I've implemented the Specification pattern for filtering some of my JpaRepositories. After I have implemented a Specification, I can use it with a JpaRepository like this:
Page<Entity> page = entityJpaRepository.findAll(entitySpecification, pageable)
Is there a feature, or planned feature, for supporting Specifications in ElasticsearchRepository?
I understand your pain however the thing is that Specification interface belongs to the JPA API that currently none of the Elastic Search Spring Data repositories implement and I don't think they will.
If you really want to use them you should rather migrate from ElasticsearchRepository coming from spring-data-elasticsearch into JPA-based repositories.
Did not try to use JPA together with ElasticSearch myself but noticed that some people does it, check out this link:
https://programmertoday.com/spring-boot-elastic-search-with-spring-data-jpa/
I don't know about Specifications, but Spring provides a bean ElasticsearchOperations which has a "search" method which accepts org.springframework.data.elasticsearch.core.query.CriteriaQuery which is similar to standard hibernate Criteria. Try mapping Specification to CriteriaQuery.
#Service
#RequiredArgsConstructor
public class FooService {
private final ElasticsearchOperations elasticsearchTemplate; // autowired bean
public void search() {
Criteria criteria = new Criteria();
criteria.and(new Criteria("foo").is(foo));
criteria.and(new Criteria("bar").in(bars));
CriteriaQuery criteriaQuery = new CriteriaQuery(criteria);
elasticsearchOperations.search(criteriaQuery,
FooElasticEntity.class).stream()
.map(SearchHit::getContent)
.collect(Collectors.toList())
}
}
Also it's worth to note that there is a SearchHitSupport utility class which adds support for Pageable.
Related
I'm struggling with a particular dependency injection problem and I just can't seem to figure it out. FYI: I'm new to guice, but I have experience with other DI frameworks - that's why I believe this shouldn't be to complicated to achieve.
What am I doing:
I'm working on Lagom multi module project and using Guice as DI.
What I would like to achieve:
Inject multiple named instances of some interface implementation (lets' call it publisher, since it will publishing messages to kafka topic) to my service.
This 'publisher' has injected some Lagom and Akka related services (ServiceLocator, ActorSystem, Materializer, etc..).
Now I would like to have two instances of such publisher and each will publish messages to different topic (So one publisher instance per topic).
How would I achieve that?
I have no problem with one instance or multiple instances for the same topic, but if I want to inject different topic name for each instance I have a problem.
So my publisher implementation constructor looks like that:
#Inject
public PublisherImpl(
#Named("topicName") String topic,
ServiceLocator serviceLocator,
ActorSystem actorSystem,
Materializer materializer,
ApplicationLifecycle applicationLifecycle) {
...
}
If I want to create one instance I would do it like this in my ServiceModule:
public class FeedListenerServiceModule extends AbstractModule implements ServiceGuiceSupport {
#Override
protected void configure() {
bindService(MyService.class, MyServiceImpl.class);
bindConstant().annotatedWith(Names.named("topicName")).to("topicOne");
bind(Publisher.class).annotatedWith(Names.named("publisherOne")).to(PublisherImpl.class);
}
}
How would I bind multiple publishers each for it's own topic?
I was playing around with implementing another private module:
public class PublisherModule extends PrivateModule {
private String publisherName;
private String topicName;
public PublisherModule(String publisherName, String topicName) {
this.publisherName = publisherName;
this.topicName = topicName;
}
#Override
protected void configure() {
bindConstant().annotatedWith(Names.named("topicName")).to(topicName);
bind(Publisher.class).annotatedWith(Names.named(publisherName)).to(PublisherImpl.class);
}
}
but this led me nowhere since you can't get injector in you module configuration method:
Injector injector = Guice.createInjector(this); // This will throw IllegalStateException : Re-entry is not allowed
injector.createChildInjector(
new PublisherModule("publisherOne", "topicOne"),
new PublisherModule("publisherTwo", "topicTwo"));
The only solution which is easy and it works is that I change my PublisherImpl to abstract, add him abstract 'getTopic()' method and add two more implementations with topic override.
But this solution is lame. Adding additional inheritance for code reuse is not exactly the best practice. Also I believe that Guice for sure must support such feature.
Any advises are welcome.
KR, Nejc
Don't create a new Injector within a configure method. Instead, install the new modules you create. No child injectors needed—as in the PrivateModule documentation, "Private modules are implemented using parent injectors", so there's a child injector involved anyway.
install(new PublisherModule("publisherOne", "topicOne"));
install(new PublisherModule("publisherTwo", "topicTwo"));
Your technique of using PrivateModule is the one I'd go with in this situation, particularly given the desire to make the bindings available through binding annotations as you have it, and particularly if the full set of topics is known at runtime. You could even put the call to install in a loop.
However, if you need an arbitrary number of implementations, you may want to create an injectable factory or provider to which you can pass a String set at runtime.
public class PublisherProvider {
// You can inject Provider<T> for all T bindings in Guice, automatically, which
// lets you configure in your Module whether or not instances are shared.
#Inject private final Provider<ServiceLocator> serviceLocatorProvider;
// ...
private final Map<String, Publisher> publisherMap = new HashMap<>();
public Publisher publisherFor(String topicName) {
if (publisherMap.containsKey(topicName)) {
return publisherMap.get(topicName);
} else {
PublisherImpl publisherImpl = new PublisherImpl(
topicName, serviceLocatorProvider.get(), actorSystemProvider.get(),
materializerProvider.get(), applicationLifecycleProvider.get());
publisherMap.put(topicName, publisherImpl);
return publisherImpl;
}
}
}
You'd probably want to make the above thread-safe; in addition, you can avoid the explicit constructor call by using assisted injection (FactoryModuleBuilder) or AutoFactory, which will automatically pass through explicit parameters like topicName while injecting DI providers like ServiceLocator (which hopefully has a specific purpose, because you may not need much service-locating within a DI framework anyway!).
(Side note: Don't forget to expose your annotated binding for your PrivateModule. If you don't find yourself injecting your topicName anywhere else, you might also consider using individual #Provides methods with the assisted injection or AutoFactory approach above, but if you expect each Publisher to need a differing object graph you might choose the PrivateModule approach anyway.)
Guice's approach to dependency injection is that the DI framework complements your instantiation logic, it doesn't replace it. Where it can, it will instantiate things for you, but it doesn't try to be too clever about it. It also doesn't confuse configuration (topic names) with dependency injection - it does one thing, DI, and does that one thing well. So you can't use it to configure things, the way you can with Spring for example.
So if you want to instantiate an object with two different parameters, then you instantiate that object with two different parameters - ie, you invoke new twice. This can be done by using provider methods, which are documented here:
https://github.com/google/guice/wiki/ProvidesMethods
In your case, it might look something like adding the following method to your module:
#Provides
#Named("publisherOne")
#Singleton
Publisher providePublisherOne(ServiceLocator serviceLocator,
ActorSystem actorSystem,
Materializer materializer,
ApplicationLifecycle applicationLifecycle) {
return new PublisherImpl("topicOne", serviceLocator,
actorSystem, materializer, applicationLifecycle);
}
Also, you probably want it to be a singleton if you're adding a lifecycle hook, otherwise you could run into memory leaks each time you add a new hook every time it's instantiated.
In my project I use Spring-Data, Spring-Data-Rest and Spring-Security.
What I need to accomplish is to implement domain object security (ACL) over these repositories. Specificaly #PostFilter over Pageable.findAll() method.
Method level security is easily implemented as outlined here.
There is also a section in docs about using security expression with #Query here.
But although I can use hasPermission(..) method inside #Query too, there is no way to include the object (SQL row) in this method - to be specific do this:
#Query("select u from #{#entityName} u where 1 = ?#{security.hasPermission(u, 'read') ? 1 : 0}")
Now I understand that this is way different than modifying the query pre-execution like this:
#Query("select m from Message m where m.to.id = ?#{ principal?.id }")
I also found the following jira issue:
https://jira.spring.io/browse/DATACMNS-293
Which I suspect that once it gets resolved there will be a solution to this, but it doesn't seem like it's going to be anytime soon.
I still need to implement this functionality and for that I would like to get your input and pointers on possible solutions.
Right now I am thinking about creating my custom annotation that will mimmick the #PostFilter one and use the same syntax but will get invoked manually inside my own BaseRepositoryImplementation. There I will get the repository interface from type and Repositories#getRepositoryInformationFor(type)#getRepositoryInterface(), find the annotation on respective method and manually invoke the security check.
Do you maybe have a different solution, or some notes about my proposed solution?
Also do you happen to know if there is any timetable on the mentioned jira issue?
One lightweight way is to do it is using the hasPermission() method and implementing your own "Permission Evaluator" at the Controller level, if that's an option for you.
#PreAuthorize("hasPermission(#employee, 'edit')")
public void editEmployee(Employee employee) {
...
}
#Component
public class PermissionEvaluatorImpl implements PermissionEvaluator {
#Override
public boolean hasPermission(Authentication auth,
Object targetDomainObject, Object permission) {
// return true if "auth" has "permission" permission for the user.
// Current-user can be obtained from auth.
}
...
}
This is described in more detail here: http://www.naturalprogrammer.com/spring-domain-object-security-logged-in-user/
So I have a need for injecting a number of different services into an authorization attribute I'm using. For simplicity I will leave this to show the configuration manager.
public class FeatureAuthorizeAttribute : AuthorizeAttribute
{
public IConfigurationManager ConfigurationManager;
private readonly string _feature;
public FeatureAuthorizeAttribute(string feature)
{
_feature = feature;
var test = ConfigurationManager.GetCdnPath();
}
}
Which would be used as follows
[FeatureAuthorize("Admin")]
I have tried to use constructor injection
public FeatureAuthorizeAttribute(string feature, IConfigurationManager configurationManager)
{
ConfigurationManager = configurationManager;
_feature = feature
}
However this just causes an error when I attempt
[FeatureAuthorize("Admin", IConfigurationManager)]
Which seems like the wrong way to go about it in the first place. I'm assuming that I need to register my custom authorization attribute with the container to get it to start picking up
Instead of trying to use Dependency Injection with attributes (which you can't do in any sane, useful way), create Passive Attributes.
Specifically, in this case, assuming that this is an ASP.NET MVC scenario, you can't derive from AuthorizeAttribute. Instead, you should make your Authorization service look for your custom attribute, and implement IAuthorizationFilter. Then add the filter to your application's configuration.
More details can be found in this answer: https://stackoverflow.com/a/7194467/126014.
I have a requirement, my current project is with ejb3, jpa and jsf. I have a core development project and customer specific project. In the customer specific project, we planned to inherit the core classes and extend or override the core functionality. So we planned to create the customer specific classes with some customer prefix. So in the final war file, we will have the core class and all customer prefix classes. For example, if Authenticator is a core class and XXAuthenticator, YYAuthenticator are customer specific classes exist in the build. So, for example if i have a line of code in a bean like this:
#Inject Authenticator authenticator;
Can i programmatically and/or dynamically inject the inherited classes based on some logic like logged in user has a customer specific functionality.
what i am expecting is, i dont want to change the above line to inject, because it will be big change in every class. But expecting some kind of dynamic logic or configuration file to change the core class injection to customer specific class..
So finally with out touching the #Inject Authenticator authenticator; line. Can I inject the xxAuthenticator or YYAuthenticator through some logic? We dont have Spring in project technology stack.. So please suggest me with out spring only.. Thanks in advance
It sounds like your use case is more around Qualifiers. If a user follows a certain, you should be injecting different qualified versions of classes to use, no?
#Inject
private Instance<SomeService> someServiceInstance;
// later on...
SomeService someService = null;
if(someCondition) {
someService = someServiceInstance.select(new FooLiteral()).get();
}
else {
someService = someServiceInstance.select(new BarLiteral()).get();
}
Where FooLiteral and BarLiteral are annotation literals for #Foo and #Bar, which are qualifiers.
In CDI this is done with "producer methods".
It would look like this:
#ApplicationScoped
public class AuthenticatorProducer {
private Authenticator xxAuthenticator; // = ...
private Authenticator yyAuthenticator; // = ...
#Produces
public Authenticator getAuthenticator() {
if (someCondition) {
return xxAuthenticator;
} else {
return yyAuthenticator;
}
}
}
No need to change injection points and Authenticators don't have to be CDI beans themselves.
I have been trying to mock grails' convention over configuration paradigm in a spring mvc application and i am finding it difficult to automate handler mappings.
Basically i have a controller like this.
#Controller
#RequestMapping(value = {"/", "/contact"})
public class ContactController {
#Autowired
private ContactService contactService;
#RequestMapping(value = {"/","/index"})
public String listContacts(Map<String, Object> map){
map.put("contact", new Contact());
map.put("contactList", contactService.listContact());
return "contact";
}
#RequestMapping(value = "/add", method = RequestMethod.POST)
public String addContact(#ModelAttribute("contact")Contact contact, BindingResult result){
contactService.addContact(contact);
return "redirect:/contact/index";
}
#RequestMapping(value = "/delete/{contactId}", method = RequestMethod.GET)
public String removeContact(#PathVariable("contactId")Long contactId){
contactService.removeContact(contactId);
return "redirect:/contact/index";
}
}
Now, i have tried "ControllerClassNameHandlerMapping", but it seems to have a limitation with three part url.
I basically want all the requests to be automatically mapped to the appropriate controller and actions, without using #RequestMapping
Any pointers will be great help
That won't be easy. Grails framework has written bunch of ASTTransformers where they inject annotations and other properties in to the class which is controller. Take a look at the source code for grails-plugin-controllers and you cans see the code under compiler.web and see what they are doing. Also if you take a look at ControllersGrailsPlugin you will see that its watching the directory grails-app under the parent folder. It won't be that easy to do. Hope this helps
UPDATE
Making AST transformations via ASM in your case, is probably the fastest way, maybe post-compilation step?
Hope it helps
It won't be that simple but what you want is likely to perform the following :
Write an annotation processor(scan classpath from classloader) to collect Controllers annotations and matching class
Hook into Spring mvc API to inject the Request Mapping based on your conventions.
Then you would also need to collect the method parameters to auto-inject pathVariables, etc.
If Spring MVC is not expecting to play with the RequestMapping annotation as soon as the Controller annotation is found (or defaults to something), then you're good to go (Post Bean Definition processors or similar mechanisms)...
Not that simple, but definitely possible...