There are two distinct Java JDK installations.  Both JDK are 1.15
- One is the JDK you access via your $JAVA_HOME environment variable
- The other is the one Tomcat uses.
Each has its own library. JSoup and Json are installed in both.

The jar command is used to create archives. We use it to create war file
- Two uses: Create and extract.


Single thread model means that the servlet runs in a single thread, 
  i.e. in normal use, each request runs in its own thread

Basic Servlet Actions
- Set the content that will be output (often text/html)
  * setContentType(...)
- Get access to the output stream back to the requesting browser
  * Method getWriter() in the response

AJAX
- Idea is to maintain the input interface on the same page where results are displayed.
  * The DIV tag is a way to do this

- Two types of request objects
  * IE: ActiveXObject  - Likely don't need anymore
  * The civilized world: XMLHttpRequest

Example to emulate: ChooseNumberOfTexts

To be able to access a servlet across servers, 
		you must have, in the servlet where you set the response type:

   response.setHeader("Access-Control-Allow-Origin", "*");


Using the jar command
- Extract...
  jar xvf ../../Wars/Quote.war
      extract, verbal, f is name of archive
	Not putting a destination means extract in current directory
- Create
  jar cvf ../../Quote.war *
      create, verbal, f is name of archive created   * means add everything in this directory and below.

To prevent caching, place a unique parameter into the query string