com.vaadin.flow.server

Class HandlerHelper

java.lang.Object

com.vaadin.flow.server.HandlerHelper

All Implemented Interfaces:

Serializable

public class HandlerHelper
extends Object
implements Serializable

Contains helper methods for VaadinServlet and generally for handling VaadinRequests.

Since:

1.0

See Also:

Serialized Form

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	HandlerHelper.RequestType Framework internal enum for tracking the type of a request.

Method Summary

Modifier and Type	Method and Description
static Locale	findLocale(VaadinSession session, VaadinRequest request) Helper to find the most most suitable Locale.
static String	getCancelingRelativePath(String pathToCancel) Gets a relative path that cancels the provided path.
static boolean	isPathUnsafe(String path) Checks if the given URL path contains the directory change instruction (dot-dot), taking into account possible double encoding in hexadecimal format, which can be injected maliciously.
static boolean	isRequestType(VaadinRequest request, HandlerHelper.RequestType requestType) Returns whether the given request is of the given type.
static void	setResponseNoCacheHeaders(BiConsumer<String,String> headerSetter, BiConsumer<String,Long> longHeaderSetter) Sets no cache headers to the specified response.

Methods inherited from class java.lang.Object

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

Method Detail

isRequestType

public static boolean isRequestType(VaadinRequest request,
                                    HandlerHelper.RequestType requestType)

Returns whether the given request is of the given type.

Parameters:

request - the request to check

requestType - the type to check for

Returns:

true if the request is of the given type, false otherwise

findLocale

public static Locale findLocale(VaadinSession session,
                                VaadinRequest request)

Helper to find the most most suitable Locale. These potential sources are checked in order until a Locale is found:

1. The passed component (or UI) if not null
2. UI.getCurrent() if defined
3. The passed session if not null
4. VaadinSession.getCurrent() if defined
5. The passed request if not null
6. VaadinService.getCurrentRequest() if defined
7. Locale.getDefault()

Parameters:

session - the session that is searched for locale or null if not available

request - the request that is searched for locale or null if not available

Returns:

the found locale

setResponseNoCacheHeaders

public static void setResponseNoCacheHeaders(BiConsumer<String,String> headerSetter,
                                             BiConsumer<String,Long> longHeaderSetter)

Sets no cache headers to the specified response.

Parameters:

headerSetter - setter for string value headers

longHeaderSetter - setter for long value headers

getCancelingRelativePath

public static String getCancelingRelativePath(String pathToCancel)

Gets a relative path that cancels the provided path. This essentially adds one .. for each part of the path to cancel.

Parameters:

pathToCancel - the path that should be canceled

Returns:

a relative path that cancels out the provided path segment

isPathUnsafe

public static boolean isPathUnsafe(String path)

Checks if the given URL path contains the directory change instruction (dot-dot), taking into account possible double encoding in hexadecimal format, which can be injected maliciously.

Parameters:

path - the URL path to be verified.

Returns:

true, if the given path has a directory change instruction, false otherwise.