Your task in this homework—which is worth no Blugolds—is to set up your repository and IntelliJ IDEA project and to acclimate yourself to the SpecChecker grading tools.
You are probably used to two kinds of systems for editing and managing files. Some tools are installed on your local machine and edit files stored on your computer or USB drives. Other tools are cloud-based and edit files stored on remote computers, perhaps through a web browser. This semester we’re using a tool called Git, which blends these two approaches.
Your project will reside remotely on computers managed by GitLab, but you will make edits on a local copy. At the end of each coding session, you push your local changes back up to GitLab. This hybrid system has several advantages:
A project has already been made for you and it is waiting for you on GitLab at this address:
https://gitlab.com/cs1_2019c/USERNAME
Visit this address, replacing USERNAME with your UWEC username, and you will find that you do not yet have permissions to access your project. Create an account using your UWEC email address on GitLab and then email your instructor, who will add you to the project. (Having to wait on your instructor is clumsy. Maybe someday GitLab will make it easier to add individuals before they create accounts.) Only your UWEC address will work for this step, but you can add other addresses later.
Once you have gained access, you will see a listing of all the files currently in your project, including .idea, speccheckers, .gitignore, and others.
To add new files or edit existing files in your project, we first clone the GitLab repository on your local computer. Complete the following steps to get your local clone:
https://gitlab.com/cs1_2019c/USERNAME for the URL, replacing USERNAME with your UWEC username.You only need to clone once per computer (or H: drive) that you use. The next time you open IDEA, navigate to this existing project.
We’re now ready to dive into the actual homework specification.
Your solution must meet the following specification:
hw0 of the project on GitLab that has been made for you.Greeter to have the following: main, which prints the line Goodbye, Pluto! to the console.Learning goes something like this:
Your instructor doesn’t want you to spend a lot of time in stage 1 and only a little time in stage 2. So, he has provided a tool called a SpecChecker that you can run as often as you want to see how well you are meeting the homework requirements. This tool isn’t designed to fix your problems for you—only to make you aware of them. You will still have to think.
To run the SpecChecker for homework 0, find the green play button in IDEA’s toolbar. To its left is a dropdown menu. Select hw0 SpecChecker and click the play button. You should see output that includes the following text:
I couldn't find a class by the name of "hw0.Greeter". Check CamelCase, spelling, and that you created your class in the right package.
The SpecChecker is telling us that it can’t find a class that’s required for the homework. If you want the 0 Blugolds that this assignment is worth, you’d better add it.
Note that the requirements state that the Greeter class must be in package hw0. Click File / New / Package, and create a new package named hw0.
Packages can be thought of as directories. You will use them to organize your code for this course. Each homework will go in its own package.
With the directory in place, let’s add the Greeter class. Right-click on the hw0 package and select New / Java Class. Enter Greeter as the name. The file Greeter.java is placed inside the hw0 package and opened for editing. It contains the following text:
package hw0;
public class Greeter {
}
Run the SpecChecker again. You should see this output:
I couldn't find method main(String[]) in class hw0.Greeter. Have you written it? Does it have the right name? The right parameters?
Though you have the required class, you do not have the required main method in that class. Let’s add it. Place your cursor so it’s on the blank line between the curly braces. Hit tab to indent one level. Clear indentation makes it easier to understand how your code is nested. Noticing patterns and structures is how you become a skilled software developer.
Now type the word psvm and hit Control-Space. Select the entry to add a main method that looks like this:
package hw0;
public class Greeter {
public static void main(String[] args) {
}
}
If your indentation doesn’t match the code above, hit Control-Alt-L or Command-Option-L to have IDEA automatically reformat your code.
Run the SpecChecker again. You should see this output:
When running Greeter.main, I did not see the expected output. Expected line 1: "Goodbye, Pluto!\n" But I didn't get line 1 from you at all.
The SpecChecker captures the output of your program and compares it to the expected output. Your program had no output, so it certainly did not match. Add a print statement to print Goodbye, Pluto... :(—which is not quite the required output. Run the SpecChecker again. You see the following output this time:
PROBLEM:
When running Greeter.main, I did not see the expected output.
This is what I expected: Goodbye, Pluto!\n
This is what I actually got: Goodbye, Pluto... :(\n
Differences: ^^^^^^^^
The carets/circumflexes highlight the differences between the expected and actual output.
Fix your print statement so it does the right thing. Test it apart from the SpecChecker so that you understand the behavior of your own code. If you treat the SpecChecker like a crutch, using it to hobble from error to error, you will have a very discouraging semester.
To run your class on its own, right-click or two-finger-click on the Greeter.java editor window and select Run Greeter.main().
When you like the result, run the SpecChecker to verify that everything’s okay. Reselect it in the dropdown menu next to the play button.
When all functionality tests pass, you will be asked to confirm that you’ve used meaningful variable names and that you’ve properly submitted your work. After you confirm, you should see the following output:
High five. You have passed all tests. Now commit and push before the deadline.
Your code works! But you’re not done yet. You still need to get your code up to GitLab so your instructor can grade it.
To submit your work for grading:
Crushed hw0.A passing SpecChecker does not guarantee you credit. Your grade is conditioned on a few things:
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