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How to create a collection of objects in SpringBoot without having the database?

I am new to SpringBoot. I don't know how to create a few objects of the same type in the way that enables to use this objects later for example in the controller.
Let's say I would like to create collection/list of objects (let's say collection of Rabbits) when the application starts:
#SpringBootApplication
public class Application {
public static void main(String[] args) {
SpringApplication.run(Application.class, args);
// I would like to create here a collection
// or a list of objects (let's say collection of Rabbits)
}
}
I would like to have the possibility to use this objects later in the controller to get some information (obtained for example by index in the list).
What is the right way to keep state of my model without having a database?

Ignoring synchronization issues.
You can create a List and inject into your controllers.
or what I like to do is wrap that in a repository. This insulates you from the underlying datasource and it can be changed later.
Note that synchronization is important for this type of data structure as you can have many threads updating the repository.
package com.example.demo;
import java.util.ArrayList;
import java.util.Collections;
import java.util.List;
import java.util.Optional;
import java.util.concurrent.atomic.AtomicInteger;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.context.annotation.Bean;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;
#SpringBootApplication
public class Demo1Application {
public static void main(String[] args) {
SpringApplication.run(Demo1Application.class, args);
}
#Bean
public RabbitRepository rabbitRepository() {
RabbitRepository rabbitRepository = new RabbitRepository();
rabbitRepository.add("Bugs");
rabbitRepository.add("Flopsy");
return rabbitRepository;
}
public static class RabbitRepository {
private List<Rabbit> rabbits = Collections.synchronizedList(new ArrayList<Rabbit>());
public List<Rabbit> getAll() {
return rabbits;
}
public Rabbit add(String rabbitName) {
Rabbit rabbit = new Rabbit(rabbitName);
this.rabbits.add(rabbit);
return rabbit;
}
public Optional<Rabbit> findById(int id) {
return this.rabbits.stream().filter(r-> r.getId() == id).findFirst();
}
}
public static class Rabbit {
private final String name;
private final int id;
private static AtomicInteger counter = new AtomicInteger();
public Rabbit(String name) {
super();
this.name = name;
this.id = counter.incrementAndGet();
}
public String getName() {
return name;
}
public int getId() {
return this.id;
}
}
#RestController
#RequestMapping("/rabbits")
public static class RabbitController {
private final RabbitRepository repository;
public RabbitController(final RabbitRepository repository) {
this.repository = repository;
}
#GetMapping
public List<Rabbit> getAll() {
return repository.getAll();
}
#PostMapping("/{name}")
//You can also use requestparam / requestbody and probably should
public Rabbit addRabbit(#PathVariable("name") String name) {
return repository.add(name);
}
#GetMapping("/id/{id}")
public Optional<Rabbit> findById(#PathVariable("id") int id) {
return repository.findById(id);
}
}
}
Curl tests
➜ ~ curl localhost:8080/rabbits
[{"name":"Bugs","id":1},{"name":"Flopsy","id":2}]%
➜ ~ curl localhost:8080/rabbits/id/2
{"name":"Flopsy","id":2}%
➜ ~ curl -XPOST localhost:8080/rabbits/Babs
{"name":"Babs","id":3}%
➜ ~ curl localhost:8080/rabbits
[{"name":"Bugs","id":1},{"name":"Flopsy","id":2},{"name":"Babs","id":3}]%

Using spring you need to create objects in the context of spring, otherwise spring created instances can't find them. A solution can be putting them in a class annotated with #Configuration and retrieve them with the annotation #Autowired.
The annotation #Configuration:
Indicates that a class declares one or more #Bean methods and may be processed by the Spring container to generate bean definitions and service requests for those beans at runtime.
You can use it as follow:
#Configuration
public class MyConfiguration {
#Bean
public MyClass getMyClass() {
MyClass myClass = ...
...
return myClass;
}
}
#Controller
public class MyController {
#Autowired
private MyClass myClass;
public void method() {
// Use myClass instance as you like
}
}
You can also generate a standard java.util.List, but in this case is better to give a name to the bean generated, for example:
#Configuration
public class MyConfiguration {
#Bean("myname") // To give an explicit name to the List
public List getMyList() {
List myList = ...
...
return myList;
}
}
#Controller
public class MyController {
#Autowired
#Qualifier("myname") // To retrieve a List with a specific name
private List myList;
public void method() {
// Use myList instance as you like
}
}

You need something like this i guess !
#Component
public class RabbitListHolder {
private List<Rabbit> rabbits = new ArrayList<Rabbit>
public void initializeList(){
rabbits.add(new Rabbit('white', 3));
...
}
}
#Controller
public class RabbitsRessource{
#Autowired
RabbitListHolder rabbitListHolder;
...
#GetMapping("/rabbits")
public List<Rabbits> getRabbits(){
rabbitListHolder.initializeList();
return rabbitListHolder.getRabbits();
}
}

Jersey HK2 Dependency Injection

I'm writing a simple microservices that exposes REST API. So I started working with Jersey and of course I need to Inject my object into jersey resources. Basically I have 2 classes that defines a set of resources and some of them need to use another service.
So basically I have:
public interface MyService {
String getServiceName();
void doService();
}
2 implementations of this interface (MyServiceBean and MyAlternativeServiceBean)
and, as far as I understood reading jersey docs, I defined an hk2 Binder:
public class MyBinder implements Binder{
#Override
public void bind(DynamicConfiguration config) {
DescriptorImpl descriptor = BuilderHelper.link(MyServiceBean.class).named("MyServiceBean").to(MyService.class).build();
config.bind(descriptor);
config.bind(BuilderHelper.link(MyAlternativeServiceBean.class).named("MyAlternativeServiceBean").to(MyService.class).build());
}
I registered this binder to the ApplicationConfig class
public class ApplicationConfig extends ResourceConfig{
public ApplicationConfig(){
property("property.value", "MyAlternativeServiceImplementation");
registerInstances(new MyBinder());
}
}
And annotated properly into the resources
#Path("first")
public class First {
#Inject #Named(value = "MyServiceBean")
private MyService myService;
//...
}
#Path("second")
public class Second {
#Inject #Named(value = "MyAlternativeServiceBean")
private MyService myService;
//...
}
All works until MyService implementation have no args constructor. But in 1 case I need to provide a dependency also to MyAlternativeServiceBean.
Here is the constructor
#Inject #Named("property.value")
public MyAlternativeServiceBean(String property){
this.property = property;
}
But I get an exception:
javax.servlet.ServletException: A MultiException has 5 exceptions. They are:|1. org.glassfish.hk2.api.UnsatisfiedDependencyException: There was no object available for injection at Injectee(requiredType=String,parent=MyAlternativeServiceBean,qualifiers={}),position=0,optional=false,self=false,unqualified=null,2080509613)|2. java.lang.IllegalArgumentException: While attempting to resolve the dependencies of com.hpe.services.MyAlternativeServiceBean errors were found|3. java.lang.IllegalStateException: Unable to perform operation: resolve on com.hpe.services.MyAlternativeServiceBean|4. java.lang.IllegalArgumentException: While attempting to resolve the dependencies of com.hpe.tests.SecondEntryPoint errors were found|5. java.lang.IllegalStateException: Unable to perform operation: resolve on com.hpe.tests.SecondEntryPoint|
at org.glassfish.jersey.servlet.WebComponent.service(WebComponent.java:392)
at org.glassfish.jersey.servlet.ServletContainer.service(ServletContainer.java:381)
at org.glassfish.jersey.servlet.ServletContainer.service(ServletContainer.java:344)
at org.glassfish.jersey.servlet.ServletContainer.service(ServletContainer.java:219)
at org.eclipse.jetty.servlet.ServletHolder.handle(ServletHolder.java:684)
at org.eclipse.jetty.servlet.ServletHandler.doHandle(ServletHandler.java:501)
at org.eclipse.jetty.server.session.SessionHandler.doHandle(SessionHandler.java:229)
at org.eclipse.jetty.server.handler.ContextHandler.doHandle(ContextHandler.java:1086)
at org.eclipse.jetty.servlet.ServletHandler.doScope(ServletHandler.java:427)
at org.eclipse.jetty.server.session.SessionHandler.doScope(SessionHandler.java:193)
at org.eclipse.jetty.server.handler.ContextHandler.doScope(ContextHandler.java:1020)
at org.eclipse.jetty.server.handler.ScopedHandler.handle(ScopedHandler.java:135)
at org.eclipse.jetty.server.handler.HandlerWrapper.handle(HandlerWrapper.java:116)
at org.eclipse.jetty.server.Server.handle(Server.java:370)
at org.eclipse.jetty.server.AbstractHttpConnection.handleRequest(AbstractHttpConnection.java:494)
at org.eclipse.jetty.server.AbstractHttpConnection.headerComplete(AbstractHttpConnection.java:973)
at org.eclipse.jetty.server.AbstractHttpConnection$RequestHandler.headerComplete(AbstractHttpConnection.java:1035)
at org.eclipse.jetty.http.HttpParser.parseNext(HttpParser.java:641)
at org.eclipse.jetty.http.HttpParser.parseAvailable(HttpParser.java:231)
at org.eclipse.jetty.server.AsyncHttpConnection.handle(AsyncHttpConnection.java:82)
at org.eclipse.jetty.io.nio.SelectChannelEndPoint.handle(SelectChannelEndPoint.java:696)
at org.eclipse.jetty.io.nio.SelectChannelEndPoint$1.run(SelectChannelEndPoint.java:53)
at org.eclipse.jetty.util.thread.QueuedThreadPool.runJob(QueuedThreadPool.java:608)
at org.eclipse.jetty.util.thread.QueuedThreadPool$3.run(QueuedThreadPool.java:543)
at java.lang.Thread.run(Thread.java:745)
Basically I don't konw how to inject properties/constants (that I can read from a configuration file for instance) in hk2
Thanks
Regards

What you can do is create a custom annotation
#Target({ElementType.FIELD, ElementType.PARAMETER})
#Retention(RetentionPolicy.RUNTIME)
public #interface Config {
String value();
}
Then create an InjectionResolver for it (which allows for injection using custom annotations)
public static class ConfigInjectionResolver implements InjectionResolver<Config> {
private static final Map<String, String> properties = new HashMap<>();
public ConfigInjectionResolver() {
properties.put("greeting.message", "Hello World");
}
#Override
public Object resolve(Injectee injectee, ServiceHandle<?> handle) {
if (String.class == injectee.getRequiredType()) {
AnnotatedElement elem = injectee.getParent();
if (elem instanceof Constructor) {
Constructor ctor = (Constructor) elem;
Config config = (Config) ctor.getParameterAnnotations()[injectee.getPosition()][0];
return properties.get(config.value());
} else {
Config config = elem.getAnnotation(Config.class);
return properties.get(config.value());
}
}
return null;
}
#Override
public boolean isConstructorParameterIndicator() { return true; }
#Override
public boolean isMethodParameterIndicator() { return false; }
}
This example just uses a Map, but I'm sure you can figure out how to make it use Properties. Once you register the InjectionResolver, you can now just do
public SomeService(#Config("some.property") String property) {}
Here is a complete test case
import org.glassfish.hk2.api.Injectee;
import org.glassfish.hk2.api.InjectionResolver;
import org.glassfish.hk2.api.ServiceHandle;
import org.glassfish.hk2.api.TypeLiteral;
import org.glassfish.hk2.utilities.binding.AbstractBinder;
import org.glassfish.jersey.filter.LoggingFilter;
import org.glassfish.jersey.server.ResourceConfig;
import org.glassfish.jersey.test.JerseyTest;
import org.junit.Test;
import javax.inject.Inject;
import javax.inject.Singleton;
import javax.ws.rs.GET;
import javax.ws.rs.Path;
import javax.ws.rs.core.Response;
import java.lang.annotation.*;
import java.lang.reflect.AnnotatedElement;
import java.lang.reflect.Constructor;
import java.util.HashMap;
import java.util.Map;
import java.util.logging.Logger;
import static org.junit.Assert.*;
/**
* Run like any other JUnit Test. Only one required dependency
*
* <dependency>
* <groupId>org.glassfish.jersey.test-framework.providers</groupId>
* <artifactId>jersey-test-framework-provider-grizzly2</artifactId>
* <version>${jersey2.version}</version>
* </dependency>
*
* #author Paul Samsotha
*/
public class ConfigExample extends JerseyTest {
#Target({ElementType.FIELD, ElementType.PARAMETER})
#Retention(RetentionPolicy.RUNTIME)
public static #interface Config {
String value();
}
public static class ConfigInjectionResolver implements InjectionResolver<Config> {
private static final Map<String, String> properties = new HashMap<>();
public ConfigInjectionResolver() {
properties.put("greeting.message", "Hello World");
}
#Override
public Object resolve(Injectee injectee, ServiceHandle<?> handle) {
if (String.class == injectee.getRequiredType()) {
AnnotatedElement elem = injectee.getParent();
if (elem instanceof Constructor) {
Constructor ctor = (Constructor) elem;
Config config = (Config) ctor.getParameterAnnotations()[injectee.getPosition()][0];
return properties.get(config.value());
} else {
Config config = elem.getAnnotation(Config.class);
return properties.get(config.value());
}
}
return null;
}
#Override
public boolean isConstructorParameterIndicator() { return true; }
#Override
public boolean isMethodParameterIndicator() { return false; }
}
private static interface GreetingService {
String getGreeting();
}
private static class ConfiguredGreetingService implements GreetingService {
private String message;
public ConfiguredGreetingService(#Config("greeting.message") String message) {
this.message = message;
}
#Override
public String getGreeting() {
return this.message;
}
}
#Path("greeting")
public static class GreetingResource {
#Inject
private GreetingService greetingService;
#GET
public String getConfigProp() {
return greetingService.getGreeting();
}
}
#Override
public ResourceConfig configure() {
ResourceConfig config = new ResourceConfig(GreetingResource.class);
config.register(new LoggingFilter(Logger.getAnonymousLogger(), true));
config.register(new AbstractBinder(){
#Override
protected void configure() {
bind(ConfiguredGreetingService.class).to(GreetingService.class).in(Singleton.class);
bind(ConfigInjectionResolver.class)
.to(new TypeLiteral<InjectionResolver<Config>>(){})
.in(Singleton.class);
}
});
return config;
}
#Test
public void should_get_configured_greeting() {
final Response response = target("greeting")
.request().get();
assertEquals("Hello World", response.readEntity(String.class));
}
}

Passing #Context argument to method in class

I have an existing class I'm trying to hook into to get some header parameters to SSO a user into our system. The class is as follows.
import java.util.Map;
import javax.ws.rs.GET;
import javax.ws.rs.Path;
import javax.ws.rs.Produces;
import javax.ws.rs.core.Context;
import javax.ws.rs.core.HttpHeaders;
import javax.ws.rs.core.MediaType;
import org.springframework.stereotype.Component;
#Component
#Path("/http")
public class HttpResource {
#GET
#Path("/getHeaders")
#Produces(MediaType.APPLICATION_JSON)
public Map<String, String> getAllHeaders(#Context HttpHeaders headers) {
Map<String, String> headerList = new HashMap<String, String>();
for (String key : headers.getRequestHeaders().keySet()) {
String value = headers.getRequestHeader(key).get(0);
System.out.println(key + " : " + value);
headerList.put(key, value);
}
return headerList;
}
}
What I'm trying to figure out is how do I call getAllHeaders() with the #Context argument? I've found a ton of examples of the class I have, but nothing that shows how to call it.
I've also tried putting the annotation inside the class instead of as an argument.
#Context
HttpHeaders httpHeaders;
but when I try to access httpHeaders.getAllHeaders() it returns null. I assume because it's not actually created because the javax documents say it will never return null.
I'm trying to call this within my SSOAuthorizationFilter.java, but have also tried accessing it via a controller as well.

Write an Annotation first.
#Retention(RUNTIME)
#Target({ PARAMETER })
#Documented
public #interface SSOAuthorization {}
And then a Resolver for that.
public class SSOAuthorizationResolver {
public static class SSOAuthorizationInjectionResolver extends
ParamInjectionResolver<SSOAuthorization> {
public SSOAuthorizationInjectionResolver() {
super(SSOAuthorizationValueFactoryProvider.class);
}
}
#Singleton
public static class SSOAuthorizationValueFactoryProvider extends
AbstractValueFactoryProvider {
#Context
private HttpHeaders httpHeaders;
#Inject
public SSOAuthorizationValueFactoryProvider(
final MultivaluedParameterExtractorProvider mpep,
final ServiceLocator injector) {
super(mpep, injector, Parameter.Source.UNKNOWN);
}
#Override
protected Factory<?> createValueFactory(final Parameter parameter) {
final Class<?> classType = parameter.getRawType();
if (!Language.class.equals(classType)
|| parameter.getAnnotation(SSOAuthorization.class) == null) {
return null;
}
return new AbstractContainerRequestValueFactory<String>() {
#Override
public String provide() {
// Can use httpHeader to get your header here.
return httpHeader.getHeaderString("SSOAuthorization");
}
};
}
}
// Binder implementation
public static class Binder extends AbstractBinder {
#Override
protected void configure() {
bind(SSOAuthorizationValueFactoryProvider.class).to(
ValueFactoryProvider.class).in(Singleton.class);
bind(SSOAuthorizationInjectionResolver.class).to(
new TypeLiteral<InjectionResolver<SSOAuthorization>>() {
}).in(Singleton.class);
}
}
}
And in the ResourceConfig just register the Resolver
public class MyResourceConfig extends ResourceConfig {
public MyResourceConfig(Class... classes) {
super(classes);
register(new SSOAuthorizationResolver.Binder());
}
}
And finally use it in your controller with the #SSOAuthorization annotation.
#GET
#Path("/get")
#Produces(MediaType.APPLICATION_JSON)
public String someMethod(#SSOAuthorization String auth) {
return auth;
}

Defining spring #EventListener in an abstract super class

I've stared to use spring's #EventListener annotation to create event handlers that handle my non-spring specific events. Initially everything went pretty well. I used a test to verify that I could put the #EventListener annotation on a method of a abstract class and everything worked as expected.
However, once I started adding generics to the mix I started getting NullPointerExceptions from ApplicationListenerMethodAdapter.java:337.
I've created a test case to illustrate the problem. Currently all the test methods fail with the exception:
java.lang.NullPointerException
at java.lang.Class.isAssignableFrom(Native Method)
at org.springframework.context.event.ApplicationListenerMethodAdapter.getResolvableType(ApplicationListenerMethodAdapter.java:337)
at org.springframework.context.event.ApplicationListenerMethodAdapter.resolveArguments(ApplicationListenerMethodAdapter.java:161)
at org.springframework.context.event.ApplicationListenerMethodAdapter.processEvent(ApplicationListenerMethodAdapter.java:142)
at org.springframework.context.event.ApplicationListenerMethodAdapter.onApplicationEvent(ApplicationListenerMethodAdapter.java:106)
at org.springframework.context.event.SimpleApplicationEventMulticaster.invokeListener(SimpleApplicationEventMulticaster.java:163)
at org.springframework.context.event.SimpleApplicationEventMulticaster.multicastEvent(SimpleApplicationEventMulticaster.java:136)
at org.springframework.context.support.AbstractApplicationContext.publishEvent(AbstractApplicationContext.java:381)
at org.springframework.context.support.AbstractApplicationContext.publishEvent(AbstractApplicationContext.java:348)
When I move the #EventListener annotation down to each concrete listener the exception disappears and things behave as expected with the exception of testSendingEventWithGenericsWithExtendedUniquePayload.
Questions
Q1) Is it a valid usage pattern to put #EventListener on a method of a abstract super class? I was hoping to implement common behavior there.
Q2) I read about implementing ResolvableTypeProvider on my event in the spring docs. My understanding was that this would allow me to avoid having to create many concrete subclasses for each payload type. This is what I'm attempting to test in testSendingEventWithGenericsWithExtendedUniquePayload. I'm expecting the event fired in this test to be handled by TestEventWithGenericsExtendedUniquePayloadListener but it's not. Have I misunderstood something here?
Spring: 4.2.4.RELEASE
Java: 1.8.0_65
Thanks for your help
Oliver
Test Code
import org.junit.Test;
import org.junit.runner.RunWith;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.context.ApplicationEventPublisher;
import org.springframework.context.annotation.ComponentScan;
import org.springframework.context.annotation.Configuration;
import org.springframework.context.event.EventListener;
import org.springframework.core.ResolvableType;
import org.springframework.core.ResolvableTypeProvider;
import org.springframework.stereotype.Component;
import org.springframework.test.annotation.DirtiesContext;
import org.springframework.test.context.ContextConfiguration;
import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;
import java.util.Collections;
import java.util.List;
import java.util.UUID;
import static org.springframework.core.ResolvableType.*;
/**
* #author Oliver Henlich
*/
#ContextConfiguration
#RunWith(SpringJUnit4ClassRunner.class)
#DirtiesContext
public class EventListenerTest {
private static final Logger log = LoggerFactory.getLogger(EventListenerTest.class);
#Autowired
protected transient ApplicationEventPublisher applicationEventPublisher;
#Test
public void testSendingEvent1() {
log.info("testSendingEvent1");
// this should go to TestEvent1Listener
applicationEventPublisher.publishEvent(new TestEvent1(new UniquePayload()));
}
#Test
public void testSendingEventWithGenerics() {
log.info("testSendingEventWithGenerics");
// this should go to TestEventWithGenericsListener
applicationEventPublisher.publishEvent(new TestEventWithGenerics<>(new UniquePayload()));
}
#Test
public void testSendingEventWithGenericsWithExtendedUniquePayload() {
log.info("testSendingEventWithGenerics");
// I was expecting this to go to TestEventWithGenericsExtendedUniquePayloadListener
applicationEventPublisher.publishEvent(new TestEventWithGenerics<>(new ExtendedUniquePayload()));
}
#Test
public void testSendingEvent2() {
log.info("testSendingEvent2");
// there is no listener for this one
applicationEventPublisher.publishEvent(new TestEvent2(new UniquePayload()));
}
// LISTENERS --------------------------------------------------------------
interface TestDataEventListener<E extends TestDataEvent> {
#SuppressWarnings("unused")
List<String> handleEvent(E event);
}
abstract static class AbstractTestDataEventListener<E extends TestDataEvent> implements TestDataEventListener<E> {
#Override
#EventListener
public final List<String> handleEvent(E event) {
return onEvent(event);
}
public abstract List<String> onEvent(E event);
}
#Component
static final class TestEvent1Listener extends AbstractTestDataEventListener<TestEvent1> {
#Override
public List<String> onEvent(TestEvent1 event) {
log.info("Listener {} handled {}", this, event);
return Collections.emptyList();
}
}
#Component
static final class TestEventWithGenericsListener extends AbstractTestDataEventListener<TestEventWithGenerics> {
#Override
public List<String> onEvent(TestEventWithGenerics event) {
log.info("Listener {} handled {}", this, event);
return Collections.emptyList();
}
}
#Component
static final class TestEventWithGenericsExtendedUniquePayloadListener extends AbstractTestDataEventListener<TestEventWithGenerics<ExtendedUniquePayload>> {
#Override
public List<String> onEvent(TestEventWithGenerics<ExtendedUniquePayload> event) {
log.info("Listener {} handled {}", this, event);
return Collections.emptyList();
}
}
// EVENTS -----------------------------------------------------------------
interface TestDataEvent<T extends Unique> extends ResolvableTypeProvider {
T load();
}
abstract static class AbstractTestDataEvent<T extends Unique> implements TestDataEvent<T> {
protected final UUID uuid;
private final ResolvableType resolvableType;
public AbstractTestDataEvent(T uniqueObject) {
uuid = uniqueObject.getUuid();
ResolvableType temp = ResolvableType.forClass(getClass());
if (temp.hasGenerics()) {
temp = forClassWithGenerics(getClass(), forInstance(uniqueObject));
}
resolvableType = temp;
log.info("class = {} resolvableType = {}", getClass(), resolvableType);
}
#Override
public ResolvableType getResolvableType() {
return resolvableType;
}
}
static final class TestEvent1 extends AbstractTestDataEvent<UniquePayload> {
public TestEvent1(UniquePayload uniqueObject) {
super(uniqueObject);
}
#Override
public UniquePayload load() {
return new UniquePayload(uuid);
}
}
static final class TestEvent2 extends AbstractTestDataEvent<UniquePayload> {
public TestEvent2(UniquePayload uniqueObject) {
super(uniqueObject);
}
#Override
public UniquePayload load() {
return new UniquePayload(uuid);
}
}
static final class TestEventWithGenerics<T extends UniquePayload> extends AbstractTestDataEvent<T> {
public TestEventWithGenerics(T uniqueObject) {
super(uniqueObject);
}
#Override
public T load() {
return (T) new UniquePayload(uuid);
}
}
static class UniquePayload implements Unique {
private final UUID uuid;
public UniquePayload() {
this(UUID.randomUUID());
}
public UniquePayload(UUID uuid) {
this.uuid = uuid;
}
#Override
public UUID getUuid() {
return uuid;
}
}
static class ExtendedUniquePayload extends UniquePayload {
}
interface Unique {
UUID getUuid();
}
#Configuration
#ComponentScan(basePackageClasses = EventListenerTest.class)
public static class ContextConfiguration {
}
}

Jersey custom method parameter injection with inbuild injection

Hello I am building an application using dropwizard, that is using jersey 2.16 internally as REST API framework.
For the whole application on all resource methods I need some information so to parse that information I defined a custom filter like below
#java.lang.annotation.Target(ElementType.PARAMETER)
#java.lang.annotation.Retention(RetentionPolicy.RUNTIME)
public #interface TenantParam {
}
The tenant factory is defined below
public class TenantFactory implements Factory<Tenant> {
private final HttpServletRequest request;
private final ApiConfiguration apiConfiguration;
#Inject
public TenantFactory(HttpServletRequest request, #Named(ApiConfiguration.NAMED_BINDING) ApiConfiguration apiConfiguration) {
this.request = request;
this.apiConfiguration = apiConfiguration;
}
#Override
public Tenant provide() {
return null;
}
#Override
public void dispose(Tenant tenant) {
}
}
I haven't actually implemented the method but structure is above. There is also a TenantparamResolver
public class TenantParamResolver implements InjectionResolver<TenantParam> {
#Inject
#Named(InjectionResolver.SYSTEM_RESOLVER_NAME)
private InjectionResolver<Inject> systemInjectionResolver;
#Override
public Object resolve(Injectee injectee, ServiceHandle<?> serviceHandle) {
if(Tenant.class == injectee.getRequiredType()) {
return systemInjectionResolver.resolve(injectee, serviceHandle);
}
return null;
}
#Override
public boolean isConstructorParameterIndicator() {
return false;
}
#Override
public boolean isMethodParameterIndicator() {
return true;
}
}
Now in my resource method I am doing like below
#POST
#Timed
public ApiResponse create(User user, #TenantParam Tenant tenant) {
System.out.println("resource method invoked. calling service method");
System.out.println("service class" + this.service.getClass().toString());
//DatabaseResult<User> result = this.service.insert(user, tenant);
//return ApiResponse.buildWithPayload(new Payload<User>().addObjects(result.getResults()));
return null;
}
Here is how I am configuring the application
#Override
public void run(Configuration configuration, Environment environment) throws Exception {
// bind auth and token param annotations
environment.jersey().register(new AbstractBinder() {
#Override
protected void configure() {
bindFactory(TenantFactory.class).to(Tenant.class);
bind(TenantParamResolver.class)
.to(new TypeLiteral<InjectionResolver<TenantParam>>() {})
.in(Singleton.class);
}
});
}
The problem is during application start I am getting below error
WARNING: No injection source found for a parameter of type public void com.proretention.commons.auth.resources.Users.create(com.proretention.commons.api.core.Tenant,com.proretention.commons.auth.model.User) at index 0.
and there is very long stack error stack and description
Below is the declaration signature of user pojo
public class User extends com.company.models.Model {
No annotations on User class. Model is a class that defines only single property id of type long and also no annotations on model class
When I remove the User parameter from above create resource method it works fine and when I removed TenantParam it also works fine. The problem only occurs when I use both User and TenantParam
What I am missing here ? how to resolve this error ?
EDITED
I just tried with two custom method param injection, that is also not working
#POST
#Path("/login")
#Timed
public void validateUser(#AuthParam AuthToken token, #TenantParam Tenant tenant) {
}
What I am missing here ? Is this a restriction in jersey ?

Method parameters are handled a little differently for injection. The component we need to implement for this, is the ValueFactoryProvider. Once you implement that, you also need to bind it in your AbstractBinder.
Jersey has a pattern that it follows for implementing the ValueFactoryProvider. This is the pattern used to handle parameters like #PathParam and #QueryParam. Jersey has a ValueFactoryProvider for each one of those, as well as others.
The pattern is as follows:
Instead of implementing the ValueFactoryProvider directly, we extend AbstractValueFactoryProvider
public static class TenantValueProvider extends AbstractValueFactoryProvider {
#Inject
public TenantValueProvider(MultivaluedParameterExtractorProvider mpep,
ServiceLocator locator) {
super(mpep, locator, Parameter.Source.UNKNOWN);
}
#Override
protected Factory<?> createValueFactory(Parameter parameter) {
if (!parameter.isAnnotationPresent(TenantParam.class)
|| !Tenant.class.equals(parameter.getRawType())) {
return null;
}
return new Factory<Tenant>() {
#Override
public Tenant provide() {
...
}
};
}
In this component, it has a method we need to implement that returns the Factory that provides the method parameter value.
The InjectionResolver is what is used to handle the custom annotation. With this pattern, instead of directly implementing it, as the OP has, we just extend ParamInjectionResolver passing in our AbstractValueFactoryProvider implementation class to super constructor
public static class TenantParamInjectionResolver
extends ParamInjectionResolver<TenantParam> {
public TenantParamInjectionResolver() {
super(TenantValueProvider.class);
}
}
And that's really it. Then just bind the two components
public static class Binder extends AbstractBinder {
#Override
public void configure() {
bind(TenantParamInjectionResolver.class)
.to(new TypeLiteral<InjectionResolver<TenantParam>>(){})
.in(Singleton.class);
bind(TenantValueProvider.class)
.to(ValueFactoryProvider.class)
.in(Singleton.class);
}
}
Below is a complete test using Jersey Test Framework. The required dependencies are listed in the javadoc comments. You can run the test like any other JUnit test
import java.lang.annotation.ElementType;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;
import java.util.logging.Logger;
import javax.inject.Inject;
import javax.inject.Singleton;
import javax.ws.rs.Consumes;
import javax.ws.rs.POST;
import javax.ws.rs.Path;
import javax.ws.rs.Produces;
import javax.ws.rs.client.Entity;
import javax.ws.rs.core.Response;
import org.glassfish.hk2.api.Factory;
import org.glassfish.hk2.api.InjectionResolver;
import org.glassfish.hk2.api.ServiceLocator;
import org.glassfish.hk2.api.TypeLiteral;
import org.glassfish.hk2.utilities.binding.AbstractBinder;
import org.glassfish.jersey.filter.LoggingFilter;
import org.glassfish.jersey.server.ContainerRequest;
import org.glassfish.jersey.server.ResourceConfig;
import org.glassfish.jersey.server.internal.inject.AbstractContainerRequestValueFactory;
import org.glassfish.jersey.server.internal.inject.AbstractValueFactoryProvider;
import org.glassfish.jersey.server.internal.inject.MultivaluedParameterExtractorProvider;
import org.glassfish.jersey.server.internal.inject.ParamInjectionResolver;
import org.glassfish.jersey.server.model.Parameter;
import org.glassfish.jersey.server.spi.internal.ValueFactoryProvider;
import org.glassfish.jersey.test.JerseyTest;
import org.junit.Test;
import static org.junit.Assert.assertEquals;
/**
* Stack Overflow https://stackoverflow.com/q/29145807/2587435
*
* Run this like any other JUnit test. Dependencies required are as the following
*
* <dependency>
* <groupId>org.glassfish.jersey.test-framework.providers</groupId>
* <artifactId>jersey-test-framework-provider-grizzly2</artifactId>
* <version>2.22</version>
* <scope>test</scope>
* </dependency>
* <dependency>
* <groupId>org.glassfish.jersey.media</groupId>
* <artifactId>jersey-media-json-jackson</artifactId>
* <version>2.22</version>
* <scope>test</scope>
* </dependency>
*
* #author Paul Samsotha
*/
public class TenantInjectTest extends JerseyTest {
#Target(ElementType.PARAMETER)
#Retention(RetentionPolicy.RUNTIME)
public static #interface TenantParam {
}
public static class User {
public String name;
}
public static class Tenant {
public String name;
public Tenant(String name) {
this.name = name;
}
}
public static class TenantValueProvider extends AbstractValueFactoryProvider {
#Inject
public TenantValueProvider(MultivaluedParameterExtractorProvider mpep,
ServiceLocator locator) {
super(mpep, locator, Parameter.Source.UNKNOWN);
}
#Override
protected Factory<?> createValueFactory(Parameter parameter) {
if (!parameter.isAnnotationPresent(TenantParam.class)
|| !Tenant.class.equals(parameter.getRawType())) {
return null;
}
return new AbstractContainerRequestValueFactory<Tenant>() {
// You can #Inject things here if needed. Jersey will inject it.
// for example #Context HttpServletRequest
#Override
public Tenant provide() {
final ContainerRequest request = getContainerRequest();
final String name
= request.getUriInfo().getQueryParameters().getFirst("tenent");
return new Tenant(name);
}
};
}
public static class TenantParamInjectionResolver
extends ParamInjectionResolver<TenantParam> {
public TenantParamInjectionResolver() {
super(TenantValueProvider.class);
}
}
public static class Binder extends AbstractBinder {
#Override
public void configure() {
bind(TenantParamInjectionResolver.class)
.to(new TypeLiteral<InjectionResolver<TenantParam>>(){})
.in(Singleton.class);
bind(TenantValueProvider.class)
.to(ValueFactoryProvider.class)
.in(Singleton.class);
}
}
}
#Path("test")
#Produces("text/plain")
#Consumes("application/json")
public static class TestResource {
#POST
public String post(User user, #TenantParam Tenant tenent) {
return user.name + ":" + tenent.name;
}
}
#Override
public ResourceConfig configure() {
return new ResourceConfig(TestResource.class)
.register(new TenantValueProvider.Binder())
.register(new LoggingFilter(Logger.getAnonymousLogger(), true));
}
#Test
public void shouldReturnTenantAndUserName() {
final User user = new User();
user.name = "peeskillet";
final Response response = target("test")
.queryParam("tenent", "testing")
.request()
.post(Entity.json(user));
assertEquals(200, response.getStatus());
assertEquals("peeskillet:testing", response.readEntity(String.class));
}
}
See Also:
Jersey 2.x Custom Injection Annotation With Attributes
My Comment in the Dropwizard issue: "No injection source found for a parameter"