Class WEnvironment

  • Direct Known Subclasses:
    WTestEnvironment

    public class WEnvironment
    extends java.lang.Object
    A class that captures information on the application environment.

    The environment provides information on the client, and gives access to startup arguments.

    Usage example:

    
     WEnvironment env = WApplication.instance().environment();
    
     // read an application startup argument
     // (passed as argument in the URL or POST'ed to the application).
     if (!env.getParameterValues("login").isEmpty()) {
     String login = env.getParameterValues("login").get(0);
     //...
     }
    
     // Check for JavaScript/AJAX availability before using JavaScript-only
     // widgets
     WTextArea textEdit;
     if (!env.isAjax())
     textEdit = new WTextEdit(); // provide an HTML text editor
     else
     textEdit = new WTextArea(); // fall-back to a plain old text area.
    
     
    • Method Summary

      All Methods Static Methods Instance Methods Concrete Methods 
      Modifier and Type Method Description
      boolean agentIsChrome()
      Returns whether the user agent is Chrome.
      boolean agentIsGecko()
      Returns whether the user agent is Gecko-based.
      boolean agentIsIE()
      Returns whether the user agent is Microsoft Internet Explorer.
      boolean agentIsIElt​(int version)
      Returns whether the user agent is an older version of IE.
      boolean agentIsIEMobile()
      Returns whether the user agent is Internet Explorer Mobile.
      boolean agentIsMobileWebKit()
      Returns whether the user agent is Mobile WebKit-based.
      boolean agentIsOpera()
      Returns whether the user agent is Opera.
      boolean agentIsSafari()
      Returns whether the user agent is Safari.
      boolean agentIsSpiderBot()
      Returns if the user agent is a (known) indexing spider bot.
      boolean agentIsWebKit()
      Returns whether the user agent is WebKit-based.
      java.lang.String getAccept()
      Returns the accept header.
      UserAgent getAgent()
      Returns the user agent type.
      java.lang.String getCgiValue​(java.lang.String varName)
      Returns a raw CGI environment variable.
      java.lang.String getClientAddress()
      Returns the IP address of the client.
      HtmlContentType getContentType()
      The type of the content provided to the browser.
      java.lang.String getCookie​(java.lang.String cookieName)
      Returns a cookie value.
      java.util.Map<java.lang.String,​java.lang.String> getCookies()
      Returns the cookies from the environment.
      java.lang.String getDeploymentPath()
      Returns the deployment path.
      double getDpiScale()
      Returns the browser-side DPI scaling factor.
      java.lang.String getHeaderValue​(java.lang.String name)
      Returns a header value.
      java.lang.String getHostName()
      Returns the server host name that is used by the client.
      java.lang.String getInternalPath()
      Returns the initial internal path.
      static java.lang.String getJavaScriptWtScope()
      Wt's JavaScript scope.
      static java.lang.String getLibraryVersion()
      Returns the version of the JWt library.
      java.util.Locale getLocale()
      Returns the preferred language indicated in the request header.
      java.lang.String getParameter​(java.lang.String name)
      Returns a single value for a query parameter.
      java.util.Map<java.lang.String,​java.lang.String[]> getParameterMap()
      Parameters passed to the application.
      java.lang.String[] getParameterValues​(java.lang.String name)
      Returns values for a query parameter.
      java.lang.String getReferer()
      Returns the referer.
      int getScreenHeight()
      Returns the vertical resolution of the client's screen.
      int getScreenWidth()
      Returns the horizontal resolution of the client's screen.
      WtServlet getServer()
      Returns the servlet.
      java.lang.String getServerAdmin()
      Returns the email address of the server admin.
      java.lang.String getServerSignature()
      Returns the web server signature.
      java.lang.String getServerSoftware()
      Returns the web server software.
      java.lang.String getTimeZoneName()
      Returns the time zone name as reported by the client.
      java.time.Duration getTimeZoneOffset()
      Returns the time zone offset as reported by the client.
      java.lang.String getUrlScheme()
      Returns the URL scheme used for the current request ("http" or "https").
      java.lang.String getUserAgent()
      Returns the user agent.
      boolean hasAjax()
      Returns whether the browser has enabled support for AJAX.
      boolean hasJavaScript()
      Returns whether the browser has enabled support for JavaScript.
      boolean hasWebGL()
      Returns whether the browser has support for WebGL.
      boolean isInternalPathUsingFragments()
      Returns whether internal paths are implemented using URI fragments.
      boolean isLikelyBotGetRequest()
      Returns whether the incoming request is treated like a bot.
      boolean isTest()
      Returns whether this is a mocked test environment.
      boolean isTreatLikeBot()
      Returns whether the request should be treated like a bot.
      boolean supportsCookies()
      Returns whether the browser has enabled support for cookies.
      boolean supportsCss3Animations()
      Returns whether this agent supports CSS3 animations.
      • Methods inherited from class java.lang.Object

        clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
    • Field Detail

      • isLikelyBotGetRequest_

        protected boolean isLikelyBotGetRequest_
      • timeZoneName_

        protected java.lang.String timeZoneName_
      • redirectSecret_

        protected java.lang.String redirectSecret_
    • Method Detail

      • getJavaScriptWtScope

        public static java.lang.String getJavaScriptWtScope()
        Wt's JavaScript scope.
      • getParameterMap

        public java.util.Map<java.lang.String,​java.lang.String[]> getParameterMap()
        Parameters passed to the application.

        Arguments passed to the application, either in the URL for a http GET, or in both the URL and data submitted in a http POST.

        See Also:
        getParameterValues(String name)
      • getParameterValues

        public java.lang.String[] getParameterValues​(java.lang.String name)
        Returns values for a query parameter.

        Returns an empty list if the parameter was not defined.

        One or more values may be associated with a single argument.

        For example a JWt application foo.wt started as http://.../foo.wt?hello=Hello&hello=World will result in both values "Hello" and "World" to be associated with the argument "hello".

        See Also:
        getParameterMap()
      • getParameter

        public java.lang.String getParameter​(java.lang.String name)
        Returns a single value for a query parameter.

        Returns the first value for a parameter, or null if the parameter is not found.

        See Also:
        getParameterValues(String name)
      • getCookies

        public java.util.Map<java.lang.String,​java.lang.String> getCookies()
        Returns the cookies from the environment.

        This returns all cookies that were present in initial request for the application. Cookies set with WApplication#setCookie() are not taken into consideration.

        Cookies allow you to persist information across sessions, but note that not all clients may support cookies or may some clients may be configured to block cookies.

        See Also:
        supportsCookies(), getCookie(String cookieName)
      • getCookie

        public java.lang.String getCookie​(java.lang.String cookieName)
        Returns a cookie value.

        Returns 0 if no value was set for the given cookie.

        See Also:
        getCookie(String cookieName)
      • getHeaderValue

        public java.lang.String getHeaderValue​(java.lang.String name)
        Returns a header value.

        Returns a header value, or an empty string if the header was present.

      • supportsCookies

        public boolean supportsCookies()
        Returns whether the browser has enabled support for cookies.

        When the user disables cookies during the visit of the page, this value is not updated.

        See Also:
        getCookies(), getCookie(String cookieName)
      • hasJavaScript

        public boolean hasJavaScript()
        Returns whether the browser has enabled support for JavaScript.

        This is the same as hasAjax(): JWt only considers using JavaScript when it has detected AJAX support.

        See Also:
        hasAjax()
      • hasWebGL

        public boolean hasWebGL()
        Returns whether the browser has support for WebGL.

        Support for WebGL is required for client-side rendering of WGLWidget.

      • getScreenWidth

        public int getScreenWidth()
        Returns the horizontal resolution of the client's screen.

        Returns -1 if screen width is not known.

        See Also:
        getScreenHeight()
      • getScreenHeight

        public int getScreenHeight()
        Returns the vertical resolution of the client's screen.

        Returns -1 if screen height is not known.

        See Also:
        getScreenWidth()
      • getDpiScale

        public double getDpiScale()
        Returns the browser-side DPI scaling factor.

        Internet Explorer scales all graphics, fonts and other elements on high-density screens to make them readable. This is controlled by the DPI setting of the display. If all goes well, you do not have to worry about this scaling factor. Unfortunately, not all elements are scaled appropriately. The scaling factor is supposed to be used only internally in JWt and is in this interface for informational purposes.

        See Also:
        WVmlImage
      • getLocale

        public java.util.Locale getLocale()
        Returns the preferred language indicated in the request header.

        The language is parsed from the HTTP Accept-Language field, if present. If not, the locale is empty.

        If multiple languages are present, the one with the highest "q"uality is assumed, and if a tie is present, the first one is taken.

        See Also:
        WApplication.setLocale(Locale locale, boolean doRefresh)
      • getTimeZoneOffset

        public java.time.Duration getTimeZoneOffset()
        Returns the time zone offset as reported by the client.

        This returns the time offset that the client has relative to UTC. A positive value thus means that the local time is ahead of UTC.

        This requires JavaScript support.

      • getTimeZoneName

        public java.lang.String getTimeZoneName()
        Returns the time zone name as reported by the client.

        Note: This requires JavaScript support and is only supported by browsers that implement the JavaScript Internationalization API. No version of Internet Explorer supports this, but modern browsers do. If not supported, this will return the empty string.

      • getHostName

        public java.lang.String getHostName()
        Returns the server host name that is used by the client.

        The hostname is the unresolved host name with optional port number, which the browser used to connect to the application.

        Examples:

        • www.mydomain.com
        • localhost:8080

        For HTTP 1.1 requests, this information is fetched from the HTTP Host header. If JWt is configured behind a reverse proxy, then the last entry in the HTTP X-Forwarded-Host header field is used instead (to infer the name of the reverse proxy instead).

        For HTTP 1.0 requests, the HTTP Host header is not required. When not present, the server host name is inferred from the configured server name, which defaults to the DNS name.

      • getUrlScheme

        public java.lang.String getUrlScheme()
        Returns the URL scheme used for the current request ("http" or "https").
      • getUserAgent

        public java.lang.String getUserAgent()
        Returns the user agent.

        The user agent, as reported in the HTTP User-Agent field.

        See Also:
        getAgent()
      • getReferer

        public java.lang.String getReferer()
        Returns the referer.

        The referer, as reported in the HTTP Referer field.

      • getAccept

        public java.lang.String getAccept()
        Returns the accept header.

        The accept header, as reported in the HTTP Accept field.

      • agentIsSpiderBot

        public boolean agentIsSpiderBot()
        Returns if the user agent is a (known) indexing spider bot.

        Note: currently the list of know bots is quite small. This method is used internally to render the web application for optimal indexing by bots:

        • there is no detection for JavaScript, instead the application is directly served assuming no JavaScript support.
        • session information is omitted from the Urls.
        • no sessions are created (they are immediately stopped after the request has been handled).
        • auto-generated id and name attributes are omitted from DOM nodes. In this way, the generated page is always exactly the same.
      • isLikelyBotGetRequest

        public boolean isLikelyBotGetRequest()
        Returns whether the incoming request is treated like a bot.

        This can be used to check whether an incoming request is likely to originate from a bot client. The request will be treated the same way as a normal bot.

        Currently, this verifies whether a newly incoming GET request carries a wtd parameter. For a new request this should never be the case, unless this page was scraped before. The session would be expired by now, and this request should then not be valid.

        Note: If a user were to get here, they would be served the same page a bot would see. This does not contain anything session-related. Once they would navigate on the page, they would be granted a new session, which will be tracked for subsequent requests.

        See Also:
        agentIsSpiderBot()
      • isTreatLikeBot

        public boolean isTreatLikeBot()
        Returns whether the request should be treated like a bot.

        If the agent matches any of the agents configured as bots agents, or if the request is suspicious, the application will handle them as a bot.

        These responses will not contain session related content, and their session will be quickly closed server-side.

        See Also:
        agentIsSpiderBot(), isLikelyBotGetRequest()
      • getServerSignature

        public java.lang.String getServerSignature()
        Returns the web server signature.

        The value of the CGI variable SERVER_SIGNATURE.

        Example: <address>Apache Server at localhost Port 80</address>.

      • getServerSoftware

        public java.lang.String getServerSoftware()
        Returns the web server software.

        The value of the CGI variable SERVER_SOFTWARE.

        Example: "Apache"

      • getServerAdmin

        public java.lang.String getServerAdmin()
        Returns the email address of the server admin.

        The value of the CGI variable SERVER_ADMIN.

        Example: "root@localhost"

      • getClientAddress

        public java.lang.String getClientAddress()
        Returns the IP address of the client.

        The (most likely) IP address of the client that is connected to this session.

        This is taken to be the first public address that is given in the Client-IP header, or in the X-Forwarded-For header (in case the client is behind a proxy). If none of these headers is present, the remote socket IP address is used.

      • getInternalPath

        public java.lang.String getInternalPath()
        Returns the initial internal path.

        This is the internal path with which the application was started.

        For an application deployed at "/stuff/app.wt", the following URL indicates an internal path "/this/there":

        
         http://www.mydomain.com/stuff/app.wt/this/there
        
         

        See Also:
        WApplication.setInternalPath(String path, boolean emitChange), getDeploymentPath()
      • getDeploymentPath

        public java.lang.String getDeploymentPath()
        Returns the deployment path.

        This is the path at which the application is deployed.

        See Also:
        getInternalPath()
      • getLibraryVersion

        public static java.lang.String getLibraryVersion()
        Returns the version of the JWt library.

        Example: "1.99.2"

      • getCgiValue

        public java.lang.String getCgiValue​(java.lang.String varName)
        Returns a raw CGI environment variable.

        Retrieves the value for the given CGI environment variable (like "SSL_CLIENT_S_DN_CN"), if it is defined, otherwise an empty string.

        See Also:
        getServerSignature(), getServerSoftware(), getServerAdmin()
      • getContentType

        public HtmlContentType getContentType()
        The type of the content provided to the browser.

        This is here for backwards compatibility, but the implementation now alwasy returns HTML5.

      • agentIsIE

        public boolean agentIsIE()
        Returns whether the user agent is Microsoft Internet Explorer.

        See Also:
        getAgent()
      • agentIsIElt

        public boolean agentIsIElt​(int version)
        Returns whether the user agent is an older version of IE.

        Returns whether the agent is an IE version older than the given version.

        See Also:
        agentIsIE()
      • agentIsIEMobile

        public boolean agentIsIEMobile()
        Returns whether the user agent is Internet Explorer Mobile.

        Returns also true when the agent is Internet Explorer 5 or older.

        See Also:
        getAgent()
      • agentIsOpera

        public boolean agentIsOpera()
        Returns whether the user agent is Opera.

        See Also:
        getAgent()
      • agentIsWebKit

        public boolean agentIsWebKit()
        Returns whether the user agent is WebKit-based.

        Webkit-based browsers include Safari, Chrome, Arora and Konquerer browsers.

        See Also:
        getAgent()
      • agentIsMobileWebKit

        public boolean agentIsMobileWebKit()
        Returns whether the user agent is Mobile WebKit-based.

        Mobile Webkit-based browsers include the Android Mobile WebKit and the iPhone Mobile WebKit browsers.

        See Also:
        getAgent()
      • agentIsSafari

        public boolean agentIsSafari()
        Returns whether the user agent is Safari.

        See Also:
        getAgent()
      • agentIsChrome

        public boolean agentIsChrome()
        Returns whether the user agent is Chrome.

        See Also:
        getAgent()
      • agentIsGecko

        public boolean agentIsGecko()
        Returns whether the user agent is Gecko-based.

        Gecko-based browsers include Firefox.

        See Also:
        getAgent()
      • getServer

        public WtServlet getServer()
        Returns the servlet.

        This returns the servlet environment of this session.

      • isInternalPathUsingFragments

        public boolean isInternalPathUsingFragments()
        Returns whether internal paths are implemented using URI fragments.

        This may be the case for older non-HTML5 browsers which do not support HTML5 History APIs.

      • supportsCss3Animations

        public boolean supportsCss3Animations()
        Returns whether this agent supports CSS3 animations.
      • isTest

        public boolean isTest()
        Returns whether this is a mocked test environment.