Programming Assignment 1: Java

(Thanks to CS145 for most of the below.)

Step 0: Read the document Web-Database Programming: CGI and Java Servlets for an overview of Servlets ( ignore the CGI section). Read the sections on Java Servlets carefully.
Step 1: Set up your directories.

Compiling Servlets in Unix requires a few changes to your PATH and CLASSPATH environment variables. These changes have been made for you in the source file /usr/class/cs157/java/code/bin/all.env. Just type source /usr/class/cs157/java/code/bin/all.env. Alternatively, you can add this command to your .cshrc file.
Within your home directory you must set up the following directory structure:
```
   servletdir
      webpages
         WEB-INF
            servlets
```
A shell script to build this hierarchy is provided at /usr/class/cs157/java/code/bin/buildServletDirectory. (Note: If you add source /usr/class/cs157/java/code/bin/all.env to your .cshrc file, you can run buildServletDirectory by just typing the command.)
You should store .html pages within this structure, in the webpages directory. All Servlets (the java code) must be located in the servlets directory.
Step 2: Copy the sample code. (If you do not want to work off our sample code, you are free to write your own.)
We are providing a sample program to demonstrate the basic functionality of Servlets and get you started with your programming. It is in the directory /usr/class/cs157/java/sample/
Please note that the instructions, code, and support we are providing are only tested on the leland Solaris machines. Copy the appropriate files to your own directory. All .html files should be placed in the webpages directory from Step 1. All .java files should be placed in the servlets directory.
Step 3:You must compile your .java files by running javac *.java. Once your directory structure is set up and your Servlets are compiled, you can run the Java JSDK 2.1 Web server manually on any leland Solaris machine (e.g., saga's, elaine's, myth's) in order to provide these documents over the Web. The steps involved in starting the server are:
1. Choose a random port number in the range 5000-65000. This will bind your server application to that port for the machine on which you're running your server. Try to choose a random number and remember it - you will be the only person on that machine who can use that port, and you will need it to have access over the Web.
2. Change to the servletdir directory, which is the root of the directory structure you created in Step 1. From there, start the server by calling "startserver -port portnum" from the Unix command line, where "portnum" is the port number you chose in the previous step. The server will begin in the background, and you can see it using the "ps -elf | grep username" command. If you do not enter a port number, the default port number 8080 will be chosen for you. (You can actually set the default yourself: After you've run the server once, it will create a configuration file called "default.cfg" for you; it finds the default port number there.)
3. From your browser, enter the URL of a Web page or Servlet contained in your servletdir hierarchy. Static HTML documents placed in the webpages directory are accessible from the Web at the address http://machineXX:portnum/page.html, where "machineXX" refers to the Solaris machine from which you're running the Web server (e.g., saga22, elaine12, myth7, etc.), "portnum" is a specific port (see above), and "page.html" is the name of the HTML page that you are serving.
4. To stop the server, issue the command "stopserver". Warning: If you log into a leland machine and cannot start a server because one is already running, do NOT type "stopserver" or you will stop someone else's server! Instead, find a different machine with no servers running on it.
5. If you want to recompile your Servlets you must stop the server, recompile, then restart the server. Static HTML pages that you are hosting from the webpages directory can be changed at will.
Step 4: Understand the sample code. Read the provided Java and HTML files and make sure you understand how they work. For detailed documentation you may want to refer to the Java Servlets Class Docs from Sun.