Abstract:
A method for creating a web service to programmatically access a network addressable location via an intermediate gateway includes analyzing a network at the location; generating, at the gateway, a service description file and an executable code for the network page; translating the service description file into a standard Web service format; deploying the service to the gateway, making the service available to a client application; providing a runtime process to enable the client application to automatically make a programmatic request of the location; translating the structure of the request to a syntax of location using SOAP; submitting the request to the location which executes the submitted request to obtain a response; translating the response to extract data satisfying the request; wrapping the extracted data in a SOAP envelope; translating the wrapped response to a host data structure of the client application; and compiling the executable code.

Description:
FIELD OF THE INVENTION 
   The present invention relates to the field of data processing, and particularly to a software system and associated method that provides an analysis process and interface for accessing data coded in a display markup language, such as HTML, and maintained in systems that are linked together over an associated network, such as the Internet. More specifically, this invention pertains to a computer software product that enables a client application to programmatically access a Web site. 
   BACKGROUND OF THE INVENTION 
   The World Wide Web (WWW) is comprised of an expansive network of interconnected computers upon which businesses, governments, groups, and individuals throughout the world maintain inter-linked computer files known as Web pages. Users navigate these pages by means of computer software programs commonly known as Internet browsers. 
   The authors of Web pages provide information known as metadata, within the body of the markup language document that defines the Web pages; commonly the markup language used is HTML, hypertext markup language. A computer software product known as a Web crawler systematically accesses Web pages by sequentially following hypertext links from page to page. The crawler indexes the pages for use by the search engines using information about a Web page as provided by its address or universal resource locator (URL), metadata, and other criteria found within the page. 
   Much of the publicly available information on the Internet is intended to be viewed by humans using browsers. These Web sites are primarily designed using the HTTP transport protocol and HTML display markup language. The use of HTML for presentation of Web data makes it difficult for application developers to gain programmatic access to the data on those Web sites. 
   The World Wide Web is increasingly used as a critical information source for both businesses and consumers. Recent advances in business-to-business (B 2 B) technologies have resulted in the definition of standard interfaces for data exchange between companies. Web services are standard mechanisms for applications to inter-operate using Web protocols, i.e., programs that access remote computers to access data or to render other services such as weather, etc. These Web services use a remote procedure call (RPC). The RPC mechanism is an established concept, but uses Web protocols and data formats such as HTTP, XML, SOAP, or UDDI. The design of application programming interfaces (API) to access Web data is relatively difficult because Web sites make data available in a presentation markup language such as HTML but not in a computer-friendly format like XML, SOAP, or UDDI. 
   As an example, a Web site provides data that a business is interested in, such as weather or stock quotes. Human users can view this site using their browser, but the business wishes to programmatically automate the retrieval of information from that site. There is currently no means to automatically create an API to access the data on the Web site of interest. 
   Access to the Web site includes the request for information by the user and the response of the Web site to that request. Currently, for every Web site or request to a specific Web site, the programmer must spend significant time and effort analyzing methods for sending the request and retrieving the desired information. This task takes a great deal of programming skill, wherein the business wishing to programmatically access the information on the desired Web site may not have an employee with sufficient skill. 
   Though the lack of application programming interfaces (API) for Web data is partially helped by recent advances in Web data extraction technologies, the problem remains that no solutions exist for creating a standard interface description for the Web at large. What is therefore needed is a system for Web site analysis and program development that aids programmers in the development of programs or applications to automatically request and retrieve data from Web sites on the Internet that use a variety of data forms and protocols. The need for such a system has heretofore remained unsatisfied. 
   SUMMARY OF THE INVENTION 
   In an exemplary embodiment, a processor-implemented method for creating a web service to programmatically access a network addressable location via an intermediate gateway. includes analyzing a network page at the network addressable location: generating, at the intermediate gateway, a service description file and an executable code for the network page; translating the service description file into an executable code; translating the service description file into a standard Web service format including at least one of WSDL, WDS, or ISD; deploying the web service to the intermediate gateway, wherein the web service includes the executable code and the service description file, making the web service available to a client application; providing a runtime process to enable the client application to automatically make a programmatic request of the network addressable location; wherein the programmatic reciuest includes a host language having a structure; translating the structure of the programmatic request to a syntax of the network addressable location using a simple object access protocol (SOAP); submitting the programmatic request that uses the translated structure to the network addressable location using SOAP; the network addressable location executing the submitted programmatic request to obtain a response; translating the response to extract data satisfying the programmatic request; wrapping the extracted data in a SOAP envelope; and translating the wrapped response to a host data structure of the client application; and compiling the executable code. 
   In another embodiment, computer program product having executable instruction codes that are stored on a computer usable medium, for creating a web service to programmatically access a network addressable location via an intermediate gateway includes a set of instruction codes for analyzing a network page at the network addressable location; a set of instruction codes for generating, at the intermediate gateway, a service description file and an executable code for the network page; a set of instruction codes for translating the service description file into an executable code; a set of instruction codes for translating the service description file into a standard Web service format including at least one of WSDL, WDS, or ISD; a set of instruction codes for deploying the web service to the intermediate gateway, wherein the web service includes the executable code and the service description file, making the web service available to a client application; a set of instruction codes for providing a runtime process to enable the client application to automatically make a programmatic request of the network addressable location; wherein the programmatic request includes a host language having a structure; a set of instruction codes for translating the structure of the Programmatic request to a syntax of the network addressable location using a simple object access protocol (SOAP); a set of instruction codes for submitting the programmatic request that uses the translated structure to the network addressable location using SOAP; the network addressable location executing the submitted programmatic request to obtain a response; a set of instruction codes for translating the response to extract data satisfying the programmatic request; a set of instruction codes for wrapping the extracted data in a SOAP envelope: a set of instruction codes for translating the wrapped response to a host data structure of the client application; and a set of instruction codes for compiling the executable code. 
   In still another embodiment, a processor-implemented system for creating a service interface to programmatically access a network addressable location via an intermediate gateway includes means for analyzing a network page at the network addressable location; means for generating, at the intermediate gateway, a service description file and an executable code for the network page; means for translating the service description file into an executable code; means for translating the service description file into a standard Web service format including at least one of WSDL, WDS, or ISD; means for deploying the web service to the intermediate gateway, wherein the web service includes the executable code and the service description file, making the web service available to a client application; means for providing a runtime process to enable the client application to automatically make a programmatic request of the network addressable location; wherein the programmatic request includes a host language having a structure; means for translating the structure of the programmatic request to a syntax of the network addressable location using a simple object access protocol (SOAP); means for submitting the Programmatic request that uses the translated structure to the network addressable location using SOAP; the network addressable location executing the submitted programmatic request to obtain a response; means for translating the response to extract data satisfying the programmatic request; means for wranpina the extracted data in a SOAP envelope; means for translating the wranned response to a host data structure of the client application; and means for compiling the executable code. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The various features of the present invention and the manner of attaining them will be described in greater detail with reference to the following description, claims, and drawings, wherein reference numerals are reused, where appropriate, to indicate a correspondence between the referenced items, and wherein: 
       FIG. 1  is a schematic illustration of an exemplary operating environment in which an automatic service interface creation system of the present invention can be used; 
       FIG. 2  illustrates a high-level of the analysis phase of the system of  FIG. 1 ; 
       FIG. 3  is a flow chart illustrating the performance of the analysis phase of the system of  FIG. 1 ; 
       FIG. 4  is a block diagram that illustrates a high-level architecture of an analyzer shown in  FIG. 2 ; 
       FIG. 5  illustrates a high-level architecture of the publishing phase and discovery and development phase of the system of  FIG. 1 ; 
       FIG. 6  illustrates a high-level architecture for a preferred embodiment of the run-time phase of the system of  FIG. 1 ; 
       FIG. 7  is comprised of  FIGS. 7A and 7B , and represents a flow chart that illustrates the performance of the system of  FIG. 1  during a preferred embodiment of the run-time phase; 
       FIG. 8  illustrates a high-level architecture of an alternative embodiment of the run-time phase of the system of  FIG. 1 ; and 
       FIG. 9  is a flow chart illustrating the performance of the system of  FIG. 1  during the alternative embodiment of the run-time phase. 
   

   DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
   The following definitions and explanations provide background information pertaining to the technical field of the present invention, and are intended to facilitate the understanding of the present invention without limiting its scope: 
   API: (Application Program Interface) A language and message format used by an application program to communicate with the operating system or some other system or control program such as a database management system (DBMS) or communications protocol. 
   Crawler: A program that automatically explores the World Wide Web by retrieving a document and recursively retrieving some or all the documents that are linked to it. 
   GUI (Graphical User Interface): A graphics-based user interface that incorporates icons, pull-down menus and a mouse. 
   HTML (Hypertext Markup Language): A standard language for attaching presentation and linking attributes to informational content within documents. During a document authoring stage, HTML “tags” are embedded within the informational content of the document. When the Web document (or “HTML document”) is subsequently transmitted by a Web server to a Web browser, the tags are interpreted by the browser and used to parse and display the document. In addition to specifying how the Web browser is to display the document, HTML tags can be used to create hyperlinks to other Web documents. 
   HTTP (HyperText Transport Protocol): The communications protocol used to connect to servers on the World Wide Web. Its primary function is to establish a connection with a Web server and transmit HTML pages to the client browser. 
   Internet: A collection of interconnected public and private computer networks that are linked together with routers by a set of standards protocols to form a global, distributed network. 
   SOAP (Simple Object Access Protocol): A message-based protocol based on XML for accessing services on the Web employing XML syntax to send text comma 
   URL (Uniform Resource Locator): A unique address that fully specifies the location of a content object on the Internet. The general format of a URL is protocol://server-address/path/filename. 
   Web browser: A software program that allows users to request and read hypertext documents. The browser gives some means of viewing the contents of Web documents and of navigating from one document to another. 
   Web document or page: A collection of data available on the World Wide Web and identified by a URL. In the simplest, most common case, a Web page is a file written in HTML and stored on a Web server. It is possible for the server to generate pages dynamically in response to a request from the user. A Web page can be in any format that the browser or a helper application can display. The format is transmitted as part of the headers of the response as a MIME type, e.g. “text/html”, “image/gif”. An HTML Web page will typically refer to other Web pages and Internet resources by including hypertext links. 
   Web site: A database or other collection of inter-linked hypertext documents (“Web documents” or “Web pages”) and associated data entities, which is accessible via a computer network, and which forms part of a larger, distributed informational system such as the WWW. In general, a Web site corresponds to a particular Internet domain name, and includes the content of a particular organization. Other types of Web sites may include, for example, a hypertext database of a corporate “intranet” (i.e., an internal network which uses standard Internet protocols), or a site of a hypertext system that uses document retrieval protocols other than those of the WWW. 
   World Wide Web (WWW, also Web): An Internet client—server hypertext distributed information retrieval system. 
   XML: eXtensible Markup Language. A standard format used to describe semi-structured documents and data. During a document authoring stage, XML “tags” are embedded within the informational content of the document. When the XML document is subsequently transmitted between computer systems, the tags are used to parse and interpret the document by the receiving system. 
     FIG. 1  portrays an exemplary overall environment in which an automatic service interface creation system  10  and associated method for discovering and creating service descriptions according to the present invention may be used. System  10  includes a software programming code or computer program product that is typically embedded within, or installed on a host server  15 . Alternatively, system  10  can be saved on a suitable storage medium such as a diskette, a CD, a hard drive, or like devices. While the system  10  will be described in connection with the WWW, the system  10  can be used with a stand-alone database of terms that may have been derived from the WWW and/or other sources. 
   The cloud-like communication network  20  is comprised of communication lines and switches connecting computers such as servers  25 ,  27 , to gateways such as gateway  30 . The servers  25 ,  27  and the gateway  30  provide the communication access to the WWW or Internet. Users, such as remote Internet users, are represented by a variety of computers such as computers  35 ,  37 ,  39 , and clients applications that can be incorporated on the network servers, such as server  27 , can query the host server  15  for desired information through the communication network  20 . Computers  35 ,  37 ,  39  each include software that will allow the user to browse the Internet and interface securely with the host server  15 . 
   The host server  15  is connected to the network  20  via a communications link  42  such as a telephone, cable, or satellite link. The servers  25 ,  27  can be connected via high-speed Internet network lines  44 ,  46  to other computers and gateways. The servers  25 ,  27  provide access to stored information such as hypertext or Web documents indicated generally at  50 ,  55 , and  60 . The hypertext documents  50 ,  55 ,  60  most likely include embedded hypertext link to other locally stored pages, and hypertext links  70 ,  72 ,  74 ,  76  to other webs sites or documents  55 ,  60  that are stored by various Web servers such as the server  27   
   The operation or use of system  10  comprises the following four phases that will be described later in more detail: the analysis phase, the publishing phase, the discovery and development phase, and the runtime phase. 
   The Web site analysis phase analyzes the Web page of interest and generates a service description (SD) file for each form. The SD file contains all the information necessary for producing the ultimate output of the system: API description in the form of Web services description language (WSDL) files, well-defined service (WDS) files, and interface service deployment (ISD) files. 
   The analysis phase is illustrated in  FIG. 2  and by method  300  of  FIG. 3 . The analyzer  200  of system  10  is connected through a network  205 , such as the Internet, to a crawler or toolkit  210 . The crawler  210  is one source of Web pages  215  for the system  10 , and it can be any one of the many currently available crawlers. Data extracted from the Web pages  215  by the analyzer  200  are stored in the service database  220 . 
   Web pages  215  can also be accessed by a user toolkit  210 . The user toolkit  210  incorporates a graphical user interface (GUI) through which the user instructs system  10  which pages or forms to analyze. One method for implementing the GUI is to embed the toolkit  210  in a Web browser. 
   While the user is browsing the Web sites, a panel next to the main viewing area provides buttons or links that allow the user to mark the current page or form for further analysis. Pages or forms selected by the user are then transferred to the analyzer  200 . The user toolkit  210  also includes a data extraction feature that instructs a data extractor component how to extract data from pages returned to system  10  when the forms are submitted for analysis. 
   With further reference to  FIG. 3 , the crawler  210  sends a request in step  302  to the Web site  215 , fetching via the Internet or other network  205  one or more “seed pages” which are Web sites  215 . These seed pages  215  contain hyperlinks, or URLs. The URLs are extracted and inserted into a URL pool. 
   The crawler  210  then iteratively fetches a URL from the pool and fetches the corresponding document from the Web site  215  in step  305 . For example, if the Web page  215  is an HTML page, URLs of the Web site  215  are again extracted and inserted in the URL pool. 
   The crawler  210  is configured to crawl only to a certain “depth”; i.e., it may only move a certain number of links away from the Web pages  215 . The distance is measured in terms of the number of links followed, so if the depth is three, the crawler will not go farther than three links away from the Web pages  215 . Other parameters may control the speed and frequency with which Web documents are accessed, and whether every link is followed or a filtering mechanism allows for only a subset of all possible links to be pursued. 
   The crawler  210  passes each page  215  retrieved from the Web to the page analyzer  200  in step  310 . The functions of the page analyzer  200  are shown in more detail in  FIG. 4 . 
   The analyzer  200  is generally comprised of a page analyzer  405 , a service extractor  410 , an executable code generator  415 , and a standard service format producer  420 . The page analyzer  405  scans the code of a Web page such as HTML page  425  and finds sections of that page that constitute a Web form. One page may contain several forms. For example, a form is identified in HTML by a “&lt;FORM&gt;” tag and contains one or more data entry tags such as “&lt;INPUT&gt;” and “&lt;SELECT&gt;”. The service extractor  410  then translates these forms into service descriptions. 
   The service extractor  410  analyzes a set of forms that originally resided on a single Web page and prepares the data for subsequent output as a service description by the standard service format producer  420 . The service extractor  410  performs the following tasks:
         Assigns a name to the service based on the title of the Web page, the URL, or an encoded value of either one.   Extracts the description (metadata) of the service from the &lt;META&gt; tags of the Web page.   Assigns a synthetic name to each form residing on the Web page based on position number of the form. For example, form number  1  would be assigned the name “method  1 ”.   Extracts the HTTP access method used in each form (GET or POST).   Translates the name of each form variable (variables listed in&lt;INPUT&gt; and &lt;SELECT&gt; tags) into a variable name compatible with the executable code language.   Defines the data type of each form variable using the XML schema language.       

   The service extractor packages the information it extracted into a service description (SD) file, and passes it on to the standard service format producer  420  and to the executable code generator  415 . The service description (SD) file is a composite file that contains all the information needed to invoke the Web service. The service extractor  410  converts forms such as HTML page  425  into Web services that can operate on a gateway (or on the client or server computer). The SD file comprises instructions for construction of the gateway. The SD file is typically written in XML. 
   The executable code generator translates the SD file into an executable code  430  such as Java that implements a SOAP interface wrapper. The executable code  430  is stored in the service database  220 . The standard service format producer  420  translates the SD file into standard Web service format such as WSDL (Web services description language), WDS (well defined service) and ISD (invocation service description). The WSDL, WDS, and ISD files are all stored in the service database  220 . 
   The second phase of system  10  is the publishing phase, as illustrated by the high-level architecture of  FIG. 5 . The service publisher  505  gathers WSDL, WDS, ISD, and executable code files from the service database  220  and prepares them for deployment. 
   The service publisher  505  first invokes an executable code compiler on each executable code file and gets executable code class files as a result. The service publisher  505  then deploys each service to a gateway at block  510  by uploading the executable code to the gateway, using the executable code class file and ISD file. 
   This process (block  510 ) makes the Web service available to the client. One method for adding Web service files to the gateway at block  510  is by invoking the appropriate method in a SOAP service manager. The SOAP service manager “hosts” SOAP services on a gateway. It receives requests from a client application and invokes the appropriate executable code class file that implements the service. Any existing SOAP service manager can be used. 
   Next, the service publisher  505  registers each service at a UDDI (universal description, discovery, and integration) registry  515  by invoking the appropriate method in the UDDI registry  515  and providing the WSDL and WDS files as input. The UDDI registry  515  is a registration service for Web servers to advertise Web services; for system  10 , the UDDI will list all services available in the SOAP service manager. A client application or programmer  520  can query the registry to find the SOAP addresses and other parameters of interesting services. Any existing UDDI registry can be used. 
   The third phase of the operation of system  10  is the discovery and development phase. In phase  3 , the programmer  520  accesses the UDDI registry  515  and develops client programs and applications that invoke the Web server at the gateway in block  510 . 
   In an alternative embodiment of system  10 , the latter can include the Web service gateway code in the client&#39;s software, thus obviating the need for the UDDI registry  515  and the gateway at block  510 . 
   The fourth phase of the operation of system  10  is the runtime phase, illustrated by the high-level architecture of  FIG. 6 . The client  605  accesses the Web sites  610  through the gateway  615  via the network  620 . The client is comprised of an application code  625  developed by a programmer and a SOAP wrapper  630  created automatically from the WSDL file by standard software development tools. The client sends a request to the gateway, as shown by network link  635 . 
   The gateway  615  then sends a request to Web site  610  via network link  640 . The Web site  610  returns to the gateway  615  a response to the request, as shown by network link  645 . The gateway  615  then transfers the response of Web site  610  to the client  615  via link  650 . 
   Web sites such as Web site  610  are designed for viewing by humans. The gateway  615  makes Web sites such as Web site  610  appear as a Web service designed for program access. The client  605  never sees the original Web site  610  form that is most likely written in HTML using the HTTP protocol. The gateway  615  translates the human readable Web site interface and presents to the client a machine readable interface most likely written in XML using the SOAP protocol. 
   The runtime phase operation or method  700  is illustrated by the flowchart of  FIGS. 7A and 7B . The client  605  wishes to make a programmatic request of the Web site  610 . This process is initiated when the application code  625  calls the wrapper function in step  705 . The SOAP wrapper  630  translates the host language structure, such as Java, to SOAP. The request of the client  605  is transferred in step  710  to the gateway via network link  635 , using SOAP protocol. In step  715 , the gateway  615  translates the SOAP request to the format required by the Web site  610 ; i.e., HTTP post. 
   The gateway  615  submits the Web form to the Web site  610  in step  720  via network link  640  using, for example, HTTP protocol. In step  725 , the Web site  610  performs the action requested by the user in step  705 , i.e., execute a database query. 
   The Web site  610  returns the response to the gateway  615  via the network link  645  in step  730 ; the data format for the response shown by network link  645  is typically HTML, using HTTP protocol. In the preferred method of system  10 , the HTTP response (step  735 ) is translated by the gateway  615  to extract data in step  740 . 
   The result of the data extraction is shown in step  745  as XML data. The XML data  745  is wrapped in a SOAP envelope by the gateway  615  in step  750 . The wrapped response is transmitted via network link  650  to the client  605  in step  755 . The protocol for network link  650  is SOAP with data format of XML. 
   Then, in step  760  the wrapped response to the original Web site  550  request is received and translated to the host data structure (e.g. Java) by the SOAP wrapper  630 . Alternatively, the HTTP response may not be translated to XML, but instead wrapped directly in a SOAP envelope as shown by optional path  765 . 
   An alternative embodiment of the run-time phase of system  10  is shown in  FIG. 8 . In this embodiment, the functions of the gateway are included in the client  805 , allowing the client to directly communicate through the network  810  to the Web site  815 . 
   The client is comprised of an application code  820  developed by a programmer and an HTTP wrapper  825 . The client sends a request to the Web site  815  via network link  830 . The request is coded in HTML using HTTP protocol. The Web site  815  responds to the request in HTML using HTTP protocol and transmits it back to the client via network link  835 . This format is recognized by the client  805  and translated as needed for the application code  820 . 
   The runtime phase operation of the alternative embodiment is illustrated by the flowchart of  FIG. 9 . The client  805  wishes to make a programmatic request of the Web site  815 . This process is initiated when the application code  820  calls the HTTP wrapper function in step  905 . The wrapper function is generated by the executable code generator. The HTTP wrapper  825  translates the host language structure, such as Java, to HTTP using the executable code that is stored in the service database. The request of the client  805  is submitted in step  910  to the Web site  815  via network link  830 , using the HTTP protocol. 
   In step  915 , the Web site  815  performs the action requested by the user in step  905 , i.e., execute a database query. The Web site  815  returns the response to the client  805  in step  920 ; the data format for the response shown by network link  835  is typically HTML, using HTTP protocol. In a preferred method of system  10 , the HTTP response (step  925 ) is processed by the client  805  to extract data in step  930 . 
   The result of the data extraction is shown in step  935  as XML data. In step  940 , the client application code  820  translates the XML data to the host language data structure such as JAVA. Alternatively, the HTTP response is not translated to XML first, but is instead translated directly from HTTP to the host language data structure in step  940 , as shown by optional link  945 . 
   It is to be understood that the specific embodiments of the invention that have been described are merely illustrative of certain application of the principle of the present invention. Numerous modifications may be made to the automatic service interface creation for Web sites invention described herein without departing from the spirit and scope of the present invention. Moreover, while the present invention is described for illustration purpose only in relation to the WWW, it should be clear that the invention is applicable as well to databases and other tables with indexed entries.