUtil.getBundle(ServiceFacade.class).getBundleContext();
ServiceReference<ExceptionManager> sR = bC.getServiceReference(ExceptionManager.class);
if (sR != null)
this.exceptionManager = bC.getService(sR);
}
#GET
#Consumes({MediaType.APPLICATION_JSON})
#Produces(MediaType.APPLICATION_JSON)
public Response sayHello() {
try {
if (exceptionManager == null)
return Response.status(Status.SERVICE_UNAVAILABLE).build();
// Do some work...
} catch (Exception e) {
exceptionManager.handle(e);
}
}
}
This Jersey class is added to the Jersey Application as a simple class, that means that every time a user hits this endpoint, a new instance of this class is created to handle the request. As you can see, the class contains a constructor which initializes the ExceptionManager Service. My question is, isn't there a simplified way of retrieving the service without going to BundleContext?
I have seen DependencyManager, but this bundle seems to only add the dependencies to the class (ServiceFacade in this case) during the Activation process, but that dependency resolution is too early this has to be done during run-time, every time an instance is created. Bellow is an approximation with DependencyManager but is not a solution for this:
public class Activator extends DependencyActivatorBase {
#Override
public void init(BundleContext bundleContext, DependencyManager dependencyManager) throws Exception {
dependencyManager.add(createComponent()
.setImplementation(ServiceFacade.class)
.add(createServiceDependency()
.setService(ExceptionManager.class)
.setRequired(true));
}
}
Thanks.-
You can obtain the reference to an OSGi service without accessing to BundleContext by using Declarative Services. A tutorial can be found here.
You can make the endpoint a singleton resource. This way you can let the dependency manager create a single instance and inject services and then add that instance to the Jersey application.
There are a few limitations, like Jersey's field or constructor injection does not work. You also have to be careful about concurrency when using fields of the resource.
So I want to change the validation messages used to validate a model through a DropWizard resource.
I'm using java bean validation annotations. For example here is one of the fields I want to validate:
#NotEmpty(message = "Password must not be empty.")
I can test this works as expected using a validator.
However when I use DropWizard to do the validation on the resource it adds some extra stuff to that message. What I see is this - password Password must not be empty. (was null) and I've found the code that does this here - https://github.com/dropwizard/dropwizard/blob/master/dropwizard-validation/src/main/java/io/dropwizard/validation/ConstraintViolations.java
Specifically this method -
public static <T> String format(ConstraintViolation<T> v) {
if (v.getConstraintDescriptor().getAnnotation() instanceof ValidationMethod) {
final ImmutableList<Path.Node> nodes = ImmutableList.copyOf(v.getPropertyPath());
final ImmutableList<Path.Node> usefulNodes = nodes.subList(0, nodes.size() - 1);
final String msg = v.getMessage().startsWith(".") ? "%s%s" : "%s %s";
return String.format(msg,
Joiner.on('.').join(usefulNodes),
v.getMessage()).trim();
} else {
return String.format("%s %s (was %s)",
v.getPropertyPath(),
v.getMessage(),
v.getInvalidValue());
}
}
Is there any way I can override this behaviour? I just want to display the message that I set in the annotation...
Here is a programmatic solution in dropwizard 0.8:
public void run(final MyConfiguration config, final Environment env) {
AbstractServerFactory sf = (AbstractServerFactory) config.getServerFactory();
// disable all default exception mappers
sf.setRegisterDefaultExceptionMappers(false);
// register your own ConstraintViolationException mapper
env.jersey().register(MyConstraintViolationExceptionMapper.class)
// restore other default exception mappers
env.jersey().register(new LoggingExceptionMapper<Throwable>() {});
env.jersey().register(new JsonProcessingExceptionMapper());
env.jersey().register(new EarlyEofExceptionMapper());
}
I think it's more reliable than a config file. And as you can see it also enables back all other default exception mappers.
ConstraintViolationExceptionMapper is the one which uses that method. In order to override it, you need to deregister it and register your own ExceptionMapper.
Remove the exception mapper(s)
Dropwizard 0.8
Add the following to your yaml file. Note that it will remove all the default exception mappers that dropwizard adds.
server:
registerDefaultExceptionMappers: false
Dropwizard 0.7.x
environment.jersey().getResourceConfig().getSingletons().removeIf(singleton -> singleton instanceof ConstraintViolationExceptionMapper);
Create and add your own exception mapper
public class ConstraintViolationExceptionMapper implements ExceptionMapper<ConstraintViolationException> {
#Override
public Response toResponse(ConstraintViolationException exception) {
// get the violation errors and return the response you want.
}
}
and add your exception mapper in your application class.
public void run(T configuration, Environment environment) throws Exception {
environment.jersey().register(ConstraintViolationExceptionMapper.class);
}
#ValidationMethod should be useful here. isn't it?
http://www.dropwizard.io/0.9.0/docs/manual/validation.html
#ValidationMethod(message="Password cannot be empty")
#JsonIgnore
public boolean isPasswordProvided() {
return false if password not provided;
}
I am using JAX-RS 2.0 with Jersey 2.6. I was wondering if it was possible to have something like this:
#GET
#Path("/get/{id}")
#MapTo(type = MyObjectDTO.class)
public MyObject getMyObject(#PathParam("id") String id){
MyObject o = ...
return o;
}
In the method above I am returning an instance of MyObject. However, I have defined the MapTo annotation to indicate that I want to map this object to MyObjectDTO. The way I was thinking this could work is to process the response early in a ContainerResponseFilter, detect the annotation MapTo and, assuming no error occurred, replace the entity in the response with an instance of MyObjectDTO created appropriately from the existing entity (of type MyObject).
However, I couldn't find a way to get the Method in the resource that was just called after the request came in, i.e., the getMyObject method, so that I can scan for the MapTo annotation.
Is there a way to achieve this in a JAX-RS-y kind of way?
Is this some serious reason you cannot return dto object? Sounds very strange...You can probably use AOP but I guess it would be bad practive
Here the Spring AOP example
http://docs.spring.io/spring/docs/2.5.4/reference/aop.html
I think I found a solution by reading this SO. I created a class that looks like this:
#Provider // or register in the configuration...
public class DTOMapperFeature implements DynamicFeature {
#Override
public void configure(ResourceInfo resourceInfo, FeatureContext context) {
for (Annotation annotation : resourceInfo.getResourceMethod().getAnnotations()) {
if (annotation instanceof MapTo) {
MapTo mapTo = (MapTo) annotation;
// Note: additional validation (return type shouldn't be void,
// collections are out etc.) is required before creating this,
// or should be pushed in the DTOMapperFilter.
// You get the gist: this filter will map the entity to an instance
// of the specified class (using a constructor in this case).
context.register(new DTOMapperFilter(
resourceInfo.getResourceMethod().getReturnType(),
mapTo.getResponseType());
}
}
}
#Priority(/* appropriate priority here! */)
public final static class DTOMapperFilter implements ContainerResponseFilter {
public DTOMapperFilter(Class<?> declaredReturnType, Class<?> responseType) {
// implementation omitted: find DTO constructor etc.
// throw if responseType does NOT have a constructor that takes an instance
// of declaredReturnType: catch errors at application bootstrap!
}
#Override
public void filter(
ContainerRequestContext requestContext,
ContainerResponseContext responseContext) throws IOException {
// implementation omitted: create instance of DTO class using constructor
}
}
}
Given sensible exceptions will be thrown from either the constructor of DTOMapperFilter or the configure method above, this should be pretty robust and errors detectable at test time.
I am developing a Client-Server app with JAX-RS / Apache CXF, JSON
I would like Apache CXF to handle my exception transparently on both ends : Which means transforming the exception into a bean, serializing it with my Jackson Serializer (JSON) and then doing the over way around on client side.
I have seen several confusing posts/answers on this subject and came up with using the #WebFault annotation :
#WebFault(name=CODE, faultBean="foo.bar.FaultBean")
public class DuplicateRuleNameFault extends Exception {
static final public String CODE = "DUPLICATE_RULE_NAME";
private FaultBean faultBean;
public DuplicateRuleNameFault(String msg) {
super(msg);
this.faultBean = new FaultBean(msg);
}
public DuplicateRuleNameFault() {
}
public FaultBean getFaultBean() {
return faultBean;
}
public void setFaultBean(FaultBean faultBean) {
this.faultBean = faultBean;
}
}
With no success ... Currently, CXF seems to happily ignore the annotation on the Exception and handle it as an unknown exception : 500 status error and no response body generated on the server side.
Is there something specific I have to configure in the "" server element of my Spring context ? I already have Spring scanning my Exception/FaultBean classes (is it even needed BTW ?).
I would appreciate if you could point me at some working example.
Thanks.
#WebFault's are not part of the JAX-RS specification. You will want to read up on section 3.3.4 of the specification, which describes the different ways you can accomplish what you are trying to do.
Option 1
Design your resource classes to throw WebApplicationException's. Set the response property of these exceptions to be a valid JAX-RS response containing the fault beans you want to send to the client.
Option 2
Define exception mapping providers. You can create a hierarchy of these to handle all the common exceptions your application will throw. Or you can create a top level exception with an embedded bean and an exception handler for it. And then derive several specific exceptions from the top level one.
public abstract class MyApplicationException<T> extends Exception {
private T faultBean;
// Constructors, setters/getters
}
#Provider
public class MyApplicationExceptionHandler implements ExceptionMapper<MyApplicationException<?>> {
// Implementation
}
One way of doing this is by using the javax.ws.rs.core.Response object like so :
#GET
#Path("/")
public Response getBlah()
{
try {
return Response.status(Response.Status.OK)
.entity(<Object you want to return>).build();
}
catch (final DuplicateRuleNameFault e) {
return Response.status(Response.Status.BAD_REQUEST)
.entity(e.getFaultBean().getMsg()).build();
}
}
I'm using the Metro stack bundled with Java 6 SE to call a web service. The web service expects XML as a parameter. I use JAXB classes to create content and pass my JAXB root element to the web service endpoint.
Now to my Problem: I can't find any way to make the marshaller include the schemaLocation of the XSD file since I can't directly access the marshaller. (If you have direct access to the marshaller it is possible do set the schemalocation as a property, but when using metro, all the marshalling seems to be happening internally.)
I've tried setting the xsi:schemaLocation in the XmlSchema annotation in the generated package-info.java class, but this had no effect on the xml generated.
Another point is that when creating a web service client and calling a web service in an Java SE environment, certain annotations like #UsesJAXBContext, #WebServiceClient and #XmlSchema seem to be ignored. (I must state here that I am a beginner in terms of Java web services)
Ok, here's what I now know. This has been a problem for me for months.
First, you have to change the JAXBContext used by JAX-WS. To do this use the #UsesJAXBContext annotation on the server. (com.sun.xml.ws.developer.UsesJAXBContext)
Then, in your factory implementation, you have to return custom Bridges in this method.
public Bridge createBridge(final TypeReference typereference)
Then your custom bridge needs to set the marshaller property to set the namespace mapper you want to use.
Here's my example.
#WebService(serviceName = ...)
#UsesJAXBContext(MyContextFactory.class)
public class SoapServer { ... }
and the factory class ...
public static class MyContextFactory implements JAXBContextFactory
{
#Override
public JAXBRIContext createJAXBContext(final SEIModel sei,
#SuppressWarnings("rawtypes") final List<Class> classesToBind, final List<TypeReference> typeReferences)
throws JAXBException
{
JAXBRIContext context = JAXBContextFactory.DEFAULT.createJAXBContext(sei, classesToBind, typeReferences);
return new MyJaxwsContext(context);
}
}
and the JAXB Context impelementation...
public class MyContext extends JAXBRIContext
{
/** the actual context */
private final JAXBRIContext delegate;
public MyContext(final JAXBRIContext createContext)
{
this.delegate = createContext;
}
public Bridge createBridge(final TypeReference arg0)
{
return new MyBridge((JAXBContextImpl) delegate, delegate.createBridge(arg0));
}
and now the Bridge implementation...
public class MyBridge extends Bridge
{
private final Bridge delegate;
protected MyBridge(final JAXBContextImpl context, final Bridge delegate)
{
super(context);
this.delegate = delegate;
}
// an example marshal call. There are many more...
public void marshal(final Marshaller m, final Object object, final ContentHandler contentHandler)
throws JAXBException
{
m.setProperty("com.sun.xml.bind.namespacePrefixMapper", namespaceMapper);
delegate.marshal(m, object, contentHandler);
}
NOTE: I have just wrapped the existing implementation. All I wanted was to be able to fix the namespace names. From my reading of the source (JAXWS), this is the only way to get to the marshaller.
NOTE2 There is a downcast to an RI final class. This only works with the reference implementation. YMMV