INSTRUCTIONS FOR GETTING STARTED IN THE ECOMMERCE COURSE

    % cd ~/htdocs
    % mkdir servlets
 

• JigAdmin is a strange tool. When it comes up it looks as though it has very little. You need to click on symbols to expand a "tree" to see more.
• Sometimes you have to click on the "name" instead of the folder icon to see something.
• You'll really need to run JigAdmin only once if you plan to put all your servlets in a single directory. Later, if you want to create additional servlet directories, then you'll have to run it again.

Let's assume you want to set up a servlets in the following two ways:

1. Creating a servlet in the /servlets directory:
   • First, in Unix, actually create a /servlets directory off of your document home. (You did this above).
   • Then fire up Jigadmin.
   • Click on the folder symbol next to "Root". This gives you a list that includes "http-server".
   • Click on the folder symbol for "http-server". This creates the following items: control, indexers, properties, realms and space.
   • Click on the folder symbol next to "space". This creates sub-items like Admin, Doc etc. One of these should be "servlets". Actually, "space" is synonymous with the document root.
   • Now click on top of the string "servlets" (NOT on the folder symbol). This will create a screen on the right-half of the Jigadmin window. This screen will have three buttons called "Resources", "Frames" and "Attributes" on top.
   • The next few steps involve the right-half of the window:
     • STEP A: Click on the "Resources" button on top. The half-screen below changes (after a while perhaps). There is an "identifier" field on top and a choice-list in the middle. Within the choice-list, click on

       	     "org.w3c.resources.DirectoryResource".
           

       Doing this will put this string into the textfield right above the choice-list and will foldup the choice-list. Then, click on the "Add Resource" button almost at the bottom of the half-screen. Now you are done with "Resources".
     • STEP B: Next, click on the "Frames" button right on top. This will create a new half-screen with a similar choice-list. In this choice list, click on

                    "org.w3c.jigsaw.servlet.ServletDirectoryFrame"
         

       which will get entered in the textfield and cause the choice-list to foldup. Then click on the "Add Frame" button below the choice-list.
     • STEP C: Now, click on the "Attribute" button right at the top. You will get a new half-screen (it takes a while sometimes). This will have fields called "Identifier", "Last Modified", "Indexer" etc. The identifier should already say "servlets". (If not, then enter the string "servlets" into that field). Next, observe the drop-down list at the right end of the "Indexer" field. Click on it to select "servlet-indexer" so that the string "servlet-indexer" appears in the Indexer text field. (You can, alternatively, enter the string yourself). Next, click on the "Commit" button near the bottom of the screen.
   • Next, look towards the left-side tree widget and click on the "control" string under "http-server". This will create four icon-buttons on the right. Click on "Save".
     NOTE: you can place additional servlets in this directory and they will automatically load when invoked. Thus, the admin stuff is done only for new directories.
2. Advanced stuff - create a new servlet subdirectory off of /servlets, e.g., /servlets/test/.
   • Follow all the steps above.
   • Then, in Unix, actually create the subdirectory /test/ and place a test servlet in it (such as HelloWorld.class).
   • Now run Jigadmin (or go to it, if it's already running).
   • Go down the tree all the way to /servlets. If the folder is unfolded, fold it back up. If the "space" hierarchy is folded, fold that back up. Foldups are done by clicking on the folder symbol again (It toggles).
   • Now unfold "space". The "servlet" item should have a folder symbol, indicating that Jigadmin knows it contains a subdirectory.
   • Now unfold down to your new directory under /servlets.
   • Click on the string "test" (but NOT on its folder symbol).
   • You will get a right-half screen with the "Resources", "Frames" and "Attributes" buttons.
   • Repeat the steps A,B,C described in (1) above.

• First, create the source file HelloWorld.java:

        import javax.servlet.*;
        import javax.servlet.http.*;
        import java.io.*;
  
        public class HelloWorld extends HttpServlet {
  
          public void doGet (HttpServletRequest req, HttpServletResponse resp)
            throws ServletException, IOException
          {
            // Set the content type of the response.
            resp.setContentType ("text/html");
  
            // Create a PrintWriter to write the response.
            java.io.PrintWriter out = new PrintWriter (resp.getOutputStream());
  
            // The first part of the response.
            out.println ("");
            out.println ("");
            out.println ("");
  
            // The greeting.
            out.println ("Yo, Hello World!");
  
            // Last part.
            out.println ("");
            out.println ("");
            out.close();
  
            // Screen I/O
            System.out.println ("Inside servlet ... servlet complete");
          }
  
          public void doPost (HttpServletRequest req, HttpServletResponse resp)
            throws ServletException, IOException
          {
            doGet (req, resp);
          }
  
        }
    

• Compile and store the class file in the servlets directory:

        % javac HelloWorld.java
        % cp HelloWorld.class ~/htdocs/servlets/.
    

• Now, fire up Jigsaw and enter the URL

        http://localhost:8502/servlets/HelloWorld
    

• This should cause the HelloWorld servlet to execute and write the string to the browser. It should also write to the screen in the window where Jigsaw was launched.
• If this did not work, do not proceed until you get this working.