Pass value to injected EJB - java

I have an EJB application that consists of two beans, ServiceEJB (web tier) and BusinessEJB (business tier), where BusinessEJBis injected in ServiceEJB.
ServiceEJBreceives HTTP requests from the browser, calls a method in BusinessEJB, gets the result, and sends the HTTP response.
Also, ServiceEJB has access to the HttpSession object, where the userId of the user that logged in is stored. BusinessEJBdoes NOT have access to the HttpSession object.
The application needs to log messages (using sl4j/logback, for example). It could log the message in ServiceEJBor BusinessEJB methods, and when it logs a message, it has to include the userId of the session in the log entry.
Since BusinessEJB doesn't have the userId, it needs to get it from ServiceEJB. The question is what is the best way to achieve that. What I DON'T want to do is to add a userId field to each method in BusinessEJB as a parameter, as there are many ServiceEJBs and BusinessEJBs in the application (and other beans called by BusinessEJB that also generate log entries), and I don't want to pollute the application with the userId field. Instead, I could have a userId field at the EJB level, but how to populate them? Is there a way to achieve this with annotations? Any suggestions will be welcome.
#Produces({MediaType.APPLICATION_JSON})
#Consumes({MediaType.APPLICATION_JSON})
#Stateless
public class ServiceEJB {
#Context
HttpServletRequest httpRequest;
#Inject
private BusinessEJB bean;
private String userId;
#Path("someurl")
public Response someMethod1() {
final HttpSession session = httpRequest.getSession();
// get the userId from the session
String s = bean.someMethod2();
// return Response
}
}
#Stateless
public class BusinessEJB {
private String userId;
public String someMethod2() {
// .... log an entry with userId
return "something";
}
}

A few pointers/comments:
If you integrate with application server security, then the user name is available at any component. EJBs can get it by calling getCallerPrincipal() on the injected variant of the EJBContext, here the javax.ejb.SessionContext:
#Resource
private SessionContext sessionCtx;
Servlets can retrieve the principal from the HttpServletRequest.getUserPrincipal(). JAX-RS components (the ServiceEJB) can retrieve it from the javax.ws.rs.core.SecurityContext.getUserPrincipal().
Is there any reason why you are NOT integrating with the application server security?
If you have a good reason NOT to integrate with application server security, I would propose a variation of the solution from the previous answer. The variation is to set the user data from a filter applied to all resources (either servlet filter or JAX-RS ContainerRequestFilter), so that you do not have to worry about setting it in multiple places.
If you ONLY NEED THE USER ID FOR LOGGING, I'd suggest you take a look at the concept of Mapped Diagnostic Contexts (MDC) in slf4j. With it you can set the user id early at the beginning of the request and make it available to all logging statements thereafter.

Create a request scoped CDI bean i.e. UserContext.
Inject it into both EJBs.
In ServiceEJB set user's id and in BusinessEJB read it.

Related

Spring REST Api -- access User details in repository

The setup of the RESPApi project is:
SpringBoot
Spring's OAuth2
In the project we have many clients, so SQL queries almost always have "... and clientId = ?" in the where clause.
We store clientId in the SecurityContext with other user details (we extend Spring's User class).
The question is: how to get the User object in the #Repository?
Possible solutions we can think of:
In every repository implementation add
SecurityContextHolder.getContext().getAuthentication()
cast the result to our custom UserDetails implementation and use it.
Cons: somehow I feel there's a better solution.
Add #AuthenticationPrincipal annotated parameters to the controllers and then pass the parameters to the service layer and then to the repository layer.
Cons: passing the paremeter though 2 layers only to obtain clientId doesn't seem reasonable.
I thought about #Autowired paramter MyUser user in the #Repository class. The first try was to create #Configuration annotated class in which there will be a method
#Bean
public MyUser getUser() {
SecurityContext context = SecurityContextHolder.getContext();
if (context != null) {
Authentication authentication = SecurityContextHolder.getContext().getAuthentication();
if (authentication != null) {
return (MyUser) authentication.getPrincipal();
}
}
return null;
}
But the bean is null and I cannot use it.
For now we've ended up with solution nr 1 but I feel there must be a better way.
Any ideas how to solve this problem?
If you're using Spring Data (or have the time to switch to using it), you can use the SecurityEvaluationContextExtension and use principal directly in your queries:
https://stackoverflow.com/a/29692158/1777072
If not, you could hide the static access if it offends (or if you want more control over it changing in future):
#Component
public class AuthenticationHelper {
public Authentication getAuthentication() {
return SecurityContextHolder.getContext().getAuthentication();
}
}
Then inject that class into your Repository.
Or your Service. That's probably a better fit than the Repository.
I like to keep Repositories dumb (ultimately using Spring Data to avoid writing them entirely).
And I like to think of Services as being separated out of the web layer, running on separate boxes (even if they aren't). In that situation, you would never pass the Authentication details over HTTP from Controller to Service. The service would obtain authentication details for itself, rather than just trusting what the web layer sent it.
So I think the Service should get the details itself, rather than the Controller passing them through.
Your bean is null because by default beans are singleton and they are created when the application starts, and as you can imagine, you are not going to have a SecurityContext at that point.
Try declaring your bean with request scope, in this way:
#Bean
#Scope(value=WebApplicationContext.SCOPE_REQUEST, proxyMode=ScopedProxyMode.TARGET_CLASS)
public MyUser getUser() {
.....
}

Spring MVC3 #SessionAttributes and #ModelAttribute will automatically get value from request

I’m trying to develop a Spring MVC application, now I encounter a question. When login successful I add the User entity to session and call http://localhost:8080/user to get the session user. Everything is OK here. But if I call the URL like this http://localhost:8080/user?username=testuser then the session user's username will change to testuser. What should I do that just get current user from session?
The code likes below
Entity:
#Entity
public class User {
private Long id;
private String username;
// ...Getter and Setter...
}
Controller:
#Controller
#RequestMapping("user")
#SessionAttributes("current_user")
public class UserController {
#RequestMapping(method=RequestMethod.GET)
#ResponseBody
public User testSession(#ModelAttribute("current_user") User user) {
return user;
}
}
Response of http://localhost:8080/user
[{"id":1,"username":"aaa111"}]
Response of http://localhost:8080/user?username=testuser; it should be same as above, but is
[{"id":1,"username":"testuser"}]
The #SessionAttributes annotation isn't intended for this. Its intend is to store objects in the session during http requests. Imagine a lengthy database call to retrieve an object you don't want to retrieve this object each time but probably reuse an existing one. The object is to be intended to be used as a #ModelAttribute, this annotation indicates that you want to use this object for binding (i.e. you have a form to change attributes of the object). When you are finished with the editing of the object you should make this clear by calling setComplete() on the SessionStatus object. See also here.
You want to store an object in the session and retrieve it when you need it. For this use the HttpSession in the normal way of calling setAttribute and getAttribute. To obtain the current HttpSession you can simply add a method argument of the type HttpSession and it will be injected for you. (See here for a list of supported method arguments).
public void myRequestHandlingMethod(HttpSession session) {
User currentUser = (User) session.getAttribute("currentUser");
}
Or as you are already using Spring you could use the WebUtils for convenience. You can use the getSessionAttribute or getRequiredSessionAttribute methods to obtain the value from the session.
public void myRequestHandlingMethod(HttpServletRequest request) {
User currentUser = (User) WebUtils.getSessionAttribute("currentUser", request)
}
Another solution would be to extend Spring MVC. Spring MVC uses a HandlerMethodArgumentResolver to handle all the different types of method arguments. This mechanism is pluggable. You could create an annotation #CurrentUser and create a CurrentUserHandlerMethodArgumentResolver that will retrieve the user from the session and injects it in that place. You could then simply add your current user to your method signature.
public void myRequestHandlingMethod(#CurrentUser User user) { ... }
Configure the custom argument resolver
<mvc:annotation-driven>
<mvc:argument-resolvers>
<bean class="com.yourcomponany.app.web.CurrentUserHandlerMethodArgumentResolver />
</mvc:argument-resolvers>
</mvc:annotation-driven>
It also looks like you are rolling your own security framework, which I would advice against. Instead I would suggest using Spring Security instead. Advantage of this is that this provides integration with the Servlet API allowing for retrieval of the current Principal by either doing it yourself (request.getUserPrincipal()) or simply adding a method argument of the type java.security.Principal. It also comes with a custom HandlerMethodArgumentResolver which allows you to obtain the current Spring Security Authentication object.
try to get session value in controller from servlet request like below
#Controller
#RequestMapping("user")
#SessionAttributes("current_user")
public class UserController{
#RequestMapping(method=RequestMethod.GET)
#ResponseBody
public User testSession(HttpServletRequest request){
//false means do not create new session
HttpSession session = request.getSession(false);
return session != null?session.getAttribute("current_user"):null;
}
}

How to create, manage, associate a session in REST Jersey Web Application

A HTML5 UI is connected to the backend (REST Jersey to business logic to Hibernate and DB).
I need to create and maintain a session for each user login until the user logs out.
Can you please guide me on what technologies/ APIs can be used.
Does something need to be handled at the REST Client end also..
Using JAX-RS for RESTful web services is fairly straightforward. Here are the basics. You usually define one or more service classes/interfaces that define your REST operations via JAX-RS annotations, like this one:
#Path("/user")
public class UserService {
// ...
}
You can have your objects automagically injected in your methods via these annotations:
// Note: you could even inject this as a method parameter
#Context private HttpServletRequest request;
#POST
#Path("/authenticate")
public String authenticate(#FormParam("username") String username,
#FormParam("password") String password) {
// Implementation of your authentication logic
if (authenticate(username, password)) {
request.getSession(true);
// Set the session attributes as you wish
}
}
HTTP Sessions are accessible from the HTTP Request object via getSession() and getSession(boolean) as usual. Other useful annotations are #RequestParam, #CookieParam or even #MatrixParam among many others.
For further info you may want to read the RESTEasy User Guide or the Jersey User Guide since both are excellent resources.

Spring controllers - thread safety and storing resources

I have a question about spring mvc and thread safety.
We are developing web application that will be stored on tomcat. If I understand right, Tomcat creates thread per request and it has some thread pool. Now, dispatcher servlet is shared between requests and probably is thread safe.
But when I create controller like this:
#Controller
#RequestMapping("/manage")
public class QuestionManagementController {
he has Singleton scope so the same controller is used by every request that comes from every user.
I am wondering how this problem is usually solved:
1: are controllers created with Session scope? (but I think that there also could be problems if one user quickly do some things that may lead to race conditions in the controller).
2: controllers are scoped as request
3: creating stateless controllers that don't share any variables at class level, or have them in read only mode
or maybe there is some better "best practice" that solves this kind of problem.
I am asking this question, because now we have them as Singleton scoped, and there is a problem, that in most methods we are querying for user in the database , and we can't store this information in class level variable because of the scope. We could try to use some thread safe collection but later there could be other resources needing synchronized access.
A lot of parameters can be added to the controller methods like request, session, principal etc to avoid your problem.
Usually there's a 3-layers architecture:
#Controller (they delegates to services)
#Service (they do the work using DAOs or Repositories)
#Repository (or DAOs, they do DB access)
So depending on what you are querying for in the DB, I would advise having a service, injected by Spring with a cache if hitting the DB is costly and everytime you need the stuff from the DB call the service (i.e. nothing stored in the controller class level)
A short example, let's say we are behind spring-security and everything need a fully logged-in user. We have an userData table where the key is the user login, we have an url /data to get a page showing my user data:
#Controller
#RequestMapping("/data")
public class UserDataController
{
#Autowired
private UserService userService;
#RequestMapping(value = "", method = RequestMethod.GET)
public ModelAndView data(final Principal principal) {
Assert.notNull(principal); // throw if assertion fails
Assert.hasText(principal.getName());
final UserData userData = this.userService.findByUserName(principal.getName());
Assert.notNull(userData, "userData not found");
return new ModelAndView("userData", "userData", userData);
}
}
#Service("userService")
public class userService
{
private static final String USERDATA_CACHE = "com.acme.foo.UserData";
#Autowired
private UserDataRepository userDataRepository;
#Cacheable(USERDATA_CACHE)
public UserData findByUserName(final String userName) {
return this.userDataRepository.findByUserName(userName);
}
}
#Repository
public class UserDataRepository
{
// or use spring-data-jpa
public UserData findByUserName(final String userName) {
// query table userData and create an UserData from results.
}
}
Here I use principal and spring ensure that this is current user one.
Refs:
#Cachable
see also Initialize Singletons in Spring Framework 3 MVC
Note sure if this answer fully to your concerns

Accessing UserName from the Web Service Implementation Class in Java

After authenticating a user using CXF WSAuthentication Interceptor... I need the username in the service implementation (Business Logic). Wondering if there is a easy way to get access to the Username in the Implementation class?
declare these in your implementation class:
#Resource
private WebServiceContext wsContext;
then in any method do:
Principal p = wsContext.getUserPrinciple();
String username = p.getName();
#Resource instructs the web service stack to inject the web service context into your wsContext attribute.
Why not create a user object and place it somewhere in the memory (in a static Map or List etc) with the userName in the wsse:security while while doing the authentication itself? Once you reach the Service endpoint implementation class, you loose the MessageContext and hence its difficult to read the headers.

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