diff --git a/core-groovy-2/src/test/groovy/com/baeldung/category/CategoryUnitTest.groovy b/core-groovy-2/src/test/groovy/com/baeldung/category/CategoryUnitTest.groovy
index 5ba7a2347c..a1f67b1e2e 100644
--- a/core-groovy-2/src/test/groovy/com/baeldung/category/CategoryUnitTest.groovy
+++ b/core-groovy-2/src/test/groovy/com/baeldung/category/CategoryUnitTest.groovy
@@ -28,17 +28,16 @@ class CategoryUnitTest extends GroovyTestCase {
         }
     }
 
-//	http://team.baeldung.com/browse/BAEL-20687
-//    void test_whenUsingTimeCategory_thenOperationOnNumber() {
-//        SimpleDateFormat sdf = new SimpleDateFormat("dd/MM/yyyy")
-//        use (TimeCategory) {
-//            assert sdf.format(5.days.from.now) == sdf.format(new Date() + 5.days)
-//
-//            sdf = new SimpleDateFormat("dd/MM/yyyy hh:mm:ss")
-//            assert sdf.format(10.minutes.from.now) == sdf.format(new Date() + 10.minutes)
-//            assert sdf.format(2.hours.ago) == sdf.format(new Date() - 2.hours)
-//        }
-//    }
+    void test_whenUsingTimeCategory_thenOperationOnNumber() {
+        SimpleDateFormat sdf = new SimpleDateFormat("dd/MM/yyyy")
+        use (TimeCategory) {
+            assert sdf.format(5.days.from.now) == sdf.format(new Date() + 5.days)
+
+            sdf = new SimpleDateFormat("dd/MM/yyyy hh:mm:ss")
+            assert sdf.format(10.minutes.from.now) == sdf.format(new Date() + 10.minutes)
+            assert sdf.format(2.hours.ago) == sdf.format(new Date() - 2.hours)
+        }
+    }
 
     void test_whenUsingDOMCategory_thenOperationOnXML() {
 
diff --git a/core-groovy-2/src/test/groovy/com/baeldung/webservice/WebserviceUnitTest.groovy b/core-groovy-2/src/test/groovy/com/baeldung/webservice/WebserviceUnitTest.groovy
index 144d5720c8..b8417b8ac1 100644
--- a/core-groovy-2/src/test/groovy/com/baeldung/webservice/WebserviceUnitTest.groovy
+++ b/core-groovy-2/src/test/groovy/com/baeldung/webservice/WebserviceUnitTest.groovy
@@ -75,7 +75,6 @@ class WebserviceManualTest extends GroovyTestCase {
         assert stories.size() == 5
     }
     
-    /* see BAEL-3753
     void test_whenConsumingSoap_thenReceiveResponse() {
         def url = "http://www.dataaccess.com/webservicesserver/numberconversion.wso"
         def soapClient = new SOAPClient(url)
@@ -90,7 +89,6 @@ class WebserviceManualTest extends GroovyTestCase {
         def words = response.NumberToWordsResponse
         assert words == "one thousand two hundred and thirty four "
     }
-    */
 
     void test_whenConsumingRestGet_thenReceiveResponse() {
         def path = "/get"
diff --git a/core-java-modules/core-java-9/README.md b/core-java-modules/core-java-9/README.md
index e2bea5f7e2..bfd426b9c1 100644
--- a/core-java-modules/core-java-9/README.md
+++ b/core-java-modules/core-java-9/README.md
@@ -9,6 +9,7 @@ This module contains articles about Java 9 core features
 - [Iterate Through a Range of Dates in Java](https://www.baeldung.com/java-iterate-date-range)
 - [Initialize a HashMap in Java](https://www.baeldung.com/java-initialize-hashmap)
 - [Immutable Set in Java](https://www.baeldung.com/java-immutable-set)
+- [Immutable ArrayList in Java](https://www.baeldung.com/java-immutable-list)
 
 Note: also contains part of the code for the article
 [How to Filter a Collection in Java](https://www.baeldung.com/java-collection-filtering).
diff --git a/core-java-modules/core-java-9/pom.xml b/core-java-modules/core-java-9/pom.xml
index 23a465caa1..a90ad0a740 100644
--- a/core-java-modules/core-java-9/pom.xml
+++ b/core-java-modules/core-java-9/pom.xml
@@ -37,6 +37,11 @@
             <version>${junit.platform.version}</version>
             <scope>test</scope>
         </dependency>
+        <dependency>
+            <groupId>org.apache.commons</groupId>
+            <artifactId>commons-collections4</artifactId>
+            <version>${commons-collections4.version}</version>
+        </dependency>
     </dependencies>
 
     <build>
@@ -69,6 +74,7 @@
         <maven.compiler.source>1.9</maven.compiler.source>
         <maven.compiler.target>1.9</maven.compiler.target>
         <guava.version>25.1-jre</guava.version>
+        <commons-collections4.version>4.1</commons-collections4.version>
     </properties>
 
 </project>
diff --git a/core-java-modules/core-java-9/src/test/java/com/baeldung/java9/list/immutable/ImmutableArrayListUnitTest.java b/core-java-modules/core-java-9/src/test/java/com/baeldung/java9/list/immutable/ImmutableArrayListUnitTest.java
new file mode 100644
index 0000000000..f148b66dad
--- /dev/null
+++ b/core-java-modules/core-java-9/src/test/java/com/baeldung/java9/list/immutable/ImmutableArrayListUnitTest.java
@@ -0,0 +1,48 @@
+package com.baeldung.java9.list.immutable;
+
+import com.google.common.collect.ImmutableList;
+import org.apache.commons.collections4.ListUtils;
+import org.junit.Test;
+
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.Collections;
+import java.util.List;
+
+public class ImmutableArrayListUnitTest {
+
+    @Test(expected = UnsupportedOperationException.class)
+    public final void givenUsingTheJdk_whenUnmodifiableListIsCreated_thenNotModifiable() {
+        final List<String> list = new ArrayList<>(Arrays.asList("one", "two", "three"));
+        final List<String> unmodifiableList = Collections.unmodifiableList(list);
+        unmodifiableList.add("four");
+    }
+
+    @Test(expected = UnsupportedOperationException.class)
+    public final void givenUsingTheJava9_whenUnmodifiableListIsCreated_thenNotModifiable() {
+        final List<String> list = new ArrayList<>(Arrays.asList("one", "two", "three"));
+        final List<String> unmodifiableList = List.of(list.toArray(new String[]{}));
+        unmodifiableList.add("four");
+    }
+
+    @Test(expected = UnsupportedOperationException.class)
+    public final void givenUsingGuava_whenUnmodifiableListIsCreated_thenNotModifiable() {
+        final List<String> list = new ArrayList<>(Arrays.asList("one", "two", "three"));
+        final List<String> unmodifiableList = ImmutableList.copyOf(list);
+        unmodifiableList.add("four");
+    }
+
+    @Test(expected = UnsupportedOperationException.class)
+    public final void givenUsingGuavaBuilder_whenUnmodifiableListIsCreated_thenNoLongerModifiable() {
+        final List<String> list = new ArrayList<>(Arrays.asList("one", "two", "three"));
+        final ImmutableList<String> unmodifiableList = ImmutableList.<String>builder().addAll(list).build();
+        unmodifiableList.add("four");
+    }
+
+    @Test(expected = UnsupportedOperationException.class)
+    public final void givenUsingCommonsCollections_whenUnmodifiableListIsCreated_thenNotModifiable() {
+        final List<String> list = new ArrayList<>(Arrays.asList("one", "two", "three"));
+        final List<String> unmodifiableList = ListUtils.unmodifiableList(list);
+        unmodifiableList.add("four");
+    }
+}
diff --git a/core-java-modules/core-java-collections-array-list/README.md b/core-java-modules/core-java-collections-array-list/README.md
index 302ea82130..3637f835cf 100644
--- a/core-java-modules/core-java-collections-array-list/README.md
+++ b/core-java-modules/core-java-collections-array-list/README.md
@@ -3,9 +3,8 @@
 This module contains articles about the Java ArrayList collection
 
 ### Relevant Articles: 
-- [Immutable ArrayList in Java](http://www.baeldung.com/java-immutable-list)
-- [Guide to the Java ArrayList](http://www.baeldung.com/java-arraylist)
-- [Add Multiple Items to an Java ArrayList](http://www.baeldung.com/java-add-items-array-list)
+- [Guide to the Java ArrayList](https://www.baeldung.com/java-arraylist)
+- [Add Multiple Items to an Java ArrayList](https://www.baeldung.com/java-add-items-array-list)
 - [ClassCastException: Arrays$ArrayList cannot be cast to ArrayList](https://www.baeldung.com/java-classcastexception-arrays-arraylist)
 - [Multi Dimensional ArrayList in Java](https://www.baeldung.com/java-multi-dimensional-arraylist)
 - [Removing an Element From an ArrayList](https://www.baeldung.com/java-arraylist-remove-element)
diff --git a/core-java-modules/core-java-collections-array-list/src/test/java/com/baeldung/collections/CoreJavaCollectionsUnitTest.java b/core-java-modules/core-java-collections-array-list/src/test/java/com/baeldung/collections/CoreJavaCollectionsUnitTest.java
index 019a569a65..5fd0e605dd 100644
--- a/core-java-modules/core-java-collections-array-list/src/test/java/com/baeldung/collections/CoreJavaCollectionsUnitTest.java
+++ b/core-java-modules/core-java-collections-array-list/src/test/java/com/baeldung/collections/CoreJavaCollectionsUnitTest.java
@@ -15,42 +15,11 @@ public class CoreJavaCollectionsUnitTest {
 
     private static final Logger LOG = LoggerFactory.getLogger(CoreJavaCollectionsUnitTest.class);
 
-
-    // tests -
-
     @Test
     public final void givenUsingTheJdk_whenArrayListIsSynchronized_thenCorrect() {
-        final List<String> list = new ArrayList<String>(Arrays.asList("one", "two", "three"));
+        final List<String> list = new ArrayList<>(Arrays.asList("one", "two", "three"));
         final List<String> synchronizedList = Collections.synchronizedList(list);
         LOG.debug("Synchronized List is: " + synchronizedList);
     }
 
-    @Test(expected = UnsupportedOperationException.class)
-    public final void givenUsingTheJdk_whenUnmodifiableListIsCreatedFromOriginal_thenNoLongerModifiable() {
-        final List<String> list = new ArrayList<String>(Arrays.asList("one", "two", "three"));
-        final List<String> unmodifiableList = Collections.unmodifiableList(list);
-        unmodifiableList.add("four");
-    }
-
-    @Test(expected = UnsupportedOperationException.class)
-    public final void givenUsingGuava_whenUnmodifiableListIsCreatedFromOriginal_thenNoLongerModifiable() {
-        final List<String> list = new ArrayList<String>(Arrays.asList("one", "two", "three"));
-        final List<String> unmodifiableList = ImmutableList.copyOf(list);
-        unmodifiableList.add("four");
-    }
-
-    @Test(expected = UnsupportedOperationException.class)
-    public final void givenUsingGuavaBuilder_whenUnmodifiableListIsCreatedFromOriginal_thenNoLongerModifiable() {
-        final List<String> list = new ArrayList<String>(Arrays.asList("one", "two", "three"));
-        final ImmutableList<String> unmodifiableList = ImmutableList.<String>builder().addAll(list).build();
-        unmodifiableList.add("four");
-    }
-
-    @Test(expected = UnsupportedOperationException.class)
-    public final void givenUsingCommonsCollections_whenUnmodifiableListIsCreatedFromOriginal_thenNoLongerModifiable() {
-        final List<String> list = new ArrayList<String>(Arrays.asList("one", "two", "three"));
-        final List<String> unmodifiableList = ListUtils.unmodifiableList(list);
-        unmodifiableList.add("four");
-    }
-
 }
diff --git a/pom.xml b/pom.xml
index 623ef03db4..7b54abba24 100644
--- a/pom.xml
+++ b/pom.xml
@@ -642,7 +642,6 @@
                 <module>spring-boot-modules</module>
                 <module>spring-boot-angular</module>
                 <module>spring-boot-bootstrap</module>
-                <module>spring-boot-camel</module>
                 <!-- <module>spring-boot-cli</module> --> <!-- Not a maven project -->
                 <module>spring-boot-client</module>
                 <module>spring-boot-config-jpa-error</module>
@@ -654,10 +653,9 @@
                 <module>spring-boot-jasypt</module>
                 <module>spring-boot-kotlin</module>
                 <module>spring-boot-libraries</module>
-                <module>spring-boot-logging-log4j2</module>
                 <module>spring-boot-mvc-2</module>
-                <module>spring-boot-nashorn</module>
                 <module>spring-boot-parent</module>
+                <module>spring-boot-performance</module>
                 <module>spring-boot-property-exp</module>
 
                 <module>spring-boot-rest</module>
@@ -1168,7 +1166,6 @@
                 <module>spring-boot-modules</module>
                 <module>spring-boot-angular</module>
                 <module>spring-boot-bootstrap</module>
-                <module>spring-boot-camel</module>
                 <!-- <module>spring-boot-cli</module> --> <!-- Not a maven project -->
                 <module>spring-boot-client</module>
                 <module>spring-boot-config-jpa-error</module>
@@ -1180,11 +1177,10 @@
                 <module>spring-boot-jasypt</module>
                 <module>spring-boot-kotlin</module>
                 <module>spring-boot-libraries</module>
-                <module>spring-boot-logging-log4j2</module>
                 <module>spring-boot-mvc</module>
                 <module>spring-boot-mvc-2</module>
-                <module>spring-boot-nashorn</module>
                 <module>spring-boot-parent</module>
+                <module>spring-boot-performance</module>
                 <module>spring-boot-property-exp</module>
 
                 <module>spring-boot-rest</module>
diff --git a/spring-boot-modules/pom.xml b/spring-boot-modules/pom.xml
index a872730c6e..a9c856cdb2 100644
--- a/spring-boot-modules/pom.xml
+++ b/spring-boot-modules/pom.xml
@@ -15,15 +15,17 @@
 
     <modules>
         <module>spring-boot-admin</module>
-        <module>spring-boot-custom-starter</module>
         <module>spring-boot-artifacts</module>
         <module>spring-boot-autoconfiguration</module>
+        <module>spring-boot-camel</module>
+        <module>spring-boot-custom-starter</module>
         <module>spring-boot-crud</module>
         <module>spring-boot-data</module>
         <!-- <module>spring-boot-gradle</module> --> <!-- Not a maven project -->
         <module>spring-boot-keycloak</module>
+        <module>spring-boot-logging-log4j2</module>
         <module>spring-boot-mvc-birt</module>
-        <module>spring-boot-performance</module>
+        <module>spring-boot-nashorn</module>
         <module>spring-boot-properties</module>
         <module>spring-boot-springdoc</module>
         <module>spring-boot-testing</module>
diff --git a/spring-boot-camel/README.md b/spring-boot-modules/spring-boot-camel/README.md
similarity index 100%
rename from spring-boot-camel/README.md
rename to spring-boot-modules/spring-boot-camel/README.md
diff --git a/spring-boot-camel/pom.xml b/spring-boot-modules/spring-boot-camel/pom.xml
similarity index 95%
rename from spring-boot-camel/pom.xml
rename to spring-boot-modules/spring-boot-camel/pom.xml
index 8bab0ed5c8..7c1e28b3ee 100644
--- a/spring-boot-camel/pom.xml
+++ b/spring-boot-modules/spring-boot-camel/pom.xml
@@ -8,8 +8,8 @@
 	<name>spring-boot-camel</name>
 	
     <parent>
-        <groupId>com.baeldung</groupId>
-        <artifactId>parent-modules</artifactId>
+        <groupId>com.baeldung.spring-boot-modules</groupId>
+        <artifactId>spring-boot-modules</artifactId>
         <version>1.0.0-SNAPSHOT</version>
     </parent>
 
diff --git a/spring-boot-camel/src/main/java/com/baeldung/camel/Application.java b/spring-boot-modules/spring-boot-camel/src/main/java/com/baeldung/camel/Application.java
similarity index 100%
rename from spring-boot-camel/src/main/java/com/baeldung/camel/Application.java
rename to spring-boot-modules/spring-boot-camel/src/main/java/com/baeldung/camel/Application.java
diff --git a/spring-boot-camel/src/main/java/com/baeldung/camel/ExampleServices.java b/spring-boot-modules/spring-boot-camel/src/main/java/com/baeldung/camel/ExampleServices.java
similarity index 100%
rename from spring-boot-camel/src/main/java/com/baeldung/camel/ExampleServices.java
rename to spring-boot-modules/spring-boot-camel/src/main/java/com/baeldung/camel/ExampleServices.java
diff --git a/spring-boot-camel/src/main/java/com/baeldung/camel/MyBean.java b/spring-boot-modules/spring-boot-camel/src/main/java/com/baeldung/camel/MyBean.java
similarity index 100%
rename from spring-boot-camel/src/main/java/com/baeldung/camel/MyBean.java
rename to spring-boot-modules/spring-boot-camel/src/main/java/com/baeldung/camel/MyBean.java
diff --git a/spring-boot-camel/src/main/resources/application.properties b/spring-boot-modules/spring-boot-camel/src/main/resources/application.properties
similarity index 100%
rename from spring-boot-camel/src/main/resources/application.properties
rename to spring-boot-modules/spring-boot-camel/src/main/resources/application.properties
diff --git a/spring-boot-camel/src/main/resources/application.yml b/spring-boot-modules/spring-boot-camel/src/main/resources/application.yml
similarity index 100%
rename from spring-boot-camel/src/main/resources/application.yml
rename to spring-boot-modules/spring-boot-camel/src/main/resources/application.yml
diff --git a/spring-boot-camel/src/main/resources/logback.xml b/spring-boot-modules/spring-boot-camel/src/main/resources/logback.xml
similarity index 100%
rename from spring-boot-camel/src/main/resources/logback.xml
rename to spring-boot-modules/spring-boot-camel/src/main/resources/logback.xml
diff --git a/spring-boot-camel/src/test/java/org/baeldung/SpringContextTest.java b/spring-boot-modules/spring-boot-camel/src/test/java/org/baeldung/SpringContextTest.java
similarity index 100%
rename from spring-boot-camel/src/test/java/org/baeldung/SpringContextTest.java
rename to spring-boot-modules/spring-boot-camel/src/test/java/org/baeldung/SpringContextTest.java
diff --git a/spring-boot-logging-log4j2/.gitignore b/spring-boot-modules/spring-boot-logging-log4j2/.gitignore
similarity index 100%
rename from spring-boot-logging-log4j2/.gitignore
rename to spring-boot-modules/spring-boot-logging-log4j2/.gitignore
diff --git a/spring-boot-logging-log4j2/README.md b/spring-boot-modules/spring-boot-logging-log4j2/README.md
similarity index 100%
rename from spring-boot-logging-log4j2/README.md
rename to spring-boot-modules/spring-boot-logging-log4j2/README.md
diff --git a/spring-boot-logging-log4j2/pom.xml b/spring-boot-modules/spring-boot-logging-log4j2/pom.xml
similarity index 98%
rename from spring-boot-logging-log4j2/pom.xml
rename to spring-boot-modules/spring-boot-logging-log4j2/pom.xml
index a7065bc925..6e709230dd 100644
--- a/spring-boot-logging-log4j2/pom.xml
+++ b/spring-boot-modules/spring-boot-logging-log4j2/pom.xml
@@ -12,7 +12,7 @@
     <parent>
         <groupId>org.springframework.boot</groupId>
         <artifactId>spring-boot-starter-parent</artifactId>
-        <version>2.2.1.RELEASE</version>
+        <version>2.2.2.RELEASE</version>
     </parent>
 
     <dependencies>
diff --git a/spring-boot-logging-log4j2/src/main/java/com/baeldung/graylog/GraylogDemoApplication.java b/spring-boot-modules/spring-boot-logging-log4j2/src/main/java/com/baeldung/graylog/GraylogDemoApplication.java
similarity index 100%
rename from spring-boot-logging-log4j2/src/main/java/com/baeldung/graylog/GraylogDemoApplication.java
rename to spring-boot-modules/spring-boot-logging-log4j2/src/main/java/com/baeldung/graylog/GraylogDemoApplication.java
diff --git a/spring-boot-logging-log4j2/src/main/java/com/baeldung/springbootlogging/LoggingController.java b/spring-boot-modules/spring-boot-logging-log4j2/src/main/java/com/baeldung/springbootlogging/LoggingController.java
similarity index 100%
rename from spring-boot-logging-log4j2/src/main/java/com/baeldung/springbootlogging/LoggingController.java
rename to spring-boot-modules/spring-boot-logging-log4j2/src/main/java/com/baeldung/springbootlogging/LoggingController.java
diff --git a/spring-boot-logging-log4j2/src/main/java/com/baeldung/springbootlogging/LombokLoggingController.java b/spring-boot-modules/spring-boot-logging-log4j2/src/main/java/com/baeldung/springbootlogging/LombokLoggingController.java
similarity index 100%
rename from spring-boot-logging-log4j2/src/main/java/com/baeldung/springbootlogging/LombokLoggingController.java
rename to spring-boot-modules/spring-boot-logging-log4j2/src/main/java/com/baeldung/springbootlogging/LombokLoggingController.java
diff --git a/spring-boot-logging-log4j2/src/main/java/com/baeldung/springbootlogging/SpringBootLoggingApplication.java b/spring-boot-modules/spring-boot-logging-log4j2/src/main/java/com/baeldung/springbootlogging/SpringBootLoggingApplication.java
similarity index 100%
rename from spring-boot-logging-log4j2/src/main/java/com/baeldung/springbootlogging/SpringBootLoggingApplication.java
rename to spring-boot-modules/spring-boot-logging-log4j2/src/main/java/com/baeldung/springbootlogging/SpringBootLoggingApplication.java
diff --git a/spring-boot-logging-log4j2/src/main/resources/application.properties b/spring-boot-modules/spring-boot-logging-log4j2/src/main/resources/application.properties
similarity index 100%
rename from spring-boot-logging-log4j2/src/main/resources/application.properties
rename to spring-boot-modules/spring-boot-logging-log4j2/src/main/resources/application.properties
diff --git a/spring-boot-logging-log4j2/src/main/resources/log4j.xml b/spring-boot-modules/spring-boot-logging-log4j2/src/main/resources/log4j.xml
similarity index 100%
rename from spring-boot-logging-log4j2/src/main/resources/log4j.xml
rename to spring-boot-modules/spring-boot-logging-log4j2/src/main/resources/log4j.xml
diff --git a/spring-boot-logging-log4j2/src/main/resources/log4j2-spring.xml b/spring-boot-modules/spring-boot-logging-log4j2/src/main/resources/log4j2-spring.xml
similarity index 100%
rename from spring-boot-logging-log4j2/src/main/resources/log4j2-spring.xml
rename to spring-boot-modules/spring-boot-logging-log4j2/src/main/resources/log4j2-spring.xml
diff --git a/spring-boot-logging-log4j2/src/test/java/org/baeldung/SpringContextTest.java b/spring-boot-modules/spring-boot-logging-log4j2/src/test/java/org/baeldung/SpringContextTest.java
similarity index 100%
rename from spring-boot-logging-log4j2/src/test/java/org/baeldung/SpringContextTest.java
rename to spring-boot-modules/spring-boot-logging-log4j2/src/test/java/org/baeldung/SpringContextTest.java
diff --git a/spring-boot-nashorn/README.md b/spring-boot-modules/spring-boot-nashorn/README.md
similarity index 100%
rename from spring-boot-nashorn/README.md
rename to spring-boot-modules/spring-boot-nashorn/README.md
diff --git a/spring-boot-nashorn/pom.xml b/spring-boot-modules/spring-boot-nashorn/pom.xml
similarity index 96%
rename from spring-boot-nashorn/pom.xml
rename to spring-boot-modules/spring-boot-nashorn/pom.xml
index af11f14fdc..c60997005d 100644
--- a/spring-boot-nashorn/pom.xml
+++ b/spring-boot-modules/spring-boot-nashorn/pom.xml
@@ -13,7 +13,7 @@
         <groupId>com.baeldung</groupId>
         <artifactId>parent-boot-2</artifactId>
         <version>0.0.1-SNAPSHOT</version>
-        <relativePath>../parent-boot-2</relativePath>
+        <relativePath>../../parent-boot-2</relativePath>
     </parent>
 
     <dependencies>
diff --git a/spring-boot-nashorn/src/main/java/com/baeldung/nashorn/Application.java b/spring-boot-modules/spring-boot-nashorn/src/main/java/com/baeldung/nashorn/Application.java
similarity index 100%
rename from spring-boot-nashorn/src/main/java/com/baeldung/nashorn/Application.java
rename to spring-boot-modules/spring-boot-nashorn/src/main/java/com/baeldung/nashorn/Application.java
diff --git a/spring-boot-nashorn/src/main/java/com/baeldung/nashorn/controller/MyRestController.java b/spring-boot-modules/spring-boot-nashorn/src/main/java/com/baeldung/nashorn/controller/MyRestController.java
similarity index 100%
rename from spring-boot-nashorn/src/main/java/com/baeldung/nashorn/controller/MyRestController.java
rename to spring-boot-modules/spring-boot-nashorn/src/main/java/com/baeldung/nashorn/controller/MyRestController.java
diff --git a/spring-boot-nashorn/src/main/java/com/baeldung/nashorn/controller/MyWebController.java b/spring-boot-modules/spring-boot-nashorn/src/main/java/com/baeldung/nashorn/controller/MyWebController.java
similarity index 100%
rename from spring-boot-nashorn/src/main/java/com/baeldung/nashorn/controller/MyWebController.java
rename to spring-boot-modules/spring-boot-nashorn/src/main/java/com/baeldung/nashorn/controller/MyWebController.java
diff --git a/spring-boot-nashorn/src/main/resources/application.properties b/spring-boot-modules/spring-boot-nashorn/src/main/resources/application.properties
similarity index 100%
rename from spring-boot-nashorn/src/main/resources/application.properties
rename to spring-boot-modules/spring-boot-nashorn/src/main/resources/application.properties
diff --git a/spring-boot-nashorn/src/main/resources/static/app.js b/spring-boot-modules/spring-boot-nashorn/src/main/resources/static/app.js
similarity index 100%
rename from spring-boot-nashorn/src/main/resources/static/app.js
rename to spring-boot-modules/spring-boot-nashorn/src/main/resources/static/app.js
diff --git a/spring-boot-nashorn/src/main/resources/static/js/react-dom-server.js b/spring-boot-modules/spring-boot-nashorn/src/main/resources/static/js/react-dom-server.js
similarity index 100%
rename from spring-boot-nashorn/src/main/resources/static/js/react-dom-server.js
rename to spring-boot-modules/spring-boot-nashorn/src/main/resources/static/js/react-dom-server.js
diff --git a/spring-boot-nashorn/src/main/resources/static/js/react-dom.js b/spring-boot-modules/spring-boot-nashorn/src/main/resources/static/js/react-dom.js
similarity index 100%
rename from spring-boot-nashorn/src/main/resources/static/js/react-dom.js
rename to spring-boot-modules/spring-boot-nashorn/src/main/resources/static/js/react-dom.js
diff --git a/spring-boot-nashorn/src/main/resources/static/js/react.js b/spring-boot-modules/spring-boot-nashorn/src/main/resources/static/js/react.js
similarity index 100%
rename from spring-boot-nashorn/src/main/resources/static/js/react.js
rename to spring-boot-modules/spring-boot-nashorn/src/main/resources/static/js/react.js
diff --git a/spring-boot-nashorn/src/main/webapp/WEB-INF/jsp/index.jsp b/spring-boot-modules/spring-boot-nashorn/src/main/webapp/WEB-INF/jsp/index.jsp
similarity index 100%
rename from spring-boot-nashorn/src/main/webapp/WEB-INF/jsp/index.jsp
rename to spring-boot-modules/spring-boot-nashorn/src/main/webapp/WEB-INF/jsp/index.jsp
diff --git a/spring-boot-modules/spring-boot-performance/README.md b/spring-boot-performance/README.md
similarity index 100%
rename from spring-boot-modules/spring-boot-performance/README.md
rename to spring-boot-performance/README.md
diff --git a/spring-boot-modules/spring-boot-performance/pom.xml b/spring-boot-performance/pom.xml
similarity index 96%
rename from spring-boot-modules/spring-boot-performance/pom.xml
rename to spring-boot-performance/pom.xml
index 882763f0bc..7bf3885618 100644
--- a/spring-boot-modules/spring-boot-performance/pom.xml
+++ b/spring-boot-performance/pom.xml
@@ -11,7 +11,7 @@
         <groupId>com.baeldung</groupId>
         <artifactId>parent-boot-2</artifactId>
         <version>0.0.1-SNAPSHOT</version>
-        <relativePath>../../parent-boot-2</relativePath>
+        <relativePath>../parent-boot-2</relativePath>
     </parent>
 
     <dependencies>
diff --git a/spring-boot-modules/spring-boot-performance/src/main/java/com/baeldung/lazyinitialization/Application.java b/spring-boot-performance/src/main/java/com/baeldung/lazyinitialization/Application.java
similarity index 100%
rename from spring-boot-modules/spring-boot-performance/src/main/java/com/baeldung/lazyinitialization/Application.java
rename to spring-boot-performance/src/main/java/com/baeldung/lazyinitialization/Application.java
diff --git a/spring-boot-modules/spring-boot-performance/src/main/java/com/baeldung/lazyinitialization/services/Writer.java b/spring-boot-performance/src/main/java/com/baeldung/lazyinitialization/services/Writer.java
similarity index 100%
rename from spring-boot-modules/spring-boot-performance/src/main/java/com/baeldung/lazyinitialization/services/Writer.java
rename to spring-boot-performance/src/main/java/com/baeldung/lazyinitialization/services/Writer.java
diff --git a/spring-boot-modules/spring-boot-performance/src/main/resources/application.yml b/spring-boot-performance/src/main/resources/application.yml
similarity index 100%
rename from spring-boot-modules/spring-boot-performance/src/main/resources/application.yml
rename to spring-boot-performance/src/main/resources/application.yml
diff --git a/spring-security-modules/spring-security-mvc-boot/src/main/java/com/baeldung/models/Tweet.java b/spring-security-modules/spring-security-mvc-boot/src/main/java/com/baeldung/models/Tweet.java
index b2e45009f6..54a96deaf3 100644
--- a/spring-security-modules/spring-security-mvc-boot/src/main/java/com/baeldung/models/Tweet.java
+++ b/spring-security-modules/spring-security-mvc-boot/src/main/java/com/baeldung/models/Tweet.java
@@ -3,14 +3,17 @@ package com.baeldung.models;
 import java.util.HashSet;
 import java.util.Set;
 
+import javax.persistence.CollectionTable;
 import javax.persistence.ElementCollection;
 import javax.persistence.Entity;
 import javax.persistence.FetchType;
 import javax.persistence.GeneratedValue;
 import javax.persistence.GenerationType;
 import javax.persistence.Id;
+import javax.persistence.Table;
 
 @Entity
+@Table(name = "Tweet")
 public class Tweet {
     @Id
     @GeneratedValue(strategy = GenerationType.SEQUENCE)
@@ -18,7 +21,8 @@ public class Tweet {
     private String tweet;
     private String owner;
     @ElementCollection(targetClass = String.class, fetch = FetchType.EAGER)
-    private Set<String> likes = new HashSet();
+    @CollectionTable(name = "Tweet_Likes")
+    private Set<String> likes = new HashSet<>();
 
     public long getId() {
         return id;
diff --git a/spring-security-modules/spring-security-mvc-boot/src/test/java/com/baeldung/relationships/SpringDataWithSecurityIntegrationTest.java b/spring-security-modules/spring-security-mvc-boot/src/test/java/com/baeldung/relationships/SpringDataWithSecurityIntegrationTest.java
index 41f220df6f..b2def82c51 100644
--- a/spring-security-modules/spring-security-mvc-boot/src/test/java/com/baeldung/relationships/SpringDataWithSecurityIntegrationTest.java
+++ b/spring-security-modules/spring-security-mvc-boot/src/test/java/com/baeldung/relationships/SpringDataWithSecurityIntegrationTest.java
@@ -1,29 +1,5 @@
 package com.baeldung.relationships;
 
-import static org.springframework.util.Assert.isTrue;
-
-import java.util.Date;
-import java.util.List;
-
-import javax.servlet.ServletContext;
-
-import org.junit.AfterClass;
-import org.junit.Before;
-import org.junit.Test;
-import org.junit.runner.RunWith;
-import org.springframework.beans.factory.annotation.Autowired;
-import org.springframework.dao.InvalidDataAccessApiUsageException;
-import org.springframework.data.domain.Page;
-import org.springframework.data.domain.PageRequest;
-import org.springframework.security.authentication.UsernamePasswordAuthenticationToken;
-import org.springframework.security.core.Authentication;
-import org.springframework.security.core.context.SecurityContextHolder;
-import org.springframework.test.annotation.DirtiesContext;
-import org.springframework.test.context.ContextConfiguration;
-import org.springframework.test.context.junit4.SpringRunner;
-import org.springframework.test.context.web.WebAppConfiguration;
-import org.springframework.web.context.support.AnnotationConfigWebApplicationContext;
-
 import com.baeldung.AppConfig;
 import com.baeldung.data.repositories.TweetRepository;
 import com.baeldung.data.repositories.UserRepository;
@@ -31,6 +7,30 @@ import com.baeldung.models.AppUser;
 import com.baeldung.models.Tweet;
 import com.baeldung.security.AppUserPrincipal;
 import com.baeldung.util.DummyContentUtil;
+import org.junit.After;
+import org.junit.Before;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.dao.InvalidDataAccessApiUsageException;
+import org.springframework.data.domain.Page;
+import org.springframework.data.domain.PageRequest;
+import org.springframework.jdbc.core.JdbcTemplate;
+import org.springframework.security.authentication.UsernamePasswordAuthenticationToken;
+import org.springframework.security.core.Authentication;
+import org.springframework.security.core.context.SecurityContextHolder;
+import org.springframework.test.annotation.DirtiesContext;
+import org.springframework.test.context.ContextConfiguration;
+import org.springframework.test.context.junit4.SpringRunner;
+import org.springframework.test.context.web.WebAppConfiguration;
+import org.springframework.test.jdbc.JdbcTestUtils;
+import org.springframework.web.context.support.AnnotationConfigWebApplicationContext;
+
+import javax.servlet.ServletContext;
+import java.util.Date;
+import java.util.List;
+
+import static org.springframework.util.Assert.isTrue;
 
 @RunWith(SpringRunner.class)
 @WebAppConfiguration
@@ -54,10 +54,22 @@ public class SpringDataWithSecurityIntegrationTest {
         tweetRepository.saveAll(DummyContentUtil.generateDummyTweets(appUsers));
     }
 
-    @AfterClass
-    public static void tearDown() {
-        tweetRepository.deleteAll();
-        userRepository.deleteAll();
+    /**
+     * This is to ensure the tables are dropped in proper order.
+     * After the Spring Boot 2.2.2 upgrade, DDL statements generated automatically try to drop Tweet table first.
+     * As a result we get org.h2.jdbc.JdbcSQLSyntaxErrorException because Tweet_Likes table depends on Tweet.
+     *
+     * @see <a href="https://stackoverflow.com/questions/59364212/integrationtest-isolation-fails-in-springboot-2-2-2-release-error-dopping-table">
+     * StackOverflow#59364212
+     * </a>
+     * @see <a href="https://stackoverflow.com/questions/59561551/hibernate-h2-specify-drop-table-order">
+     * StackOverflow#59561551
+     * </a>
+     */
+    @After
+    public void tearDown() {
+        JdbcTemplate jdbcTemplate = ctx.getBean(JdbcTemplate.class);
+        JdbcTestUtils.dropTables(jdbcTemplate, "Tweet_Likes", "Tweet");
     }
 
     @Test