CSE135prep

This repository is to help UCSD CSE 135 Spring 2014 students for their project. What follows is a walkthrough for students that explains how to get started with the CSE 135 project, including how to install all the required libraries and frameworks and example application. Only the following technologies are required for the project :

• Apache Tomcat Server
• PostgreSQL DBMS
• Java/JSP development

The other technologies are personal suggestions that I believe will make your life easier. For example, I will be able to help those who follow my suggestions much better :).

Directory Structure

This git repository contains different files to help you get setup :

• the presentations folder includes the slides I used for the week 3 discussion session.
• the tomcat-config folder contains files to help you setup tomcat.
• the eclipse-examples contains eclipse compatible projects.
• the tomcat-examples contains projects to be put under the webapps folder of tomcat. Note that each example should have an eclipse compatible and a tomcat compatible version. If it does not have it yet, it's because it's coming soon.

Install a Ubuntu Virtual Machine

I suggest you use a Ubuntu virtual machine to build your project.

There are several reasons for this suggestion :

• You have no risk on crashing your computer while doing the project.
• Linux Ubuntu is probably the best platform to develop open source software.
• It will make grading for us easier ( I know, that's selfish :p).
• I don't want to write a cross platform guide.

The only part of this guide that will be cross platform will be how to obtain and install the Ubuntu VM. The rest of the guide will assume that you will be using Ubuntu.

• The best way to obtain a free VM is to use Oracle's Virtual Box. On this page you will see download links available for all major platforms, as well as a platform dependent installation guide.
• You can find a download link for Ubuntu here. Please choose version 12.04 (not 13.10).

You should now have a Ubuntu .iso file and Virtual Box installed. Follow these steps to create a Ubuntu VM :

• Start Virtual Box and select the New tab. You will be asked the type and the version for the operating system of the VM. Make sure to select Linux (type) Ubuntu (version).
• You may want to allocate at least 512MB of RAM (although probably more), it should be sufficient for our purposes, but you can increase it if you want.
• The next page should ask you if you want to create a virtual disk. You should select option Create a virtual disk now.
• When asked which format for the virtual disk, select .vdi.
• On the next pane you will be asked to specify the disk storage. Make sure to choose dynamically allocated.
• Choose how much space you want your virtual disk to use (I chose 8GB) and select Create. Congrats, you now have a new VM!
• You know have to install Ubuntu on your VM. You should be on the VM manager page of Virtual Box. Select the VM you just created and select the Configuration tab. A new window will pop up.
• In the new window, select the Storage tab. On the left hand side of the window, you should see a pane with a field called Controller : IDE. On the right side of that field a little disk icon should be visible. Select it, and choose the option Choose Disk. This will ask you to choose an .iso file and you can use the Ubuntu version you downloaded.
• You can now start your VM on the main menu and it should boot ubuntu on a seperate window!
• It will take you through the installation process.

Install Git

One personal suggestion is that you use a revision control system to manage the program such as Git to build your project. I also suggest building your project as a private repository on Github and add members of your group as collaborators. In case you didn't know, you have up to 5 free private GitHub repositories as long as you are a student, see this link.

It is very easy to install git on ubuntu. Just type the following command on the terminal :

sudo apt-get install git

You can now clone the repository CSE135prep onto your vm by issuing the command git clone https://github.com/jtestard/CSE135prep.

Setup Java + Tomcat

I have written a script called tomcat-config/tomcat_setup.sh that should be included in this git repository. Make sure to make it executable by using the command chmod +x tomcat_setup.sh before executing it. You can execute this script on your machine. It will install java (v1.6) and Tomcat (v7.0.53) on your VM, move them to appropriate directories and setup your $CATALINA_HOME and $JAVA_HOME variables.

The only thing this script does not do is setup your tomcat users :

• copy the file tomcat-config/tomcat_users.xml from this repository into $CATALINA_HOME/conf.

Install Eclipse

You can download eclipse by going on the Ubuntu Software Center and looking for Eclipse.

Setup Postgres

Issue the following command on your terminal (you need admin privileges) :

    sudo apt-get install postgresql postgresql-contrib

This way, you should get a recent version of PostgreSQL. The PostgreSQL installation creates a unix user called postgres which is the only one allowed (at first) to create databases.

It would be better if you could do that yourself :

• Enter the command sudo passwd postgres on your terminal. This lets you create a new password for the postgres user (for some reason, the postgres user does not have a default password).

• Enter the command su postgres and use the password to login into the postgres user.

• Enter the following commands :

   createuser -s YOUR_UNIX_USERNAME
   createdb cse135
  

• Log out from the postgres user and enter the command psql -d cse135. This connects you to the database, from here you can issue SQL statements.

• To quit psql, just issue the command \q.

You can setup an example database with the SQL/enrollment.sql file from this repository (also available on the course website). You can use psql -f enrollment.sql.

Setup A Tomcat server on Eclipse

• 1. Configure the run time server :
  • Go to Eclipse > Preferences > Server > Run Time Environments
  • Add...
  • Choose Apache Tomcat 7.0, then next.
  • Make sure Tomcat installation path is the one you get when you execute echo $CATALINA_HOME on a terminal.
  • Click on Finish
• 2. Add a new server :
  • Go on Window > Show View > Servers
  • Open new server wizard from the servers window pane (should be on the bottom of your screen).
  • Make sure Server Host Name is localhost and Server Runtime Environment Apache Tomcat v7.0 then select Finish.
  • The server should now appear in the server window. Right-click and the server and press start. You should know be able to see the tomcat main page on http://localhost:8080.
  • Some people (including I) may see a 404 page error at this step. Don't worry, your tomcat is running. We just need to do an extra configuration.
  • Back on Eclipse, double-click on the server name and a server configuration window should appear. Make sure the radio button User Tomcat Installation is ticked. Verify that the Server Path is also set to /usr/local/apache-tomcat-70.0.52.
  • Restart the server. You should know see the Tomcat server normally.
  • If you have done the tomcat user setup (see Setup Java+Tomcat section), then you should be able to logon onto the Tomcat manager app and see all your current applications. The username and password are both "admin". The manager app will allow you to access your app more easily in the future from the Tomcat main page.

Write your first Tomcat web application

You can follow this srccodes tutorial. You now have a working HelloWorld simple JSP web app. However, if go on http://localhost:8080/HelloWorldJSP/, you will get a 404 error. This is because the web.xml file which manages your web app did not include your HelloWorld.jsp file as a welcome file. You can fix this the following way :

• I have included the web.xml you want in this repository under eclispe-examples/jsp-examples/HelloWorldJSP/WebContent/WEB-INF/web.xml.
• You should put this file in the WEBINF directory of your application.
• If you restart the application using Eclipse (as described in the tutorial for this section), you can now access http://localhost:8080/HelloWorldJSP/ and get the correct output.

Write your first JSP program

You should have pulled this git repo onto your VM by now. You should see the three examples yannis provided under the jsp-examples folder. Now go on Eclipse, you will see how to run the MultiplierJSP example (from eclipse-examples) from scratch:

• Create a new dynamic web project (like you did in the srccodes tutorial) and use MultiplierJSP as the name of your project and go on finish.
• Notice that your project does not contain a web.xml file yet. Copy the web.xml file from the MultiplierJSP example in the git repository into your eclipse under WebContent/WEB-INF.
• Copy the three .jsp files from the MultiplierJSP example in the git repository and add them under WebContent in your eclipse project.
• Run your app on the server like you did in the srccodes tutorial.

Write your first Java JDBC app

You need to have completed the tomcat setup and postgres setup to start this section. In particular, you should have created the cse135 database. We will cover the student-with-database example (from eclipse example) :

• The example uses a hardcoded database name (cse135) and username (postgres) with password (postgres). You can change that in the code yourself or follow these instructions to setup the user and database accordingly.
  • You first need to populate the database. You should already have created the database cse135. Go to the folder of the student-with-database example and execute the command psql -f ddl.sql.
  • You can setup the user by issuing the following command from within psql : ALTER USER postgres WITH PASSWORD 'postgres'.
• You can now setup your jsp program as you did before and the app should work fine.