The concept of a Web Server and a Servlet is similar to the following:

Figure 3-B: Web Server and Servlet Concept

The following components are needed to run the WebClient (i-pull):

WEB SERVER – As stated previously, a Web Server is a computer that delivers (serves up) web pages.  Every Web server has an IP Address and possibly a domain name.  For example, if you enter the URL http://www.loftware.com/index.cfm in your browser, this sends a request to the server whose domain name is loftware.com.  The server then fetches the page named index.cfm and sends it to your browser.

·      Any computer can be turned into a Web server by installing server software and connecting the machine to the Internet.  The Web Server must be up and running prior to any installation of servlets, etc.

·      You may set up restricted access (security) to your Web Server, which requires a User Name and Password when starting Loftware’s Web Client.  The Web Server secures or protects a resource, like the Loftware URI.

·      room or on the next continent.  Some common Web Servers and Servlet Engines are listed below:

SERVLET ENGINE – Servlet Engines take one of three forms:

·      Stand-alone – A standalone engine is a server that includes built-in support for servlets.  These work well for initial tasking but usually lack the power of a dedicated web server.

·      Embeddable – An embeddable engine is a lightweight servlet deployment platform that can be embedded in another application.

·      Add-on – An add-on servlet engine functions as a plug-in to an existing server.  It adds servlet support to a server that was not originally designed with servlets in mind.  For many companies (including Loftware) that already have servers, this type of servlet engine is often a good choice.  The add-on servlet engines utilized by Loftware in the development of the WebClient are Jakarta’s “Tomcat”, found at http://tomcat.apache.org/ and Allaire’s “JRun 3.0”, found at http://www.adobe.com/software/JRun/

Loftware does not recommend or endorse any particular servlet engine, just as we do not endorse any printers.  There are many servlet engines to choose from, and your selection should be based on what engine serves your company’s needs best.  It is similar to buying a car, in that thought must be taken as to the features that are needed most.  Take your servlet engine for a “test drive” first to see if it works well for your application.

Tomcat IIS How To – If you intend to use IIS with Tomcat, please go to this link:

http://tomcat.apache.org/tomcat-3.2-doc/tomcat-iis-howto.html

In the section entitled “Adding additional Contexts”, the new context settings should read:

/loftware/*=ajp12
/loftware=ajp12

Follow the rest of the instructions in the document for some very helpful information on using IIS with Tomcat.

LPS WEB SERVLET - The LPS Web Servlet is found in the LPS Premier Edition.  The LPS Web Servlet is Java-based web application that enables data communications from the WebClient to the Loftware Print Server through the Internet. The LPS Web Servlet Application has two main functions:

·      The first main function consists of a Java Servlet that facilitates the communications between the WebClient (i-pull) and the LPS.  Servlets are powerful, portable, efficient, and have great endurance.  Since it is written in Java, the LPS Web Servlet can go from being deployed on a Windows machine to a high-end Unix server.  URL access, multi-threading, data compression, and database connectivity are all part of this package.  Using the Internet as the conduit, when the WebClient is opened, the URL configuration (address) lets the WebClient know what server to go to.  The WebClient establishes a virtual connection with the Loftware Print Server using the LPS Web Servlet as a mediator.  Transactions are marshaled by the WebClient throughout the [Web] Client / Server [LPS] interaction.  The LPS gathers the requested data and sends it back to the LPS Web Servlet, and the Web Servlet then sends the data back to the WebClient.  Transmissions take place as fast as your Internet connection allows.

·      The second main function is administrative.  It is displayed through a JSP page used in a browser such as Internet Explorer or Netscape and is an interface to the LPS Web Servlet for troubleshooting and diagnostic purposes.  The page contains critical configuration data about the servlet and the LPS.  The LPS Web Servlet has been packaged as a Web Archive file (.WAR, in this case, loftware.war)

A Web Archive file is a zip (jar) file that takes the form of a standard file archive format for the Java Platform for deployment to a Java-enabled web server.  War files are compatible with all JSP containers that comply with Version 1.1 of the JSP specification.  The examples used in this chapter are Jakarta’s Tomcat 3.1 and Allaire’s JRun 3.0.

LOFTWARE PRINT SERVER - The LPS is described in Chapter 1.  The LPS forms the basis of Loftware’s “Server-Centric” approach to bar code labeling systems. Server-Centric means that all bar code label printing in an area, building or enterprise is controlled from a centralized PC on the network.

·      The LPS is capable of printing labels from your ERP/MRP II and/or WMS systems, regardless of the platform on which they reside.

·      Host computers and operating systems, such as UNIX, AS/400, HP 9000, DEC VAX and Risc/6000 can also request labels through the LPS.  It is also a viable solution for client/server PC and RF applications.

·      The WebClient (i-pull) is used in conjunction with the LPS, gathering label information, such as data, layout, design, etc.  It is suggested that you install the LPS to a different machine than the one on which the Web Server resides, so if either of these applications develops a problem, the other component is not affected.  (See the Performance Considerations section on the Loftware Website or in Chapter 1 of this guide for more information on this.)