diff --git a/core-java-modules/core-java/pom.xml b/core-java-modules/core-java/pom.xml
index b0f9fea26e..7942f3e7e2 100644
--- a/core-java-modules/core-java/pom.xml
+++ b/core-java-modules/core-java/pom.xml
@@ -454,7 +454,7 @@
         <gson.version>2.8.2</gson.version>
 
         <!-- util -->
-        <commons-lang3.version>3.5</commons-lang3.version>
+        <commons-lang3.version>3.9</commons-lang3.version>
         <commons-io.version>2.5</commons-io.version>
         <commons-math3.version>3.6.1</commons-math3.version>
         <decimal4j.version>1.0.3</decimal4j.version>
diff --git a/core-java/src/main/java/com/baeldung/exceptions/RootCauseFinder.java b/core-java-modules/core-java/src/main/java/com/baeldung/exceptions/RootCauseFinder.java
similarity index 90%
rename from core-java/src/main/java/com/baeldung/exceptions/RootCauseFinder.java
rename to core-java-modules/core-java/src/main/java/com/baeldung/exceptions/RootCauseFinder.java
index 064ae27ac1..cf449110e6 100644
--- a/core-java/src/main/java/com/baeldung/exceptions/RootCauseFinder.java
+++ b/core-java-modules/core-java/src/main/java/com/baeldung/exceptions/RootCauseFinder.java
@@ -30,7 +30,7 @@ public class RootCauseFinder {
         private AgeCalculator() {
         }
 
-        public static int calculateAge(String birthDate) throws CalculationException {
+        public static int calculateAge(String birthDate) {
             if (birthDate == null || birthDate.isEmpty()) {
                 throw new IllegalArgumentException();
             }
@@ -44,7 +44,7 @@ public class RootCauseFinder {
             }
         }
 
-        private static LocalDate parseDate(String birthDateAsString) throws DateParseException {
+        private static LocalDate parseDate(String birthDateAsString) {
 
             LocalDate birthDate;
             try {
@@ -62,14 +62,14 @@ public class RootCauseFinder {
 
     }
 
-    static class CalculationException extends Exception {
+    static class CalculationException extends RuntimeException {
 
         CalculationException(DateParseException ex) {
             super(ex);
         }
     }
 
-    static class DateParseException extends Exception {
+    static class DateParseException extends RuntimeException {
 
         DateParseException(String input) {
             super(input);
diff --git a/core-java/src/test/java/com/baeldung/exceptions/RootCauseFinderUnitTest.java b/core-java-modules/core-java/src/test/java/com/baeldung/exceptions/RootCauseFinderUnitTest.java
similarity index 100%
rename from core-java/src/test/java/com/baeldung/exceptions/RootCauseFinderUnitTest.java
rename to core-java-modules/core-java/src/test/java/com/baeldung/exceptions/RootCauseFinderUnitTest.java
diff --git a/core-java/pom.xml b/core-java/pom.xml
deleted file mode 100644
index 661e787149..0000000000
--- a/core-java/pom.xml
+++ /dev/null
@@ -1,492 +0,0 @@
-<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>
-    <artifactId>core-java</artifactId>
-    <version>0.1.0-SNAPSHOT</version>
-    <name>core-java</name>
-    <packaging>jar</packaging>
-
-    <parent>
-        <groupId>com.baeldung</groupId>
-        <artifactId>parent-java</artifactId>
-        <version>0.0.1-SNAPSHOT</version>
-        <relativePath>../parent-java</relativePath>
-    </parent>
-
-
-    <dependencies>
-        <dependency>
-            <groupId>commons-io</groupId>
-            <artifactId>commons-io</artifactId>
-            <version>${commons-io.version}</version>
-        </dependency>
-        <dependency>
-            <groupId>org.apache.commons</groupId>
-            <artifactId>commons-lang3</artifactId>
-            <version>${commons-lang3.version}</version>
-        </dependency>
-        <dependency>
-            <groupId>org.unix4j</groupId>
-            <artifactId>unix4j-command</artifactId>
-            <version>${unix4j.version}</version>
-        </dependency>
-        <dependency>
-            <groupId>com.googlecode.grep4j</groupId>
-            <artifactId>grep4j</artifactId>
-            <version>${grep4j.version}</version>
-        </dependency>
-        <!-- web -->
-        <!-- marshalling -->
-        <dependency>
-            <groupId>com.fasterxml.jackson.core</groupId>
-            <artifactId>jackson-databind</artifactId>
-            <version>${jackson.version}</version>
-        </dependency>
-        <dependency>
-            <groupId>com.google.code.gson</groupId>
-            <artifactId>gson</artifactId>
-            <version>${gson.version}</version>
-        </dependency>
-        <!-- logging -->
-        <dependency>
-            <groupId>log4j</groupId>
-            <artifactId>log4j</artifactId>
-            <version>${log4j.version}</version>
-        </dependency>
-        <dependency> <!-- needed to bridge to slf4j for projects that use the log4j APIs directly -->
-            <groupId>org.slf4j</groupId>
-            <artifactId>log4j-over-slf4j</artifactId>
-            <version>${org.slf4j.version}</version>
-        </dependency>
-        <dependency>
-            <groupId>org.projectlombok</groupId>
-            <artifactId>lombok</artifactId>
-            <version>${lombok.version}</version>
-            <scope>provided</scope>
-        </dependency>
-        <!-- test scoped -->
-        <dependency>
-            <groupId>org.assertj</groupId>
-            <artifactId>assertj-core</artifactId>
-            <version>${assertj-core.version}</version>
-            <scope>test</scope>
-        </dependency>
-        <dependency>
-            <groupId>org.javamoney</groupId>
-            <artifactId>moneta</artifactId>
-            <version>${javamoney.moneta.version}</version>
-        </dependency>
-        <dependency>
-            <groupId>org.owasp.esapi</groupId>
-            <artifactId>esapi</artifactId>
-            <version>${esapi.version}</version>
-        </dependency>
-        <dependency>
-            <groupId>com.sun.messaging.mq</groupId>
-            <artifactId>fscontext</artifactId>
-            <version>${fscontext.version}</version>
-        </dependency>
-        <dependency>
-            <groupId>com.codepoetics</groupId>
-            <artifactId>protonpack</artifactId>
-            <version>${protonpack.version}</version>
-        </dependency>
-        <dependency>
-            <groupId>one.util</groupId>
-            <artifactId>streamex</artifactId>
-            <version>${streamex.version}</version>
-        </dependency>
-        <dependency>
-            <groupId>io.vavr</groupId>
-            <artifactId>vavr</artifactId>
-            <version>${vavr.version}</version>
-        </dependency>
-        <dependency>
-            <groupId>org.openjdk.jmh</groupId>
-            <artifactId>jmh-core</artifactId>
-            <version>${jmh-core.version}</version>
-        </dependency>
-        <dependency>
-            <groupId>org.openjdk.jmh</groupId>
-            <artifactId>jmh-generator-annprocess</artifactId>
-            <version>${jmh-generator-annprocess.version}</version>
-        </dependency>
-        <dependency>
-            <groupId>com.h2database</groupId>
-            <artifactId>h2</artifactId>
-            <version>${h2database.version}</version>
-        </dependency>
-        <!-- instrumentation -->
-        <dependency>
-            <groupId>org.javassist</groupId>
-            <artifactId>javassist</artifactId>
-            <version>${javaassist.version}</version>
-        </dependency>
-        <dependency>
-            <groupId>com.sun</groupId>
-            <artifactId>tools</artifactId>
-            <version>${sun.tools.version}</version>
-            <scope>system</scope>
-            <systemPath>${java.home}/../lib/tools.jar</systemPath>
-        </dependency>
-    </dependencies>
-
-    <build>
-        <finalName>core-java</finalName>
-        <resources>
-            <resource>
-                <directory>src/main/resources</directory>
-                <filtering>true</filtering>
-            </resource>
-        </resources>
-
-        <plugins>
-            <plugin>
-                <groupId>org.apache.maven.plugins</groupId>
-                <artifactId>maven-dependency-plugin</artifactId>
-                <executions>
-                    <execution>
-                        <id>copy-dependencies</id>
-                        <phase>prepare-package</phase>
-                        <goals>
-                            <goal>copy-dependencies</goal>
-                        </goals>
-                        <configuration>
-                            <outputDirectory>${project.build.directory}/libs</outputDirectory>
-                        </configuration>
-                    </execution>
-                </executions>
-            </plugin>
-
-            <plugin>
-                <groupId>org.apache.maven.plugins</groupId>
-                <artifactId>maven-jar-plugin</artifactId>
-                <version>${maven-jar-plugin.version}</version>
-                <configuration>
-                    <archive>
-                        <manifest>
-                            <addClasspath>true</addClasspath>
-                            <classpathPrefix>libs/</classpathPrefix>
-                            <mainClass>org.baeldung.executable.ExecutableMavenJar</mainClass>
-                        </manifest>
-                    </archive>
-                </configuration>
-            </plugin>
-
-            <plugin>
-                <groupId>org.apache.maven.plugins</groupId>
-                <artifactId>maven-assembly-plugin</artifactId>
-                <executions>
-                    <execution>
-                        <phase>package</phase>
-                        <goals>
-                            <goal>single</goal>
-                        </goals>
-                        <configuration>
-                            <archiveBaseDirectory>${project.basedir}</archiveBaseDirectory>
-                            <archive>
-                                <manifest>
-                                    <mainClass>org.baeldung.executable.ExecutableMavenJar</mainClass>
-                                </manifest>
-                            </archive>
-                            <descriptorRefs>
-                                <descriptorRef>jar-with-dependencies</descriptorRef>
-                            </descriptorRefs>
-                        </configuration>
-                    </execution>
-                </executions>
-            </plugin>
-
-            <plugin>
-                <groupId>org.apache.maven.plugins</groupId>
-                <artifactId>maven-shade-plugin</artifactId>
-                <version>${maven-shade-plugin.version}</version>
-                <executions>
-                    <execution>
-                        <goals>
-                            <goal>shade</goal>
-                        </goals>
-                        <configuration>
-                            <shadedArtifactAttached>true</shadedArtifactAttached>
-                            <transformers>
-                                <transformer implementation="org.apache.maven.plugins.shade.resource.ManifestResourceTransformer">
-                                    <mainClass>org.baeldung.executable.ExecutableMavenJar</mainClass>
-                                </transformer>
-                            </transformers>
-                        </configuration>
-                    </execution>
-                </executions>
-            </plugin>
-
-            <plugin>
-                <groupId>com.jolira</groupId>
-                <artifactId>onejar-maven-plugin</artifactId>
-                <version>${onejar-maven-plugin.version}</version>
-                <executions>
-                    <execution>
-                        <configuration>
-                            <mainClass>org.baeldung.executable.ExecutableMavenJar</mainClass>
-                            <attachToBuild>true</attachToBuild>
-                            <filename>${project.build.finalName}-onejar.${project.packaging}</filename>
-                        </configuration>
-                        <goals>
-                            <goal>one-jar</goal>
-                        </goals>
-                    </execution>
-                </executions>
-            </plugin>
-
-            <plugin>
-                <groupId>org.springframework.boot</groupId>
-                <artifactId>spring-boot-maven-plugin</artifactId>
-                <version>${spring-boot-maven-plugin.version}</version>
-                <executions>
-                    <execution>
-                        <goals>
-                            <goal>repackage</goal>
-                        </goals>
-                        <configuration>
-                            <classifier>spring-boot</classifier>
-                            <mainClass>org.baeldung.executable.ExecutableMavenJar</mainClass>
-                        </configuration>
-                    </execution>
-                </executions>
-            </plugin>
-
-            <plugin>
-                <groupId>org.codehaus.mojo</groupId>
-                <artifactId>exec-maven-plugin</artifactId>
-                <version>${exec-maven-plugin.version}</version>
-                <configuration>
-                    <executable>java</executable>
-                    <mainClass>com.baeldung.outofmemoryerror.OutOfMemoryGCLimitExceed</mainClass>
-                    <arguments>
-                        <argument>-Xmx300m</argument>
-                        <argument>-XX:+UseParallelGC</argument>
-                        <argument>-classpath</argument>
-                        <classpath />
-                        <argument>com.baeldung.outofmemoryerror.OutOfMemoryGCLimitExceed</argument>
-                    </arguments>
-                </configuration>
-            </plugin>
-            
-            <plugin>
-                <groupId>org.apache.maven.plugins</groupId>
-                <artifactId>maven-javadoc-plugin</artifactId>
-                <version>${maven-javadoc-plugin.version}</version>
-                <configuration>
-                    <source>1.8</source>
-                    <target>1.8</target>
-                </configuration>
-            </plugin>
-        </plugins>
-    </build>
-
-    <profiles>
-        <profile>
-            <id>integration</id>
-            <build>
-                <plugins>
-                    <plugin>
-                        <groupId>org.apache.maven.plugins</groupId>
-                        <artifactId>maven-surefire-plugin</artifactId>
-                        <executions>
-                            <execution>
-                                <phase>integration-test</phase>
-                                <goals>
-                                    <goal>test</goal>
-                                </goals>
-                                <configuration>
-                                    <excludes>
-                                        <exclude>**/*ManualTest.java</exclude>
-                                    </excludes>
-                                    <includes>
-                                        <include>**/*IntegrationTest.java</include>
-                                        <include>**/*IntTest.java</include>
-                                    </includes>
-                                </configuration>
-                            </execution>
-                        </executions>
-                        <configuration>
-                            <systemPropertyVariables>
-                                <test.mime>json</test.mime>
-                            </systemPropertyVariables>
-                        </configuration>
-                    </plugin>
-                    <plugin>
-                        <groupId>org.codehaus.mojo</groupId>
-                        <artifactId>exec-maven-plugin</artifactId>
-                        <version>${exec-maven-plugin.version}</version>
-                        <executions>
-                            <execution>
-                                <id>run-benchmarks</id>
-                                <!-- <phase>integration-test</phase> -->
-                                <phase>none</phase>
-                                <goals>
-                                    <goal>exec</goal>
-                                </goals>
-                                <configuration>
-                                    <classpathScope>test</classpathScope>
-                                    <executable>java</executable>
-                                    <arguments>
-                                        <argument>-classpath</argument>
-                                        <classpath />
-                                        <argument>org.openjdk.jmh.Main</argument>
-                                        <argument>.*</argument>
-                                    </arguments>
-                                </configuration>
-                            </execution>
-                        </executions>
-                    </plugin>
-                </plugins>
-            </build>
-        </profile>
-
-        <!-- java instrumentation profiles to build jars -->
-        <profile>
-            <id>buildAgentLoader</id>
-            <build>
-                <plugins>
-                    <plugin>
-                        <groupId>org.apache.maven.plugins</groupId>
-                        <artifactId>maven-jar-plugin</artifactId>
-                        <executions>
-                            <execution>
-                                <phase>package</phase>
-                                <goals>
-                                    <goal>jar</goal>
-                                </goals>
-                                <configuration>
-                                    <classifier>agentLoader</classifier>
-                                    <classesDirectory>target/classes</classesDirectory>
-                                    <archive>
-                                        <manifest>
-                                            <addClasspath>true</addClasspath>
-                                        </manifest>
-                                        <manifestFile>${project.build.outputDirectory}/META-INF/MANIFEST.MF</manifestFile>
-                                    </archive>
-
-                                    <includes>
-                                        <include>com/baeldung/instrumentation/application/AgentLoader.class</include>
-                                        <include>com/baeldung/instrumentation/application/Launcher.class</include>
-                                    </includes>
-                                </configuration>
-                            </execution>
-                        </executions>
-                    </plugin>
-                </plugins>
-            </build>
-        </profile>
-        <profile>
-            <id>buildApplication</id>
-            <build>
-                <plugins>
-                    <plugin>
-                        <groupId>org.apache.maven.plugins</groupId>
-                        <artifactId>maven-jar-plugin</artifactId>
-                        <executions>
-                            <execution>
-                                <phase>package</phase>
-                                <goals>
-                                    <goal>jar</goal>
-                                </goals>
-                                <configuration>
-                                    <classifier>application</classifier>
-                                    <classesDirectory>target/classes</classesDirectory>
-                                    <archive>
-                                        <manifest>
-                                            <addClasspath>true</addClasspath>
-                                        </manifest>
-                                        <manifestFile>${project.build.outputDirectory}/META-INF/MANIFEST.MF</manifestFile>
-                                    </archive>
-
-                                    <includes>
-                                        <include>com/baeldung/instrumentation/application/MyAtm.class</include>
-                                        <include>com/baeldung/instrumentation/application/MyAtmApplication.class</include>
-                                        <include>com/baeldung/instrumentation/application/Launcher.class</include>
-                                    </includes>
-                                </configuration>
-                            </execution>
-                        </executions>
-                    </plugin>
-                </plugins>
-            </build>
-        </profile>
-        <profile>
-            <id>buildAgent</id>
-            <build>
-                <plugins>
-                    <plugin>
-                        <groupId>org.apache.maven.plugins</groupId>
-                        <artifactId>maven-jar-plugin</artifactId>
-                        <executions>
-                            <execution>
-                                <phase>package</phase>
-                                <goals>
-                                    <goal>jar</goal>
-                                </goals>
-                                <configuration>
-                                    <classifier>agent</classifier>
-                                    <classesDirectory>target/classes</classesDirectory>
-                                    <archive>
-                                        <manifest>
-                                            <addClasspath>true</addClasspath>
-                                        </manifest>
-                                        <manifestFile>${project.build.outputDirectory}/META-INF/MANIFEST.MF</manifestFile>
-                                    </archive>
-
-                                    <includes>
-                                        <include>com/baeldung/instrumentation/agent/AtmTransformer.class</include>
-                                        <include>com/baeldung/instrumentation/agent/MyInstrumentationAgent.class</include>
-                                    </includes>
-                                </configuration>
-                            </execution>
-                        </executions>
-                    </plugin>
-                </plugins>
-            </build>
-        </profile>
-    </profiles>
-
-    <properties>
-        
-        <!-- marshalling -->
-        <gson.version>2.8.2</gson.version>
-
-        <!-- util -->
-        <commons-lang3.version>3.9</commons-lang3.version>
-        <commons-io.version>2.5</commons-io.version>
-        <commons-math3.version>3.6.1</commons-math3.version>
-        <decimal4j.version>1.0.3</decimal4j.version>
-        <unix4j.version>0.4</unix4j.version>
-        <grep4j.version>1.8.7</grep4j.version>
-        <fscontext.version>4.6-b01</fscontext.version>
-        <protonpack.version>1.13</protonpack.version>
-        <streamex.version>0.6.5</streamex.version>
-        <vavr.version>0.9.0</vavr.version>
-
-        <!-- testing -->
-        <assertj-core.version>3.10.0</assertj-core.version>
-
-        <!-- maven plugins -->
-        <maven-surefire-plugin.version>2.21.0</maven-surefire-plugin.version>
-        
-        <javamoney.moneta.version>1.1</javamoney.moneta.version>
-        <h2database.version>1.4.197</h2database.version>
-        <esapi.version>2.1.0.1</esapi.version>
-        <jmh-core.version>1.19</jmh-core.version>
-       
-        <jmh-generator-annprocess.version>1.19</jmh-generator-annprocess.version>
-        <maven-javadoc-plugin.version>3.0.0-M1</maven-javadoc-plugin.version>
-        <maven-jar-plugin.version>3.0.2</maven-jar-plugin.version>
-        <onejar-maven-plugin.version>1.4.4</onejar-maven-plugin.version>
-        <maven-shade-plugin.version>3.1.1</maven-shade-plugin.version>
-        <spring-boot-maven-plugin.version>2.0.3.RELEASE</spring-boot-maven-plugin.version>
-        <exec-maven-plugin.version>1.6.0</exec-maven-plugin.version>
-        <icu4j.version>61.1</icu4j.version>
-        <!-- instrumentation -->
-        <javaassist.version>3.21.0-GA</javaassist.version>
-        
-        <sun.tools.version>1.8.0</sun.tools.version>
-    </properties>
-</project>