BAEL-2436 Criteria Queries Using Hibernate Metamodel

* BAEL-2436 Type Safe Criteria Queries Using Hibernate Metamodel

* Formattng fixes

* Formatting fixes

persistence-modules/hibernate5/pom.xml

@@ -1,5 +1,6 @@
 <?xml version="1.0"?>
-<project xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd" xmlns="http://maven.apache.org/POM/4.0.0"
+<project xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd"
+         xmlns="http://maven.apache.org/POM/4.0.0"
          xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
     <modelVersion>4.0.0</modelVersion>
     <groupId>com.baeldung</groupId>
@@ -66,6 +67,13 @@
             <artifactId>byte-buddy</artifactId>
             <version>1.9.5</version>
         </dependency>
+
+        <dependency>
+            <groupId>org.hibernate</groupId>
+            <artifactId>hibernate-jpamodelgen</artifactId>
+            <version>${hibernate.version}</version>
+            <scope>provided</scope>
+        </dependency>
     </dependencies>
 
     <build>

persistence-modules/hibernate5/src/main/java/com/baeldung/hibernate/criteriaquery/HibernateUtil.java

@@ -0,0 +1,61 @@
+package com.baeldung.hibernate.criteriaquery;
+
+import com.baeldung.hibernate.customtypes.LocalDateStringType;
+import org.hibernate.SessionFactory;
+import org.hibernate.boot.Metadata;
+import org.hibernate.boot.MetadataSources;
+import org.hibernate.boot.registry.StandardServiceRegistryBuilder;
+import org.hibernate.service.ServiceRegistry;
+
+import java.io.FileInputStream;
+import java.io.IOException;
+import java.net.URL;
+import java.util.Properties;
+
+public class HibernateUtil {
+    private static SessionFactory sessionFactory;
+
+    private HibernateUtil() {
+    }
+
+    public static SessionFactory getSessionFactory() {
+        if (sessionFactory == null) {
+            sessionFactory = buildSessionFactory();
+        }
+        return sessionFactory;
+    }
+
+    private static SessionFactory buildSessionFactory() {
+        try {
+            ServiceRegistry serviceRegistry = configureServiceRegistry();
+
+            MetadataSources metadataSources = new MetadataSources(serviceRegistry);
+
+            metadataSources.addAnnotatedClass(Student.class);
+            Metadata metadata = metadataSources.getMetadataBuilder()
+                    .applyBasicType(LocalDateStringType.INSTANCE)
+                    .build();
+
+            return metadata.getSessionFactoryBuilder().build();
+        } catch (IOException ex) {
+            throw new ExceptionInInitializerError(ex);
+        }
+    }
+
+
+    private static ServiceRegistry configureServiceRegistry() throws IOException {
+        Properties properties = getProperties();
+        return new StandardServiceRegistryBuilder().applySettings(properties).build();
+    }
+
+    private static Properties getProperties() throws IOException {
+        Properties properties = new Properties();
+        URL propertiesURL = Thread.currentThread()
+                .getContextClassLoader()
+                .getResource("hibernate.properties");
+        try (FileInputStream inputStream = new FileInputStream(propertiesURL.getFile())) {
+            properties.load(inputStream);
+        }
+        return properties;
+    }
+}

persistence-modules/hibernate5/src/main/java/com/baeldung/hibernate/criteriaquery/Student.java

@@ -0,0 +1,58 @@
+package com.baeldung.hibernate.criteriaquery;
+
+import javax.persistence.Column;
+import javax.persistence.Entity;
+import javax.persistence.GeneratedValue;
+import javax.persistence.GenerationType;
+import javax.persistence.Id;
+import javax.persistence.Table;
+
+@Entity
+@Table(name = "students")
+public class Student {
+
+    @Id
+    @GeneratedValue(strategy = GenerationType.AUTO)
+    private int id;
+
+    @Column(name = "first_name")
+    private String firstName;
+
+    @Column(name = "last_name")
+    private String lastName;
+
+    @Column(name = "grad_year")
+    private int gradYear;
+
+    public int getId() {
+        return id;
+    }
+
+    public void setId(int id) {
+        this.id = id;
+    }
+
+    public String getFirstName() {
+        return firstName;
+    }
+
+    public void setFirstName(String firstName) {
+        this.firstName = firstName;
+    }
+
+    public String getLastName() {
+        return lastName;
+    }
+
+    public void setLastName(String lastName) {
+        this.lastName = lastName;
+    }
+
+    public int getGradYear() {
+        return gradYear;
+    }
+
+    public void setGradYear(int gradYear) {
+        this.gradYear = gradYear;
+    }
+}

persistence-modules/hibernate5/src/test/java/com/baeldung/hibernate/criteriaquery/TypeSafeCriteriaIntegrationTest.java

@@ -0,0 +1,89 @@
+package com.baeldung.hibernate.criteriaquery;
+
+import com.baeldung.hibernate.criteriaquery.HibernateUtil;
+import org.hibernate.Session;
+import org.hibernate.SessionFactory;
+import org.hibernate.query.Query;
+import org.junit.After;
+import org.junit.AfterClass;
+import org.junit.Before;
+import org.junit.BeforeClass;
+import org.junit.Test;
+
+import javax.persistence.criteria.CriteriaBuilder;
+import javax.persistence.criteria.CriteriaQuery;
+import javax.persistence.criteria.Root;
+import java.io.IOException;
+import java.util.List;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertNotNull;
+
+
+public class TypeSafeCriteriaIntegrationTest {
+
+    private static SessionFactory sessionFactory;
+
+    private Session session;
+
+    @BeforeClass
+    public static void beforeTests() throws IOException {
+        sessionFactory = HibernateUtil.getSessionFactory();
+    }
+
+    @Before
+    public void setUp() {
+        session = sessionFactory.openSession();
+        session.beginTransaction();
+    }
+
+    @Test
+    public void givenStudentData_whenUsingTypeSafeCriteriaQuery_thenSearchAllStudentsOfAGradYear() {
+
+        prepareData();
+        CriteriaBuilder cb = session.getCriteriaBuilder();
+        CriteriaQuery<Student> criteriaQuery = cb.createQuery(Student.class);
+
+        Root<Student> root = criteriaQuery.from(Student.class);
+        criteriaQuery.select(root).where(cb.equal(root.get(Student_.gradYear), 1965));
+
+        Query<Student> query = session.createQuery(criteriaQuery);
+        List<Student> results = query.getResultList();
+
+        assertNotNull(results);
+        assertEquals(1, results.size());
+
+        Student student = results.get(0);
+
+        assertEquals("Ken", student.getFirstName());
+        assertEquals("Thompson", student.getLastName());
+        assertEquals(1965, student.getGradYear());
+    }
+
+    private void prepareData() {
+        Student student1 = new Student();
+        student1.setFirstName("Ken");
+        student1.setLastName("Thompson");
+        student1.setGradYear(1965);
+
+        session.save(student1);
+
+        Student student2 = new Student();
+        student2.setFirstName("Dennis");
+        student2.setLastName("Ritchie");
+        student2.setGradYear(1963);
+
+        session.save(student2);
+        session.getTransaction().commit();
+    }
+
+    @After
+    public void tearDown() {
+        session.close();
+    }
+
+    @AfterClass
+    public static void afterTests() {
+        sessionFactory.close();
+    }
+}