Project: File IO

Table of Contents

• Project: File IO
  • Table of Contents
  • Good work pledge
  • Getting started
  • The Project
  • Committing your Changes and Turning In The Project
  • Grading

Good work pledge

We are here to broaden your exposure to Computer Science. We can only achieve that purpose when you work hard and honestly. It may be tempting to copy-paste code from a classmate, or let a classmate do all your work for you—don't! You will be cheating yourself from the most valuable thing course has to offer—overcoming challenges.

We know that hard, and honest work doesn't come easily. If you feel like you are falling behind:

1. Don't copy-paste code, or let someone do your work for you
2. Ask for help!
3. Tell the teaching-team you need more time

Getting started

1. Open the assignment link your teacher posts in Teams or OneNote, and accept the assignment. GitHub will create a private project just for you.
2. On your new project page, click the green Code button, copy the link, and clone the project into IntelliJ (File → New → Project from Version Control, then paste the link).
3. When IntelliJ asks if you trust the project, say yes / trust it so it can finish setting things up.
4. If IntelliJ asks you to pick a Java version (JDK), choose 17 or newer.
5. Use the green play dropdown near the top-right of IntelliJ and choose Main to run the program. Choose UnitTests to run the automated checks for your methods.

If anything looks confusing the first time you open the project, ask a teacher — IntelliJ asks a few one-time setup questions, and then day-to-day work is just writing code and using that green play button.

The Project

In this project, you will be implementing functionality to read data from a file and write data to a file. Along with reading and writing to a file, you will get a flavor for dealing with exceptions and sorting.

The program allows you to run several commands that allows you to read data, manipulate data, and write data. The only manipulation we will be doing is sorting. Here are the commands that the program allows you to run:

• Read: takes in a file path and reads the weather data from the file.
• Sort: must be called after at least one 'read'. This command sorts the weather data that was read into the program in order of highest average temperature (the city with the highest average temperature will come first).
• Write: must be called after at least one 'read'. This commmand takes in a path and writes the data we have read into the file at that path. If the file already contains data, it is overwritten.
• Append: must be called after at least one 'read'. This commmand takes in a path and writes the data we have read into the file at that path. If the file already contains data, the new data will be appended to the existing contents.
• Quit: ends the program.

These are the functions you will implement:

• In Main.java:

  • ReadFile: Reads a file from the given path and puts the information into an ArrayList. If the file does not exist, catch the exception, print a message, and return an empty ArrayList — do not rethrow and do not return null.

  • PrintWeatherData: Prints the weather data ArrayList to the console. Each weather data item should go on a new line:

    [City1], [Average Temperature], [Average Humidity] [City2], [Average Temperature], [Average Humidity]

  • SortWeatherData: Sorts the given ArrayList from hottest average temperature to coldest average temperature.

  • WriteFile: Writes the weather data information into the file with the given path. If shouldAppend is false, replace the existing contents; if true, append. Catch create/write failures, print a message, and do not crash. Note: some PrintWriter constructors take a boolean that means autoFlush, not append — check which constructor you use.

• In WeatherData.java:

  • toString: Returns a string representation of WeatherData with a comma and space between each part. Example:

    Seattle Wash., 50.2, 37.07

    Do not put a newline inside toString — newlines belong in printing / writing.

  • compareTo: Compare by average temperature only (ignore humidity). A hotter city should compare as greater than a colder city (return a positive number). Same temperature → 0. SortWeatherData must end up hottest → coldest; how you get there is up to you. See also: https://docs.oracle.com/javase/8/docs/api/java/lang/Comparable.html#compareTo-T-

CSV parsing: Input lines look like City,50.2,37.07 or City, 50.2, 37.07. After you split on commas, make sure each piece is usable as a number (whitespace can sneak in). Skip malformed lines that do not have three fields. Written output should match the toString format above.

Committing your Changes and Turning In The Project

At the end of every class period, commit and push your work from IntelliJ:

1. Click Git > Commit… (or use the Commit tool window).
2. Review the changed files. You can double-click a file to see the diff.
3. Enter a short commit message, then choose Commit and Push….
4. Confirm the push to your project's main branch.
5. On GitHub, confirm your latest commits are visible.

Pushing to main is how you turn in work for this assignment. You can keep improving and pushing after the deadline if your teacher allows late work — ask about any late penalty.

Grading

Your grade for each project will fall into one of four categories:

Grade Level	Explanation
Exceeds Expectations	Quality is outstanding.
Excellent	Overall quality is high.
Satisfactory	Overall quality is good. Improvements can be made to bring the quality up to Excellent.
Needs Improvement	Overall quality is not yet high enough and the submission will not be accepted. Improvements must be made to bring the quality up to at least Satisfactory.