examples

.gitignore

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+target/
+!.mvn/wrapper/maven-wrapper.jar
+!**/src/main/**/target/
+!**/src/test/**/target/
+
+### IntelliJ IDEA ###
+.idea/modules.xml
+.idea/jarRepositories.xml
+.idea/compiler.xml
+.idea/libraries/
+*.iws
+*.iml
+*.ipr
+
+### Eclipse ###
+.apt_generated
+.classpath
+.factorypath
+.project
+.settings
+.springBeans
+.sts4-cache
+
+### NetBeans ###
+/nbproject/private/
+/nbbuild/
+/dist/
+/nbdist/
+/.nb-gradle/
+build/
+!**/src/main/**/build/
+!**/src/test/**/build/
+
+### VS Code ###
+.vscode/
+
+### Mac OS ###
+.DS_Store
+/.idea/

pom.xml

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+<?xml version="1.0" encoding="UTF-8"?>
+<project xmlns="http://maven.apache.org/POM/4.0.0"
+         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+    <modelVersion>4.0.0</modelVersion>
+
+    <groupId>dev.struchkov.example</groupId>
+    <artifactId>hibernates-statelesssession</artifactId>
+    <version>1.0-SNAPSHOT</version>
+
+    <properties>
+        <maven.compiler.source>17</maven.compiler.source>
+        <maven.compiler.target>17</maven.compiler.target>
+    </properties>
+
+    <dependencies>
+        <dependency>
+            <groupId>org.hibernate.orm</groupId>
+            <artifactId>hibernate-core</artifactId>
+            <version>6.1.1.Final</version>
+        </dependency>
+        <dependency>
+            <groupId>com.h2database</groupId>
+            <artifactId>h2</artifactId>
+            <version>2.1.214</version>
+        </dependency>
+        <dependency>
+            <groupId>org.projectlombok</groupId>
+            <artifactId>lombok</artifactId>
+            <version>1.18.24</version>
+        </dependency>
+
+        <dependency>
+            <groupId>ch.qos.logback</groupId>
+            <artifactId>logback-classic</artifactId>
+            <version>1.2.11</version>
+        </dependency>
+
+        <dependency>
+            <groupId>org.slf4j</groupId>
+            <artifactId>slf4j-api</artifactId>
+            <version>1.7.36</version>
+        </dependency>
+    </dependencies>
+
+</project>

src/main/java/dev/struchkov/example/hibernate/statelesssession/Main.java

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+package dev.struchkov.example.hibernate.statelesssession;
+
+import dev.struchkov.example.hibernate.statelesssession.domain.Post;
+import dev.struchkov.example.hibernate.statelesssession.domain.PostComment;
+import org.hibernate.Session;
+import org.hibernate.SessionFactory;
+import org.hibernate.StatelessSession;
+import org.hibernate.boot.registry.StandardServiceRegistryBuilder;
+import org.hibernate.cfg.AvailableSettings;
+import org.hibernate.cfg.Configuration;
+import org.hibernate.service.ServiceRegistry;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import java.util.Properties;
+
+public class Main {
+
+    private static final Logger log = LoggerFactory.getLogger(Main.class);
+
+    public static void main(String[] args) {
+        final SessionFactory sessionFactory = getSessionFactory();
+        firstExample(sessionFactory);
+//        secondExample(sessionFactory);
+//        thirdExample(sessionFactory);
+//        thirdExampleWithSession(sessionFactory);
+    }
+
+    private static void firstExample(SessionFactory sessionFactory) {
+        final StatelessSession statelessSession = sessionFactory.openStatelessSession();
+
+        statelessSession.getTransaction().begin();
+
+        final Post post = new Post();
+        post.setTitle("New Past");
+
+        statelessSession.insert(post);
+
+        post.setTitle("New Post");
+
+        statelessSession.update(post);
+
+        statelessSession.getTransaction().commit();
+    }
+
+    private static void secondExample(SessionFactory sessionFactory) {
+        final StatelessSession statelessSession = sessionFactory.openStatelessSession();
+
+        statelessSession.getTransaction().begin();
+
+        final Post post = statelessSession.createQuery("""
+                        SELECT p
+                        FROM Post p
+                            JOIN FETCH p.comments
+                        WHERE p.id=:id""", Post.class)
+                .setParameter("id", 1L)
+                .getSingleResult();
+
+        log.info(post.getId() + " " + post.getTitle());
+        log.info("Comments size: " + post.getComments().size());
+
+        statelessSession.getTransaction().commit();
+    }
+
+    private static void thirdExample(SessionFactory sessionFactory) {
+        final StatelessSession statelessSession = sessionFactory.openStatelessSession();
+
+        statelessSession.getTransaction().begin();
+
+        final Post post1 = statelessSession.createQuery("""
+                        SELECT p
+                        FROM Post p
+                            JOIN FETCH p.comments
+                        WHERE p.id=:id""", Post.class)
+                .setParameter("id", 1L)
+                .getSingleResult();
+
+        final Post post2 = statelessSession.createQuery("""
+                        SELECT p
+                        FROM Post p
+                            JOIN FETCH p.comments
+                        WHERE p.id=:id""", Post.class)
+                .setParameter("id", 1L)
+                .getSingleResult();
+
+        System.out.println();
+
+        statelessSession.getTransaction().commit();
+    }
+
+    private static void thirdExampleWithSession(SessionFactory sessionFactory) {
+        final Session session = sessionFactory.openSession();
+
+        session.getTransaction().begin();
+
+        final Post post1 = session.createQuery("""
+                        SELECT p
+                        FROM Post p
+                            JOIN FETCH p.comments
+                        WHERE p.id=:id""", Post.class)
+                .setParameter("id", 1L)
+                .getSingleResult();
+
+        final Post post2 = session.createQuery("""
+                        SELECT p
+                        FROM Post p
+                            JOIN FETCH p.comments
+                        WHERE p.id=:id""", Post.class)
+                .setParameter("id", 1L)
+                .getSingleResult();
+
+        System.out.println();
+
+        session.getTransaction().commit();
+        session.close();
+    }
+
+    public static SessionFactory getSessionFactory() {
+        final Properties settings = new Properties();
+        settings.put(AvailableSettings.DRIVER, "org.h2.Driver");
+        settings.put(AvailableSettings.URL, "jdbc:h2:file:./data/demo");
+        settings.put(AvailableSettings.USER, "sa");
+        settings.put(AvailableSettings.DIALECT, "org.hibernate.dialect.H2Dialect");
+        settings.put(AvailableSettings.FORMAT_SQL, "true");
+        settings.put(AvailableSettings.HBM2DDL_AUTO, "none");
+
+        final Configuration configuration = new Configuration();
+        configuration.setProperties(settings);
+        configuration.addAnnotatedClass(Post.class);
+        configuration.addAnnotatedClass(PostComment.class);
+
+        final ServiceRegistry serviceRegistry = new StandardServiceRegistryBuilder().applySettings(configuration.getProperties()).build();
+
+        return configuration.buildSessionFactory(serviceRegistry);
+    }
+
+}

src/main/java/dev/struchkov/example/hibernate/statelesssession/domain/Post.java

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+
+package dev.struchkov.example.hibernate.statelesssession.domain;
+
+import jakarta.persistence.CascadeType;
+import jakarta.persistence.Entity;
+import jakarta.persistence.GeneratedValue;
+import jakarta.persistence.Id;
+import jakarta.persistence.JoinColumn;
+import jakarta.persistence.JoinTable;
+import jakarta.persistence.ManyToMany;
+import jakarta.persistence.OneToMany;
+import lombok.Getter;
+import lombok.Setter;
+
+import java.util.ArrayList;
+import java.util.List;
+
+@Entity
+@Getter
+@Setter
+public class Post {
+
+    @Id
+    @GeneratedValue
+    private Long id;
+
+    private String title;
+
+    @OneToMany(
+            mappedBy = "post",
+            cascade = CascadeType.ALL,
+            orphanRemoval = true
+    )
+    private List<PostComment> comments = new ArrayList<>();
+
+    public void addComment(PostComment postComment) {
+        postComment.setPost(this);
+        comments.add(postComment);
+    }
+
+}

src/main/java/dev/struchkov/example/hibernate/statelesssession/domain/PostComment.java

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+package dev.struchkov.example.hibernate.statelesssession.domain;
+
+import jakarta.persistence.Entity;
+import jakarta.persistence.GeneratedValue;
+import jakarta.persistence.Id;
+import jakarta.persistence.ManyToOne;
+import lombok.Getter;
+import lombok.Setter;
+
+@Entity
+@Getter
+@Setter
+public class PostComment {
+
+    @Id
+    @GeneratedValue
+    private Long id;
+
+    @ManyToOne
+    private Post post;
+
+    private String review;
+
+}
+

src/main/resources/logback.xml

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+<configuration>
+    <appender name="STDOUT" class="ch.qos.logback.core.ConsoleAppender">
+        <encoder>
+            <pattern>%d{HH:mm:ss.SSS} [%thread] %-5level %logger{36} - %msg%n</pattern>
+        </encoder>
+    </appender>
+
+    <logger name="org.hibernate.SQL" level="DEBUG" />
+    <logger name="org.hibernate.type" level="TRACE" />
+
+    <root level="info">
+        <appender-ref ref="STDOUT"/>
+    </root>
+
+</configuration>