Package com.vaadin.flow.server

Class VaadinService

java.lang.Object
com.vaadin.flow.server.VaadinService
All Implemented Interfaces:
Serializable
Direct Known Subclasses:
VaadinServletService
public abstract class VaadinService extends Object implements Serializable
An abstraction of the underlying technology, e.g. servlets, for handling browser requests.
Since:
1.0.
Author:
Vaadin Ltd
See Also:

  • Field Details

    • INVALID_ATMOSPHERE_VERSION_WARNING

      public static final String INVALID_ATMOSPHERE_VERSION_WARNING
      See Also:

    • ATMOSPHERE_MISSING_ERROR

      public static final String ATMOSPHERE_MISSING_ERROR

  • Constructor Details

    • VaadinService

      public VaadinService(DeploymentConfiguration deploymentConfiguration)
      Creates a new vaadin service based on a deployment configuration.
      Parameters:
      deploymentConfiguration - the deployment configuration for the service

    • VaadinService

      protected VaadinService()
      Creates a service. This method is for use by dependency injection frameworks etc. and must be followed by a call to setClassLoader(ClassLoader) or setDefaultClassLoader() before use. Furthermore getDeploymentConfiguration() and getContext() should be overridden (or otherwise intercepted) not to return null.

  • Method Details

    • init

      public void init() throws ServiceException
      Initializes this service. The service should be initialized before it is used.
      Throws:
      ServiceException - if a problem occurs when creating the service

    • getRouteRegistry

      protected abstract RouteRegistry getRouteRegistry()
      Find a route registry to use for this service.
      Returns:
      the route registry to use, not null

    • getPwaRegistry

      protected abstract PwaRegistry getPwaRegistry()

    • getContextRootRelativePath

      public abstract String getContextRootRelativePath(VaadinRequest request)
      Returns relative context path for given request. Override this method in subclasses.
      Parameters:
      request - Request.
      Returns:
      Relative context root path for that request.

    • createRequestHandlers

      protected List<RequestHandler> createRequestHandlers() throws ServiceException
      Called during initialization to add the request handlers for the service. Note that the returned list will be reversed so the last handler will be called first. This enables overriding this method and using add on the returned list to add a custom request handler which overrides any predefined handler.
      Returns:
      The list of request handlers used by this service.
      Throws:
      ServiceException - if a problem occurs when creating the request handlers

    • createVaadinRequestInterceptors

      protected List<VaadinRequestInterceptor> createVaadinRequestInterceptors() throws ServiceException
      Called during initialization to add the request handlers for the service. Note that the returned list will be reversed so the last interceptor will be called first. This enables overriding this method and using add on the returned list to add a custom request interceptors which overrides any predefined handler.
      Returns:
      The list of request handlers used by this service.
      Throws:
      ServiceException - if a problem occurs when creating the request interceptors

    • createInstantiator

      protected Instantiator createInstantiator() throws ServiceException
      Creates an instantiator to use with this service.

      A custom Vaadin service implementation can override this method to pick an instantiator. The method loadInstantiators() is used to find a custom instantiator. If there is no one found then the default is used. You may override this method or loadInstantiators() in your custom service.

      Returns:
      an instantiator to use, not null
      Throws:
      ServiceException - if there are multiple applicable instantiators
      See Also:

    • loadInstantiators

      protected Optional<Instantiator> loadInstantiators() throws ServiceException
      Loads and initializes instantiators.

      A custom Vaadin service implementation can override this method to pick an instantiator in some other way instead of the default implementation that uses ServiceLoader.

      There may be only one applicable instantiator. Otherwise ServiceException will be thrown.

      Returns:
      an optional instantator, or an empty optional if no instantiator found
      Throws:
      ServiceException - if there are multiple applicable instantiators
      See Also:

    • getInstantiator

      public Instantiator getInstantiator()
      Gets the instantiator used by this service.
      Returns:
      the used instantiator, or null if this service has not yet been initialized
      See Also:

    • getClassLoader

      public ClassLoader getClassLoader()
      Gets the class loader to use for loading classes loaded by name, e.g. custom UI classes. This is by default the class loader that was used to load the Servlet class to which this service belongs.
      Returns:
      the class loader to use, or null
      See Also:

    • setClassLoader

      public void setClassLoader(ClassLoader classLoader)
      Sets the class loader to use for loading classes loaded by name, e.g. custom UI classes. Invokers of this method should be careful to not break any existing class loader hierarchy, e.g. by ensuring that a class loader set for this service delegates to the previously set class loader if the class is not found.
      Parameters:
      classLoader - the new class loader to set, not null.
      See Also:

    • getMimeType

      public abstract String getMimeType(String resourceName)
      Returns the MIME type of the specified file, or null if the MIME type is not known. The MIME type is determined by the configuration of the container, and may be specified in a deployment descriptor. Common MIME types are "text/html" and "image/gif".
      Parameters:
      resourceName - a String specifying the name of a file
      Returns:
      a String specifying the file's MIME type
      See Also:
      • ServletContext.getMimeType(String)

    • getDeploymentConfiguration

      public DeploymentConfiguration getDeploymentConfiguration()
      Gets the deployment configuration. Should be overridden (or otherwise intercepted) if the no-arg constructor is used in order to prevent NPEs.
      Returns:
      the deployment configuration

    • setSystemMessagesProvider

      public void setSystemMessagesProvider(SystemMessagesProvider systemMessagesProvider)
      Sets the system messages provider to use for getting system messages to display to users of this service.
      Parameters:
      systemMessagesProvider - the system messages provider; null is not allowed.
      See Also:

    • getSystemMessagesProvider

      public SystemMessagesProvider getSystemMessagesProvider()
      Gets the system messages provider currently defined for this service.

      By default, the DefaultSystemMessagesProvider which always provides the built-in default SystemMessages is used.

      Returns:
      the system messages provider; not null
      See Also:

    • getSystemMessages

      public SystemMessages getSystemMessages(Locale locale, VaadinRequest request)
      Gets the system message to use for a specific locale. This method may also be implemented to use information from current instances of various objects, which means that this method might return different values for the same locale under different circumstances.
      Parameters:
      locale - the desired locale for the system messages
      request - the request being processed
      Returns:
      the system messages to use

    • addSessionInitListener

      public Registration addSessionInitListener(SessionInitListener listener)
      Adds a listener that gets notified when a new Vaadin service session is initialized for this service.

      Because of the way different service instances share the same session, the listener is not necessarily notified immediately when the session is created but only when the first request for that session is handled by this service.

      Parameters:
      listener - the Vaadin service session initialization listener
      Returns:
      a handle that can be used for removing the listener
      See Also:

    • addUIInitListener

      public Registration addUIInitListener(UIInitListener listener)
      Adds a listener that gets notified when a new UI has been initialized.
      Parameters:
      listener - the UI initialization listener
      Returns:
      a handle that can be used for removing the listener
      See Also:

    • addSessionDestroyListener

      public Registration addSessionDestroyListener(SessionDestroyListener listener)
      Adds a listener that gets notified when a Vaadin service session that has been initialized for this service is destroyed.

      The session being destroyed is locked and its UIs have been removed when the listeners are called.

      Parameters:
      listener - the vaadin service session destroy listener
      Returns:
      a handle that can be used for removing the listener
      See Also:

    • modifyIndexHtmlResponse

      public void modifyIndexHtmlResponse(IndexHtmlResponse response)
      Fires the IndexHtmlRequestListener.modifyIndexHtmlResponse(IndexHtmlResponse) event to all registered IndexHtmlRequestListener. This is called internally when the Index HTML response is created, so listeners can intercept the creation and change the result HTML.
      Parameters:
      response - The object containing all relevant info needed by listeners to change the Index HTML response.

    • fireSessionDestroy

      public void fireSessionDestroy(VaadinSession vaadinSession)
      Handles destruction of the given session. Internally ensures proper locking is done.
      Parameters:
      vaadinSession - The session to destroy

    • findVaadinSession

      public VaadinSession findVaadinSession(VaadinRequest request) throws SessionExpiredException
      Attempts to find a Vaadin service session associated with this request.

      Handles locking of the session internally to avoid creation of duplicate sessions by two threads simultaneously.

      Parameters:
      request - the request to get a vaadin service session for.
      Returns:
      the vaadin service session for the request, or null if no session is found and this is a request for which a new session shouldn't be created.
      Throws:
      SessionExpiredException - if the session has already expired
      See Also:

    • getSessionLock

      protected Lock getSessionLock(WrappedSession wrappedSession)
      Gets the lock instance used to lock the VaadinSession associated with the given wrapped session.

      This method uses the wrapped session instead of VaadinSession to be able to lock even before the VaadinSession has been initialized.

      Parameters:
      wrappedSession - The wrapped session
      Returns:
      A lock instance used for locking access to the wrapped session

    • lockSession

      protected Lock lockSession(WrappedSession wrappedSession)
      Locks the given session for this service instance. Typically you want to call VaadinSession.lock() instead of this method.

      Note: The method and its signature has been changed to return lock instance in Vaadin X.X.X. If you have overriden this method, you need to update your implementation.

      Note: Overriding this method is not recommended, for custom lock storage strategy override getSessionLock(WrappedSession) and setSessionLock(WrappedSession,Lock) instead.

      Parameters:
      wrappedSession - The session to lock
      Returns:
      Lock instance
      Throws:
      IllegalStateException - if the session is invalidated before it can be locked

    • unlockSession

      protected void unlockSession(WrappedSession wrappedSession, Lock lock)
      Releases the lock for the given session for this service instance. Typically, you want to call VaadinSession.unlock() instead of this method.

      Note: The method and its signature has been changed to get lock instance as parameter in Vaadin X.X.0. If you have overriden this method, you need to update your implementation.

      Note: Overriding this method is not recommended, for custom lock storage strategy override getSessionLock(WrappedSession) and setSessionLock(WrappedSession,Lock) instead.

      Parameters:
      wrappedSession - The session to unlock
      lock - Lock instance to unlock

    • createVaadinSession

      protected VaadinSession createVaadinSession(VaadinRequest request)
      Creates a new Vaadin session for this service and request.
      Parameters:
      request - The request for which to create a VaadinSession
      Returns:
      A new VaadinSession

    • getExistingSession

      protected VaadinSession getExistingSession(VaadinRequest request, boolean allowSessionCreation) throws SessionExpiredException
      Throws:
      SessionExpiredException

    • requestCanCreateSession

      protected abstract boolean requestCanCreateSession(VaadinRequest request)
      Checks whether it's valid to create a new service session as a result of the given request.
      Parameters:
      request - the request
      Returns:
      true if it's valid to create a new service session for the request; else false

    • getCurrent

      public static VaadinService getCurrent()
      Gets the currently used Vaadin service. The current service is automatically defined when processing requests related to the service (see ThreadLocal) and in VaadinSession.access(Command) and UI.access(Command). In other cases, (e.g. from background threads), the current service is not automatically defined.
      Returns:
      the current Vaadin service instance if available, otherwise null
      See Also:

    • setCurrentInstances

      public void setCurrentInstances(VaadinRequest request, VaadinResponse response)
      Sets the this Vaadin service as the current service and also sets the current Vaadin request and Vaadin response. This method is used by the framework to set the current instances when a request related to the service is processed and they are cleared when the request has been processed.

      The application developer can also use this method to define the current instances outside the normal request handling, e.g. when initiating custom background threads.

      Parameters:
      request - the Vaadin request to set as the current request, or null if no request should be set.
      response - the Vaadin response to set as the current response, or null if no response should be set.
      See Also:

    • setCurrent

      public static void setCurrent(VaadinService service)
      Sets the given Vaadin service as the current service.
      Parameters:
      service - the service to set

    • getCurrentRequest

      public static VaadinRequest getCurrentRequest()
      Gets the currently processed Vaadin request. The current request is automatically defined when the request is started. The current request can not be used in e.g. background threads because of the way server implementations reuse request instances.
      Returns:
      the current Vaadin request instance if available, otherwise null
      See Also:

    • getCurrentResponse

      public static VaadinResponse getCurrentResponse()
      Gets the currently processed Vaadin response. The current response is automatically defined when the request is started. The current response can not be used in e.g. background threads because of the way server implementations reuse response instances.
      Returns:
      the current Vaadin response instance if available, otherwise null
      See Also:

    • getServiceName

      public abstract String getServiceName()
      Gets a unique name for this service. The name should be unique among different services of the same type but the same for corresponding instances running in different JVMs in a cluster. This is typically based on e.g. the configured servlet's name.
      Returns:
      the unique name of this service instance.

    • findUI

      public UI findUI(VaadinRequest request)
      Finds the UI that belongs to the provided request. This is generally only supported for UIDL requests as other request types are not related to any particular UI or have the UI information encoded in a non-standard way. The returned UI is also set as the current UI ( UI.setCurrent(UI)).
      Parameters:
      request - the request for which a UI is desired
      Returns:
      the UI belonging to the request or null if no UI is found

    • reinitializeSession

      public static void reinitializeSession(VaadinRequest request)
      Discards the current session and creates a new session with the same contents. The purpose of this is to introduce a new session key in order to avoid session fixation attacks.

      Please note that this method makes certain assumptions about how data is stored in the underlying session and may thus not be compatible with some environments.

      Parameters:
      request - The Vaadin request for which the session should be reinitialized

    • getMainDivId

      public abstract String getMainDivId(VaadinSession session, VaadinRequest request)
      Creates and returns a unique ID for the DIV where the UI is to be rendered.
      Parameters:
      session - The service session to which the bootstrapped UI will belong.
      request - The request for which a div id is needed
      Returns:
      the id to use in the DOM

    • closeSession

      public void closeSession(VaadinSession session)
      Sets the given session to be closed and all its UI state to be discarded at the end of the current request, or at the end of the next request if there is no ongoing one.

      After the session has been discarded, any UIs that have been left open will give a Session Expired error and a new session will be created for serving new UIs.

      Parameters:
      session - the session to close
      See Also:

    • isUIActive

      public boolean isUIActive(UI ui)
      Returns whether the given UI is active (the client-side actively communicates with the server) or whether it can be removed from the session and eventually collected.

      A UI is active if and only if its isClosing returns false and getHeartbeatTimeout is negative or has not yet expired.

      Parameters:
      ui - The UI whose status to check
      Returns:
      true if the UI is active, false if it could be removed.

    • requestStart

      public void requestStart(VaadinRequest request, VaadinResponse response)
      Called before the framework starts handling a request.
      Parameters:
      request - The request
      response - The response

    • requestEnd

      public void requestEnd(VaadinRequest request, VaadinResponse response, VaadinSession session)
      Called after the framework has handled a request and the response has been written.
      Parameters:
      request - The request object
      response - The response object
      session - The session which was used during the request or null if the request did not use a session

    • getRequestHandlers

      public Iterable<RequestHandler> getRequestHandlers()
      Returns the request handlers that are registered with this service. The iteration order of the returned collection is the same as the order in which the request handlers will be invoked when a request is handled.
      Returns:
      a collection of request handlers in the order they are invoked
      See Also:

    • getVaadinRequestInterceptors

      public Iterable<VaadinRequestInterceptor> getVaadinRequestInterceptors()
      Returns the request interceptors that are registered with this service. The iteration order of the returned collection is the same as the order in which the request handlers will be invoked when a request is handled.
      Returns:
      a collection of request interceptors in the order they are invoked
      See Also:

    • getDependencyFilters

      public Iterable<DependencyFilter> getDependencyFilters()
      Gets the filters which all resource dependencies are passed through before being sent to the client for loading.
      Returns:
      the dependency filters to pass resources dependencies through before loading

    • handleRequest

      public void handleRequest(VaadinRequest request, VaadinResponse response) throws ServiceException
      Handles the incoming request and writes the response into the response object. Uses getRequestHandlers() for handling the request.

      If a session expiration is detected during request handling then each request handler has an opportunity to handle the expiration event if it implements SessionExpiredHandler. If no request handler handles session expiration a default expiration message will be written.

      Parameters:
      request - The incoming request
      response - The outgoing response
      Throws:
      ServiceException - Any exception that occurs during response handling will be wrapped in a ServiceException

    • writeStringResponse

      public void writeStringResponse(VaadinResponse response, String contentType, String responseString) throws IOException
      Writes the given string as a response using the given content type.
      Parameters:
      response - The response reference
      contentType - The content type of the response
      responseString - The actual response
      Throws:
      IOException - If an error occurred while writing the response

    • writeUncachedStringResponse

      public void writeUncachedStringResponse(VaadinResponse response, String contentType, String responseString) throws IOException
      Writes the given string as a response with headers to prevent caching and using the given content type.
      Parameters:
      response - The response reference
      contentType - The content type of the response
      responseString - The actual response
      Throws:
      IOException - If an error occurred while writing the response

    • handleSessionExpired

      protected void handleSessionExpired(VaadinRequest request, VaadinResponse response) throws ServiceException
      Called when the session has expired and the request handling is therefore aborted.
      Parameters:
      request - The request
      response - The response
      Throws:
      ServiceException - Thrown if there was any problem handling the expiration of the session

    • createCriticalNotificationJSON

      public static String createCriticalNotificationJSON(String caption, String message, String details, String url)
      Creates a JSON message which, when sent to client as-is, will cause a critical error to be shown with the given details.
      Parameters:
      caption - The caption of the error or null to omit
      message - The error message or null to omit
      details - Additional error details or null to omit
      url - A url to redirect to. If no other details are given then the user will be immediately redirected to this URL. Otherwise the message will be shown and the browser will redirect to the given URL only after the user acknowledges the message. If null then the browser will refresh the current page.
      Returns:
      A JSON string to be sent to the client

    • createCriticalNotificationJSON

      public static String createCriticalNotificationJSON(String caption, String message, String details, String url, String querySelector)
      Creates a JSON message which, when sent to client as-is, will cause a critical error to be shown with the given details.
      Parameters:
      caption - The caption of the error or null to omit
      message - The error message or null to omit
      details - Additional error details or null to omit
      url - A url to redirect to. If no other details are given then the user will be immediately redirected to this URL. Otherwise the message will be shown and the browser will redirect to the given URL only after the user acknowledges the message. If null then the browser will refresh the current page.
      querySelector - Query selector to find the element under which the error will be added. If the element is not found the message is not shown. If the selector is null, the body element is used.
      Returns:
      A JSON string to be sent to the client

    • createSessionExpiredJSON

      public static String createSessionExpiredJSON(boolean async)
      Creates the JSON to send to the client when the session has expired.
      Parameters:
      async - a boolean indicating whether the message is sent synchronously or asynchronously.
      Returns:
      the JSON used to inform the client about a session expiration, as a string

    • createUINotFoundJSON

      public static String createUINotFoundJSON(boolean async)
      Creates the JSON to send to the client when the UI cannot be found.
      Parameters:
      async - a boolean indicating whether the message is sent synchronously or asynchronously.
      Returns:
      the JSON used to inform the client that the UI cannot be found, as a string

    • ensurePushAvailable

      public boolean ensurePushAvailable()
      Enables push if push support is available and push has not yet been enabled. If push support is not available, a warning explaining the situation will be logged at least the first time this method is invoked.
      Returns:
      true if push can be used; false if push is not available.

    • isAtmosphereAvailable

      protected boolean isAtmosphereAvailable()
      Checks whether Atmosphere is available for use.
      Returns:
      true if Atmosphere is available, false otherwise

    • verifyNoOtherSessionLocked

      public static void verifyNoOtherSessionLocked(VaadinSession session)
      Checks that another VaadinSession instance is not locked. This is internally used by VaadinSession.accessSynchronously(Command) and UI.accessSynchronously(Command) to help avoid causing deadlocks.
      Parameters:
      session - the session that is being locked
      Throws:
      IllegalStateException - if the current thread holds the lock for another session

    • isOtherSessionLocked

      public static boolean isOtherSessionLocked(VaadinSession session)
      Checks whether there might be some VaadinSession other than the provided one for which the current thread holds a lock. This method might not detect all cases where some other session is locked, but it should cover the most typical situations.
      Parameters:
      session - the session that is expected to be locked
      Returns:
      true if another session is also locked by the current thread; false if no such session was found

    • isCsrfTokenValid

      public static boolean isCsrfTokenValid(UI ui, String requestToken)
      Verifies that the given CSRF token (synchronizer token pattern) is valid for the given UI. This is used to protect against Cross Site Request Forgery attacks.

      This protection is enabled by default, but it might need to be disabled to allow a certain type of testing. For these cases, the check can be disabled by setting the init parameter disable-xsrf-protection to true.

      Parameters:
      ui - the UI for which the check should be done
      requestToken - the CSRF token provided in the request
      Returns:
      true if the token is valid or if the protection is disabled; false if protection is enabled and the token is invalid
      See Also:

    • accessSession

      public Future<Void> accessSession(VaadinSession session, Command command)
      Implementation for VaadinSession.access(Command). This method is implemented here instead of in VaadinSession to enable overriding the implementation without using a custom subclass of VaadinSession.
      Parameters:
      session - the vaadin session to access
      command - the command to run with the session locked
      Returns:
      a future that can be used to check for task completion and to cancel the task
      See Also:

    • ensureAccessQueuePurged

      public void ensureAccessQueuePurged(VaadinSession session)
      Makes sure the pending access queue is purged for the provided session. If the session is currently locked by the current thread or some other thread, the queue will be purged when the session is unlocked. If the lock is not held by any thread, it is acquired and the queue is purged right away.
      Parameters:
      session - the session for which the access queue should be purged

    • runPendingAccessTasks

      public void runPendingAccessTasks(VaadinSession session)
      Purges the queue of pending access invocations enqueued with VaadinSession.access(Command).

      This method is automatically run by the framework at appropriate situations and is not intended to be used by application developers.

      Parameters:
      session - the vaadin session to purge the queue for

    • addServiceDestroyListener

      public Registration addServiceDestroyListener(ServiceDestroyListener listener)
      Adds a service destroy listener that gets notified when this service is destroyed.

      The listeners may be invoked in a non-deterministic order. In particular, it is not guaranteed that listeners will be invoked in the order they were added.

      Parameters:
      listener - the service destroy listener to add
      Returns:
      a handle that can be used for removing the listener
      See Also:

    • destroy

      public void destroy()
      Called when the servlet or similar for this service is being destroyed. After this method has been called, no more requests will be handled by this service.
      See Also:

    • setDefaultClassLoader

      protected void setDefaultClassLoader()
      Tries to acquire default class loader and sets it as a class loader for this VaadinService if found. If current security policy disallows acquiring class loader instance it will log a message and re-throw SecurityException
      Throws:
      SecurityException - If current security policy forbids acquiring class loader

    • storeSession

      protected void storeSession(VaadinSession session, WrappedSession wrappedSession)
      Called when the VaadinSession should be stored.

      By default stores the VaadinSession in the underlying HTTP session.

      Parameters:
      session - the VaadinSession to store
      wrappedSession - the underlying HTTP session

    • writeToHttpSession

      protected void writeToHttpSession(WrappedSession wrappedSession, VaadinSession session)
      Performs the actual write of the VaadinSession to the underlying HTTP session after sanity checks have been performed.

      Called by storeSession(VaadinSession, WrappedSession)

      Parameters:
      wrappedSession - the underlying HTTP session
      session - the VaadinSession to store

    • loadSession

      protected VaadinSession loadSession(WrappedSession wrappedSession)
      Called when the VaadinSession should be loaded from the underlying HTTP session.
      Parameters:
      wrappedSession - the underlying HTTP session
      Returns:
      the VaadinSession in the HTTP session or null if not found

    • readFromHttpSession

      protected VaadinSession readFromHttpSession(WrappedSession wrappedSession)
      Performs the actual read of the VaadinSession from the underlying HTTP session after sanity checks have been performed.

      If a VaadinSession that was ignored during serialization is found, it is removed from the session and null is returned so a new, proper session can be created.

      Called by loadSession(WrappedSession).

      Parameters:
      wrappedSession - the underlying HTTP session
      Returns:
      the VaadinSession or null if no session was found

    • removeSession

      public void removeSession(WrappedSession wrappedSession)
      Called when the VaadinSession should be removed from the underlying HTTP session.
      Parameters:
      wrappedSession - the underlying HTTP session

    • removeFromHttpSession

      protected void removeFromHttpSession(WrappedSession wrappedSession)
      Performs the actual removal of the VaadinSession from the underlying HTTP session after sanity checks have been performed.
      Parameters:
      wrappedSession - the underlying HTTP session

    • getSessionAttributeName

      protected String getSessionAttributeName()
      Returns the name used for storing the VaadinSession in the underlying HTTP session.
      Returns:
      the attribute name used for storing the VaadinSession

    • getRouter

      public Router getRouter()
      Gets the router used for UIs served by this service.
      Returns:
      the router, not null

    • fireUIInitListeners

      public void fireUIInitListeners(UI ui)
      Fire UI initialization event to all registered UIInitListeners.
      Parameters:
      ui - the initialized UI

    • getStaticResource

      public abstract URL getStaticResource(String url)
      Returns a URL to the static resource at the given URI or null if no file found.
      Parameters:
      url - the URL for the resource
      Returns:
      the resource located at the named path, or null if there is no resource at that path

    • getResource

      public abstract URL getResource(String url)
      Returns a URL to the resource at the given Vaadin URI.
      Parameters:
      url - the untranslated Vaadin URL for the resource
      Returns:
      the resource located at the named path, or null if there is no resource at that path

    • getResourceAsStream

      public abstract InputStream getResourceAsStream(String url)
      Opens a stream to to the resource at the given Vaadin URI.
      Parameters:
      url - the untranslated Vaadin URL for the resource
      Returns:
      a stream for the resource or null if no resource exists at the specified path

    • isResourceAvailable

      public boolean isResourceAvailable(String url)
      Checks if a resource is available at the given Vaadin URI.
      Parameters:
      url - the untranslated Vaadin URL for the resource
      Returns:
      true if a resource is found and can be read using getResourceAsStream(String), false if it is not found

    • resolveResource

      public abstract String resolveResource(String url)
      Resolves the given url resource to be useful for getResource(String) and getResourceAsStream(String).
      Parameters:
      url - the resource to resolve, not null
      Returns:
      the resolved URL or the same as the input url if no translation was performed

    • constructVaadinContext

      protected abstract VaadinContext constructVaadinContext()
      Constructs VaadinContext for this service. This method will be called only once, upon first call to getContext().
      Returns:
      Context. This may never be null.

    • getContext

      public VaadinContext getContext()
      Returns VaadinContext for this service.
      Returns:
      A non-null context instance.

    • getBootstrapInitialPredicate

      public BootstrapInitialPredicate getBootstrapInitialPredicate()
      Get the predicate for including the initial Uidl fragment in the bootstrap page.

      By default it returns an instance that instruct to include the fragment in the case

      Returns:
      a non-null instance.

    • setBootstrapInitialPredicate

      public void setBootstrapInitialPredicate(BootstrapInitialPredicate bootstrapInitialPredicate)
      Set the predicate that decides whether to include the initial Uidl fragment in the bootstrap page.
      Parameters:
      bootstrapInitialPredicate - the predicate.

    • getBootstrapUrlPredicate

      public BootstrapUrlPredicate getBootstrapUrlPredicate()
      Get the predicate for testing whether the request has a valid URL for rendering the bootstrap page.

      By default it returns an instance that returns true for all requests.

      Returns:
      a non-null instance.

    • setBootstrapUrlPredicate

      public void setBootstrapUrlPredicate(BootstrapUrlPredicate bootstrapUrlPredicate)
      Set the predicate that decides whether the request has a valid URL for rendering the bootstrap page.
      Parameters:
      bootstrapUrlPredicate - the predicate.

    • getCsrfTokenAttributeName

      public static String getCsrfTokenAttributeName()
      Get the name of the CSRF Token attribute in HTTP session.
      Returns:
      the attribute name string