com.vaadin.flow.server

Class BootstrapHandler

java.lang.Object

com.vaadin.flow.server.SynchronizedRequestHandler

com.vaadin.flow.server.BootstrapHandler

All Implemented Interfaces:

RequestHandler, Serializable

Direct Known Subclasses:

WebComponentBootstrapHandler

public class BootstrapHandler
extends SynchronizedRequestHandler

Request handler which handles bootstrapping of the application, i.e. the initial GET request.

Since:

1.0

Author:

Vaadin Ltd

See Also:

Serialized Form

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
protected static class	BootstrapHandler.BootstrapContext Provides context information for the bootstrap process.
protected static class	BootstrapHandler.BootstrapPageBuilder Builds bootstrap pages.
static class	BootstrapHandler.BootstrapUriResolver The URI resolver used in the bootstrap process.
static interface	BootstrapHandler.PageBuilder Interface for objects capable of building the bootstrap page.

Field Summary

Fields

Modifier and Type	Field and Description
static String	POLYFILLS_JS
static String	SERVICE_WORKER_HEADER

Constructor Summary

Constructors

Modifier	Constructor and Description
	BootstrapHandler() Creates an instance of the handler with default BootstrapHandler.PageBuilder.
protected	BootstrapHandler(BootstrapHandler.PageBuilder pageBuilder) Creates an instance of the handler using provided page builder.

Method Summary

Modifier and Type	Method and Description
static void	addLicenseChecker(org.jsoup.nodes.Document indexDocument, DeploymentConfiguration config) Adds the needed overrides for the license checker to work when in development mode.
protected boolean	canHandleRequest(VaadinRequest request) Check whether a request may be handled by this handler.
protected BootstrapHandler.BootstrapContext	createAndInitUI(Class<? extends UI> uiClass, VaadinRequest request, VaadinResponse response, VaadinSession session)
protected BootstrapHandler.BootstrapContext	createBootstrapContext(VaadinRequest request, VaadinResponse response, UI ui, Function<VaadinRequest,String> contextPathCallback) Creates a new instance of BootstrapHandler.BootstrapContext for given request, response and ui.
protected elemental.json.JsonObject	getInitialUidl(UI ui) Generates the initial UIDL message which is included in the initial bootstrap page.
protected BootstrapHandler.PageBuilder	getPageBuilder() Returns the current page builder object.
protected static String	getServiceUrl(BootstrapHandler.BootstrapContext context) Gets the service URL as a URL relative to the request URI.
protected static Class<? extends UI>	getUIClass(VaadinRequest request) Returns the UI class mapped for servlet that handles the given request.
protected void	initializeUIWithRouter(VaadinRequest request, UI ui)
protected static String	readResource(String fileName)
protected static Optional<String>	resolvePageTitle(BootstrapHandler.BootstrapContext context) Resolves the initial page title for the given bootstrap context and cancels any pending JS execution for it.
protected void	setupPushConnectionFactory(PushConfiguration pushConfiguration, BootstrapHandler.BootstrapContext context)
boolean	synchronizedHandleRequest(VaadinSession session, VaadinRequest request, VaadinResponse response) Identical to SynchronizedRequestHandler.handleRequest(VaadinSession, VaadinRequest, VaadinResponse) except the VaadinSession is locked before this is called and unlocked after this has completed.
protected boolean	writeErrorCodeIfRequestLocationIsInvalid(VaadinRequest request, VaadinResponse response) Checks whether the request is for a valid location, and if not, writes the error code for the response.

Methods inherited from class com.vaadin.flow.server.SynchronizedRequestHandler

handleRequest

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

POLYFILLS_JS

public static final String POLYFILLS_JS

See Also:

Constant Field Values

SERVICE_WORKER_HEADER

public static final String SERVICE_WORKER_HEADER

See Also:

Constant Field Values

Constructor Detail

BootstrapHandler

public BootstrapHandler()

Creates an instance of the handler with default BootstrapHandler.PageBuilder.

BootstrapHandler

protected BootstrapHandler(BootstrapHandler.PageBuilder pageBuilder)

Creates an instance of the handler using provided page builder.

Parameters:

pageBuilder - Page builder to use.

Method Detail

getPageBuilder

protected BootstrapHandler.PageBuilder getPageBuilder()

Returns the current page builder object.

Returns:

Page builder in charge of constructing the resulting page.

canHandleRequest

protected boolean canHandleRequest(VaadinRequest request)

Description copied from class: SynchronizedRequestHandler

Check whether a request may be handled by this handler. This can be used as an optimization to avoid locking the session just to investigate some method property. The default implementation just returns true which means that all requests will be handled by calling SynchronizedRequestHandler.synchronizedHandleRequest(VaadinSession, VaadinRequest, VaadinResponse) with the session locked.

Overrides:

canHandleRequest in class SynchronizedRequestHandler

Parameters:

request - the request to handle

Returns:

true if the request handling should continue once the session has been locked; false if there's no need to lock the session since the request would still not be handled.

synchronizedHandleRequest

public boolean synchronizedHandleRequest(VaadinSession session,
                                         VaadinRequest request,
                                         VaadinResponse response)
                                  throws IOException

Description copied from class: SynchronizedRequestHandler

Identical to SynchronizedRequestHandler.handleRequest(VaadinSession, VaadinRequest, VaadinResponse) except the VaadinSession is locked before this is called and unlocked after this has completed.

Specified by:

synchronizedHandleRequest in class SynchronizedRequestHandler

Parameters:

session - The session for the request

request - The request to handle

response - The response object to which a response can be written.

Returns:

true if a response has been written and no further request handlers should be called, otherwise false

Throws:

IOException - If an IO error occurred

See Also:

SynchronizedRequestHandler.handleRequest(VaadinSession, VaadinRequest, VaadinResponse)

addLicenseChecker

public static void addLicenseChecker(org.jsoup.nodes.Document indexDocument,
                                     DeploymentConfiguration config)

Adds the needed overrides for the license checker to work when in development mode.

writeErrorCodeIfRequestLocationIsInvalid

protected boolean writeErrorCodeIfRequestLocationIsInvalid(VaadinRequest request,
                                                           VaadinResponse response)
                                                    throws IOException

Checks whether the request is for a valid location, and if not, writes the error code for the response.

Parameters:

request - the request to check

response - the response to write

Returns:

true if location was invalid and error code was written, false if not (location was valid)

Throws:

IOException - in case writing to response fails

getServiceUrl

protected static String getServiceUrl(BootstrapHandler.BootstrapContext context)

Gets the service URL as a URL relative to the request URI.

Parameters:

context - the bootstrap context

Returns:

the relative service URL

resolvePageTitle

protected static Optional<String> resolvePageTitle(BootstrapHandler.BootstrapContext context)

Resolves the initial page title for the given bootstrap context and cancels any pending JS execution for it.

Parameters:

context - the bootstrap context

Returns:

the optional initial page title

createAndInitUI

protected BootstrapHandler.BootstrapContext createAndInitUI(Class<? extends UI> uiClass,
                                                            VaadinRequest request,
                                                            VaadinResponse response,
                                                            VaadinSession session)

initializeUIWithRouter

protected void initializeUIWithRouter(VaadinRequest request,
                                      UI ui)

createBootstrapContext

protected BootstrapHandler.BootstrapContext createBootstrapContext(VaadinRequest request,
                                                                   VaadinResponse response,
                                                                   UI ui,
                                                                   Function<VaadinRequest,String> contextPathCallback)

Creates a new instance of BootstrapHandler.BootstrapContext for given request, response and ui.

Parameters:

request - the request object

response - the response object

ui - the UI object

Returns:

a new bootstrap context instance

setupPushConnectionFactory

protected void setupPushConnectionFactory(PushConfiguration pushConfiguration,
                                          BootstrapHandler.BootstrapContext context)

getUIClass

protected static Class<? extends UI> getUIClass(VaadinRequest request)

Returns the UI class mapped for servlet that handles the given request.

This method is protected for testing purposes.

Parameters:

request - the request for the UI

Returns:

the UI class for the request

readResource

protected static String readResource(String fileName)

getInitialUidl

protected elemental.json.JsonObject getInitialUidl(UI ui)

Generates the initial UIDL message which is included in the initial bootstrap page.

Parameters:

ui - the UI for which the UIDL should be generated

Returns:

a JSON object with the initial UIDL message