|
JavaXT
|
|||||||||
ServletContext ClassProvides a mechanism to store application data across servlets. The ServletContext is initialized when the web server is initialized. There is only one context per Java Virtual Machine. This class is a partial implementation of the javax.servlet.ServletContext interface defined in Version 2.5 of the Java Servlet API.
ConstructorsPropertiesPathSeparator
Public MethodsgetMajorVersion( ) returns int Returns the major version of the Java Servlet API that this servlet container supports. getMinorVersion( ) returns int Returns the minor version of the Servlet API that this servlet container supports. getAttribute( String name ) returns Object Returns the servlet container attribute with the given name, or null if there is no attribute by that name. setAttribute( String name, Object value ) returns void Binds an object to a given attribute name in this servlet context. If the name specified is already used for an attribute, this method will replace the attribute with the new to the new attribute. If a null value is passed, the effect is the same as calling removeAttribute(). If listeners are configured on the ServletContext the container notifies them accordingly. removeAttribute( String name ) returns void Removes the attribute with the given name from the servlet context. If listeners are configured on the ServletContext the container notifies them accordingly. getAttributeNames( ) returns java.util.Enumeration<String> Returns an Enumeration containing the attribute names available within this servlet context. Use the getAttribute() method with an attribute name to get the value of an attribute. getContext( String uripath ) returns javax.servlet.ServletContext Returns a ServletContext object that corresponds to a specified URL on the server, or null if either none exists or the container wishes to restrict this access. This method allows servlets to gain access to the context for various parts of the server, and as needed obtain {@link RequestDispatcher} objects from the context. The given path must be begin with "/", is interpreted relative to the server's document root and is matched against the context roots of other web applications hosted on this container. getServletContextName( ) returns String Returns the name of the web application or null if no name has been declared in the deployment descriptor. getMimeType( String file ) returns String Returns the MIME type of the specified file, or null if the MIME type is not known. The MIME type is determined by the configuration of the servlet container, and may be specified in a web application deployment descriptor. Common MIME types are "text/html" and "image/gif".getResourcePaths( String path ) returns java.util.Set<String> Returns a directory-like listing of all the paths to resources within the web application whose longest sub-path matches the supplied path argument. Paths indicating subdirectory paths end with a '/'. The returned paths are all relative to the root of the web application and have a leading '/'. Consider, for example, a web application containing:
/welcome.html
/catalog/index.html
/catalog/products.html
/catalog/offers/books.html
/catalog/offers/music.html
/customer/login.jsp
/WEB-INF/web.xml
/WEB-INF/classes/com.acme.OrderServlet.class context.getResourcePaths("/") would return "/welcome.html", "/catalog/", "/customer/", "/WEB-INF/"context.getResourcePaths("/catalog/") would return "/catalog/index.html", "/catalog/products.html", "/catalog/offers/".
getResource( String path ) returns java.net.URL Returns a URL to the resource that is mapped to a specified path. The path must begin with a "/" and is interpreted as relative to the current context root. This method allows the servlet container to make a resource available to servlets from any source. Resources can be located on a local or remote file system, in a database, or in a The servlet container must implement the URL handlers and This method returns Some containers may allow writing to the URL returned by this method using the methods of the URL class. The resource content is returned directly, so be aware that requesting a This method has a different purpose than
getResourceAsStream( String path ) returns java.io.InputStream Returns the resource located at the named path as an InputStream. The data in the Meta-information such as content length and content type that is available via The servlet container must implement the URL handlers and This method is different from getRequestDispatcher( String path ) returns Object Returns a RequestDispatcher that acts as a wrapper for a resource located at the given path. A RequestDispatcher can be used to forward a request to the resource or to include the resource in a response. The resource can be dynamic or static. The pathname must begin with a "/" and is interpreted as relative to the current context root. Use getContext to obtain a RequestDispatcher for resources in foreign contexts. This method returns null if the ServletContext cannot return a RequestDispatcher.getNamedDispatcher( String name ) returns Object Returns a RequestDispatcher that acts as a wrapper for the named servlet. Returns a null if the ServletContext cannot return a RequestDispatcher for any reason. Servlets are given names programatically or via a web application deployment descriptor. A servlet instance can determine its name using ServletConfig.getServletName().
log( String message, Throwable throwable ) returns void Writes an explanatory message and a stack trace for a given Throwable exception to the servlet log file. getRealPath( String path ) returns String Returns a String containing the real path for a given virtual path. For example, the path "/index.html" found in: http://localhost:8080/WebApplication/index.htmlmight represent a physical file found in: D:\WebApps\WebApplication\index.htmlThe real path returned will be in a form appropriate to the computer and operating system on which the servlet container is running, including the proper path separators. This method returns null if the servlet container cannot translate the virtual path to a real path for any reason.
getServerInfo( ) returns String Returns the name and version of the servlet container on which the servlet is running. The form of the returned string is servername/versionnumber. Example: JavaServer Web Dev Kit/1.0The servlet container may return other optional information after the primary string, in parentheses. Example: JavaXT Web Server/3.0 getInitParameter( String name ) returns String Returns the value of the named context-wide initialization parameter, or null if the parameter does not exist. Initialization parameters are used to store configuration information for an entire "web application". For example, it can provide a webmaster's email address or the name of a system that holds critical data. getInitParameterNames( ) returns java.util.Enumeration<String> Returns the names of the context's initialization parameters as an Enumeration of String objects, or an empty Enumeration if the context has no initialization parameters. |
|||||||||