Hibernate Fetching Update (#607)

* BAEL-212
Contains:
1. Hibernate Criteria Query Classes
2. Hibernate Criteria Query Test

* Updating the config file and the HibernateUtil class

* Hibernate Criteria Queries Example

* Hibernate Fetching : Eager Loading vs Lazy Loading

* Hibernate Criteria Query files

* Hibernate Eager Loading and Lazy Loading Changes

* Latest Changes on Fetching

* Fetching Changes

* Latest Changes

* Latest Changes

* Undoing the changes

spring-hibernate4/src/main/java/com/baeldung/hibernate/fetching/model/OrderDetail.java

@@ -12,7 +12,6 @@ public class OrderDetail implements Serializable {
 	private User user;
 	
 	public OrderDetail(){	
-
 	}
 		
 	public OrderDetail(Date orderDate, String orderDesc) {
@@ -24,27 +23,21 @@ public class OrderDetail implements Serializable {
 	public Date getOrderDate() {
 		return orderDate;
 	}
-
 	public void setOrderDate(Date orderDate) {
 		this.orderDate = orderDate;
 	}
-
 	public String getOrderDesc() {
 		return orderDesc;
 	}
-
 	public void setOrderDesc(String orderDesc) {
 		this.orderDesc = orderDesc;
 	}
-
 	public User getUser() {
 		return user;
 	}
-
 	public void setUser(User user) {
 		this.user = user;
 	}
-
 	@Override
 	public int hashCode() {
 		final int prime = 31;
@@ -52,7 +45,6 @@ public class OrderDetail implements Serializable {
 		result = prime * result + ((orderId == null) ? 0 : orderId.hashCode());
 		return result;
 	}
-
 	@Override
 	public boolean equals(Object obj) {
 		if (this == obj)
@@ -70,13 +62,12 @@ public class OrderDetail implements Serializable {
 		
 		return true;
 	}
-
 	public Long getOrderId() {
 		return orderId;
 	}
-
 	public void setOrderId(Long orderId) {
 		this.orderId = orderId;
 	}
-
 }
+
+

spring-hibernate4/src/main/java/com/baeldung/hibernate/fetching/model/User.java

@@ -22,7 +22,6 @@ public class User implements Serializable {
 	this.userName = userName;
 	this.firstName = firstName;
 	this.lastName = lastName;
-
     }
 
     @Override

spring-hibernate4/src/main/java/com/baeldung/hibernate/fetching/util/HibernateUtil.java

@@ -1,6 +1,7 @@
 package com.baeldung.hibernate.fetching.util;
 
 import org.hibernate.Session;
+import org.hibernate.SessionFactory;
 import org.hibernate.cfg.Configuration;
 
 public class HibernateUtil {
@@ -10,14 +11,16 @@ public class HibernateUtil {
 		//two config files are there
 		//one with lazy loading enabled 
 		//another lazy = false
+		SessionFactory sf = null;
+		if ("lazy".equals(fetchMethod)) {
+			sf = new Configuration().configure("fetchingLazy.cfg.xml").buildSessionFactory();
+		} else {
+			sf = new Configuration().configure("fetching.cfg.xml").buildSessionFactory();
+		}
 		
-        final String configFileName = "lazy".equals(fetchMethod) ?
+		// fetching.cfg.xml is used for this example
-          "fetchingLazy.cfg.xml" :
+		final Session session = sf.openSession();
-          "fetching.cfg.xml";
+		return session;
-
-        return new Configuration()
-          .configure(configFileName)
-          .buildSessionFactory().openSession();
 	}
 
     public static Session getHibernateSession() {

spring-hibernate4/src/main/java/com/baeldung/hibernate/fetching/view/FetchingAppView.java

@@ -22,25 +22,27 @@ public class FetchingAppView {
 		
 	}
 	
-    public boolean lazyLoaded() {
+	//lazily loaded 
+	public Set<OrderDetail> lazyLoaded(){
 		final Session sessionLazy = HibernateUtil.getHibernateSession("lazy");
 		List<User> users = sessionLazy.createQuery("From User").list();
-        User userLazyLoaded = users.get(3);
+		User userLazyLoaded = new User();
+		userLazyLoaded = users.get(3); 
 		//since data is lazyloaded so data won't be initialized
 		Set<OrderDetail> orderDetailSet = userLazyLoaded.getOrderDetail();
-
+		return (orderDetailSet);	
-        return (Hibernate.isInitialized(orderDetailSet));
 	}
 	
-    public boolean eagerLoaded() {
+	//eagerly loaded
+	public Set<OrderDetail> eagerLoaded(){
 		final Session sessionEager = HibernateUtil.getHibernateSession();
 		//data should be loaded in the following line
 		//also note the queries generated
 		List<User> users =sessionEager.createQuery("From User").list();
-        User userEagerLoaded = users.get(3);
+		User userEagerLoaded = new User();
+		userEagerLoaded = users.get(3); 
 		Set<OrderDetail> orderDetailSet = userEagerLoaded.getOrderDetail();
-
+		return orderDetailSet;	
-        return (Hibernate.isInitialized(orderDetailSet));
 	}
 	
 	
@@ -49,8 +51,8 @@ public class FetchingAppView {
 	public void createTestData() {
 
 		final Session session = HibernateUtil.getHibernateSession();
-        Transaction tx = session.beginTransaction();
+		Transaction tx = null;
-
+		tx = session.beginTransaction();
 		final User user1 = new User();
 		final User user2 = new User();
 		final User user3 = new User();
@@ -96,15 +98,14 @@ public class FetchingAppView {
 		order5.setOrderDate(new Date(2014, 9, 11));
 		order5.setUser(user3);
 		
-
 		session.saveOrUpdate(order1);
 		session.saveOrUpdate(order2);
 		session.saveOrUpdate(order3);
 		session.saveOrUpdate(order4);
 		session.saveOrUpdate(order5);
 
-        // session.saveOrUpdate(user1);
 		tx.commit();
 		session.close();
+
 	}
 }

spring-hibernate4/src/test/java/com/baeldung/hibernate/fetching/HibernateFetchingTest.java

@@ -1,24 +1,43 @@
 package com.baeldung.hibernate.fetching;
 
 import static org.junit.Assert.*;
+import java.util.Set;
 
+import org.hibernate.Hibernate;
+import org.junit.Before;
 import org.junit.Test;
 
+import com.baeldung.hibernate.fetching.model.OrderDetail;
+
 import com.baeldung.hibernate.fetching.view.FetchingAppView;
 
 public class HibernateFetchingTest {
 
+
+	//this loads sample data in the database
+	@Before 
+	public void addFecthingTestData(){
+		FetchingAppView fav = new FetchingAppView();
+		fav.createTestData();
+	}
+	
+	//testLazyFetching() tests the lazy loading
+	//Since it lazily loaded so orderDetalSetLazy won't
+	//be initialized
 	@Test
 	public void testLazyFetching() {
 		FetchingAppView fav = new FetchingAppView();
-		fav.createTestData();
+		Set<OrderDetail> orderDetalSetLazy = fav.lazyLoaded();
-		assertFalse(fav.lazyLoaded());
+		assertFalse(Hibernate.isInitialized(orderDetalSetLazy));
 	}
 	
+	//testEagerFetching() tests the eager loading
+	//Since it eagerly loaded so orderDetalSetLazy would
+	//be initialized
 	@Test
 	public void testEagerFetching() {
 		FetchingAppView fav = new FetchingAppView();
-		assertTrue(fav.eagerLoaded());
+		Set<OrderDetail> orderDetalSetEager = fav.eagerLoaded();
+		assertTrue(Hibernate.isInitialized(orderDetalSetEager));
 	}
-
 }