The world-leading fictional Danmaku video website, Synchronized User-generated Subtitle Technology Company (SUSTC), is now hiring your team to build a new backend system for them. Please use the code in this repository as a template to start your work.

• JDK: This template requires JDK 8+ and is compatible up to Java 20. We will use JDK 20 to work around your submitted jar file.

  Other JVM languages (Kotlin, Groovy) are supported as long as you build a jar file that can pass the local benchmark.

• Database: You need to host your own PostgreSQL database when developing. We will use PostgreSQL 16 to run the final benchmark.

  As we may require you to return the sorted result in some query, please create the database with LC_COLLATE='C' option, which provides the platform-independent sorting result.

  CREATE DATABASE sustc WITH ENCODING = 'UTF8' LC_COLLATE = 'C' TEMPLATE = template0;

Create a private copy of the template repository by clicking the Use this template button, or download a zip copy to work without using git.

Consider watching the template repository to track discussions/issues, and receive notifications when we update the template.

# this command is only required for the first time
git remote add upstream https://github.com/hezean/sustc.git  # or `[email protected]:hezean/sustc.git` for git protocol

git fetch upstream
# better to commit your changes before merging
git merge upstream/main --allow-unrelated-histories
# then resolve the conflicts (if any) and commit the changes

.
├── sustc-api                                              # You should work around this directory
│   ├── build.gradle.kts                                   # You may add any utility libraries here
│   └── src/main/java
│                └── io.sustc
│                    ├── dto                               # The passed arguments and return values of services are defined as DTO (Data Transfer Object)
│                    │   └... User.java                    # You should not modify the defined fields or methods, but you may add new ones
│                    ├── exceptions                        # You should throw correct exceptions as instructed in JavaDoc
│                    │   └... EntityNotFoundException.java
│                    └── service                           # The interfaces of services are defined here
│                        ├... DatabaseService.java
│                        └── impl                          # We suggest you to place your implementation here. Actually, any package is OK, as long as annotating the class as `@Service`
│                            └... DatabaseServiceImpl.java
└── sustc-runner                                           # We've provided you an interactive command line runner, a benchmark runner with sample data, and unit tests
    ├── compose.yml                                        # You may optionally use a container-based database to prevent polluting your local database
    ├── data                                               # Contains records to import and test cases
    └── src/main
            ├── java
            │   └── io.sustc
            │       └── command                            # You may call the services here, type `help` in shell to list all commands
            │           └... UserCommand.java
            └── resources
                └── application.yml                        # Configure your database connection and benchmark behavior here

The project is managed by Gradle to help you manage dependencies, run locally, and build the submission.

• sustc-api is the module where you should implement your services.
• sustc-runner module provides you an interactive command line runner and a benchmark runner with sample data.

Basically, you only need to focus on three directories:

1. io.sustc.service package contains the interfaces of services you need to implement. You should not modify the interfaces. A demo implementation is provided in DatabaseServiceImpl. Please also update the getGroupMembers method to help us identify your submission.

2. io.sustc.dto package contains the definitions of DTOs (Data Transfer Objects) that act as the arguments and return values of services. You should not modify the defined fields or methods, but you may add new ones.

3. application.yml is the configuration file for running the program. You may configure your database connection and benchmark behavior here.

Please note that your submission is built by the sustc-api module, any modification to the sustc-runner module will not take effect in the final benchmark.

After setting up your database and modifying the configuration file, you may run the program locally in two modes.

You can test your services by typing commands in any sequence, with any data. Run the Gradle task named bootRun to start the interactive shell.

./gradlew :sustc-runner:bootRun  # or simply   ./gradlew bootRun

If you are using IntelliJ IDEA, you may find the list of Gradle tasks on the right side of the window.

You may type help after the application starts up to see the list of available commands.

The benchmark service works exactly the same as how we will judge your submission, which grades your services based on both correctness and performance. To run the benchmark, use the benchmark Gradle task.

Note that you need to implement all service interfaces to run the benchmark. You may create dummy implementations (e.g. throw UnsupportedOperationException) before actually implementing them.

As previously mentioned, you need to submit a jar file that contains your implementation of the services (and any dependencies you added). To build it, run the submitJar Gradle task.

./gradlew submitJar

Then you should find a submit folder under the root of project, containing a single jar file (its size should be about 8~10 MB if you didn't add any additional dependencies). We don't accept jar files larger than 20 MB, so please don't add too much dependencies.

If any jar file presents in the submit folder, the runner will use it instead of the latest code in sustc-api module.

Then create exactly one SQL file (any filename is acceptable) under the submit folder that could properly initialize your database. You don't need to include a create database statement in your submission, as we will create the database for you.

submit              # Under the root of project
├── schema.sql      # Any filename is acceptable
└── sustc-api.jar   # Produced by `submitJar` task

Then zip the submit folder (unzip should produce a folder named submit, instead of any other folder name, or the separated jar and sql files).

Also, similar to other courses, we require you to submit your source code for academic purposes and plagiarism detection. Please run the clean task before archiving your source code, which will delete the built files.

./gradlew clean

After cleaning up, the source archive of sustc-api should not be larger than 10 MB.

Finally, upload these zip files with any other resources as specified to Blackboard.

Please also read the project requirements document posted on Blackboard.

If there's anything ambiguous about the document or the instruction above, feel free to open an issue and ask. Your question may also help others to better understand this project. 🔥

• PostgreSQL 16 Documentation
  • Backward Compatibility
• SpringBoot 2.7 Documentation
• Lombok Documentation
• Gradle User Manual
  • Managing dependencies with Gradle

The project is designed for educational purpose for the course CS307 Principles of Database Systems and CS213 Principles of Database Systems (H) at Southern University of Science and Technology.

The code template is licensed under the MIT License — see the LICENSE file for details.