Added in API level 1

Summary: Constants | Ctors | Methods | Inherited Methods

WebViewClient

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Kotlin |Java

public class WebViewClient
extends Object

java.lang.Object
↳	android.webkit.WebViewClient

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Summary

Constants
int	ERROR_AUTHENTICATION User authentication failed on server
int	ERROR_BAD_URL Malformed URL
int	ERROR_CONNECT Failed to connect to the server
int	ERROR_FAILED_SSL_HANDSHAKE Failed to perform SSL handshake
int	ERROR_FILE Generic file error
int	ERROR_FILE_NOT_FOUND File not found
int	ERROR_HOST_LOOKUP Server or proxy hostname lookup failed
int	ERROR_IO Failed to read or write to the server
int	ERROR_PROXY_AUTHENTICATION User authentication failed on proxy
int	ERROR_REDIRECT_LOOP Too many redirects
int	ERROR_TIMEOUT Connection timed out
int	ERROR_TOO_MANY_REQUESTS Too many requests during this load
int	ERROR_UNKNOWN Generic error
int	ERROR_UNSAFE_RESOURCE Resource load was canceled by Safe Browsing
int	ERROR_UNSUPPORTED_AUTH_SCHEME Unsupported authentication scheme (not basic or digest)
int	ERROR_UNSUPPORTED_SCHEME Unsupported URI scheme
int	SAFE_BROWSING_THREAT_BILLING The resource was blocked because it may trick the user into a billing agreement.
int	SAFE_BROWSING_THREAT_MALWARE The resource was blocked because it contains malware.
int	SAFE_BROWSING_THREAT_PHISHING The resource was blocked because it contains deceptive content.
int	SAFE_BROWSING_THREAT_UNKNOWN The resource was blocked for an unknown reason.
int	SAFE_BROWSING_THREAT_UNWANTED_SOFTWARE The resource was blocked because it contains unwanted software.

Public constructors
WebViewClient()

Public methods
void	doUpdateVisitedHistory(WebView view, String url, boolean isReload) Notify the host application to update its visited links database.
void	onFormResubmission(WebView view, Message dontResend, Message resend) As the host application if the browser should resend data as the requested page was a result of a POST.
void	onLoadResource(WebView view, String url) Notify the host application that the WebView will load the resource specified by the given url.
void	onPageCommitVisible(WebView view, String url) Notify the host application that WebView content left over from previous page navigations will no longer be drawn.
void	onPageFinished(WebView view, String url) Notify the host application that a page has finished loading.
void	onPageStarted(WebView view, String url, Bitmap favicon) Notify the host application that a page has started loading.
void	onReceivedClientCertRequest(WebView view, ClientCertRequest request) Notify the host application to handle a SSL client certificate request.
void	onReceivedError(WebView view, int errorCode, String description, String failingUrl) This method was deprecated in API level 23. Use onReceivedError(WebView, WebResourceRequest, WebResourceError) instead.
void	onReceivedError(WebView view, WebResourceRequest request, WebResourceError error) Report web resource loading error to the host application.
void	onReceivedHttpAuthRequest(WebView view, HttpAuthHandler handler, String host, String realm) Notifies the host application that the WebView received an HTTP authentication request.
void	onReceivedHttpError(WebView view, WebResourceRequest request, WebResourceResponse errorResponse) Notify the host application that an HTTP error has been received from the server while loading a resource.
void	onReceivedLoginRequest(WebView view, String realm, String account, String args) Notify the host application that a request to automatically log in the user has been processed.
void	onReceivedSslError(WebView view, SslErrorHandler handler, SslError error) Notifies the host application that an SSL error occurred while loading a resource.
boolean	onRenderProcessGone(WebView view, RenderProcessGoneDetail detail) Notify host application that the given WebView's render process has exited.
void	onSafeBrowsingHit(WebView view, WebResourceRequest request, int threatType, SafeBrowsingResponse callback) Notify the host application that a loading URL has been flagged by Safe Browsing.
void	onScaleChanged(WebView view, float oldScale, float newScale) Notify the host application that the scale applied to the WebView has changed.
void	onTooManyRedirects(WebView view, Message cancelMsg, Message continueMsg) This method was deprecated in API level 15. This method is no longer called. When the WebView encounters a redirect loop, it will cancel the load.
void	onUnhandledKeyEvent(WebView view, KeyEvent event) Notify the host application that a key was not handled by the WebView.
WebResourceResponse	shouldInterceptRequest(WebView view, WebResourceRequest request) Notify the host application of a resource request and allow the application to return the data.
WebResourceResponse	shouldInterceptRequest(WebView view, String url) This method was deprecated in API level 21. Use shouldInterceptRequest(WebView, WebResourceRequest) instead.
boolean	shouldOverrideKeyEvent(WebView view, KeyEvent event) Give the host application a chance to handle the key event synchronously.
boolean	shouldOverrideUrlLoading(WebView view, WebResourceRequest request) Give the host application a chance to take control when a URL is about to be loaded in the current WebView.
boolean	shouldOverrideUrlLoading(WebView view, String url) This method was deprecated in API level 24. Use shouldOverrideUrlLoading(WebView, WebResourceRequest) instead.

Inherited methods

From class java.lang.Object Object clone() Creates and returns a copy of this object. boolean equals(Object obj) Indicates whether some other object is "equal to" this one. void finalize() Called by the garbage collector on an object when garbage collection determines that there are no more references to the object. final Class<?> getClass() Returns the runtime class of this Object. int hashCode() Returns a hash code value for the object. final void notify() Wakes up a single thread that is waiting on this object's monitor. final void notifyAll() Wakes up all threads that are waiting on this object's monitor. String toString() Returns a string representation of the object. final void wait(long timeoutMillis, int nanos) Causes the current thread to wait until it is awakened, typically by being notified or interrupted, or until a certain amount of real time has elapsed. final void wait(long timeoutMillis) Causes the current thread to wait until it is awakened, typically by being notified or interrupted, or until a certain amount of real time has elapsed. final void wait() Causes the current thread to wait until it is awakened, typically by being notified or interrupted.

Constants

ERROR_AUTHENTICATION

Added in API level 5

public static final int ERROR_AUTHENTICATION

User authentication failed on server

Constant Value: -4 (0xfffffffc)

ERROR_BAD_URL

Added in API level 5

public static final int ERROR_BAD_URL

Malformed URL

Constant Value: -12 (0xfffffff4)

ERROR_CONNECT

Added in API level 5

public static final int ERROR_CONNECT

Failed to connect to the server

Constant Value: -6 (0xfffffffa)

ERROR_FAILED_SSL_HANDSHAKE

Added in API level 5

public static final int ERROR_FAILED_SSL_HANDSHAKE

Failed to perform SSL handshake

Constant Value: -11 (0xfffffff5)

ERROR_FILE

Added in API level 5

public static final int ERROR_FILE

Generic file error

Constant Value: -13 (0xfffffff3)

ERROR_FILE_NOT_FOUND

Added in API level 5

public static final int ERROR_FILE_NOT_FOUND

File not found

Constant Value: -14 (0xfffffff2)

ERROR_HOST_LOOKUP

Added in API level 5

public static final int ERROR_HOST_LOOKUP

Server or proxy hostname lookup failed

Constant Value: -2 (0xfffffffe)

ERROR_IO

Added in API level 5

public static final int ERROR_IO

Failed to read or write to the server

Constant Value: -7 (0xfffffff9)

ERROR_PROXY_AUTHENTICATION

Added in API level 5

public static final int ERROR_PROXY_AUTHENTICATION

User authentication failed on proxy

Constant Value: -5 (0xfffffffb)

ERROR_REDIRECT_LOOP

Added in API level 5

public static final int ERROR_REDIRECT_LOOP

Too many redirects

Constant Value: -9 (0xfffffff7)

ERROR_TIMEOUT

Added in API level 5

public static final int ERROR_TIMEOUT

Connection timed out

Constant Value: -8 (0xfffffff8)

ERROR_TOO_MANY_REQUESTS

Added in API level 5

public static final int ERROR_TOO_MANY_REQUESTS

Too many requests during this load

Constant Value: -15 (0xfffffff1)

ERROR_UNKNOWN

Added in API level 5

public static final int ERROR_UNKNOWN

Generic error

Constant Value: -1 (0xffffffff)

ERROR_UNSAFE_RESOURCE

Added in API level 26

public static final int ERROR_UNSAFE_RESOURCE

Resource load was canceled by Safe Browsing

Constant Value: -16 (0xfffffff0)

ERROR_UNSUPPORTED_AUTH_SCHEME

Added in API level 5

public static final int ERROR_UNSUPPORTED_AUTH_SCHEME

Unsupported authentication scheme (not basic or digest)

Constant Value: -3 (0xfffffffd)

ERROR_UNSUPPORTED_SCHEME

Added in API level 5

public static final int ERROR_UNSUPPORTED_SCHEME

Unsupported URI scheme

Constant Value: -10 (0xfffffff6)

SAFE_BROWSING_THREAT_BILLING

Added in API level 29

public static final int SAFE_BROWSING_THREAT_BILLING

The resource was blocked because it may trick the user into a billing agreement.

This constant is only used when targetSdkVersion is at least Build.VERSION_CODES.Q. Otherwise, SAFE_BROWSING_THREAT_UNKNOWN is used instead.

Constant Value: 4 (0x00000004)

SAFE_BROWSING_THREAT_MALWARE

Added in API level 27

public static final int SAFE_BROWSING_THREAT_MALWARE

The resource was blocked because it contains malware.

Constant Value: 1 (0x00000001)

SAFE_BROWSING_THREAT_PHISHING

Added in API level 27

public static final int SAFE_BROWSING_THREAT_PHISHING

The resource was blocked because it contains deceptive content.

Constant Value: 2 (0x00000002)

SAFE_BROWSING_THREAT_UNKNOWN

Added in API level 27

public static final int SAFE_BROWSING_THREAT_UNKNOWN

The resource was blocked for an unknown reason.

Constant Value: 0 (0x00000000)

SAFE_BROWSING_THREAT_UNWANTED_SOFTWARE

Added in API level 27

public static final int SAFE_BROWSING_THREAT_UNWANTED_SOFTWARE

The resource was blocked because it contains unwanted software.

Constant Value: 3 (0x00000003)

Public constructors

WebViewClient

public WebViewClient ()

Public methods

doUpdateVisitedHistory

Added in API level 1

public void doUpdateVisitedHistory (WebView view, 
                String url, 
                boolean isReload)

Notify the host application to update its visited links database.

Parameters
view	WebView: The WebView that is initiating the callback.
url	String: The url being visited.
isReload	boolean: true if this url is being reloaded.

onFormResubmission

Added in API level 1

public void onFormResubmission (WebView view, 
                Message dontResend, 
                Message resend)

As the host application if the browser should resend data as the requested page was a result of a POST. The default is to not resend the data.

Parameters
view	WebView: The WebView that is initiating the callback.
dontResend	Message: The message to send if the browser should not resend
resend	Message: The message to send if the browser should resend data

onLoadResource

Added in API level 1

public void onLoadResource (WebView view, 
                String url)

Notify the host application that the WebView will load the resource specified by the given url.

Parameters
view	WebView: The WebView that is initiating the callback.
url	String: The url of the resource the WebView will load.

onPageCommitVisible

Added in API level 23

public void onPageCommitVisible (WebView view, 
                String url)

Notify the host application that WebView content left over from previous page navigations will no longer be drawn.

This callback can be used to determine the point at which it is safe to make a recycled WebView visible, ensuring that no stale content is shown. It is called at the earliest point at which it can be guaranteed that WebView#onDraw will no longer draw any content from previous navigations. The next draw will display either the background color of the WebView, or some of the contents of the newly loaded page.

This method is called when the body of the HTTP response has started loading, is reflected in the DOM, and will be visible in subsequent draws. This callback occurs early in the document loading process, and as such you should expect that linked resources (for example, CSS and images) may not be available.

For more fine-grained notification of visual state updates, see WebView.postVisualStateCallback(long, VisualStateCallback).

Please note that all the conditions and recommendations applicable to WebView#postVisualStateCallback also apply to this API.

This callback is only called for main frame navigations.

Parameters
view	WebView: The WebView for which the navigation occurred.
url	String: The URL corresponding to the page navigation that triggered this callback.

onPageFinished

Added in API level 1

public void onPageFinished (WebView view, 
                String url)

Notify the host application that a page has finished loading. This method is called only for main frame. Receiving an onPageFinished() callback does not guarantee that the next frame drawn by WebView will reflect the state of the DOM at this point. In order to be notified that the current DOM state is ready to be rendered, request a visual state callback with WebView#postVisualStateCallback and wait for the supplied callback to be triggered.

Parameters
view	WebView: The WebView that is initiating the callback.
url	String: The url of the page.

onPageStarted

Added in API level 1

public void onPageStarted (WebView view, 
                String url, 
                Bitmap favicon)

Notify the host application that a page has started loading. This method is called once for each main frame load so a page with iframes or framesets will call onPageStarted one time for the main frame. This also means that onPageStarted will not be called when the contents of an embedded frame changes, i.e. clicking a link whose target is an iframe, it will also not be called for fragment navigations (navigations to #fragment_id).

Parameters
view	WebView: The WebView that is initiating the callback.
url	String: The url to be loaded.
favicon	Bitmap: The favicon for this page if it already exists in the database.

onReceivedClientCertRequest

Added in API level 21

public void onReceivedClientCertRequest (WebView view, 
                ClientCertRequest request)

Notify the host application to handle a SSL client certificate request. The host application is responsible for showing the UI if desired and providing the keys. There are three ways to respond: ClientCertRequest#proceed, ClientCertRequest#cancel, or ClientCertRequest.ignore(). Webview stores the response in memory (for the life of the application) if ClientCertRequest#proceed or ClientCertRequest#cancel is called and does not call onReceivedClientCertRequest() again for the same host and port pair. Webview does not store the response if ClientCertRequest#ignore is called. Note that, multiple layers in chromium network stack might be caching the responses, so the behavior for ignore is only a best case effort. This method is called on the UI thread. During the callback, the connection is suspended. For most use cases, the application program should implement the KeyChainAliasCallback interface and pass it to KeyChain.choosePrivateKeyAlias(Activity, KeyChainAliasCallback, String, Principal, Uri, String) to start an activity for the user to choose the proper alias. The keychain activity will provide the alias through the callback method in the implemented interface. Next the application should create an async task to call KeyChain.getPrivateKey(Context, String) to receive the key. An example implementation of client certificates can be seen at AOSP Browser The default behavior is to cancel, returning no client certificate.

Parameters
view	WebView: The WebView that is initiating the callback
request	ClientCertRequest: An instance of a ClientCertRequest

onReceivedError

Added in API level 1
Deprecated in API level 23

public void onReceivedError (WebView view, 
                int errorCode, 
                String description, 
                String failingUrl)

This method was deprecated in API level 23.
Use onReceivedError(WebView, WebResourceRequest, WebResourceError) instead.

Report an error to the host application. These errors are unrecoverable (i.e. the main resource is unavailable). The errorCode parameter corresponds to one of the ERROR_* constants.

Parameters
view	WebView: The WebView that is initiating the callback.
errorCode	int: The error code corresponding to an ERROR_* value.
description	String: A String describing the error.
failingUrl	String: The url that failed to load.

onReceivedError

Added in API level 23

public void onReceivedError (WebView view, 
                WebResourceRequest request, 
                WebResourceError error)

Report web resource loading error to the host application. These errors usually indicate inability to connect to the server. Note that unlike the deprecated version of the callback, the new version will be called for any resource (iframe, image, etc.), not just for the main page. Thus, it is recommended to perform minimum required work in this callback.

Parameters
view	WebView: The WebView that is initiating the callback.
request	WebResourceRequest: The originating request.
error	WebResourceError: Information about the error occurred.

onReceivedHttpAuthRequest

Added in API level 1

public void onReceivedHttpAuthRequest (WebView view, 
                HttpAuthHandler handler, 
                String host, 
                String realm)

Notifies the host application that the WebView received an HTTP authentication request. The host application can use the supplied HttpAuthHandler to set the WebView's response to the request. The default behavior is to cancel the request.

Note: The supplied HttpAuthHandler must be used on the UI thread.

Parameters
view	WebView: the WebView that is initiating the callback
handler	HttpAuthHandler: the HttpAuthHandler used to set the WebView's response
host	String: the host requiring authentication
realm	String: the realm for which authentication is required

See also:

• WebView.getHttpAuthUsernamePassword(String, String)

onReceivedHttpError

Added in API level 23

public void onReceivedHttpError (WebView view, 
                WebResourceRequest request, 
                WebResourceResponse errorResponse)

Notify the host application that an HTTP error has been received from the server while loading a resource. HTTP errors have status codes >= 400. This callback will be called for any resource (iframe, image, etc.), not just for the main page. Thus, it is recommended to perform minimum required work in this callback. Note that the content of the server response may not be provided within the errorResponse parameter.

Parameters
view	WebView: The WebView that is initiating the callback.
request	WebResourceRequest: The originating request.
errorResponse	WebResourceResponse: Information about the error occurred.

onReceivedLoginRequest

Added in API level 12

public void onReceivedLoginRequest (WebView view, 
                String realm, 
                String account, 
                String args)

Notify the host application that a request to automatically log in the user has been processed.

Parameters
view	WebView: The WebView requesting the login.
realm	String: The account realm used to look up accounts.
account	String: An optional account. If not null, the account should be checked against accounts on the device. If it is a valid account, it should be used to log in the user.
args	String: Authenticator specific arguments used to log in the user.

onReceivedSslError

Added in API level 8

public void onReceivedSslError (WebView view, 
                SslErrorHandler handler, 
                SslError error)

Notifies the host application that an SSL error occurred while loading a resource. The host application must call either SslErrorHandler#cancel() or SslErrorHandler#proceed().

Warning: Application overrides of this method can be used to display custom error pages or to silently log issues, but the host application should always call SslErrorHandler#cancel() and never proceed past errors.

Note: Do not prompt the user about SSL errors. Users are unlikely to be able to make an informed security decision, and WebView does not provide a UI for showing the details of the error in a meaningful way.

The decision to call proceed() or cancel() may be retained to facilitate responses to future SSL errors. The default behavior is to cancel the resource loading process.

This API is called only for recoverable SSL certificate errors. For non-recoverable errors (such as when the server fails the client), the WebView calls onReceivedError(WebView, WebResourceRequest, WebResourceError) with the ERROR_FAILED_SSL_HANDSHAKE argument.

Parameters
view	WebView: WebView that initiated the callback.
handler	SslErrorHandler: SslErrorHandler that handles the user's response.
error	SslError: SSL error object.

onRenderProcessGone

Added in API level 26

public boolean onRenderProcessGone (WebView view, 
                RenderProcessGoneDetail detail)

Notify host application that the given WebView's render process has exited. Multiple WebView instances may be associated with a single render process; onRenderProcessGone will be called for each WebView that was affected. The application's implementation of this callback should only attempt to clean up the specific WebView given as a parameter, and should not assume that other WebView instances are affected. The given WebView can't be used, and should be removed from the view hierarchy, all references to it should be cleaned up, e.g any references in the Activity or other classes saved using View.findViewById(int) and similar calls, etc. To cause an render process crash for test purpose, the application can call loadUrl("chrome://crash") on the WebView. Note that multiple WebView instances may be affected if they share a render process, not just the specific WebView which loaded chrome://crash.

Parameters
view	WebView: The WebView which needs to be cleaned up.
detail	RenderProcessGoneDetail: the reason why it exited.

Returns
boolean	true if the host application handled the situation that process has exited, otherwise, application will crash if render process crashed, or be killed if render process was killed by the system.

onSafeBrowsingHit

Added in API level 27

public void onSafeBrowsingHit (WebView view, 
                WebResourceRequest request, 
                int threatType, 
                SafeBrowsingResponse callback)

Notify the host application that a loading URL has been flagged by Safe Browsing. The application must invoke the callback to indicate the preferred response. The default behavior is to show an interstitial to the user, with the reporting checkbox visible. If the application needs to show its own custom interstitial UI, the callback can be invoked asynchronously with SafeBrowsingResponse#backToSafety or SafeBrowsingResponse.proceed(boolean), depending on user response.

Parameters
view	WebView: The WebView that hit the malicious resource.
request	WebResourceRequest: Object containing the details of the request.
threatType	int: The reason the resource was caught by Safe Browsing, corresponding to a SAFE_BROWSING_THREAT_* value. Value is SAFE_BROWSING_THREAT_UNKNOWN, SAFE_BROWSING_THREAT_MALWARE, SAFE_BROWSING_THREAT_PHISHING, SAFE_BROWSING_THREAT_UNWANTED_SOFTWARE, or SAFE_BROWSING_THREAT_BILLING
callback	SafeBrowsingResponse: Applications must invoke one of the callback methods.

onScaleChanged

Added in API level 1

public void onScaleChanged (WebView view, 
                float oldScale, 
                float newScale)

Notify the host application that the scale applied to the WebView has changed.

Parameters
view	WebView: The WebView that is initiating the callback.
oldScale	float: The old scale factor
newScale	float: The new scale factor

onTooManyRedirects

Added in API level 1
Deprecated in API level 15

public void onTooManyRedirects (WebView view, 
                Message cancelMsg, 
                Message continueMsg)

This method was deprecated in API level 15.
This method is no longer called. When the WebView encounters a redirect loop, it will cancel the load.

Notify the host application that there have been an excessive number of HTTP redirects. As the host application if it would like to continue trying to load the resource. The default behavior is to send the cancel message.

Parameters
view	WebView: The WebView that is initiating the callback.
cancelMsg	Message: The message to send if the host wants to cancel
continueMsg	Message: The message to send if the host wants to continue

onUnhandledKeyEvent

Added in API level 1

public void onUnhandledKeyEvent (WebView view, 
                KeyEvent event)

Notify the host application that a key was not handled by the WebView. Except system keys, WebView always consumes the keys in the normal flow or if shouldOverrideKeyEvent(WebView, KeyEvent) returns true. This is called asynchronously from where the key is dispatched. It gives the host application a chance to handle the unhandled key events.

Parameters
view	WebView: The WebView that is initiating the callback.
event	KeyEvent: The key event.

shouldInterceptRequest

Added in API level 21

public WebResourceResponse shouldInterceptRequest (WebView view, 
                WebResourceRequest request)

Notify the host application of a resource request and allow the application to return the data. If the return value is null, the WebView will continue to load the resource as usual. Otherwise, the return response and data will be used.

This callback is invoked for a variety of URL schemes (e.g., http(s):, data:, file:, etc.), not only those schemes which send requests over the network. This is not called for javascript: URLs, blob: URLs, or for assets accessed via file:///android_asset/ or file:///android_res/ URLs.

In the case of redirects, this is only called for the initial resource URL, not any subsequent redirect URLs.

Note: This method is called on a thread other than the UI thread so clients should exercise caution when accessing private data or the view system.

Note: When Safe Browsing is enabled, these URLs still undergo Safe Browsing checks. If this is undesired, you can use WebView#setSafeBrowsingWhitelist to skip Safe Browsing checks for that host or dismiss the warning in onSafeBrowsingHit(WebView, WebResourceRequest, int, SafeBrowsingResponse) by calling SafeBrowsingResponse#proceed.

Parameters
view	WebView: The WebView that is requesting the resource.
request	WebResourceRequest: Object containing the details of the request.

Returns
WebResourceResponse	A WebResourceResponse containing the response information or null if the WebView should load the resource itself.

shouldInterceptRequest

Added in API level 11
Deprecated in API level 21

public WebResourceResponse shouldInterceptRequest (WebView view, 
                String url)

This method was deprecated in API level 21.
Use shouldInterceptRequest(WebView, WebResourceRequest) instead.

Notify the host application of a resource request and allow the application to return the data. If the return value is null, the WebView will continue to load the resource as usual. Otherwise, the return response and data will be used.

This callback is invoked for a variety of URL schemes (e.g., http(s):, data:, file:, etc.), not only those schemes which send requests over the network. This is not called for javascript: URLs, blob: URLs, or for assets accessed via file:///android_asset/ or file:///android_res/ URLs.

In the case of redirects, this is only called for the initial resource URL, not any subsequent redirect URLs.

Note: This method is called on a thread other than the UI thread so clients should exercise caution when accessing private data or the view system.

Note: When Safe Browsing is enabled, these URLs still undergo Safe Browsing checks. If this is undesired, you can use WebView#setSafeBrowsingWhitelist to skip Safe Browsing checks for that host or dismiss the warning in onSafeBrowsingHit(WebView, WebResourceRequest, int, SafeBrowsingResponse) by calling SafeBrowsingResponse#proceed.

Parameters
view	WebView: The WebView that is requesting the resource.
url	String: The raw url of the resource.

Returns
WebResourceResponse	A WebResourceResponse containing the response information or null if the WebView should load the resource itself.

shouldOverrideKeyEvent

Added in API level 1

public boolean shouldOverrideKeyEvent (WebView view, 
                KeyEvent event)

Give the host application a chance to handle the key event synchronously. e.g. menu shortcut key events need to be filtered this way. If return true, WebView will not handle the key event. If return false, WebView will always handle the key event, so none of the super in the view chain will see the key event. The default behavior returns false.

Parameters
view	WebView: The WebView that is initiating the callback.
event	KeyEvent: The key event.

Returns
boolean	true if the host application wants to handle the key event itself, otherwise return false

shouldOverrideUrlLoading

Added in API level 24

public boolean shouldOverrideUrlLoading (WebView view, 
                WebResourceRequest request)

Give the host application a chance to take control when a URL is about to be loaded in the current WebView. If a WebViewClient is not provided, by default WebView will ask Activity Manager to choose the proper handler for the URL. If a WebViewClient is provided, returning true causes the current WebView to abort loading the URL, while returning false causes the WebView to continue loading the URL as usual.

This callback is not called for all page navigations. In particular, this is not called for navigations which the app initiated with loadUrl(): this callback would not serve a purpose in this case, because the app already knows about the navigation. This callback lets the app know about navigations initiated by the web page (such as navigations initiated by JavaScript code), by the user (such as when the user taps on a link), or by an HTTP redirect (ex. if loadUrl("foo.com") redirects to "bar.com" because of HTTP 301).

Note: Do not call WebView#loadUrl(String) with the request's URL and then return true. This unnecessarily cancels the current load and starts a new load with the same URL. The correct way to continue loading a given URL is to simply return false, without calling WebView#loadUrl(String).

Note: This method is not called for POST requests.

Note: This method may be called for subframes and with non-HTTP(S) schemes; calling WebView#loadUrl(String) with such a URL will fail.

Parameters
view	WebView: The WebView that is initiating the callback.
request	WebResourceRequest: Object containing the details of the request.

Returns
boolean	true to cancel the current load, otherwise return false.

shouldOverrideUrlLoading

Added in API level 1
Deprecated in API level 24

public boolean shouldOverrideUrlLoading (WebView view, 
                String url)

This method was deprecated in API level 24.
Use shouldOverrideUrlLoading(WebView, WebResourceRequest) instead.

Give the host application a chance to take control when a URL is about to be loaded in the current WebView. If a WebViewClient is not provided, by default WebView will ask Activity Manager to choose the proper handler for the URL. If a WebViewClient is provided, returning true causes the current WebView to abort loading the URL, while returning false causes the WebView to continue loading the URL as usual.

Note: Do not call WebView#loadUrl(String) with the same URL and then return true. This unnecessarily cancels the current load and starts a new load with the same URL. The correct way to continue loading a given URL is to simply return false, without calling WebView#loadUrl(String).

Note: This method is not called for POST requests.

Note: This method may be called for subframes and with non-HTTP(S) schemes; calling WebView#loadUrl(String) with such a URL will fail.

Parameters
view	WebView: The WebView that is initiating the callback.
url	String: The URL to be loaded.

Returns
boolean	true to cancel the current load, otherwise return false.