WebViewClient
  public
  
  
  
  class
  WebViewClient
  
    extends Object
  
  
  
  
  
  
| java.lang.Object | |
| ↳ | android.webkit.WebViewClient | 
Summary
| Constants | |
|---|---|
| int | ERROR_AUTHENTICATIONUser authentication failed on server | 
| int | ERROR_BAD_URLMalformed URL | 
| int | ERROR_CONNECTFailed to connect to the server | 
| int | ERROR_FAILED_SSL_HANDSHAKEFailed to perform SSL handshake | 
| int | ERROR_FILEGeneric file error | 
| int | ERROR_FILE_NOT_FOUNDFile not found | 
| int | ERROR_HOST_LOOKUPServer or proxy hostname lookup failed | 
| int | ERROR_IOFailed to read or write to the server | 
| int | ERROR_PROXY_AUTHENTICATIONUser authentication failed on proxy | 
| int | ERROR_REDIRECT_LOOPToo many redirects | 
| int | ERROR_TIMEOUTConnection timed out | 
| int | ERROR_TOO_MANY_REQUESTSToo many requests during this load | 
| int | ERROR_UNKNOWNGeneric error | 
| int | ERROR_UNSAFE_RESOURCEResource load was canceled by Safe Browsing | 
| int | ERROR_UNSUPPORTED_AUTH_SCHEMEUnsupported authentication scheme (not basic or digest) | 
| int | ERROR_UNSUPPORTED_SCHEMEUnsupported URI scheme | 
| int | SAFE_BROWSING_THREAT_BILLINGThe resource was blocked because it may trick the user into a billing agreement. | 
| int | SAFE_BROWSING_THREAT_MALWAREThe resource was blocked because it contains malware. | 
| int | SAFE_BROWSING_THREAT_PHISHINGThe resource was blocked because it contains deceptive content. | 
| int | SAFE_BROWSING_THREAT_UNKNOWNThe resource was blocked for an unknown reason. | 
| int | SAFE_BROWSING_THREAT_UNWANTED_SOFTWAREThe 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  | 
| 
        
        
        
        
        
        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  | 
| 
        
        
        
        
        
        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  | 
| 
        
        
        
        
        
        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  | 
| Inherited methods | |
|---|---|
Constants
ERROR_AUTHENTICATION
public static final int ERROR_AUTHENTICATION
User authentication failed on server
Constant Value: -4 (0xfffffffc)
ERROR_BAD_URL
public static final int ERROR_BAD_URL
Malformed URL
Constant Value: -12 (0xfffffff4)
ERROR_CONNECT
public static final int ERROR_CONNECT
Failed to connect to the server
Constant Value: -6 (0xfffffffa)
ERROR_FAILED_SSL_HANDSHAKE
public static final int ERROR_FAILED_SSL_HANDSHAKE
Failed to perform SSL handshake
Constant Value: -11 (0xfffffff5)
ERROR_FILE
public static final int ERROR_FILE
Generic file error
Constant Value: -13 (0xfffffff3)
ERROR_FILE_NOT_FOUND
public static final int ERROR_FILE_NOT_FOUND
File not found
Constant Value: -14 (0xfffffff2)
ERROR_HOST_LOOKUP
public static final int ERROR_HOST_LOOKUP
Server or proxy hostname lookup failed
Constant Value: -2 (0xfffffffe)
ERROR_IO
public static final int ERROR_IO
Failed to read or write to the server
Constant Value: -7 (0xfffffff9)
ERROR_PROXY_AUTHENTICATION
public static final int ERROR_PROXY_AUTHENTICATION
User authentication failed on proxy
Constant Value: -5 (0xfffffffb)
ERROR_REDIRECT_LOOP
public static final int ERROR_REDIRECT_LOOP
Too many redirects
Constant Value: -9 (0xfffffff7)
ERROR_TIMEOUT
public static final int ERROR_TIMEOUT
Connection timed out
Constant Value: -8 (0xfffffff8)
ERROR_TOO_MANY_REQUESTS
public static final int ERROR_TOO_MANY_REQUESTS
Too many requests during this load
Constant Value: -15 (0xfffffff1)
ERROR_UNKNOWN
public static final int ERROR_UNKNOWN
Generic error
Constant Value: -1 (0xffffffff)
ERROR_UNSAFE_RESOURCE
public static final int ERROR_UNSAFE_RESOURCE
Resource load was canceled by Safe Browsing
Constant Value: -16 (0xfffffff0)
ERROR_UNSUPPORTED_AUTH_SCHEME
public static final int ERROR_UNSUPPORTED_AUTH_SCHEME
Unsupported authentication scheme (not basic or digest)
Constant Value: -3 (0xfffffffd)
ERROR_UNSUPPORTED_SCHEME
public static final int ERROR_UNSUPPORTED_SCHEME
Unsupported URI scheme
Constant Value: -10 (0xfffffff6)
SAFE_BROWSING_THREAT_BILLING
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
public static final int SAFE_BROWSING_THREAT_MALWARE
The resource was blocked because it contains malware.
Constant Value: 1 (0x00000001)
SAFE_BROWSING_THREAT_PHISHING
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
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
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
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:trueif this url is being reloaded. | 
onFormResubmission
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
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
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: TheWebViewfor which the navigation occurred. | 
| url | String: The URL corresponding to the page navigation that triggered this callback. | 
onPageFinished
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
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
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 aClientCertRequest | 
onReceivedError
public void onReceivedError (WebView view, int errorCode, String description, String failingUrl)
      This method was deprecated
      in API level 23.
    Use onReceivedError(WebView, WebResourceRequest, WebResourceError) on Build.VERSION_CODES.M and above.
  
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
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
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 | 
onReceivedHttpError
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
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 notnull, 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
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:WebViewthat initiated the callback. | 
| handler | SslErrorHandler:SslErrorHandlerthat handles the user's response. | 
| error | SslError: SSL error object. | 
onRenderProcessGone
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 | trueif 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
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 aSAFE_BROWSING_THREAT_*value.
 Value isSAFE_BROWSING_THREAT_UNKNOWN,SAFE_BROWSING_THREAT_MALWARE,SAFE_BROWSING_THREAT_PHISHING,SAFE_BROWSING_THREAT_UNWANTED_SOFTWARE, orSAFE_BROWSING_THREAT_BILLING | 
| callback | SafeBrowsingResponse: Applications must invoke one of the callback methods. | 
onScaleChanged
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
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
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
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: TheWebViewthat is requesting the
             resource. | 
| request | WebResourceRequest: Object containing the details of the request. | 
| Returns | |
|---|---|
| WebResourceResponse | A WebResourceResponsecontaining the
         response information ornullif the WebView should load the
         resource itself. | 
shouldInterceptRequest
public WebResourceResponse shouldInterceptRequest (WebView view, String url)
      This method was deprecated
      in API level 21.
    Use shouldInterceptRequest(WebView, WebResourceRequest) on Build.VERSION_CODES.M and above.
  
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: TheWebViewthat is requesting the
             resource. | 
| url | String: The raw url of the resource. | 
| Returns | |
|---|---|
| WebResourceResponse | A WebResourceResponsecontaining the
         response information ornullif the WebView should load the
         resource itself. | 
shouldOverrideKeyEvent
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 | trueif the host application wants to handle the key event
         itself, otherwise returnfalse | 
shouldOverrideUrlLoading
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 | trueto cancel the current load, otherwise returnfalse. | 
shouldOverrideUrlLoading
public boolean shouldOverrideUrlLoading (WebView view, String url)
      This method was deprecated
      in API level 24.
    Use shouldOverrideUrlLoading(WebView, WebResourceRequest) on Build.VERSION_CODES.N and above.
  
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 | trueto cancel the current load, otherwise returnfalse. | 
