FINAL PROJECT GUIDELINES (compilied by Sam G, from
G-Unit)
1. MySQL
MySQL is the database server that we will be using
to store
and retrieve information. The files used to run the MySQL server are in
the
folder C:\mysql. The two important
locations that you should be aware of are C:\mysql\bin,
which has executable files to start
and interact with the server, and C:\mysql\docs,
which has extensive documentation on the MySQL version that we have
installed.
I will now give you some basic heads up to get you started with using MySQL. Details on this can be found in the documentation in your directory.
1.1 Starting the MySQL
server
In order to use MySQL in your applications, you need to start the MySQL server installed in your machines from the command prompt. Here are the steps you make:
- go to START->command prompt
- navigate to the folder C:\mysql\bin from the command prompt.
- Start the MySQL server by typing in mysqld-nt. If successful, typing in this command should return no output.
Once the server has started successfully, you can log in to the server and execute queries from the command prompt. The command used to log in to the server is mysql –u root.
If successful, this command will display a welcome message and present the MySQL prompt, to which you will be entering your queries.
What follows is a brief overview of some of the basic SQL statements that were covered in class on Monday. For a more extensive review of that material, you should look through Chapter 3 in the manual.html page in your C:\mysql\docs folder.
1.2 Viewing and
Creating Databases
You can see the list of databases already created in MySQL by typing in the command:
show
databases;
Creating a database is also simple. The command for doing this is:
create
database databaseName;
You can also delete a database by using the command
drop
database databaseName;
Be careful when you use this command because once you delete a database, there is no going back.
1.3 Working on a
database
Once you have created a database, you can add tables to it by using the create table keyword.
Other important SQL keywords that you should know about are: Insert, select, update and alter. These are described in great detail in the MySQL manual that is already installed in the C:\mysql\docs folder.
2. TOMCAT
Tomcat is a commercial web server that helps display the output of your JSP pages. This web server has been installed in separate locations in many of the machines. A good place to look would be C:/tomcat.
The important folders that you will be working with are the webapps folder and the conf folder (which contains the server.xml file). We have created a tomcat folder in your desktop with shortcuts to all the files that you will be using to write your web application. Besides shortcuts to webapps and server.xml, this folder also contains shortcuts to the two executables that startup and shutdown the tomcat server.
2.1 Creating a new
Web Application in Tomcat
2.1.1 Where to put
your files
In order to use tomcat to run your web applications, you must put all your files in the webapps folder of the tomcat installation. For example, for the lecture application that we created on Monday, we created a new folder named lecture and put that folder in webapps.
After creating the application’s folder (lecture in this case), you should arrange all other files in the way that I outlined during lecture. In general, you should put all the files in the presentation layer in the lecture folder directly (that includes all html, JSP and images). You should then create a new folder named WEB-INF, and in the WEB-INF folder, create a new folder called classes that will hold all the java files necessary to run your application.
2.1.2 Editing the
server.xml file (do it once for every new web module)
After creating all the files for the web application, or whenever you are ready to see the output of your work, you should inform tomcat about the existence of a new web module before starting the server. This is done by adding the context path to the application in the server.xml file.
Usually, the context path is added near the very bottom of the server.xml file. If you want to find the right place to add a new context path, find the string “context path” in the file (ctrl-f in JCreator). This will direct you to the section of the file that contains context paths. For the lecture application, these are the lines that we added:
<!--
This is a comment. Lecture Application context -->
<Context
path="/lecture" docBase="lecture"
debug="0"
reloadable="true" crossContext="true"/>
After adding these lines, save and close the server.xml file. You are now ready to use tomcat to view the output of your JSP pages.
2.1.3 Starting Tomcat
You are now ready to see the output of your work. To start tomcat, just go to the tomcat folder on your desktop and click on the shortcut to startup icon. This will open a command prompt window with information on the status of tomcat as it starts. DO NOT CLOSE THIS WINDOW. Closing this window amounts to shutting down tomcat without following the right procedure. The right way to shut down tomcat is by clicking on the shortcut to shutdown icon on the tomcat folder in your desktop.
Once tomcat is up and running, open Internet Explorer and click on the localhost shortcut in the favorites tab. If successful, this should display the default homepage of the Apache-tomcat web server.
To see the output of a web module, add the name of the web module at the end of the current URL on the browser. For example, if the homepage is running at http://localhost, go to http://localhost/lecture to see the output of the lecture application. This should display a listing of the files that are associated with the lecture web module.
Please note that you may need to restart the tomcat server from time to time to see changes that you make to files in your web module. The right way to do this is by using the shortcuts in the tomcat folder on your desktop. Do not close the tomcat window directly. Be sure to refresh Internet Explorer after restarting the server to see any changes.
3 Interfacing MySQL
with your JSP Pages
Getting JSP to work with your MySQL pages may seem
like a
daunting task, but it is much simpler that it appears at first. This is
because
MySQL (and Samuel), have already provided an API to help interface it
with
java, and all you have to do is add the classes that have already been
created
to your own WEB-INF/classes folder.
I will therefore ask you to copy the following folders and files from the D:\aiti\jsp folder into your own web application’s WEB-INF/classes folder:
- the folders org and com, which are provided for you by MYSQL
-The file DbConnect.java, which I
wrote to make calls to classes in the org
and com folder and also the javax.sql classes. Make sure you compile
this file
before running your web application
I have included a file UsingDatabases.java
in the D:\aiti\jsp folder, which
has a method that shows you how to connect to a MySQL database and run
some
queries on it.
Make
sure you have
the mysql server running before you ask tomcat to execute any jsp
script that
uses the database.