Fuel Calculator – Database Setup Guide

This project uses a MySQL/MariaDB database to store:

• Localized UI strings (instead of property files)
• Fuel calculation records

All UI text is loaded dynamically from the database based on the selected language.

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1. Prerequisites

Before setting up the database, ensure you have the following installed:

• MySQL or MariaDB
• Java JDK 17 or newer
• MySQL Connector/J (JDBC driver)
  (added via Maven or manually as a JAR dependency)

Make sure the database server is running.

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2. Database Overview

The database is named: fuel_calculator_localization

It contains two tables:

localization_strings

Stores all UI text for each supported language.

• key – UI identifier (e.g. distance, calculate)
• value – Localized text
• language – Language code (en, fr, jp, fa)

calculation_records

Stores each fuel calculation made in the application.

• distance – Trip distance
• consumption – Fuel consumption
• price – Fuel price
• total_fuel – Calculated fuel
• total_cost – Calculated cost
• language – Active language

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3. Creating and Populating the Database

A complete SQL setup file is provided: database_script.sql

This file:

• Drops any existing database with the same name
• Creates the database and tables
• Inserts all localization strings for all supported languages

Supported Languages

Language	Code
English	en
French	fr
Japanese	jp
Persian	fa

The language codes must match exactly with those used in the Java code.

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4. Importing the SQL File

Option A: Using MySQL Workbench

1. Open MySQL Workbench
2. Connect to your local MySQL server
3. Open a new SQL tab
4. Paste the contents of database_script.sql
5. Click Execute

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Option B: Using Command Line

From the directory containing the SQL file:

mysql -u root -p database_script.sql

Enter your MySQL password when prompted.

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5. Verifying the Data

After importing, verify that localization data exists for all languages:

SELECT language, key, value FROM localization_strings ORDER BY language, key;

Each language must contain six keys:

title, distance, consumption, price, calculate, result

If any key is missing, the UI will display placeholders like: !distance!

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6. Database Connection Configuration

The application connects to the database using: jdbc:mysql://localhost:3306/fuel_calculator_localization

Update credentials in: DatabaseConnection.java

Example:

private static final String USER = "root"; private static final String PASSWORD = "your_password";

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7. JDBC Driver Requirement

The MySQL JDBC driver must be available on the classpath.

Maven dependency (recommended):

<groupId>com.mysql</groupId>
<artifactId>mysql-connector-j</artifactId>
<version>8.3.0</version>

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8. Common Issues

UI shows !distance!, !price!, etc.

• Localization key is missing in the database
• Language codes in the database do not match the application
• Database was not re-imported after changes

Database connection errors

• MySQL service is not running
• Incorrect username or password
• JDBC driver missing from classpath