Added database connection, added test and start with Testcontainers.

.env.example

@@ -0,0 +1,3 @@
+POSTGRES_PASSWORD=""
+POSTGRES_USER=""
+POSTGRES_DB=""

.gitignore

@@ -36,4 +36,5 @@ build/
 .vscode/
 
 ### Mac OS ###
-.DS_Store
+.DS_Store
+.env

README.md

@@ -15,5 +15,5 @@
 
 
 ## TODO:
-- [ ] Fabryka połączenia do bazy danych
-- [ ] Testy bazy
+- [x] Fabryka połączenia do bazy danych
+- [x] Testy bazy

docker-compose.yaml

@@ -0,0 +1,18 @@
+services:
+
+  db:
+    image: postgres:18.3
+    restart: always
+    shm_size: 128mb
+    environment:
+      POSTGRES_PASSWORD: ${POSTGRES_PASSWORD}
+      POSTGRES_USER: ${POSTGRES_USER}
+      POSTGRES_DB: ${POSTGRES_DB}
+    ports:
+      - 12900:5432
+
+  adminer:
+    image: adminer
+    restart: always
+    ports:
+      - 12901:8080

pom.xml

@@ -14,4 +14,44 @@
         <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
     </properties>
 
+    <dependencies>
+        <dependency>
+            <groupId>com.zaxxer</groupId>
+            <artifactId>HikariCP</artifactId>
+            <version>7.0.2</version>
+        </dependency>
+
+        <dependency>
+            <groupId>org.postgresql</groupId>
+            <artifactId>postgresql</artifactId>
+            <version>42.7.10</version>
+        </dependency>
+
+        <dependency>
+            <groupId>io.github.cdimascio</groupId>
+            <artifactId>dotenv-java</artifactId>
+            <version>3.2.0</version>
+        </dependency>
+
+        <dependency>
+            <groupId>junit</groupId>
+            <artifactId>junit</artifactId>
+            <version>4.13.2</version>
+            <scope>test</scope>
+        </dependency>
+
+        <dependency>
+            <groupId>org.testcontainers</groupId>
+            <artifactId>postgresql</artifactId>
+            <version>1.19.8</version>
+            <scope>test</scope>
+        </dependency>
+        <dependency>
+            <groupId>org.junit.jupiter</groupId>
+            <artifactId>junit-jupiter</artifactId>
+            <version>5.9.3</version>
+            <scope>test</scope>
+        </dependency>
+    </dependencies>
+
 </project>

src/main/java/util/DatabaseConnection.java

@@ -0,0 +1,33 @@
+package util;
+
+import com.zaxxer.hikari.HikariConfig;
+import com.zaxxer.hikari.HikariDataSource;
+import io.github.cdimascio.dotenv.Dotenv;
+
+import java.sql.Connection;
+import java.sql.SQLException;
+
+public class DatabaseConnection {
+
+    private static Dotenv dotenv = Dotenv.load();
+
+    private static HikariConfig config = new HikariConfig();
+    private static HikariDataSource ds;
+
+    static {
+        config.setJdbcUrl(dotenv.get("JDBC"));
+        config.setUsername(dotenv.get("POSTGRES_USER"));
+        config.setPassword(dotenv.get("POSTGRES_PASSWORD"));
+        config.setDriverClassName("org.postgresql.Driver");
+        config.setMaximumPoolSize(10);
+        config.setMinimumIdle(2);
+        ds = new HikariDataSource(config);
+    }
+
+    private DatabaseConnection() {};
+
+    public static Connection getConnection() throws SQLException {
+        return ds.getConnection();
+    }
+
+}

src/test/java/DatabaseConnectionTest.java

@@ -0,0 +1,37 @@
+import org.junit.jupiter.api.BeforeAll;
+import org.junit.jupiter.api.AfterAll;
+import org.junit.jupiter.api.Test;
+import static org.junit.Assert.assertFalse;
+
+import java.sql.Connection;
+import java.sql.DriverManager;
+
+import org.testcontainers.containers.PostgreSQLContainer;
+
+public class DatabaseConnectionTest {
+
+    static PostgreSQLContainer<?> postgres = new PostgreSQLContainer<>(
+            "postgres:16-alpine"
+    );
+
+    @BeforeAll
+    static void beforeAll() {
+        postgres.start();
+    }
+
+    @AfterAll
+    static void afterAll() {
+        postgres.stop();
+    }
+
+    @Test
+    public void shouldConnect() throws Exception {
+        try (Connection conn = DriverManager.getConnection(
+                postgres.getJdbcUrl(),
+                postgres.getUsername(),
+                postgres.getPassword()
+        )) {
+            assertFalse(conn.isClosed());
+        }
+    }
+}