feat: Database model & configuration

src/main/java/eu/ztsh/wymiana/data/config/DatabaseConfiguration.java

@@ -0,0 +1,54 @@
+package eu.ztsh.wymiana.data.config;
+
+import com.zaxxer.hikari.HikariConfig;
+import com.zaxxer.hikari.HikariDataSource;
+import org.hsqldb.persist.HsqlProperties;
+import org.hsqldb.server.Server;
+import org.hsqldb.server.ServerAcl;
+import org.springframework.boot.autoconfigure.jdbc.DataSourceProperties;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+
+import java.io.IOException;
+
+@Configuration
+public class DatabaseConfiguration {
+
+    /**
+     * Create HSQL Database instance that is accessible from outside of application
+     *
+     * @return server instance
+     * @throws ServerAcl.AclFormatException when instantiating ServerAcl
+     * @throws IOException                  when instantiating ServerAcl
+     */
+    @Bean
+    public Server hsqlServer(HsqlDbProperties properties) throws ServerAcl.AclFormatException, IOException {
+        var server = new Server();
+        var props = new HsqlProperties();
+        props.setProperty("server.database.0", String.format("mem:%s", properties.name()));
+        props.setProperty("server.dbname.0", properties.name());
+        props.setProperty("server.no_system_exit", true);
+        props.setProperty("server.port", properties.port());
+        server.setProperties(props);
+        server.start();
+        return server;
+    }
+
+    /**
+     * As we manually create database instance, we need also create datasource instance.
+     * HSQL instance is passed to force spring to create {@link Server} before pool.
+     *
+     * @param dataSourceProperties spring.datasource.* properties
+     * @return datasource instance
+     */
+    @Bean
+    public HikariDataSource hikariDataSource(DataSourceProperties dataSourceProperties, Server ignore) {
+        var config = new HikariConfig();
+        config.setJdbcUrl(dataSourceProperties.getUrl());
+        config.setUsername(dataSourceProperties.getUsername());
+        config.setPassword(dataSourceProperties.getPassword());
+        config.setDriverClassName(dataSourceProperties.getDriverClassName());
+        return new HikariDataSource(config);
+    }
+
+}

src/main/java/eu/ztsh/wymiana/data/config/HsqlDbProperties.java

@@ -0,0 +1,8 @@
+package eu.ztsh.wymiana.data.config;
+
+import org.springframework.boot.context.properties.ConfigurationProperties;
+
+@ConfigurationProperties("hsqldb")
+public record HsqlDbProperties(String name, int port) {
+
+}