JPA - JPA with Eclipse Link and H2 database Example

package com.logicbig.example;

import javax.persistence.*;
import javax.persistence.criteria.CriteriaBuilder;
import javax.persistence.criteria.CriteriaQuery;
import java.util.Arrays;
import java.util.List;

public class JPAKickStartExample {

    public static void main(String[] args) {

        EntityManagerFactory emf =
                Persistence.createEntityManagerFactory("testPersistenceUnit");
        EntityManager entityManager = emf.createEntityManager();
        entityManager.getTransaction().begin();

        MyObject myObject = new MyObject();
        myObject.setStr("one");
        entityManager.persist(myObject);

        myObject = new MyObject();
        myObject.setStr("two");
        entityManager.persist(myObject);

        entityManager.getTransaction().commit();

        findObjectById(entityManager);
        queryWithJPQL(entityManager);
        typedQueryWithJPQL(entityManager);
        criteriaQuery(entityManager);
        queryNative(entityManager);
    }

    private static void findObjectById(EntityManager entityManager) {
        System.out.println("----\nfinding object by id");
        MyObject o = entityManager.find(MyObject.class, 2L);
        System.out.println(o);
    }

    private static void queryWithJPQL(EntityManager entityManager) {
        System.out.println("----\nQuerying using JPQL");
        Query query = entityManager.createQuery("select t from MyObject t");
        List resultList1 = query.getResultList();
        System.out.println(resultList1);
    }

    private static void typedQueryWithJPQL(EntityManager entityManager) {
        System.out.println("----\nTyped Querying using JPQL");
        TypedQuery<MyObject> q =
                entityManager.createQuery("select t from MyObject t"
                        , MyObject.class);
        System.out.println(q.getResultList());
    }

    private static void queryNative(EntityManager entityManager) {
        System.out.println("----\nnative query");
        Query nativeQuery = entityManager.createNativeQuery("select * from MyObject");
        List resultList = nativeQuery.getResultList();
        for (Object o : resultList) {
            if (o.getClass().isArray()) {
                Object oa[] = (Object[]) o;
                System.out.println(Arrays.asList(oa));
            } else {
                System.out.println(o);
            }
        }
    }


    private static void criteriaQuery(EntityManager entityManager) {
        System.out.println("----\ncriteria query");
        CriteriaBuilder cb = entityManager.getCriteriaBuilder();
        CriteriaQuery<Object> query = cb.createQuery();
        CriteriaQuery<Object> select = query.select(query.from(MyObject.class));

        TypedQuery<Object> typedQuery = entityManager.createQuery(select);
        System.out.println(typedQuery.getResultList());

    }
}

package com.logicbig.example;

import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.Id;

@Entity
public class MyObject {
    @Id
    @GeneratedValue
    private long objId;
    private String str;

    public long getObjId () {
        return objId;
    }

    public void setObjId (long objId) {
        this.objId = objId;
    }

    public String getStr () {
        return str;
    }

    public void setStr (String str) {
        this.str = str;
    }

    @Override
    public String toString () {
        return "MyObject{" +
                            "objId=" + objId +
                            ", str='" + str + '\'' +
                            '}';
    }
}

<?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>com.logicbig.example</groupId>
 <artifactId>jpa-kickstart-example</artifactId>
 <version>1.0-SNAPSHOT</version>

 <dependencies>
 <dependency>
  <groupId>com.h2database</groupId>
  <artifactId>h2</artifactId>
  <version>1.4.193</version>
 </dependency>

 <dependency>
  <groupId>org.eclipse.persistence</groupId>
  <artifactId>eclipselink</artifactId>
  <version>2.6.4</version>
 </dependency>

 <dependency>
  <groupId>org.eclipse.persistence</groupId>
  <artifactId>javax.persistence</artifactId>
  <version>2.1.1</version>
 </dependency>
</dependencies>

 <build>
  <plugins>
   <plugin>
    <groupId>org.apache.maven.plugins</groupId>
    <artifactId>maven-compiler-plugin</artifactId>
    <version>3.5.1</version>
    <configuration>
     <source>1.8</source>
     <target>1.8</target>
     <encoding>UTF-8</encoding>
    </configuration>
   </plugin>
  </plugins>
 </build>
</project>