Eager Loading vs Lazy Loading (#600)

* 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

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

@@ -16,7 +16,6 @@ public class HibernateUtil {
 		if ("lazy".equals(fetchMethod)) {
 			sf = new Configuration().configure("fetchingLazy.cfg.xml").buildSessionFactory();
 		} else {
-
 			sf = new Configuration().configure("fetching.cfg.xml").buildSessionFactory();
 		}
 		// fetching.cfg.xml is used for this example
@@ -25,7 +24,6 @@ public class HibernateUtil {
 	}
 
 	public static Session getHibernateSession() {
-		System.out.println("Loading eager");
 		SessionFactory sf = null;
 		sf = new Configuration().configure("fetching.cfg.xml").buildSessionFactory();
 		final Session session = sf.openSession();

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

@@ -51,9 +51,7 @@ public class FetchingAppView {
 	public void createTestData() {
 
 		final Session session = HibernateUtil.getHibernateSession();
-
 		Transaction tx = null;
-
 		tx = session.beginTransaction();
 		final User user1 = new User();
 		final User user2 = new User();

spring-hibernate4/src/main/resources/fetching.cfg.xml

@@ -10,6 +10,7 @@
 		<property name="hibernate.connection.username">root</property>
 		<property name="hibernate.connection.password">iamtheking</property>
 		<property name="hibernate.dialect">org.hibernate.dialect.MySQLDialect</property>
+		<property name="show_sql">true</property>
 		<mapping resource="com/baeldung/hibernate/fetching/model/User.hbm.xml" />
 		<mapping resource="com/baeldung/hibernate/fetching/model/OrderDetail.hbm.xml" />
 	</session-factory>

spring-hibernate4/src/main/resources/fetchingLazy.cfg.xml

@@ -10,6 +10,7 @@
 		<property name="hibernate.connection.username">root</property>
 		<property name="hibernate.connection.password">iamtheking</property>
 		<property name="hibernate.dialect">org.hibernate.dialect.MySQLDialect</property>
+		<property name="show_sql">true</property>
 		<mapping resource="com/baeldung/hibernate/fetching/model/OrderDetail.hbm.xml" />
 		<mapping resource="com/baeldung/hibernate/fetching/model/UserLazy.hbm.xml" />
 	</session-factory>

spring-hibernate4/src/test/java/com/baeldung/hibernate/criteria/HibernateCriteriaTestRunner.java

@@ -0,0 +1,15 @@
+package com.baeldung.hibernate.criteria;
+
+import org.junit.runner.JUnitCore;
+import org.junit.runner.Result;
+import org.junit.runner.notification.Failure;
+
+public class HibernateCriteriaTestRunner {
+
+	public static void main(final String[] args) {
+		Result result = JUnitCore.runClasses(HibernateCriteriaTestSuite.class);
+		for (Failure failure : result.getFailures()) {
+			
+		}
+	}
+}

spring-hibernate4/src/test/java/com/baeldung/hibernate/criteria/HibernateCriteriaTestSuite.java

@@ -0,0 +1,11 @@
+package com.baeldung.hibernate.criteria;
+
+import org.junit.runner.RunWith;
+import org.junit.runners.Suite;
+
+@RunWith(Suite.class)
+@Suite.SuiteClasses({ HibernateCriteriaTest.class })
+
+public class HibernateCriteriaTestSuite {
+	
+}

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

@@ -0,0 +1,24 @@
+package com.baeldung.hibernate.fetching;
+
+import static org.junit.Assert.*;
+
+import org.junit.Test;
+
+import com.baeldung.hibernate.fetching.view.FetchingAppView;
+
+public class HibernateFetchingTest {
+
+	@Test
+	public void testLazyFetching() {
+		FetchingAppView fav = new FetchingAppView();
+		fav.createTestData();
+		assertFalse(fav.lazyLoaded());
+	}
+
+	@Test
+	public void testEagerFetching() {
+		FetchingAppView fav = new FetchingAppView();
+		assertTrue(fav.eagerLoaded());
+	}
+
+}

spring-hibernate4/src/test/resources/fetching.cfg.xml

@@ -0,0 +1,17 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!DOCTYPE hibernate-configuration PUBLIC
+"-//Hibernate/Hibernate Configuration DTD 3.0//EN"
+"http://www.hibernate.org/dtd/hibernate-configuration-3.0.dtd">
+
+<hibernate-configuration>
+	<session-factory>
+		<property name="hibernate.connection.driver_class">com.mysql.jdbc.Driver</property>
+		<property name="hibernate.connection.url">jdbc:mysql://localhost:3306/test</property>
+		<property name="hibernate.connection.username">root</property>
+		<property name="hibernate.connection.password">iamtheking</property>
+		<property name="hibernate.dialect">org.hibernate.dialect.MySQLDialect</property>
+		<property name="show_sql">true</property>
+		<mapping resource="com/baeldung/hibernate/fetching/model/User.hbm.xml" />
+		<mapping resource="com/baeldung/hibernate/fetching/model/OrderDetail.hbm.xml" />
+	</session-factory>
+</hibernate-configuration>

spring-hibernate4/src/test/resources/fetchingLazy.cfg.xml

@@ -0,0 +1,17 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!DOCTYPE hibernate-configuration PUBLIC
+"-//Hibernate/Hibernate Configuration DTD 3.0//EN"
+"http://www.hibernate.org/dtd/hibernate-configuration-3.0.dtd">
+
+<hibernate-configuration>
+	<session-factory>
+		<property name="hibernate.connection.driver_class">com.mysql.jdbc.Driver</property>
+		<property name="hibernate.connection.url">jdbc:mysql://localhost:3306/test</property>
+		<property name="hibernate.connection.username">root</property>
+		<property name="hibernate.connection.password">iamtheking</property>
+		<property name="hibernate.dialect">org.hibernate.dialect.MySQLDialect</property>
+		<property name="show_sql">true</property>
+		<mapping resource="com/baeldung/hibernate/fetching/model/OrderDetail.hbm.xml" />
+		<mapping resource="com/baeldung/hibernate/fetching/model/UserLazy.hbm.xml" />
+	</session-factory>
+</hibernate-configuration>