Tut00 - james-bern/CS136 GitHub Wiki

README

This somewhat terrifying tutorial will get you ready to code Java in the (relatively) simple Eclipse IDE!
- Learning how to use your IDE is a really good time investment 🙂👍
We will also fill in some gaps in your knowledge of computer basics
NOTE: If you have any problems feel free to email Jim or we can fix them together on the first day of class 🙂👍

Definitions

A window is made up of panes
A GUI (pronounced "gooey") lets you interact with a computer program using the mouse (includes checkboxes, buttons, icons, etc.)
- Most programs you use have a GUI, but some, like the Terminal/Command Prompt, do not
A text editor lets you edit text
A debugger helps you find bugs in your code
- A "graphical debugger" has a GUI, and is usually a lot easier to use than a pure "command-line debugger"
An IDE is a text editor plus other stuff (debugger, etc.)

How to copy and paste

🍏 Mac

Highlight text by clicking and dragging the mouse
Press ⌘ + C to copy
Press ⌘ + V to paste
NOTE: There is also ⌘ + X to "cut," which copies the text and deletes it

🤷‍♂️ Windows

Highlight text by clicking and dragging the mouse
Press CONTROL + C to copy
Press CONTROL + V to paste
NOTE: There is also CONTROL + X to "cut," which copies the text and deletes it

How to right click on a Macbook

Click the trackpad with two fingers

How to open a Terminal/Command Prompt and Navigate to the Desktop

🍏 Mac

Open a Terminal by pressing ⌘ + SPACE, typing terminal, and pressing ENTER
A Terminal should pop up in the home directory (denoted by a ~)
- If not in the home directory, in the Terminal, type cd ~ and press ENTER to change directory to the home directory
In the Terminal, type cd Desktop and press ENTER

🤷‍♂️ Windows

Open a Command Prompt by pressing ⊞ Win, type cmd, and pressing Enter
A Command Prompt should pop up in the home directory (mine is C:\Users\jbern)
In the Command Prompt, type cd Desktop and press ENTER

How to Put GitHub into Light Mode

It will be easier to read the course webpage in "light mode" (black text on white background).

Option A (easier): Set you system theme to a light mode
- 🍏 Mac: Press ⌘ + SPACE type Appearance and press Enter; select a light theme.
- 🤷‍♂️ Windows: Press ⊞ Win, type Turn on light mode systemwide, and press Enter; select Light
Option B: Change theme of Github only.
- Log in to Github (make an account if you don't already have one) and click the circular icon in the top right -> Settings -> Appearance; set Theme mode to Single theme and select Light default.

Misc Setup

🧑‍🔬 NOTE: If you are working on a Lab Machine, please skip to Clone the Codebase.

Install Git

🍏 Mac

Install Homebrew
- In the Terminal, type /bin/bash -c "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/HEAD/install.sh)" and press ENTER
- Read the bottom of the message that brew prints to your Terminal.
  - If there are additional instructions there, follow them as well. 🙂👍
Install Git
- In the Terminal, type brew install git and press ENTER

🤷‍♂️ Windows

Download Installer
Open the downloaded file (it can be found by clicking the ⬇️ button at the right-top corner of Edge)
You may get a User Account Control popup
- Press 'Yes'
Click Next
Click Next
Select Components window
- Uncheck all boxes
Click Next
Click Next
Choosing the default editor used by Git window
- Choose Use Notepad as Git's default editor
Mash Next/Install until it starts actually installing
Congratulations, you have installed Git

Uninstall Java

Uninstall any versions of Java already on your computer.

Open a Terminal and run java -version
If you get an error (command java not found or similar): You have no Java! Please continue to the next step 🙂👍
If a recent-ish Java version (e.g., Java 17) is installed: This is actually probably fine. Continue to the next step 🙂👍
If an ancient Java version (e.g., 1.8) is installed: We need to uninstall Java!
- Windows: Press ⊞ Win, type add or remove programs, and press Enter; Uninstall Java
- Mac: Open a Terminal and run the following commands (you can copy them all at once by clicking the icon in the top right (⧉))
```
sudo rm -rf /Library/Internet\ Plug-Ins/JavaAppletPlugin.plugin
sudo rm -rf /Library/PreferencePanes/JavaControlPanel.prefPane
sudo rm -rf /Library/Application\ Support/Oracle/Java/
sudo rm -rf /Library/Java/JavaVirtualMachines
```

Install Eclipse

🍏 Mac

Download the right Eclipse 2021-12-R installer for your Mac
- Click the Apple icon at the top left of your screen -> About This Mac
  - M1 or M2 Download Link
  - Intel Download Link
Double-click the downloaded file (it can be found by clicking the ⬇️ button at the right-top corner of Safari)
A Finder window should pop up
Click and drag Eclipse (🔮) into the Applications shortcut (📁) to install Eclipse
Click the red x (❌) to close the Finder window
There Eclipse installer (⬜️) is still on your Desktop; eject it by right clicking its icon and pressing Eject "Eclipse"

🤷‍♂️ Windows

Download Zip Folder
Open the downloaded file (it can be found by clicking the ⬇️ button at the right-top corner of Edge)
Click Extract all
Make sure Show extracted files when complete box is checked
Click Extract
The unzipped folder should pop up
Click and drag the inner eclipse folder to your Desktop
Close the File Explorer window
Double-click the eclipse folder to open it
Hold the ALT key and drag eclipse.exe onto your Desktop to make a desktop shortcut
Close the File Explorer window

Clone The Codebase

Open a new Terminal
Navigate to the Desktop
Type git clone https://github.com/james-bern/CS136.git
Press ENTER

Launch Eclipse

⚠️ IMPORTANT: Never update Eclipse
Open Eclipse
- 🍏 Press ⌘ + SPACE, type eclipse, and press ENTER to open Eclipse
- 🤷‍♂️ Double-click eclipse.exe - Shortcut to open Eclipse
A window titled Eclipse IDE Launcher should pop up
Check the box for Use this as default and do not ask again
Press Launch
A webpage may open (for...some reason)
- Close it
Close the Welcome pane

Open Project

In Eclipse, File -> Open Projects from File System...
Directory...
Desktop -> CS136
Press Open
Press Finish
In Package Explorer on the left...
- Click the > next to CS136
- Click the > next to (default package)
- Double-click HelloCow.java

Run HelloCow (in the Debugger)

⚠️ IMPORTANT: If Eclipse ever offers to switch its Perspective automatically, check Remember my decision and say NO 🙅
- If you mess this (or any other stuff) up, just lemme know 🙂👍
⚠️ IMPORTANT: If Eclipse ever offers to save your file before running, check Remember my decision and say YES 🙆
⚠️ IMPORTANT: If Eclipse wants say it needs to go around your firewall, ALLOW 🙆
Option A: Press the Debug button (🪲)
Option B: Press the keyboard shortcut for Debug
- NOTE: You can find it in the top menu under Run -> Debug
- NOTE: On a laptop, you may F11 may actually be Fn + F11
Press the keyboard shortcut (something involving F11)
🥳 Amuse yourself with a rousing game of Tic Tac Toe

Configure Eclipse Prefences

Open the Preferences
- 🍏 Eclipse -> Settings...
- 🤷‍♂️ Window -> Preferences
Disable Content Assist Auto Activation
- Java -> Editor -> Content Assist
  - NOTE: You will need to click the >'s to drop down the menus
- Uncheck the box for Enable auto activation
Disable Initial Folding
- Java -> Editor -> Folding
- Make sure Enable folding is checked (leave it alone)
- Make sure all other boxes are unchecked (you should have to uncheck two boxes)
Press Apply and Close

Configure Eclipse Panes

Make your Eclipse looks like this (you will need to spend ~5-10 minutes with dragging the panes around):
- NOTE: If you don't already have the Variables and Debug panes, you can add them with something like...
  - 🍏 Window -> Show View -> Variables
  - 🤷‍♂️ Window -> Show View -> click > by Debug -> Variables -> Open
- NOTE: If you don't already have the Console pane, try Window -> Show View -> Console
- 🍏 NOTE: You may need to drag the Problem pane's Description column separator over to the right to see anything.
- NOTE: There is a Maximize button on the right-top (looks kinda like 💾) that will make the text editor bigger. Use Restore (⧉) to go back.

How to use Eclipse

Create HW00.java

In the Project Explorer, right click CS136 and press New -> File
Type HW00.java
Press Finish
Open HW00 in a new window or tab (right-click on the link for options)
Scroll down to the Starter Code
Copy the Starter Code by pressing the button in its right-top corner (⧉)
Paste the Starter Code into HW00.java by clicking inside of HW00.java and pressing...
- 🍏 ⌘ + V
- 🤷‍♂️ CONTROL + V

Auto-Indent the Starter Code (you want usually have to do this), by clicking inside of HW00.java and pressing

🍏 ⌘ + A (select all) then ⌘ + I (auto indent)
🤷‍♂️ CONTROL + A then CONTROL + I

Run the Starter Code

Run HW00 by pressing the bug (🪲) or your computer's F11 hotkey combination that you looked up earlier

Compile Error

You should get an Errors in Workspace popup
Press Cancel
Verify that you can read the compile error (missing semicolon) in the Problems pane like this:

Add the missing semicolon
Run again

Runtime Error

Read the runtime error (divide by zero) in the Variables pane like this:
- NOTE: You will need to click on main() is throwing

Press the Resume button (yellow and green icon kinda like ⏯️) to crash the program (and terminate the debugging session)
Replace 0 with 6
Run again

Assert Error

Read the assert error (2 + 2 == 5) in the Debug pane like this:
- NOTE: You will need to click one call below the ASSERT(...) call in the stack trace
- NOTE: A message will also be printed to the Console.

Press the Resume button (yellow and green icon kinda like ⏯️) to crash the program (and terminate the debugging session)
Replace 5 with 4
Run again

Console Message

Read the console message (7) in the Console pane like this:

Warning

Read the warning (Comparing identical expressions) in the Problems pane like this:

Delete the very silly ASSERT(2 + 2 == 4);
Run again
🙂👍