Installing Java and Eclipse Installing Java and Eclipse CS 159: Advanced Programming Throughout the course, we will use Eclipse as our primary development environment. This page shows you how to install and configure Eclipse on your own computer. Step 1: Install Java Skip this step if you're on a CS lab machine; Java is already installed. In order to compile Java programs on your computer, you will first need to install the Java Development Kit (JDK). The JDK we recommend is OpenJDK, an open source implementation of Java SE (Standard Edition). Java SE 11 is the current Long-Term Support (LTS) release and is the version installed on our servers and lab machines. Linux (Ubuntu/Mint): Simply run the command: sudo apt install openjdk-11-jdk openjdk-11-source Windows and macOS: Visit the AdoptOpenJDK website and download OpenJDK 11 for your operating system (Figure 1). Run the installer, and follow the instructions (Figure 2). To verify the installation, open a Terminal and type java -version (Figure 3). Your version might be a bit newer than the images below. Figure 1 Figure 2 Figure 3 Step 2: Install Eclipse Skip this step if you're on a CS lab machine; Eclipse is already installed. Eclipse is an integrated development environment (IDE) for building applications based on Java, C/C++, Python, and many other languages. It's free and open source, and it's widely used by professionals around the world. Download and run the installer for your operating system (Figure 4). The current version is 2020-12. When asked, select the "Eclipse IDE for Java Developers" package (Figure 5). The installation might take several minutes. Figure 4 Figure 5 Step 3: Create Workspace When you run Eclipse, it will prompt you to select a workspace location. The default location is a directory named eclipse-workspace. Change the name to CS159 (with no space between CS and 159), as shown in Figure 6. Notice that /cs/home/stu/username is the location of your home directory on the CS lab machines. This location will likely be different on your own computer. An Eclipse "workspace" is a folder (or directory) that contains projects and settings. Typically students create a separate workspace for each course and a separate project for each assignment. Figure 6 Step 4: Install Checkstyle Checkstyle is a tool that can be used to determine if your source code follows a set of style rules. More importantly, it also checks for common programming mistakes, such as empty statements and accidental assignment. Go to Help > Install New Software... in the Eclipse menu. For "work with", enter the URL https://checkstyle.org/eclipse-cs/update and press Enter. Check the box to install Checkstyle and click "Next", as shown in Figure 7. The installation will take a minute or two. Accept the license terms, and click "Finish". When given the security warning, click "Install anyway". Then click "Restart Now" to apply the changes. Figure 7 Step 5: Set up Checkstyle Download the configuration file Checkstyle.xml (right-click and "Save link as..."), and save it under your CS159 workspace folder (not your Downloads folder). Then in Eclipse, go to the Window > Preferences menu (or Eclipse > Preferences on a Mac). Click "Checkstyle" on the left, and then click "New..." on the right. Enter the following information shown in Figure 8: Type: External Configuration File Name: ThinkJavaCode2 Location: .../CS159/Checkstyle.xml (where ... is your home directory location) After you click the "OK" button, select ThinkJavaCode2 in the list and then click "Set as Default", as shown in Figure 9. There should be a green check mark to the right of the ThinkJavaCode2 configuration. Finally, click "Apply and Close". Figure 8 Figure 9 Step 6: Set up Formatter The Eclipse formatter will automatically fix most style errors in your programs. Download the configuration file Formatter.xml (right-click and "Save link as..."), and save it under your CS159 workspace folder (not your Downloads folder). Go back to the Window > Preferences menu (or Eclipse > Preferences on a Mac). Search for the word formatter, and click "Formatter" under "Java > Code Style". Then click the "Import" button, and navigate to the Formatter.xml file. When finished, you should have "Think Java, 2nd Edition" as the active profile, as shown in Figure 10. Click "Apply and Close" to save your progress. Figure 10 Step 7: Other Settings The following settings are recommended, based on the work we'll be doing in CS 159. They are all found under Window > Preferences (or Eclipse > Preferences on a Mac). Disable notifications, unless you like to be interrupted while you work. Show the print margin (under Text Editors) to see the 80-character limit. Do not initially fold any code elements, so you can see the whole file. Ignore resource leaks (this "feature" is unfortunately a bug in Eclipse). Specify a "user defined dictionary" (filename) for the spell checker. This file will store new words you add to the dictionary. You will need to create an empty file named user.dict in your workspace location first. Refresh workspace on startup and confirm exit when closing last window. Don't forget to click "Apply and Close" at the end! Step 8: Create Project An Eclipse "project" is a collection of files that make up a single application. Typically each lab or assignment will be its own project. Figure 11 Click the "New" button on the Eclipse toolbar (Figure 11), select "Java Project", click "Next", and enter a name (e.g., HW1). Make sure "Use project folder as root for sources and class files" is selected (Figure 12). You can click on "Configure default..." so this will always be the case. Figure 12 Checkstyle must be turned on manually for each project. Go to the Project > Properties menu, click "Checkstyle" on the left, and check the boxes "Checkstyle active for this project" and "files not opened in editor", as shown in Figure 13. Figure 13 Congratulations! You now have Eclipse all set up to do some serious programming this semester.
