LabTV REST Server

A Spring project aimed at simulating IMDb-API.

It provides JSON responses through any REST API Client such as Postman, but was actually intended to work as a backend for LabTV REST Client.

This project was built with Spring Framework v5.3.20, Hibernate v5.6.5 and Maven v3.8.4 against JavaSE-11. Its Persistence Unit is configured to work with MariaDB v10.4.24 provided by XAMPP v8.1.6.

Database Structure and JPA Entities

Behind the scenes is a MySQL database built around the snapshot of a "Most Popular Movies" query from around June 2022 provided by our web development school and initially represented by the "evidenza" table only. We were tasked to create the "film" and "trailer" tables with specific fields and to make the according relationships.

Hibernate was set to create and update tables and fields thanks to the hibernate.hbm2ddl.auto property.

Each table (except join tables) are mapped as JPA Entities and feature @OneToOne and @ManyToMany uni- and bi-directional relationships. To take advantage of FetchType.LAZY and to avoid troubles with Hibernate's session and transaction management I ended up needing some more properties:

hibernate.enable_lazy_load_no_trans=true
hibernate.event.merge.entity_copy_observer=allow

I also included hibernate-enhance-maven-plugin to improve lazy loading.

In order to fill the database with missing entries, I made an ad-hoc component in LabTV REST Client accessible via /onetime where i fetched data from IMDb-API by making "Movie Title" and "Movie Trailer" queries. To avoid adding new entries everytime so to just work with a snapshot, each query response was saved to a *.har file and fetching methods were commented out. These files were then sent from the client to a dedicated Spring @RestController via POST methods.

JSON response modeling

Since database tables are shaped to reflect IMDb-API's JSON response structure and in order to take advantage of the redundancy of some fields, I decided not to map Entities against DTOs, but to map requests and responses directly onto Entities by making use of some Jackson annotations such as @JsonPropertyOrder, @JsonGetter and @JsonIgnore. I aimed at producing the same output as IMDb-API, so that LabTV needed minimal changes to keep on working seamlessly.

Instructions

1. Tomcat Server

This project was meant to work with Tomcat v9.x and won't work on any other version. Add Tomcat to Eclipse and make sure it is configured to run on HTTP/1.1 port 8082 as LabTV REST Client will be making calls directly to http://localhost:8082/labtv-api/.

2. Eclipse Configuration

Eclipse IDE for Enterprise Java and Web Developers is preferred.

• Import this project folder by selecting it from File -> Open Projects from File System... ;
• Right click on the project name from the Project Explorer and run Maven -> Update Project... (you may need to check Force Update of Snapshots/Releases);
• Right click on the project, select Properties, then Web Project Settings and make sure that Context root is set to labtv-api.

3. Database Import

The Persistence Unit is configured to work on a stock MySQL configuration as provided by XAMPP, so just make sure your MySQL process is running on port 3306 and that you haven't added a password.

Full Import (recommended)

• Make sure to backup any database named labtv, if any. The provided *.sql files will automatically create or select a database named exactly "labtv".
• Open your phpMyAdmin's homepage (don't select any database);
• Select Import;
• Browse for a file and select labtv_full.sql from the project root;
• Leave the rest as it is and clic the Import button.

If done correctly, you will find a database named "labtv" in your database list. You can now go back to Eclipse:

• Right click on the project, Run As and then Run on Server (if prompted, select your "Tomcat v9.0 Server").

You can safely close the browser window and check the server logs from Eclipse's Console. LabTV REST Server is now listening on port 8082.

You can now switch to LabTV REST Client or use any client to try the available queries.

Initial Import

You can choose to import a minimal version of the database consisting of only one table (as provided by the school) and fill it later from LabTV REST Client's "OneTime" component to see how Hibernate handles INSERTs.

• The instructions are the same as above, with the exception of selecting labtv_initial.sql from the Import page instead of the full variant.

If done correctly, you will find a database named "labtv" in your database list. You can now go back to Eclipse:

• Right click on the project, Run As and then Run on Server (if prompted, select your "Tomcat v9.0 Server");
• Hibernate will automatically create the missing tables and set their fields, indexes and relationships.

You can safely close the browser window and check the server logs from Eclipse's Console. LabTV REST Server is now listening on port 8082.

Now, it's time to switch to the frontend to fill the database:

• Follow LabTV REST Client's instructions and fire it up;
• Manually navigate to /onetime (example: http://localhost:4200/onetime);
• click on Send All Movies and wait for it to finish;
• click on Send All Trailers and wait for it to finish.

You can now use LabTV REST Client as normal or use any client to try the available queries.

Build

Requirements

A Windows build is also provided, but still requires Tomcat v9.x to be deployed correctly.

It is advised not to run Tomcat from Eclipse. Instructions will reference your Tomcat installation directory.

Instructions

• Download labtv-api.war;
• Locate your Tomcat v9.x installation folder;
• Place the war file into the webapps subfolder;
• Go back to the Tomcat installation folder and open the conf folder;
• Right click the server.xml file and Open with an editor of your choice such as Notepad;
• Replace any occurrence of 8080 with 8082 and save;
• Go back to the Tomcat installation folder and open the bin folder;
• Press CTRL + L to highlight the address bar (it could be CTRL + D on certain machines);
• type powershell and press enter to open PowerShell directly from that folder;
• type ./startup and press Enter;
• Tomcat will start in a new window and will automatically deploy the war file.

LabTV REST Server is now listening on port 8082. You can now use LabTV REST Client as normal or use any client to try the available queries.

Queries

• Most Popular Movies http://localhost:8082/labtv-api/api/evidenze

• Find Movie By Id http://localhost:8082/labtv-api/api/films/<id>

• Find Movie By Title http://localhost:8082/labtv-api/api/films/titoli/<title>

• Get Movie Trailer By Id http://localhost:8082/labtv-api/api/trailers/<id>

• Get All Most Popular Entries http://localhost:8082/labtv-api/api/all-evidenze

• Get Most Popular Movie By Id http://localhost:8082/labtv-api/api/evidenza/<id>