I'm getting an exception while trying to access a Spring session scoped bean inside a thread of rxjava Schedulers.io()
Caused by: java.lang.IllegalStateException: No thread-bound request found: Are you referring to request attributes outside of an actual web request, or processing a request outside of the originally receiving thread? If you are actually operating within a web request and still receive this message, your code is probably running outside of DispatcherServlet/DispatcherPortlet: In this case, use RequestContextListener or RequestContextFilter to expose the current request.
Here is my scoped bean
#Component
#Scope(value = WebApplicationContext.SCOPE_SESSION, proxyMode = ScopedProxyMode.TARGET_CLASS)
#Getter
#Setter
public class SearchSession {
List<String> results;
}
And my controller
#Controller
#AllArgsConstructor(onConstructor=#__(#Autowired))
#Slf4j
public class SearchController {
private SearchService searchService;
private SearchSession searchSession;
#GetMapping("/search")
public DeferredResult<ModelAndView> getResults() {
DeferredResult<ModelAndView> deferredResult = new DeferredResult<>();
searchService.search("param1", "param2")
.map(results -> {
searchSession.setResults(results);
return results;
)
.subscribeOn(Schedulers.io())
.subscribe(
results -> {
ModelAndView view = new ModelAndView("search");
view.addObject("results", results);
deferredResult.setResult(view);
);
return deferredResult;
}
}
I tried to define a class which extends RequestContextListener and set parameter inheritable to true when calling RequestContextHolder.setRequestAttributes to allow inheritance between the thread which initially handle the request and the RxJava thread but it didn't work.
public class InheritableRequestContextListener extends RequestContextListener {
private static final String REQUEST_ATTRIBUTES_ATTRIBUTE =
InheritableRequestContextListener.class.getName() + ".REQUEST_ATTRIBUTES";
#Override
public void requestInitialized(ServletRequestEvent requestEvent) {
if (!(requestEvent.getServletRequest() instanceof HttpServletRequest)) {
throw new IllegalArgumentException(
"Request is not an HttpServletRequest: " + requestEvent.getServletRequest());
}
HttpServletRequest request = (HttpServletRequest) requestEvent.getServletRequest();
ServletRequestAttributes attributes = new ServletRequestAttributes(request);
request.setAttribute(REQUEST_ATTRIBUTES_ATTRIBUTE, attributes);
LocaleContextHolder.setLocale(request.getLocale());
RequestContextHolder.setRequestAttributes(attributes, true);
}
}
I also tried to create a custom RxJava scheduler managed by Spring but it didn't work.
#Bean
public Scheduler scheduler() {
final ThreadFactory threadFactory = new ThreadFactoryBuilder()
.setNameFormat("SearchThread-%d")
.setDaemon(true)
.build();
return Schedulers.from(Executors.newFixedThreadPool(10, threadFactory));
}
Do you have any idea on how could I access my Spring session scoped bean inside RxJava thread ?
Related
Am trying to start activiti engine from jsf
#ManagedBean(name = "activitiProcess")
#ViewScoped
public class ActivitiProcess implements Serializable {
private String filename = "D:/WORKSPACE/activiti1/src/main/resources/diagrams/MyProcess.bpmn";
public ActivitiProcess() {
}
public void startProcess() {
System.out.println("hello world");
try {
ProcessEngine engine = ProcessEngines.getDefaultProcessEngine(); //returns null
RepositoryService repositoryService = engine.getRepositoryService();
repositoryService.createDeployment().addInputStream("myProcess.bpmn20.xml", new FileInputStream(filename)).deploy();
RuntimeService runtimeService = engine.getRuntimeService();
ProcessDefinition definition = engine.getRepositoryService().createProcessDefinitionQuery().processDefinitionKey("myProcess").singleResult();
FormService formService = engine.getFormService();
// List<FormProperty> formList = formService.getStartFormData(definition.getId()).getFormProperties();
Map<String, String> formProperties = new HashMap<String, String>();
/* use the jsf variable instead */
formProperties.put("filePath", "D://somePath");
formService.submitStartFormData(definition.getId(), formProperties);
} catch (Exception e) {
e.printStackTrace();
}
}
}
the engine always returns as null , I read that the activiti.cfg.xml file should be in the class path , I've put the file under web-inf/classes but still , engine returns null which means activiti can't initialize the engine , any ideas ?
add this
#Inject
private ProcessEngine engine;
if you want to run a CDI Bean inside a container, you are not allowed to use the new keyword. Instead, you need to inject the bean and the container does the
rest, meaning, the container is the one responsible for managing the life cycle of the bean: it creates the instance; it gets rid of it. So how do you initialize a bean if you can’t call a constructor? Well, the container gives you a handle after constructing an instance and before destroying it.
I need to run daily a process in order to do maintenance work on the server (update records).
I have a singleton scope class that runs a timer and an inner class with the injection of the service I need. When I run the programm the timer throws a NullPointerException because the service has not been injected.
#Named("demonService")
#Singleton
public class DemonImpl implements IDemonService
{
private static Logger log = Logger.getLogger(DemonioImpl.class);
#PostConstruct
public void init()
{
log.info("-->Demon");
Calendar today = new GregorianCalendar();//Every day at 2:00am (from now)
today.set(Calendar.HOUR_OF_DAY, 2);
today.set(Calendar.MINUTE, 0);
today.set(Calendar.SECOND, 0);
try
{
Timer timer = new Timer(true);
timer.schedule(new Updater(), today.getTime(), 24*60*60*1000);
}
catch(Exception e)
{
log.fatal(e.getLocalizedMessage());
e.printStackTrace();
}
log.info("--> Demon: exit");
}
private class Updater extends TimerTask
{
private Logger log = Logger.getLogger(Updater.class);
#Inject
#Named("updaterService")
private IUpdaterService updaterService;
#Override
public void run()
{
log.info("Task: update records (start)");
List<Record> list = updaterService.getAll();//<-- This throws the exception
for(Record item : list)
{
updaterService.update(item);
}
log.info("Task: update records (exit)");
}
}
The error is
Exception in thread "Timer-3" java.lang.NullPointerException
at test.service.impl.DemonImpl$Updater.run(DemonImpl.java:66)
at java.util.TimerThread.mainLoop(Timer.java:555)
at java.util.TimerThread.run(Timer.java:505)
The application works fine except for this class. How can I inject the service when the application is fully working?
Normally you have a NPE when the Class is not a CDI Bean. If you make new Updater() this is not considered by CDI. you have to #Inject the Updater in your Singleton.
CDI won't manage the instance since you instantiate your Updater by calling the constructor of it yourself.
Now there are two ways to fix this:
Inject an instance of the Updater class in DemonImpl and use that one.
Create a new CDI managed instance at runtime by injecting a Provider<Updater> instance in DemonImpl and get a new instance of the Updater class from it.
I'm trying to create a long running windows service, so I need to run the actual worker class on a separate thread, to avoid the "service did not respond in a timely fashion" error when I right click and select start in Windows Service Manager.
The worker class ("NotificationProcess") has a whole raft of dependencies and I'm using Autofac to satisfy these.
I'm really not sure how to set up Autofac for the worker class. At the moment I'm getting errors telling me that the DbContext has been disposed when I go to use it in the "Execute" method of the worker class.
I guess I'm looking for how to write a windows service and use a new thread for the worker class with dependencies satisfied by autofac.
I've googled and can't find any examples of this.
Any suggestions would be awesome.
Here's what I've got so far...
Program.cs:
static class Program
{
static void Main()
{
using (var container = ServiceStarter.CreateAutoFacContainer())
{
var service = container.Resolve<NotificationService>();
if (Environment.UserInteractive)
{
service.Debug();
}
else
{
ServiceBase.Run(container.Resolve<NotificationService>());
}
}
The Service class:
public partial class NotificationService : ServiceBase
{
private NotificationProcess _app;
readonly ILifetimeScope _lifetimeScope;
public NotificationService(ILifetimeScope lifetimeScope)
{
_lifetimeScope = lifetimeScope;
InitializeComponent();
}
protected override void OnStart(string[] args)
{
_app = _lifetimeScope.Resolve<NotificationProcess>();
_app.Start();
}
The worker class:
public class NotificationProcess
{
private Thread _thread;
private readonly IBankService _bankService;
private readonly IRateService _rateService;
private readonly IEmailService _emailService;
private readonly IRateChangeSubscriberService _rateChangeSubscriberService;
private readonly IRateChangeNotificationService _rateChangeNotificationService;
private readonly ILogManager _logManager;
public NotificationProcess(IBankService bankService, ILogManager logManager, IRateService rateService, IEmailService emailService,
IRateChangeSubscriberService rateChangeSubscriberService, IRateChangeNotificationService rateChangeNotificationService)
{
_bankService = bankService;
_rateService = rateService;
_emailService = emailService;
_rateChangeSubscriberService = rateChangeSubscriberService;
_rateChangeNotificationService = rateChangeNotificationService;
_logManager = logManager;
}
public void Start()
{
_thread = new Thread(new ThreadStart(Execute));
_thread.Start();
}
public void Execute()
{
try
{
var rateChangeToNotify = _rateService.GetRateChangesForNotification();
foreach (var rateChange in rateChangeToNotify)
{
//do whatever business logic.....
}
}
}
The answer is actually simple: use scoping! You should do the following:
Register all services (such as DbContext) that should live for the duration of a request or action with the LifetimeScope lifestyle. You'll usually have a timer in your windows service. Each 'pulse' can be considered a request.
On the beginning of each request begin a lifetime scope.
Within that scope, resolve the root object from the object graph and call its method.
Dispose the scope.
In your case that means you need to change your design, since NotificationService is resolved once and its dependencies are reused on another thread. This is a no-no in dependency injection land.
Here's an alternative design:
// This method is called on a background thread
// (possibly in a timely manner)
public void Run()
{
try
{
using (var scope = container.BeginLifetimeScope())
{
var service = scope.Resolve<NotificationService>();
service.Execute();
}
}
catch (Exception ex)
{
// IMPORTANT: log exception.
// Not logging an exception will leave us in the dark.
// Not catching the exception will kill our service
// because we run in a background thread.
}
}
Using a lifetime scope allows you to get a fresh DbContext for every request and it would even allow you to run requests in parallel (with each request its own DbContext).
I am attempting to create functionality in a JSF1.2/ADF web app that will periodically & dynamically generate a sitemap for a website that will have hundreds of pages whose content will change daily. The catch is that I need to read some config from the application to use as the basis of the sitemap and to do so, I need FacesContext.
Here is what I have attempted to do: I created a class that implements a ServletContextListener and instantiates an application scoped bean. This bean does the heavy lifting to create sitemap.xml using FacesContext. I created a class that extends TimerTask that accesses the bean from application scope, calls the sitemap method and schedules future occurrences. When I run the application, the class that implements ServletContextListener fires and the bean appears to be created, but the class that extends TimerTask is never fired. Any help would be appreciated. If I can answer any questions or if I left anything out, please let me know.
Here are my code samples:
public class WebhomesApplicationContextListener implements ServletContextListener {
private static final String attribute = "SiteMapGenerator";
public void contextInitialized(ServletContextEvent event) {
SiteMapGenerator myObject = new SiteMapGenerator();
event.getServletContext().setAttribute(attribute, myObject);
}
public void contextDestroyed(ServletContextEvent event) {
SiteMapGenerator myObject = (SiteMapGenerator) event.getServletContext().getAttribute(attribute);
event.getServletContext().removeAttribute(attribute);
}
}
public class SiteMapGenerator {
public void generateSitemap() {
// code to generate map...
}
}
public class Scheduler extends TimerTask {
public void run() {
SiteMapGenerator sitemap = (SiteMapGenerator)FacesContext.getCurrentInstance().getExternalContext().getApplicationMap().get("SiteMapGenerator");
sitemap.generateSitemap();
}
}
class MainApplication {
public static void main(String[] args) {
Timer timer = new Timer();
timer.schedule(
new Scheduler(),
1000 * 60);
}
}
No, you can't. The FacesContext is only available in the thread associated with the HTTP servlet request whose URL matched the URL pattern of the FacesServlet and has invoked it. Instead, just pass the SiteMapGenerator to the Scheduler on its construction.
public class Scheduler {
private SiteMapGenerator sitemap;
public Scheduler(SiteMapGenerator sitemap) {
this.sitemap = sitemap;
}
// ...
}
The SiteMapGenerator is surely available at the point you're constructing the Scheduler.
Unrelated to the concrete problem, It's strongly discouraged to use TimerTask in a Java EE application. See also Spawning threads in a JSF managed bean for scheduled tasks using a timer.
I have a service that needs to invoke a runnable class.
Here are the lines of code that are being used in my service.
#Autowired
private LinkBrc2MemberProfile brcTask;
// Background Task.
SimpleAsyncTaskExecutor sate = new SimpleAsyncTaskExecutor();
sate.createThread(new LinkBrc2MemberProfile(user));
Here is my Runnable class
#Service
public class LinkBrc2MemberProfile implements Runnable {
private final Logger log = LoggerFactory.getLogger(LinkBrc2MemberProfile.class);
#Autowired
private LoyaltyDao dao;
private Member member;
public LinkBrc2MemberProfile() {
super();
}
public LinkBrc2MemberProfile(Member member) {
this.member = member;
}
public void run() {
log.debug("*** Member User Name: " + member.getString("USER_NAME"));
String emailAddress = member.getString("USER_NAME");
Map<String, Object> map = dao.findBrcByEmailAddress( emailAddress );
log.debug("==========================================================");
if( ! map.isEmpty() ) {
try {
//a.CUSTOMER_ID, a.EMAIL_ADDRESS, b.card_no
String customerId = (String) map.get("CUSTOMER_ID");
String brcCardNumber = (String) map.get("CARD_NO");
log.debug("\ncustomerId: " + customerId + " brcCardNumber: " + brcCardNumber);
if(!brcCardNumber.equals("")) {
// Add the Be Rewarded Card.
HashMap<String, String> userAttributes = new HashMap<String, String>();
String brcNumber = member.getString("BREWARDED_CARD_NO");
if (brcNumber.equals("")) {
userAttributes.put("BREWARDED_CARD_NO", brcCardNumber);
try {
member.putAll(userAttributes);
} catch (Exception e) {
String errorMessage = "Unable to save user's BRC information due to: " + e.getMessage();
log.error("{}", errorMessage);
}
}
}
} catch (Exception e) {
log.error(e.getMessage());
e.printStackTrace();
}
}
}
I'm not seeing any errors in the log but at the same time it does not appear to be invoking the Runnable class. Am I missing an annotation somewhere? Are there any good examples that you can point me to, the only ones I have found use XML files to configure the runnable class I would like to use annotations. Thanks in Advance.
I've updated my service to do the following.
Please help, my DAO is NULL so it looks like my #Autowired in my Runnable class is not wiring it in.
I've added the following bean to my bean-config.xml file.
<bean id="brcType" class="com.ws.ocp.service.LinkBrc2MemberProfile" scope="prototype"/>
I removed my #Autowired annotation and added the following to my service class.
ClassPathResource rsrc = new ClassPathResource("bean-config.xml");
XmlBeanFactory factory = new XmlBeanFactory(rsrc);
LinkBrc2MemberProfile brcTask = (LinkBrc2MemberProfile) factory.getBean("brcType");
SimpleAsyncTaskExecutor sate = new SimpleAsyncTaskExecutor();
// Set Member attribute
brcTask.setMember(user);
// Executer
sate.execute(brcTask);
Why is my dao still null?
The runnable will throw a NullPointerException, since you create it yourself (using the new operator), instead of letting Spring create it. This obviously means that the autowired DAO attribute won't be autowired, which will lead to a NPE when calling dao.findBrcByEmailAddress(...).
You should get your Runnable instance from the bean factory (as a prototype), set its member attribute, and then submit it to the executor.
To answer your question of how to properly use a Prototype-Bean, this is my favorite way:
#Component
abstract class MyBean {
/* Factory method that will be installed by Spring */
#Lookup
protected abstract YourPrototypeBean createBean();
void someCode() {
YourPrototypeBean bean = createBean();
}
}
Since it's a factory method, you can create as many instances as you like.