Setup Hibernate for DB Nodes + PostgreSQL

SymphonyDatabaseNode/pom.xml

@@ -15,6 +15,35 @@
             <artifactId>gson</artifactId>
             <version>2.11.0</version>
         </dependency>
+
+        <dependency>
+            <groupId>org.hibernate.orm</groupId>
+            <artifactId>hibernate-core</artifactId>
+            <version>6.6.3.Final</version>
+        </dependency>
+
+        <dependency>
+            <groupId>jakarta.persistence</groupId>
+            <artifactId>jakarta.persistence-api</artifactId>
+            <version>3.2.0</version>
+        </dependency>
+
+        <dependency>
+            <groupId>org.postgresql</groupId>
+            <artifactId>postgresql</artifactId>
+            <version>42.7.4</version>
+        </dependency>
+
+        <dependency>
+            <groupId>org.apache.logging.log4j</groupId>
+            <artifactId>log4j-api</artifactId>
+            <version>2.24.2</version>
+        </dependency>
+        <dependency>
+            <groupId>org.apache.logging.log4j</groupId>
+            <artifactId>log4j-core</artifactId>
+            <version>2.24.2</version>
+        </dependency>
     </dependencies>
 
     <build>

SymphonyDatabaseNode/src/main/java/io/github/lumijiez/Data.java

@@ -0,0 +1,23 @@
+package io.github.lumijiez;
+
+import jakarta.persistence.EntityManager;
+import jakarta.persistence.EntityManagerFactory;
+import jakarta.persistence.Persistence;
+
+public class Data {
+    private static final EntityManagerFactory entityManagerFactory;
+
+    static {
+        entityManagerFactory = Persistence.createEntityManagerFactory("mainUnit");
+    }
+
+    public static EntityManager getEntityManager() {
+        return entityManagerFactory.createEntityManager();
+    }
+
+    public static void close() {
+        if (entityManagerFactory != null && entityManagerFactory.isOpen()) {
+            entityManagerFactory.close();
+        }
+    }
+}

SymphonyDatabaseNode/src/main/java/io/github/lumijiez/Main.java

@@ -1,7 +1,13 @@
 package io.github.lumijiez;
 
+import jakarta.persistence.EntityManager;
+
 public class Main {
     public static void main(String[] args) {
         System.out.println("Node up");
+        EntityManager em = Data.getEntityManager();
+
+        System.out.println("Connected to DB << symphony >>");
+        em.close();
     }
 }

SymphonyDatabaseNode/src/main/java/io/github/lumijiez/User.java

@@ -0,0 +1,47 @@
+package io.github.lumijiez;
+
+import jakarta.persistence.Entity;
+import jakarta.persistence.Id;
+import jakarta.persistence.Table;
+
+@Entity
+@Table(name="users")
+public class User {
+
+    @Id
+    private Long id;
+    private String name;
+    private String email;
+
+    public User() {}
+
+    public User(Long id, String name, String email) {
+        this.id = id;
+        this.name = name;
+        this.email = email;
+    }
+
+    public Long getId() {
+        return id;
+    }
+
+    public void setId(Long id) {
+        this.id = id;
+    }
+
+    public String getName() {
+        return name;
+    }
+
+    public void setName(String name) {
+        this.name = name;
+    }
+
+    public String getEmail() {
+        return email;
+    }
+
+    public void setEmail(String email) {
+        this.email = email;
+    }
+}

SymphonyDatabaseNode/src/main/resources/META-INF/persistence.xml

@@ -0,0 +1,40 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<persistence xmlns="https://jakarta.ee/xml/ns/persistence"
+             xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+             xsi:schemaLocation="https://jakarta.ee/xml/ns/persistence
+                                 https://jakarta.ee/xml/ns/persistence/persistence_3_0.xsd"
+             version="3.0">
+    <persistence-unit name="mainUnit" transaction-type="RESOURCE_LOCAL">
+        <provider>org.hibernate.jpa.HibernatePersistenceProvider</provider>
+
+        <class>io.github.lumijiez.User</class>
+
+        <exclude-unlisted-classes>false</exclude-unlisted-classes>
+
+        <properties>
+            <property name="jakarta.persistence.jdbc.driver" value="org.postgresql.Driver" />
+            <property name="jakarta.persistence.jdbc.url" value="jdbc:postgresql://postgres_db:5432/symphony" />
+            <property name="jakarta.persistence.jdbc.user" value="symphony" />
+            <property name="jakarta.persistence.jdbc.password" value="symphony" />
+
+            <property name="hibernate.dialect" value="org.hibernate.dialect.PostgreSQLDialect" />
+
+            <property name="hibernate.c3p0.min_size" value="5"/>
+            <property name="hibernate.c3p0.max_size" value="20"/>
+            <property name="hibernate.c3p0.timeout" value="300"/>
+            <property name="hibernate.c3p0.idle_test_period" value="3000"/>
+            <property name="hibernate.c3p0.max_statements" value="50"/>
+
+            <property name="hibernate.show_sql" value="true" />
+            <property name="hibernate.format_sql" value="true" />
+
+            <property name="hibernate.hbm2ddl.auto" value="update" />
+
+            <property name="hibernate.cache.use_second_level_cache" value="false" />
+
+            <property name="hibernate.current_session_context_class" value="thread" />
+
+            <property name="hibernate.generate_statistics" value="true" />
+        </properties>
+    </persistence-unit>
+</persistence>