Merge remote-tracking branch 'upstream/master' into BAEL-1754

README.md

@@ -34,3 +34,9 @@ CI - Jenkins
 ================================
 This tutorials project is being built **[>> HERE](https://rest-security.ci.cloudbees.com/job/tutorials-unit/)**
 
+### Relevant Articles: 
+================================
+
+- [Apache Maven Standard Directory Layout](http://www.baeldung.com/maven-directory-structure)
+- [Apache Maven Tutorial](http://www.baeldung.com/maven)
+- [Designing a User Friendly Java Library](http://www.baeldung.com/design-a-user-friendly-java-library)

algorithms/README.md

@@ -21,3 +21,4 @@
 - [Create a Sudoku Solver in Java](http://www.baeldung.com/java-sudoku)
 - [Displaying Money Amounts in Words](http://www.baeldung.com/java-money-into-words)
 - [A Collaborative Filtering Recommendation System in Java](http://www.baeldung.com/java-collaborative-filtering-recommendations)
+- [Find All Pairs of Numbers in an Array That Add Up to a Given Sum](http://www.baeldung.com/java-algorithm-number-pairs-sum)

asciidoctor/README.md

@@ -2,3 +2,4 @@
 
 - [Introduction to Asciidoctor](http://www.baeldung.com/introduction-to-asciidoctor)
 - [Generating a Book with Asciidoctor](http://www.baeldung.com/asciidoctor-book)
+- [Introduction to Asciidoctor in Java](http://www.baeldung.com/asciidoctor)

autovalue/pom.xml

@@ -18,10 +18,29 @@
             <artifactId>auto-value</artifactId>
             <version>${auto-value.version}</version>
         </dependency>
+        <dependency>
+            <groupId>com.google.auto.factory</groupId>
+            <artifactId>auto-factory</artifactId>
+            <version>${auto-factory.version}</version>
+            <exclusions>
+                <exclusion>
+                    <groupId>com.google.guava</groupId>
+                    <artifactId>guava</artifactId>
+                </exclusion>
+            </exclusions>
+        </dependency>
+
+        <dependency>
+            <groupId>com.google.inject</groupId>
+            <artifactId>guice</artifactId>
+            <version>${guice.version}</version>
+        </dependency>
     </dependencies>
 
     <properties>
         <auto-value.version>1.3</auto-value.version>
+        <auto-factory.version>1.0-beta5</auto-factory.version>
+        <guice.version>4.2.0</guice.version>
     </properties>
 
 </project>

autovalue/src/main/java/com/baeldung/autofactory/App.java

@@ -0,0 +1,21 @@
+package com.baeldung.autofactory;
+
+import com.baeldung.autofactory.model.Camera;
+import com.baeldung.autofactory.model.Phone;
+import com.baeldung.autofactory.model.PhoneFactory;
+import com.baeldung.autofactory.modules.SonyCameraModule;
+import com.google.inject.Guice;
+import com.google.inject.Injector;
+
+public class App {
+
+    public static void main(String[] args) {
+        PhoneFactory phoneFactory = new PhoneFactory(() -> new Camera("Unknown", "XXX"));
+        Phone simplePhone = phoneFactory.create("other parts");
+
+        Injector injector = Guice.createInjector(new SonyCameraModule());
+        PhoneFactory injectedFactory = injector.getInstance(PhoneFactory.class);
+        Phone xperia = injectedFactory.create("Xperia");
+    }
+
+}

autovalue/src/main/java/com/baeldung/autofactory/CustomStorage.java

@@ -0,0 +1,12 @@
+package com.baeldung.autofactory;
+
+import com.baeldung.autofactory.custom.SmartPhone;
+
+/**
+ * @author aiet
+ */
+public interface CustomStorage {
+
+    SmartPhone customROMInGB(int romSize);
+
+}

autovalue/src/main/java/com/baeldung/autofactory/custom/AbstractFactory.java

@@ -0,0 +1,10 @@
+package com.baeldung.autofactory.custom;
+
+/**
+ * @author aiet
+ */
+public abstract class AbstractFactory {
+
+    abstract CustomPhone newInstance(String brand);
+
+}

autovalue/src/main/java/com/baeldung/autofactory/custom/CustomPhone.java

@@ -0,0 +1,16 @@
+package com.baeldung.autofactory.custom;
+
+import com.google.auto.factory.AutoFactory;
+
+/**
+ * @author aiet
+ */
+@AutoFactory(extending = AbstractFactory.class)
+public class CustomPhone {
+
+    private final String brand;
+
+    public CustomPhone(String brand) {
+        this.brand = brand;
+    }
+}

autovalue/src/main/java/com/baeldung/autofactory/custom/SmartPhone.java

@@ -0,0 +1,18 @@
+package com.baeldung.autofactory.custom;
+
+import com.baeldung.autofactory.CustomStorage;
+import com.google.auto.factory.AutoFactory;
+
+/**
+ * @author aiet
+ */
+@AutoFactory(className = "SamsungFactory", allowSubclasses = true, implementing = CustomStorage.class)
+public class SmartPhone {
+
+    private int romSize;
+
+    public SmartPhone(int romSize) {
+        this.romSize = romSize;
+    }
+
+}

autovalue/src/main/java/com/baeldung/autofactory/model/Camera.java

@@ -0,0 +1,24 @@
+package com.baeldung.autofactory.model;
+
+/**
+ * @author aiet
+ */
+public class Camera {
+
+    private final String manufacturer;
+    private final String serial;
+
+    public Camera(String manufacturer, String serial) {
+        this.manufacturer = manufacturer;
+        this.serial = serial;
+    }
+
+    public String getManufacturer() {
+        return manufacturer;
+    }
+
+    public String getSerial() {
+        return serial;
+    }
+
+}

autovalue/src/main/java/com/baeldung/autofactory/model/ClassicPhone.java

@@ -0,0 +1,38 @@
+package com.baeldung.autofactory.model;
+
+import com.google.auto.factory.AutoFactory;
+import com.google.auto.factory.Provided;
+
+/**
+ * @author aiet
+ */
+public class ClassicPhone {
+
+    private final String dialpad;
+    private final String ringer;
+    private String otherParts;
+
+    @AutoFactory
+    public ClassicPhone(@Provided String dialpad, @Provided String ringer) {
+        this.dialpad = dialpad;
+        this.ringer = ringer;
+    }
+
+    @AutoFactory
+    public ClassicPhone(String otherParts) {
+        this("defaultDialPad", "defaultRinger");
+        this.otherParts = otherParts;
+    }
+
+    public String getDialpad() {
+        return dialpad;
+    }
+
+    public String getRinger() {
+        return ringer;
+    }
+
+    public String getOtherParts() {
+        return otherParts;
+    }
+}

autovalue/src/main/java/com/baeldung/autofactory/model/Phone.java

@@ -0,0 +1,34 @@
+package com.baeldung.autofactory.model;
+
+import com.google.auto.factory.AutoFactory;
+import com.google.auto.factory.Provided;
+
+import javax.inject.Named;
+
+/**
+ * @author aiet
+ */
+@AutoFactory
+public class Phone {
+
+    private Camera camera;
+    private String otherParts;
+
+    public Phone(@Provided @Named("Sony") Camera camera, String otherParts) {
+        this.camera = camera;
+        this.otherParts = otherParts;
+    }
+
+    /* required when used as a base class for AutoFactory */
+    public Phone() {
+    }
+
+    public Camera getCamera() {
+        return camera;
+    }
+
+    public String getOtherParts() {
+        return otherParts;
+    }
+
+}

autovalue/src/main/java/com/baeldung/autofactory/modules/SonyCameraModule.java

@@ -0,0 +1,22 @@
+package com.baeldung.autofactory.modules;
+
+import com.baeldung.autofactory.model.Camera;
+import com.google.inject.AbstractModule;
+import com.google.inject.Provides;
+
+import javax.inject.Named;
+
+/**
+ * @author aiet
+ */
+public class SonyCameraModule extends AbstractModule {
+
+    private static int SONY_CAMERA_SERIAL = 1;
+
+    @Named("Sony")
+    @Provides
+    Camera cameraProvider() {
+        return new Camera("Sony", String.format("%03d", SONY_CAMERA_SERIAL++));
+    }
+
+}

autovalue/src/main/java/com/baeldung/autofactory/provided/IntermediateAssembler.java

@@ -0,0 +1,22 @@
+package com.baeldung.autofactory.provided;
+
+import com.google.auto.factory.AutoFactory;
+import com.google.auto.factory.Provided;
+import javafx.scene.Camera;
+
+import javax.inject.Provider;
+
+/**
+ * @author aiet
+ */
+@AutoFactory
+public class IntermediateAssembler {
+
+    private final Provider<Camera> camera;
+    private final String otherParts;
+
+    public IntermediateAssembler(@Provided Provider<Camera> camera, String otherParts) {
+        this.camera = camera;
+        this.otherParts = otherParts;
+    }
+}

autovalue/src/main/java/com/baeldung/autofactory/provider/SonyCameraProvider.java

@@ -0,0 +1,18 @@
+package com.baeldung.autofactory.provider;
+
+import com.baeldung.autofactory.model.Camera;
+import com.google.inject.Provider;
+
+/**
+ * @author aiet
+ */
+public class SonyCameraProvider implements Provider<Camera> {
+
+    private static int sonyCameraSerial = 1;
+
+    @Override
+    public Camera get() {
+        return new Camera("Sony", String.format("%03d", sonyCameraSerial++));
+    }
+
+}

aws/README.md

@@ -5,4 +5,8 @@
 - [AWS Lambda With Java](http://www.baeldung.com/java-aws-lambda)
 - [Managing EC2 Instances in Java](http://www.baeldung.com/ec2-java)
 - [http://www.baeldung.com/aws-s3-multipart-upload](https://github.com/eugenp/tutorials/tree/master/aws)
+- [Multipart Uploads in Amazon S3 with Java](http://www.baeldung.com/aws-s3-multipart-upload)
+- [Integration Testing with a Local DynamoDB Instance](http://www.baeldung.com/dynamodb-local-integration-tests)
+- [Using the JetS3t Java Client With Amazon S3](http://www.baeldung.com/jets3t-amazon-s3)
+- [Managing Amazon SQS Queues in Java](http://www.baeldung.com/aws-queues-java)
 

cas/cas-secured-app/README.md

@@ -1,2 +1,3 @@
 ## Relevant articles:
 - [CAS SSO With Spring Security](http://www.baeldung.com/spring-security-cas-sso)
+- [Code Analysis with SonarQube](http://www.baeldung.com/sonar-qube)

cdi/pom.xml

@@ -8,16 +8,12 @@
 
     <parent>
         <groupId>com.baeldung</groupId>
-        <artifactId>parent-modules</artifactId>
+        <artifactId>parent-spring</artifactId>
-        <version>1.0.0-SNAPSHOT</version>
+        <version>0.0.1-SNAPSHOT</version>
+        <relativePath>../parent-spring</relativePath>
     </parent>
 
     <dependencies>
-        <dependency>
-            <groupId>org.springframework</groupId>
-            <artifactId>spring-core</artifactId>
-            <version>${spring.version}</version>
-        </dependency>
         <dependency>
             <groupId>org.springframework</groupId>
             <artifactId>spring-context</artifactId>

core-groovy/pom.xml

@@ -28,12 +28,6 @@
             <artifactId>groovy-sql</artifactId>
             <version>${groovy-sql.version}</version>
         </dependency>
-        <dependency>
-            <groupId>org.junit.jupiter</groupId>
-            <artifactId>junit-jupiter-engine</artifactId>
-            <version>${junit.jupiter.version}</version>
-            <scope>test</scope>
-        </dependency>
         <dependency>
             <groupId>org.junit.platform</groupId>
             <artifactId>junit-platform-runner</artifactId>

core-java-10/src/test/java/com/baeldung/java10/Java10FeaturesUnitTest.java

@@ -0,0 +1,61 @@
+package com.baeldung.java10;
+
+import static org.hamcrest.CoreMatchers.is;
+import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertTrue;
+
+import java.util.ArrayList;
+import java.util.List;
+import java.util.stream.Collectors;
+
+import org.junit.Before;
+import org.junit.Test;
+
+public class Java10FeaturesUnitTest {
+
+    private List<Integer> someIntList;
+    
+    @Before
+    public void setup() {
+        someIntList = new ArrayList<>();
+        
+        someIntList.add(1);
+        someIntList.add(2);
+        someIntList.add(3);
+    }
+
+    @Test
+    public void whenVarInitWithString_thenGetStringTypeVar() {
+        var message = "Hello, Java 10";
+        assertTrue(message instanceof String);
+    }
+
+    @Test
+    public void whenVarInitWithAnonymous_thenGetAnonymousType() {
+        var obj = new Object() {};
+        assertFalse(obj.getClass().equals(Object.class));
+    }
+
+    @Test(expected = UnsupportedOperationException.class)
+    public void whenModifyCopyOfList_thenThrowsException() {
+        List<Integer> copyList = List.copyOf(someIntList);
+        copyList.add(4);
+    }
+
+    @Test(expected = UnsupportedOperationException.class)
+    public void whenModifyToUnmodifiableList_thenThrowsException() {
+        List<Integer> evenList = someIntList.stream()
+          .filter(i -> i % 2 == 0)
+          .collect(Collectors.toUnmodifiableList());
+        evenList.add(4);
+    }
+
+    @Test
+    public void whenListContainsInteger_OrElseThrowReturnsInteger() {
+        Integer firstEven = someIntList.stream()
+          .filter(i -> i % 2 == 0)
+          .findFirst()
+          .orElseThrow();
+        is(firstEven).equals(Integer.valueOf(2));
+    }
+}

core-java-8/README.md

@@ -44,3 +44,10 @@
 - [Java 8 StringJoiner](http://www.baeldung.com/java-string-joiner)
 - [Introduction to Spliterator in Java](http://www.baeldung.com/java-spliterator)
 - [Java 8 Math New Methods](http://www.baeldung.com/java-8-math)
+- [Overview of Java Built-in Annotations](http://www.baeldung.com/java-default-annotations)
+- [Finding Min/Max in an Array with Java](http://www.baeldung.com/java-array-min-max)
+- [Internationalization and Localization in Java 8](http://www.baeldung.com/java-8-localization)
+- [Filtering Kotlin Collections](http://www.baeldung.com/kotlin-filter-collection)
+- [How to Find an Element in a List with Java](http://www.baeldung.com/find-list-element-java)
+- [Measure Elapsed Time in Java](http://www.baeldung.com/java-measure-elapsed-time)
+

core-java-8/pom.xml

@@ -9,17 +9,12 @@
 
     <parent>
         <groupId>com.baeldung</groupId>
-        <artifactId>parent-modules</artifactId>
+        <artifactId>parent-java</artifactId>
-        <version>1.0.0-SNAPSHOT</version>
+    	<version>0.0.1-SNAPSHOT</version>
+    	<relativePath>../parent-java</relativePath>
     </parent>
 
     <dependencies>
-        <!-- utils -->
-        <dependency>
-            <groupId>com.google.guava</groupId>
-            <artifactId>guava</artifactId>
-            <version>${guava.version}</version>
-        </dependency>
         <dependency>
             <groupId>org.apache.commons</groupId>
             <artifactId>commons-collections4</artifactId>

core-java-9/README.md

@@ -23,3 +23,4 @@
 - [Exploring the New HTTP Client in Java 9](http://www.baeldung.com/java-9-http-client)
 - [Method Handles in Java](http://www.baeldung.com/java-method-handles)
 - [Introduction to Chronicle Queue](http://www.baeldung.com/java-chronicle-queue)
+- [A Guide to Java 9 Modularity](http://www.baeldung.com/java-9-modularity)

core-java-collections/pom.xml

@@ -8,10 +8,11 @@
 	<name>core-java-collections</name>
 
 	<parent>
-		<groupId>com.baeldung</groupId>
+        <groupId>com.baeldung</groupId>
-		<artifactId>parent-modules</artifactId>
+        <artifactId>parent-java</artifactId>
-		<version>1.0.0-SNAPSHOT</version>
+    	<version>0.0.1-SNAPSHOT</version>
-	</parent>
+    	<relativePath>../parent-java</relativePath>
+    </parent>
 
 	<dependencies>
 		<dependency>
@@ -25,11 +26,6 @@
 			<artifactId>collections-generic</artifactId>
 			<version>${collections-generic.version}</version>
 		</dependency>
-		<dependency>
-			<groupId>com.google.guava</groupId>
-			<artifactId>guava</artifactId>
-			<version>${guava.version}</version>
-		</dependency>
 		<dependency>
 			<groupId>org.apache.commons</groupId>
 			<artifactId>commons-collections4</artifactId>
@@ -55,7 +51,6 @@
 	</dependencies>
 
 	<properties>
-		<guava.version>22.0</guava.version>
 		<commons-lang3.version>3.5</commons-lang3.version>
 		<commons-collections4.version>4.1</commons-collections4.version>
 		<collections-generic.version>4.01</collections-generic.version>

core-java-concurrency/pom.xml

@@ -9,17 +9,12 @@
 
     <parent>
         <groupId>com.baeldung</groupId>
-        <artifactId>parent-modules</artifactId>
+        <artifactId>parent-java</artifactId>
-        <version>1.0.0-SNAPSHOT</version>
+    	<version>0.0.1-SNAPSHOT</version>
+    	<relativePath>../parent-java</relativePath>
     </parent>
 
     <dependencies>
-        <!-- utils -->
-        <dependency>
-            <groupId>com.google.guava</groupId>
-            <artifactId>guava</artifactId>
-            <version>${guava.version}</version>
-        </dependency>
         <dependency>
             <groupId>org.apache.commons</groupId>
             <artifactId>commons-collections4</artifactId>

core-java-io/README.md

@@ -25,3 +25,5 @@
 - [Zipping and Unzipping in Java](http://www.baeldung.com/java-compress-and-uncompress)
 - [Java NIO2 Path API](http://www.baeldung.com/java-nio-2-path)
 - [A Guide to WatchService in Java NIO2](http://www.baeldung.com/java-nio2-watchservice)
+- [Guide to Java NIO2 Asynchronous Channel APIs](http://www.baeldung.com/java-nio-2-async-channels)
+- [A Guide to NIO2 Asynchronous Socket Channel](http://www.baeldung.com/java-nio2-async-socket-channel)

core-java-io/pom.xml

@@ -9,8 +9,9 @@
 
     <parent>
         <groupId>com.baeldung</groupId>
-        <artifactId>parent-modules</artifactId>
+        <artifactId>parent-java</artifactId>
-        <version>1.0.0-SNAPSHOT</version>
+    	<version>0.0.1-SNAPSHOT</version>
+    	<relativePath>../parent-java</relativePath>
     </parent>
 
     <dependencies>
@@ -20,11 +21,6 @@
             <artifactId>collections-generic</artifactId>
             <version>${collections-generic.version}</version>
         </dependency>
-        <dependency>
-            <groupId>com.google.guava</groupId>
-            <artifactId>guava</artifactId>
-            <version>${guava.version}</version>
-        </dependency>
         <dependency>
             <groupId>org.apache.commons</groupId>
             <artifactId>commons-collections4</artifactId>

core-java-sun/pom.xml

@@ -8,8 +8,9 @@
 
     <parent>
         <groupId>com.baeldung</groupId>
-        <artifactId>parent-modules</artifactId>
+        <artifactId>parent-java</artifactId>
-        <version>1.0.0-SNAPSHOT</version>
+    	<version>0.0.1-SNAPSHOT</version>
+    	<relativePath>../parent-java</relativePath>
     </parent>
 
     <dependencies>
@@ -19,11 +20,6 @@
             <artifactId>collections-generic</artifactId>
             <version>${collections-generic.version}</version>
         </dependency>
-        <dependency>
-            <groupId>com.google.guava</groupId>
-            <artifactId>guava</artifactId>
-            <version>${guava.version}</version>
-        </dependency>
         <dependency>
             <groupId>org.apache.commons</groupId>
             <artifactId>commons-collections4</artifactId>

core-java/README.md

@@ -116,7 +116,7 @@
 - [Comparing Strings in Java](http://www.baeldung.com/java-compare-strings)
 - [Guide to Inheritance in Java](http://www.baeldung.com/java-inheritance)
 - [Guide to Externalizable Interface in Java](http://www.baeldung.com/java-externalizable)
-- [The Observer Pattern in Java](https://github.com/eugenp/tutorials/tree/master/core-java)
+- [The Observer Pattern in Java](http://www.baeldung.com/java-observer-pattern)
 - [Flyweight Pattern in Java](http://www.baeldung.com/java-flyweight)
 - [Object Type Casting in Java](http://www.baeldung.com/java-type-casting)
 - [A Practical Guide to DecimalFormat](http://www.baeldung.com/java-decimalformat)
@@ -127,4 +127,23 @@
 - [Inheritance and Composition (Is-a vs Has-a relationship) in Java](http://www.baeldung.com/java-inheritance-composition)
 - [Finding Max/Min of a List or Collection](http://www.baeldung.com/java-collection-min-max)
 - [The "final" Keyword in Java](http://www.baeldung.com/java-final)
+- [What is the serialVersionUID?](http://www.baeldung.com/java-serial-version-uid)
+- [A Guide To UDP In Java](http://www.baeldung.com/udp-in-java)
+- [A Guide to the Java LinkedList](http://www.baeldung.com/java-linkedlist)
+- [A Guide to Java Enums](http://www.baeldung.com/a-guide-to-java-enums)
+- [A Guide to the ResourceBundle](http://www.baeldung.com/java-resourcebundle)
+- [Quick Guide to java.lang.System](http://www.baeldung.com/java-lang-system)
+- [Class Loaders in Java](http://www.baeldung.com/java-classloaders)
+- [Find Sum and Average in a Java Array](http://www.baeldung.com/java-array-sum-average)
+- [Java List UnsupportedOperationException](http://www.baeldung.com/java-list-unsupported-operation-exception)
 - [Service Locator Pattern](http://www.baeldung.com/java-service-locator-pattern)
+- [Type Erasure in Java Explained](http://www.baeldung.com/java-type-erasure)
+- [BigDecimal and BigInteger in Java](http://www.baeldung.com/java-bigdecimal-biginteger)
+- [Display All Time Zones With GMT And UTC in Java](http://www.baeldung.com/java-time-zones)
+- [Join and Split Arrays and Collections in Java](http://www.baeldung.com/java-join-and-split)
+- [Check If Two Lists are Equal in Java](http://www.baeldung.com/java-test-a-list-for-ordinality-and-equality)
+- [Sending Emails with Java](http://www.baeldung.com/java-email)
+- [Introduction to SSL in Java](http://www.baeldung.com/java-ssl)
+- [Java KeyStore API](http://www.baeldung.com/java-keystore)
+- [Double-Checked Locking with Singleton](http://www.baeldung.com/java-singleton-double-checked-locking)
+- [Guide to Java Clock Class](http://www.baeldung.com/java-clock)

core-java/pom.xml

@@ -9,17 +9,12 @@
 
     <parent>
         <groupId>com.baeldung</groupId>
-        <artifactId>parent-modules</artifactId>
+        <artifactId>parent-java</artifactId>
-        <version>1.0.0-SNAPSHOT</version>
+    	<version>0.0.1-SNAPSHOT</version>
+    	<relativePath>../parent-java</relativePath>
     </parent>
 
     <dependencies>
-        <!-- utils -->
-        <dependency>
-            <groupId>com.google.guava</groupId>
-            <artifactId>guava</artifactId>
-            <version>${guava.version}</version>
-        </dependency>
         <dependency>
             <groupId>commons-io</groupId>
             <artifactId>commons-io</artifactId>
@@ -438,7 +433,6 @@
         <log4j.version>1.2.17</log4j.version>
 
         <!-- util -->
-        <guava.version>22.0</guava.version>
         <commons-lang3.version>3.5</commons-lang3.version>
         <bouncycastle.version>1.55</bouncycastle.version>
         <commons-codec.version>1.10</commons-codec.version>

core-java/src/main/java/com/baeldung/designpatterns/creational/abstractfactory/Color.java

@@ -1,5 +0,0 @@
-package com.baeldung.designpatterns.creational.abstractfactory;
-
-public interface Color {
-    String getColor();
-}

core-java/src/main/java/com/baeldung/designpatterns/creational/factory/Polygon.java

@@ -1,5 +0,0 @@
-package com.baeldung.designpatterns.creational.factory;
-
-public interface Polygon {
-    String getType();
-}

core-java/src/main/java/com/baeldung/numberofdigits/NumberOfDigitsDriver.java

@@ -1,10 +1,12 @@
 package com.baeldung.numberofdigits;
 
-import static com.baeldung.designpatterns.util.LogerUtil.LOG;
+import org.apache.log4j.Logger;
 
 public class NumberOfDigitsDriver {
     private static NumberOfDigits numberOfDigits;
     
+    private static Logger LOG = Logger.getLogger(NumberOfDigitsDriver.class);
+    
     static {
         numberOfDigits = new NumberOfDigits();
     }

core-java/src/main/java/com/baeldung/stringisnumeric/Benchmarking.java

@@ -0,0 +1,75 @@
+package com.baeldung.stringisnumeric;
+
+import java.util.concurrent.TimeUnit;
+
+import org.openjdk.jmh.annotations.Benchmark;
+import org.openjdk.jmh.annotations.BenchmarkMode;
+import org.openjdk.jmh.annotations.Mode;
+import org.openjdk.jmh.annotations.OutputTimeUnit;
+import org.openjdk.jmh.annotations.Scope;
+import org.openjdk.jmh.annotations.State;
+import org.openjdk.jmh.runner.Runner;
+import org.openjdk.jmh.runner.RunnerException;
+import org.openjdk.jmh.runner.options.Options;
+import org.openjdk.jmh.runner.options.OptionsBuilder;
+
+
+public class Benchmarking {
+    public static void main(String[] args) throws RunnerException {
+        Options opt = new OptionsBuilder()
+                .include(Benchmarking.class.getSimpleName())
+                .forks(1)
+                .build();
+
+        new Runner(opt).run();
+    }
+
+    @State(Scope.Thread)
+    public static class ExecutionPlan {
+        public String number = Integer.toString(Integer.MAX_VALUE);
+        public boolean isNumber = false;
+        public IsNumeric isNumeric= new IsNumeric();
+    }
+    
+    @Benchmark 
+    @BenchmarkMode(Mode.AverageTime)
+    @OutputTimeUnit(TimeUnit.NANOSECONDS)
+    public void usingCoreJava(ExecutionPlan plan) {
+        plan.isNumber = plan.isNumeric.usingCoreJava(plan.number);
+    }
+    
+    @Benchmark 
+    @BenchmarkMode(Mode.AverageTime)
+    @OutputTimeUnit(TimeUnit.NANOSECONDS)
+    public void usingRegularExpressions(ExecutionPlan plan) {
+        plan.isNumber = plan.isNumeric.usingRegularExpressions(plan.number);
+    }
+    
+    @Benchmark 
+    @BenchmarkMode(Mode.AverageTime)
+    @OutputTimeUnit(TimeUnit.NANOSECONDS)
+    public void usingNumberUtils_isCreatable(ExecutionPlan plan) {
+        plan.isNumber = plan.isNumeric.usingNumberUtils_isCreatable(plan.number);
+    }
+    
+    @Benchmark 
+    @BenchmarkMode(Mode.AverageTime)
+    @OutputTimeUnit(TimeUnit.NANOSECONDS)
+    public void usingNumberUtils_isParsable(ExecutionPlan plan) {
+        plan.isNumber = plan.isNumeric.usingNumberUtils_isParsable(plan.number);
+    }
+    
+    @Benchmark 
+    @BenchmarkMode(Mode.AverageTime)
+    @OutputTimeUnit(TimeUnit.NANOSECONDS)
+    public void usingStringUtils_isNumeric(ExecutionPlan plan) {
+        plan.isNumber = plan.isNumeric.usingStringUtils_isNumeric(plan.number);
+    }
+    
+    @Benchmark 
+    @BenchmarkMode(Mode.AverageTime)
+    @OutputTimeUnit(TimeUnit.NANOSECONDS)
+    public void usingStringUtils_isNumericSpace(ExecutionPlan plan) {
+        plan.isNumber = plan.isNumeric.usingStringUtils_isNumericSpace(plan.number);
+    }
+}

core-java/src/main/java/com/baeldung/stringisnumeric/IsNumeric.java

@@ -0,0 +1,35 @@
+package com.baeldung.stringisnumeric;
+
+import org.apache.commons.lang3.StringUtils;
+import org.apache.commons.lang3.math.NumberUtils;
+
+public class IsNumeric {
+    public boolean usingCoreJava(String strNum) {
+        try {
+            double d = Double.parseDouble(strNum);
+        } catch (NumberFormatException | NullPointerException nfe) {
+            return false;
+        }
+        return true;
+    }
+    
+    public boolean usingRegularExpressions(String strNum) {
+        return strNum.matches("-?\\d+(\\.\\d+)?");
+    }
+    
+    public boolean usingNumberUtils_isCreatable(String strNum) {
+        return NumberUtils.isCreatable(strNum);
+    }
+    
+    public boolean usingNumberUtils_isParsable(String strNum) {
+        return NumberUtils.isParsable(strNum);
+    }
+    
+    public boolean usingStringUtils_isNumeric(String strNum) {
+        return StringUtils.isNumeric(strNum);
+    }
+    
+    public boolean usingStringUtils_isNumericSpace(String strNum) {
+        return StringUtils.isNumericSpace(strNum);
+    }
+}

core-java/src/main/java/com/baeldung/stringisnumeric/IsNumericDriver.java

@@ -0,0 +1,34 @@
+package com.baeldung.stringisnumeric;
+
+import org.apache.log4j.Logger;
+
+public class IsNumericDriver {
+    private static IsNumeric isNumeric;
+    private static Logger LOG = Logger.getLogger(IsNumericDriver.class);
+    static {
+        isNumeric =new IsNumeric();
+        
+    }
+    
+    public static void main(String[] args) {
+        LOG.info("Testing all methods...");
+        
+        boolean res = isNumeric.usingCoreJava("1001");
+        LOG.info("Using Core Java : " + res);
+        
+        res = isNumeric.usingRegularExpressions("1001");
+        LOG.info("Using Regular Expressions : " + res);
+        
+        res =isNumeric.usingNumberUtils_isCreatable("1001");
+        LOG.info("Using NumberUtils.isCreatable : " + res);
+        
+        res =isNumeric.usingNumberUtils_isParsable("1001");
+        LOG.info("Using NumberUtils.isParsable : " + res);
+        
+        res =isNumeric.usingStringUtils_isNumeric("1001");
+        LOG.info("Using StringUtils.isNumeric : " + res);
+        
+        res =isNumeric.usingStringUtils_isNumericSpace("1001");
+        LOG.info("Using StringUtils.isNumericSpace : " + res);
+    }
+}

core-java/src/test/java/com/baeldung/stringisnumeric/CoreJavaIsNumericUnitTest.java

@@ -0,0 +1,31 @@
+package com.baeldung.stringisnumeric;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+import org.junit.Test;
+
+public class CoreJavaIsNumericUnitTest {
+    public static boolean isNumeric(String strNum) {
+        try {
+            double d = Double.parseDouble(strNum);
+        } catch (NumberFormatException | NullPointerException nfe) {
+            return false;
+        }
+        return true;
+    }
+    
+    @Test
+    public void whenUsingCoreJava_thenTrue() {
+        // Valid Numbers
+        assertThat(isNumeric("22")).isTrue();
+        assertThat(isNumeric("5.05")).isTrue();
+        assertThat(isNumeric("-200")).isTrue(); 
+        assertThat(isNumeric("10.0d")).isTrue();
+        assertThat(isNumeric("   22   ")).isTrue();
+         
+        // Invalid Numbers
+        assertThat(isNumeric(null)).isFalse();
+        assertThat(isNumeric("")).isFalse();
+        assertThat(isNumeric("abc")).isFalse();
+    }
+}

core-java/src/test/java/com/baeldung/stringisnumeric/NumberUtilsIsCreatableUnitTest.java

@@ -0,0 +1,28 @@
+package com.baeldung.stringisnumeric;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+import org.apache.commons.lang3.math.NumberUtils;
+import org.junit.Test;
+
+public class NumberUtilsIsCreatableUnitTest {
+    @Test
+    public void givenApacheCommons_whenUsingIsParsable_thenTrue() {
+        // Valid Numbers
+        assertThat(NumberUtils.isCreatable("22")).isTrue();
+        assertThat(NumberUtils.isCreatable("5.05")).isTrue();
+        assertThat(NumberUtils.isCreatable("-200")).isTrue();
+        assertThat(NumberUtils.isCreatable("10.0d")).isTrue();
+        assertThat(NumberUtils.isCreatable("1000L")).isTrue();
+        assertThat(NumberUtils.isCreatable("0xFF")).isTrue();
+        assertThat(NumberUtils.isCreatable("07")).isTrue();
+        assertThat(NumberUtils.isCreatable("2.99e+8")).isTrue();
+         
+        // Invalid Numbers
+        assertThat(NumberUtils.isCreatable(null)).isFalse();
+        assertThat(NumberUtils.isCreatable("")).isFalse();
+        assertThat(NumberUtils.isCreatable("abc")).isFalse();
+        assertThat(NumberUtils.isCreatable(" 22 ")).isFalse();
+        assertThat(NumberUtils.isCreatable("09")).isFalse();
+    }
+}

core-java/src/test/java/com/baeldung/stringisnumeric/NumberUtilsIsParsableUnitTest.java

@@ -0,0 +1,26 @@
+package com.baeldung.stringisnumeric;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+import org.apache.commons.lang3.math.NumberUtils;
+import org.junit.Test;
+
+public class NumberUtilsIsParsableUnitTest {
+    @Test
+    public void givenApacheCommons_whenUsingIsParsable_thenTrue() {
+        // Valid Numbers
+        assertThat(NumberUtils.isParsable("22")).isTrue();
+        assertThat(NumberUtils.isParsable("-23")).isTrue();
+        assertThat(NumberUtils.isParsable("2.2")).isTrue();
+        assertThat(NumberUtils.isParsable("09")).isTrue();
+        
+        // Invalid Numbers
+        assertThat(NumberUtils.isParsable(null)).isFalse();
+        assertThat(NumberUtils.isParsable("")).isFalse();
+        assertThat(NumberUtils.isParsable("6.2f")).isFalse();
+        assertThat(NumberUtils.isParsable("9.8d")).isFalse();
+        assertThat(NumberUtils.isParsable("22L")).isFalse();
+        assertThat(NumberUtils.isParsable("0xFF")).isFalse();
+        assertThat(NumberUtils.isParsable("2.99e+8")).isFalse();
+    }
+}

core-java/src/test/java/com/baeldung/stringisnumeric/RegularExpressionsUnitTest.java

@@ -0,0 +1,22 @@
+package com.baeldung.stringisnumeric;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+import org.junit.Test;
+
+public class RegularExpressionsUnitTest {
+    public static boolean isNumeric(String strNum) {
+        return strNum.matches("-?\\d+(\\.\\d+)?");
+    }
+    
+    @Test
+    public void whenUsingRegularExpressions_thenTrue() {
+        // Valid Numbers
+        assertThat(isNumeric("22")).isTrue();
+        assertThat(isNumeric("5.05")).isTrue();
+        assertThat(isNumeric("-200")).isTrue();
+         
+        // Invalid Numbers
+        assertThat(isNumeric("abc")).isFalse();
+    }
+}

core-java/src/test/java/com/baeldung/stringisnumeric/StringUtilsIsNumericSpaceUnitTest.java

@@ -0,0 +1,23 @@
+package com.baeldung.stringisnumeric;
+
+import org.apache.commons.lang3.StringUtils;
+import org.junit.Test;
+import static org.assertj.core.api.Assertions.assertThat;
+
+public class StringUtilsIsNumericSpaceUnitTest {
+    @Test
+    public void givenApacheCommons_whenUsingIsNumericSpace_thenTrue() {
+        // Valid Numbers
+        assertThat(StringUtils.isNumericSpace("123")).isTrue();
+        assertThat(StringUtils.isNumericSpace("١٢٣")).isTrue();
+        assertThat(StringUtils.isNumericSpace("")).isTrue();
+        assertThat(StringUtils.isNumericSpace("  ")).isTrue();
+        assertThat(StringUtils.isNumericSpace("12 3")).isTrue();
+         
+        // Invalid Numbers
+        assertThat(StringUtils.isNumericSpace(null)).isFalse();
+        assertThat(StringUtils.isNumericSpace("ab2c")).isFalse();
+        assertThat(StringUtils.isNumericSpace("12.3")).isFalse();
+        assertThat(StringUtils.isNumericSpace("-123")).isFalse();
+    }
+}

core-java/src/test/java/com/baeldung/stringisnumeric/StringUtilsIsNumericUnitTest.java

@@ -0,0 +1,24 @@
+package com.baeldung.stringisnumeric;
+
+import org.apache.commons.lang3.StringUtils;
+import org.junit.Test;
+import static org.assertj.core.api.Assertions.assertThat;
+
+public class StringUtilsIsNumericUnitTest {
+    @Test
+    public void givenApacheCommons_whenUsingIsNumeric_thenTrue() {
+        // Valid Numbers
+        assertThat(StringUtils.isNumeric("123")).isTrue();
+        assertThat(StringUtils.isNumeric("١٢٣")).isTrue();
+        assertThat(StringUtils.isNumeric("१२३")).isTrue();
+         
+        // Invalid Numbers
+        assertThat(StringUtils.isNumeric(null)).isFalse();
+        assertThat(StringUtils.isNumeric("")).isFalse();
+        assertThat(StringUtils.isNumeric("  ")).isFalse();
+        assertThat(StringUtils.isNumeric("12 3")).isFalse();
+        assertThat(StringUtils.isNumeric("ab2c")).isFalse();
+        assertThat(StringUtils.isNumeric("12.3")).isFalse();
+        assertThat(StringUtils.isNumeric("-123")).isFalse();
+    }
+}

core-kotlin/README.md

@@ -25,3 +25,4 @@
 - [Objects in Kotlin](http://www.baeldung.com/kotlin-objects)
 - [Reading from a File in Kotlin](http://www.baeldung.com/kotlin-read-file)
 - [Guide to Kotlin @JvmField](http://www.baeldung.com/kotlin-jvm-field-annotation)
+- [Filtering Kotlin Collections](http://www.baeldung.com/kotlin-filter-collection)

core-kotlin/pom.xml

@@ -25,12 +25,6 @@
             <artifactId>commons-math3</artifactId>
             <version>${commons-math3.version}</version>
         </dependency>
-        <dependency>
-            <groupId>org.junit.jupiter</groupId>
-            <artifactId>junit-jupiter-engine</artifactId>
-            <version>${junit.jupiter.version}</version>
-            <scope>test</scope>
-        </dependency>
         <dependency>
             <groupId>org.junit.platform</groupId>
             <artifactId>junit-platform-runner</artifactId>
@@ -69,6 +63,24 @@
             <artifactId>kotlinx-coroutines-core</artifactId>
             <version>${kotlinx.version}</version>
         </dependency>
+        <dependency>
+            <groupId>org.jetbrains.spek</groupId>
+            <artifactId>spek-api</artifactId>
+            <version>1.1.5</version>
+            <scope>test</scope>
+        </dependency>
+        <dependency>
+            <groupId>org.jetbrains.spek</groupId>
+            <artifactId>spek-subject-extension</artifactId>
+            <version>1.1.5</version>
+            <scope>test</scope>
+        </dependency>
+        <dependency>
+            <groupId>org.jetbrains.spek</groupId>
+            <artifactId>spek-junit-platform-engine</artifactId>
+            <version>1.1.5</version>
+            <scope>test</scope>
+        </dependency>
         <dependency>
             <groupId>com.nhaarman</groupId>
             <artifactId>mockito-kotlin</artifactId>

core-kotlin/src/main/kotlin/com/baeldung/filesystem/FileWriter.kt

@@ -0,0 +1,19 @@
+package com.baeldung.filesystem
+
+import java.io.File
+
+class FileWriter {
+
+    fun writeFileUsingPrintWriter(fileName: String, fileContent: String) =
+            File(fileName).printWriter().use { out -> out.print(fileContent) }
+
+    fun writeFileUsingBufferedWriter(fileName: String, fileContent: String) =
+            File(fileName).bufferedWriter().use { out -> out.write(fileContent) }
+
+    fun writeFileDirectly(fileName: String, fileContent: String) =
+            File(fileName).writeText(fileContent)
+
+    fun writeFileDirectlyAsBytes(fileName: String, fileContent: String) =
+            File(fileName).writeBytes(fileContent.toByteArray())
+
+}

core-kotlin/src/test/kotlin/com/baeldung/filesystem/FileWriterTest.kt

@@ -0,0 +1,43 @@
+package com.baeldung.filesystem
+
+import org.junit.jupiter.api.Test
+import java.io.File
+import kotlin.test.assertEquals
+
+internal class FileWriterTest {
+
+    private val fileName = "src/test/resources/Kotlin.out"
+
+    private val fileContent = "Kotlin\nConcise, Safe, Interoperable, Tool-friendly"
+
+    private val fileWriter = FileWriter()
+
+    @Test
+    fun whenWrittenWithPrintWriter_thenCorrect() {
+        fileWriter.writeFileUsingPrintWriter(fileName, fileContent)
+
+        assertEquals(fileContent, File(fileName).readText())
+    }
+
+    @Test
+    fun whenWrittenWithBufferedWriter_thenCorrect() {
+        fileWriter.writeFileUsingBufferedWriter(fileName, fileContent)
+
+        assertEquals(fileContent, File(fileName).readText())
+    }
+
+    @Test
+    fun whenWrittenDirectly_thenCorrect() {
+        fileWriter.writeFileDirectly(fileName, fileContent)
+
+        assertEquals(fileContent, File(fileName).readText())
+    }
+
+    @Test
+    fun whenWrittenDirectlyAsBytes_thenCorrect() {
+        fileWriter.writeFileDirectlyAsBytes(fileName, fileContent)
+
+        assertEquals(fileContent, File(fileName).readText())
+    }
+
+}

core-kotlin/src/test/kotlin/com/baeldung/kotlin/spek/CalculatorSubjectTest5.kt

@@ -0,0 +1,19 @@
+package com.baeldung.kotlin.spek
+
+import com.baeldung.kotlin.junit5.Calculator
+import org.jetbrains.spek.api.dsl.describe
+import org.jetbrains.spek.api.dsl.it
+import org.jetbrains.spek.subject.SubjectSpek
+import org.junit.jupiter.api.Assertions.assertEquals
+
+class CalculatorSubjectTest5 : SubjectSpek<Calculator>({
+    subject { Calculator() }
+    describe("A calculator") {
+        describe("Addition") {
+            val result = subject.add(3, 5)
+            it("Produces the correct answer") {
+                assertEquals(8, result)
+            }
+        }
+    }
+})

core-kotlin/src/test/kotlin/com/baeldung/kotlin/spek/CalculatorTest5.kt

@@ -0,0 +1,32 @@
+package com.baeldung.kotlin.spek
+
+import com.baeldung.kotlin.junit5.Calculator
+import org.jetbrains.spek.api.Spek
+import org.jetbrains.spek.api.dsl.describe
+import org.jetbrains.spek.api.dsl.given
+import org.jetbrains.spek.api.dsl.it
+import org.jetbrains.spek.api.dsl.on
+import org.junit.jupiter.api.Assertions.assertEquals
+
+class CalculatorTest5 : Spek({
+    given("A calculator") {
+        val calculator = Calculator()
+        on("Adding 3 and 5") {
+            val result = calculator.add(3, 5)
+            it("Produces 8") {
+                assertEquals(8, result)
+            }
+        }
+    }
+
+    describe("A calculator") {
+        val calculator = Calculator()
+        describe("Addition") {
+            val result = calculator.add(3, 5)
+            it("Produces the correct answer") {
+                assertEquals(8, result)
+            }
+        }
+    }
+
+})

core-kotlin/src/test/kotlin/com/baeldung/kotlin/spek/DataDrivenTest5.kt

@@ -0,0 +1,21 @@
+package com.baeldung.kotlin.spek
+
+import org.jetbrains.spek.api.Spek
+import org.jetbrains.spek.api.dsl.describe
+import org.jetbrains.spek.api.dsl.it
+import org.junit.jupiter.api.Assertions
+
+class DataDrivenTest5 : Spek({
+    describe("A data driven test") {
+        mapOf(
+                "hello" to "HELLO",
+                "world" to "WORLD"
+        ).forEach { input, expected ->
+            describe("Capitalising $input") {
+                it("Correctly returns $expected") {
+                    Assertions.assertEquals(expected, input.toUpperCase())
+                }
+            }
+        }
+    }
+})

core-kotlin/src/test/kotlin/com/baeldung/kotlin/spek/GroupTest5.kt

@@ -0,0 +1,62 @@
+package com.baeldung.kotlin.spek
+
+import org.jetbrains.spek.api.Spek
+import org.jetbrains.spek.api.dsl.describe
+import org.jetbrains.spek.api.dsl.it
+
+class GroupTest5 : Spek({
+    describe("Outer group") {
+        beforeEachTest {
+            System.out.println("BeforeEachTest 0")
+        }
+        beforeGroup {
+            System.out.println("BeforeGroup 0")
+        }
+        afterEachTest {
+            System.out.println("AfterEachTest 0")
+        }
+        afterGroup {
+            System.out.println("AfterGroup 0")
+        }
+        describe("Inner group 1") {
+            beforeEachTest {
+                System.out.println("BeforeEachTest 1")
+            }
+            beforeGroup {
+                System.out.println("BeforeGroup 1")
+            }
+            afterEachTest {
+                System.out.println("AfterEachTest 1")
+            }
+            afterGroup {
+                System.out.println("AfterGroup 1")
+            }
+            it("Test 1") {
+                System.out.println("Test 1")
+            }
+            it("Test 2") {
+                System.out.println("Test 2")
+            }
+        }
+        describe("Inner group 2") {
+            beforeEachTest {
+                System.out.println("BeforeEachTest 2")
+            }
+            beforeGroup {
+                System.out.println("BeforeGroup 2")
+            }
+            afterEachTest {
+                System.out.println("AfterEachTest 2")
+            }
+            afterGroup {
+                System.out.println("AfterGroup 2")
+            }
+            it("Test 3") {
+                System.out.println("Test 3")
+            }
+            it("Test 4") {
+                System.out.println("Test 4")
+            }
+        }
+    }
+})

drools/pom.xml

@@ -5,10 +5,11 @@
     <artifactId>drools</artifactId>
 
     <parent>
-        <groupId>com.baeldung</groupId>
+		<groupId>com.baeldung</groupId>
-        <artifactId>parent-modules</artifactId>
+		<artifactId>parent-spring</artifactId>
-        <version>1.0.0-SNAPSHOT</version>
+		<version>0.0.1-SNAPSHOT</version>
-    </parent>
+		<relativePath>../parent-spring</relativePath>
+	</parent>
 
     <dependencies>
         <dependency>
@@ -47,18 +48,13 @@
             <artifactId>poi-ooxml</artifactId>
             <version>${apache-poi-version}</version>
         </dependency>
-        <dependency>
-            <groupId>org.springframework</groupId>
-            <artifactId>spring-core</artifactId>
-            <version>${spring-core.version}</version>
-        </dependency>
     </dependencies>
 
     <properties>
         <http-component-version>4.4.6</http-component-version>
         <drools-version>7.4.1.Final</drools-version>
         <apache-poi-version>3.13</apache-poi-version>
-        <spring-core.version>4.3.6.RELEASE</spring-core.version>
+        <spring.version>4.3.6.RELEASE</spring.version>
     </properties>
 
 </project>

ethereumj/README.md

@@ -2,3 +2,4 @@
 
 ### Relevant Articles:
 - [Introduction to EthereumJ](http://www.baeldung.com/ethereumj)
+- [Creating and Deploying Smart Contracts with Solidity](http://www.baeldung.com/smart-contracts-ethereum-solidity)

gson/pom.xml

@@ -8,8 +8,9 @@
 
     <parent>
         <groupId>com.baeldung</groupId>
-        <artifactId>parent-modules</artifactId>
+        <artifactId>parent-java</artifactId>
-        <version>1.0.0-SNAPSHOT</version>
+    	<version>0.0.1-SNAPSHOT</version>
+    	<relativePath>../parent-java</relativePath>
     </parent>
 
     <dependencies>
@@ -19,11 +20,6 @@
             <artifactId>joda-time</artifactId>
             <version>${joda-time.version}</version>
         </dependency>
-        <dependency>
-            <groupId>com.google.guava</groupId>
-            <artifactId>guava</artifactId>
-            <version>${guava.version}</version>
-        </dependency>
         <dependency>
             <groupId>commons-io</groupId>
             <artifactId>commons-io</artifactId>

guava-modules/guava-18/pom.xml

@@ -8,19 +8,11 @@
 
     <parent>
         <groupId>com.baeldung</groupId>
-        <artifactId>parent-modules</artifactId>
+        <artifactId>parent-java</artifactId>
-        <version>1.0.0-SNAPSHOT</version>
+    	<version>0.0.1-SNAPSHOT</version>
-        <relativePath>../../</relativePath>
+    	<relativePath>../../parent-java</relativePath>
     </parent>
 
-    <dependencies>
-        <dependency>
-            <groupId>com.google.guava</groupId>
-            <artifactId>guava</artifactId>
-            <version>${guava.version}</version>
-        </dependency>
-    </dependencies>
-
     <properties>
         <guava.version>18.0</guava.version>
     </properties>

guava-modules/guava-19/pom.xml

@@ -8,19 +8,11 @@
 
     <parent>
         <groupId>com.baeldung</groupId>
-        <artifactId>parent-modules</artifactId>
+        <artifactId>parent-java</artifactId>
-        <version>1.0.0-SNAPSHOT</version>
+    	<version>0.0.1-SNAPSHOT</version>
-        <relativePath>../../</relativePath>
+    	<relativePath>../../parent-java</relativePath>
     </parent>
 
-    <dependencies>
-        <dependency>
-            <groupId>com.google.guava</groupId>
-            <artifactId>guava</artifactId>
-            <version>${guava.version}</version>
-        </dependency>
-    </dependencies>
-
     <properties>
         <guava.version>19.0</guava.version>
     </properties>

guava-modules/guava-21/pom.xml

@@ -7,18 +7,12 @@
 
     <parent>
         <groupId>com.baeldung</groupId>
-        <artifactId>parent-modules</artifactId>
+        <artifactId>parent-java</artifactId>
-        <version>1.0.0-SNAPSHOT</version>
+    	<version>0.0.1-SNAPSHOT</version>
-        <relativePath>../../</relativePath>
+    	<relativePath>../../parent-java</relativePath>
     </parent>
 
     <dependencies>
-        <dependency>
-            <groupId>com.google.guava</groupId>
-            <artifactId>guava</artifactId>
-            <version>${guava.version}</version>
-        </dependency>
-
         <dependency>
             <groupId>org.jooq</groupId>
             <artifactId>jool</artifactId>

guava/pom.xml

@@ -8,17 +8,13 @@
 
     <parent>
         <groupId>com.baeldung</groupId>
-        <artifactId>parent-modules</artifactId>
+        <artifactId>parent-java</artifactId>
-        <version>1.0.0-SNAPSHOT</version>
+    	<version>0.0.1-SNAPSHOT</version>
+    	<relativePath>../parent-java</relativePath>
     </parent>
 
     <dependencies>
         <!-- utils -->
-        <dependency>
-            <groupId>com.google.guava</groupId>
-            <artifactId>guava</artifactId>
-            <version>${guava.version}</version>
-        </dependency>
         <dependency>
             <groupId>org.apache.commons</groupId>
             <artifactId>commons-collections4</artifactId>
@@ -36,6 +32,14 @@
             <version>${assertj.version}</version>
             <scope>test</scope>
         </dependency>
+
+        <!-- https://mvnrepository.com/artifact/org.hamcrest/java-hamcrest -->
+        <dependency>
+            <groupId>org.hamcrest</groupId>
+            <artifactId>java-hamcrest</artifactId>
+            <version>${java-hamcrest.version}</version>
+            <scope>test</scope>
+        </dependency>
     </dependencies>
 
     <build>
@@ -56,6 +60,7 @@
 
         <!-- testing -->
         <assertj.version>3.6.1</assertj.version>
+        <java-hamcrest.version>2.0.0.0</java-hamcrest.version>
     </properties>
 
 </project>

guava/src/test/java/org/baeldung/hamcrest/HamcrestCoreMatchersTest.java

@@ -0,0 +1,259 @@
+package org.baeldung.hamcrest;
+
+
+import com.google.common.collect.Lists;
+import org.junit.Test;
+
+import java.util.List;
+
+import static org.hamcrest.CoreMatchers.*;
+import static org.hamcrest.MatcherAssert.assertThat;
+import static org.hamcrest.core.StringEndsWith.endsWith;
+import static org.hamcrest.core.StringStartsWith.startsWith;
+
+public class HamcrestCoreMatchersTest {
+
+    @Test
+    public void givenTestInput_WhenUsingIsForMatch() {
+
+        // GIVEN
+        String testString = "hamcrest core";
+
+        // ASSERT
+        assertThat(testString, is("hamcrest core"));
+        assertThat(testString, is(equalTo("hamcrest core")));
+    }
+
+    @Test
+    public void givenDifferentStaticTypeTestInput_WhenUsingEqualToObject_ThenCorrect() {
+
+        // GIVEN
+        Object original = 100;
+
+        // ASSERT
+        assertThat(original, equalToObject(100));
+    }
+
+    @Test
+    public void givenTestInput_WhenUsingInstanceOfForClassTypeCheck() {
+
+        assertThat("hamcrest", is(instanceOf(String.class)));
+    }
+
+    @Test
+    public void givenTestInput_WhenUsingIsA_ThenAssertType() {
+
+        assertThat("hamcrest core", isA(String.class));
+    }
+
+    @Test
+    public void givenTestInput_WhenUsingEqualToMatcherForEquality() {
+
+        // GIVEN
+        String actualString = "Hamcrest Core";
+        List<String> actualList = Lists.newArrayList("hamcrest", "core");
+
+        // ASSERT
+        assertThat(actualString, is(equalTo("Hamcrest Core")));
+        assertThat(actualList, is(equalTo(Lists.newArrayList("hamcrest", "core"))));
+    }
+
+    @Test
+    public void givenTestInput_WhenUsingNotForMatch() {
+
+        // GIVEN
+        String testString = "hamcrest";
+
+        // ASSERT
+        assertThat(testString, not("hamcrest core"));
+        assertThat(testString, is(not(equalTo("hamcrest core"))));
+        assertThat(testString, is(not(instanceOf(Integer.class))));
+    }
+
+    @Test
+    public void givenTestInput_WhenUsingNullValueForNullCheck() {
+
+        // GIVEN
+        Integer nullObject = null;
+
+        // ASSERT
+        assertThat(nullObject, is(nullValue()));
+        assertThat(nullObject, is(nullValue(Integer.class)));
+    }
+
+    @Test
+    public void givenTestInput_WhenUsingNotNullValueForNotNullCheck() {
+
+        // GIVEN
+        Integer testNumber = 123;
+
+        // ASSERT
+        assertThat(testNumber, is(notNullValue()));
+        assertThat(testNumber, is(notNullValue(Integer.class)));
+    }
+
+    @Test
+    public void givenString_WhenStartsWith_ThenCorrect() {
+
+        // GIVEN
+        String testString = "hamcrest core";
+
+        // ASSERT
+        assertThat(testString, startsWith("hamcrest"));
+    }
+
+    @Test
+    public void giveString_WhenStartsWithIgnoringCase_ThenCorrect() {
+
+        // GIVEN
+        String testString = "hamcrest core";
+
+        // ASSERT
+        assertThat(testString, startsWithIgnoringCase("HAMCREST"));
+    }
+
+    @Test
+    public void givenString_WhenEndsWith_ThenCorrect() {
+
+        // GIVEN
+        String testString = "hamcrest core";
+
+        // ASSERT
+        assertThat(testString, endsWith("core"));
+    }
+
+    @Test
+    public void givenString_WhenEndsWithIgnoringCase_ThenCorrect() {
+
+        // GIVEN
+        String testString = "hamcrest core";
+
+        // ASSERT
+        assertThat(testString, endsWithIgnoringCase("CORE"));
+    }
+
+    @Test
+    public void givenString_WhenContainsString_ThenCorrect() {
+
+        // GIVEN
+        String testString = "hamcrest core";
+
+        // ASSERT
+        assertThat(testString, containsString("co"));
+    }
+
+    @Test
+    public void givenString_WhenContainsStringIgnoringCase_ThenCorrect() {
+
+
+        // GIVEN
+        String testString = "hamcrest core";
+
+        // ASSERT
+        assertThat(testString, containsStringIgnoringCase("CO"));
+    }
+
+    @Test
+    public void givenTestInput_WhenUsingHasItemInCollection() {
+
+        // GIVEN
+        List<String> list = Lists.newArrayList("java", "spring", "baeldung");
+
+        // ASSERT
+        assertThat(list, hasItem("java"));
+        assertThat(list, hasItem(isA(String.class)));
+    }
+
+
+    @Test
+    public void givenTestInput_WhenUsingHasItemsInCollection() {
+
+        // GIVEN
+        List<String> list = Lists.newArrayList("java", "spring", "baeldung");
+
+        // ASSERT
+        assertThat(list, hasItems("java", "baeldung"));
+        assertThat(list, hasItems(isA(String.class), endsWith("ing")));
+    }
+
+    @Test
+    public void givenTestInput_WhenUsingAnyForClassType() {
+
+        assertThat("hamcrest", is(any(String.class)));
+        assertThat("hamcrest", is(any(Object.class)));
+    }
+
+    @Test
+    public void givenTestInput_WhenUsingAllOfForAllMatchers() {
+
+        // GIVEN
+        String testString = "Hamcrest Core";
+
+        // ASSERT
+        assertThat(testString, allOf(startsWith("Ham"), endsWith("ore"), containsString("Core")));
+    }
+
+    @Test
+    public void givenTestInput_WhenUsingAnyOfForAnyMatcher() {
+
+        // GIVEN
+        String testString = "Hamcrest Core";
+
+        // ASSERT
+        assertThat(testString, anyOf(startsWith("Ham"), containsString("baeldung")));
+    }
+
+    @Test
+    public void givenTestInput_WhenUsingBothForMatcher() {
+
+        // GIVEN
+        String testString = "Hamcrest Core Matchers";
+
+        // ASSERT
+        assertThat(testString, both(startsWith("Ham")).and(containsString("Core")));
+    }
+
+    @Test
+    public void givenTestInput_WhenUsingEitherForMatcher() {
+
+        // GIVEN
+        String testString = "Hamcrest Core Matchers";
+
+        // ASSERT
+        assertThat(testString, either(startsWith("Bael")).or(containsString("Core")));
+    }
+
+
+    @Test
+    public void givenTestInput_WhenUsingEveryItemForMatchInCollection() {
+
+        // GIVEN
+        List<String> testItems = Lists.newArrayList("Common", "Core", "Combinable");
+
+        // ASSERT
+        assertThat(testItems, everyItem(startsWith("Co")));
+    }
+
+    @Test
+    public void givenTwoTestInputs_WhenUsingSameInstanceForMatch() {
+
+        // GIVEN
+        String string1 = "hamcrest";
+        String string2 = string1;
+
+        // ASSERT
+        assertThat(string1, is(sameInstance(string2)));
+    }
+
+    @Test
+    public void givenTwoTestInputs_WhenUsingTheInstanceForMatch() {
+        // GIVEN
+        String string1 = "hamcrest";
+        String string2 = string1;
+
+        // ASSERT
+        assertThat(string1, is(theInstance(string2)));
+    }
+
+}
+

guava/src/test/java/org/baeldung/hamcrest/HamcrestExamplesUnitTest.java

@@ -12,6 +12,7 @@ import static org.hamcrest.Matchers.hasItems;
 import static org.hamcrest.Matchers.hasSize;
 import static org.hamcrest.Matchers.not;
 import static org.junit.Assert.assertThat;
+import static org.hamcrest.Matchers.emptyIterable;
 
 import java.util.Collections;
 import java.util.List;
@@ -58,6 +59,12 @@ public class HamcrestExamplesUnitTest {
         assertThat(collection, empty());
     }
     
+    @Test
+    public final void givenIterableIsEmpty_whenChecking_thenEmpty() {
+        final Iterable<String> collection = Lists.newArrayList();
+        assertThat(collection, emptyIterable());
+    }
+
     @Test
     public final void givenCollectionIsNotEmpty_whenChecking_thenNotEmpty() {
         final List<String> collection = Lists.newArrayList("a");

guava/src/test/java/org/baeldung/hamcrest/README.md

@@ -1,2 +1,3 @@
 ### Relevant Articles:
 - [Testing with Hamcrest](http://www.baeldung.com/java-junit-hamcrest-guide)
+- [Hamcrest File Matchers](http://www.baeldung.com/hamcrest-file-matchers)

guest/junit5-example/pom.xml

@@ -11,11 +11,6 @@
         <relativePath>../../</relativePath>
     </parent>
     <dependencies>
-        <dependency>
-            <groupId>org.junit.jupiter</groupId>
-            <artifactId>junit-jupiter-engine</artifactId>
-            <version>5.0.0-M4</version>
-        </dependency>
         <dependency>
             <groupId>org.junit.jupiter</groupId>
             <artifactId>junit-jupiter-params</artifactId>
@@ -62,4 +57,8 @@
             </plugin>
         </plugins>
     </build>
+    
+    <properties>
+    	
+    </properties>
 </project>

handling-spring-static-resources/pom.xml

@@ -10,8 +10,9 @@
 
     <parent>
         <groupId>com.baeldung</groupId>
-        <artifactId>parent-modules</artifactId>
+        <artifactId>parent-spring</artifactId>
-        <version>1.0.0-SNAPSHOT</version>
+    	<version>0.0.1-SNAPSHOT</version>
+    	<relativePath>../parent-spring</relativePath>
     </parent>
 
     <dependencies>

hibernate5/README.md

@@ -9,3 +9,4 @@
 - [Hibernate Interceptors](http://www.baeldung.com/hibernate-interceptor)
 - [JPA Attribute Converters](http://www.baeldung.com/jpa-attribute-converters)
 - [Mapping LOB Data in Hibernate](http://www.baeldung.com/hibernate-lob)
+- [@Immutable in Hibernate](http://www.baeldung.com/hibernate-immutable)

httpclient/pom.xml

@@ -8,17 +8,13 @@
 
     <parent>
         <groupId>com.baeldung</groupId>
-        <artifactId>parent-modules</artifactId>
+        <artifactId>parent-java</artifactId>
-        <version>1.0.0-SNAPSHOT</version>
+    	<version>0.0.1-SNAPSHOT</version>
+    	<relativePath>../parent-java</relativePath>
     </parent>
 
     <dependencies>
         <!-- utils -->
-        <dependency>
-            <groupId>com.google.guava</groupId>
-            <artifactId>guava</artifactId>
-            <version>${guava.version}</version>
-        </dependency>
         <dependency>
             <groupId>org.apache.commons</groupId>
             <artifactId>commons-lang3</artifactId>

httpclient/src/test/java/org/baeldung/httpclient/sec/HttpClientAuthLiveTest.java

@@ -24,6 +24,7 @@ import org.junit.Test;
 
 import java.io.IOException;
 import java.nio.charset.Charset;
+import java.nio.charset.StandardCharsets;
 
 import static org.hamcrest.Matchers.equalTo;
 import static org.junit.Assert.assertThat;
@@ -89,7 +90,7 @@ public class HttpClientAuthLiveTest {
     public final void givenAuthorizationHeaderIsSetManually_whenExecutingGetRequest_thenSuccess2() throws IOException {
         final HttpGet request = new HttpGet(URL_SECURED_BY_BASIC_AUTHENTICATION);
         final String auth = DEFAULT_USER + ":" + DEFAULT_PASS;
-        final byte[] encodedAuth = Base64.encodeBase64(auth.getBytes(Charset.forName("ISO-8859-1")));
+        final byte[] encodedAuth = Base64.encodeBase64(auth.getBytes(StandardCharsets.ISO_8859_1));
         final String authHeader = "Basic " + new String(encodedAuth);
         request.setHeader(HttpHeaders.AUTHORIZATION, authHeader);
 
@@ -129,7 +130,7 @@ public class HttpClientAuthLiveTest {
 
     private String authorizationHeader(final String username, final String password) {
         final String auth = username + ":" + password;
-        final byte[] encodedAuth = Base64.encodeBase64(auth.getBytes(Charset.forName("ISO-8859-1")));
+        final byte[] encodedAuth = Base64.encodeBase64(auth.getBytes(StandardCharsets.ISO_8859_1));
 
         return "Basic " + new String(encodedAuth);
     }

influxdb/README.md

@@ -1,7 +1,8 @@
 ## Influx SDK Tutorial Project
 
 ### Relevant Article:
-- [Introduction to using InfluxDB with Java](http://www.baeldung.com/using-influxdb-with-java/)
+- [Using InfluxDB with Java](http://www.baeldung.com/java-influxdb)
+
 
 ### Overview
 This Maven project contains the Java code for the article linked above.

jackson/pom.xml

@@ -8,18 +8,13 @@
 
     <parent>
         <groupId>com.baeldung</groupId>
-        <artifactId>parent-modules</artifactId>
+        <artifactId>parent-java</artifactId>
-        <version>1.0.0-SNAPSHOT</version>
+    	<version>0.0.1-SNAPSHOT</version>
+    	<relativePath>../parent-java</relativePath>
     </parent>
 
     <dependencies>
         <!-- utils -->
-        <dependency>
-            <groupId>com.google.guava</groupId>
-            <artifactId>guava</artifactId>
-            <version>${guava.version}</version>
-        </dependency>
-
         <dependency>
             <groupId>commons-io</groupId>
             <artifactId>commons-io</artifactId>

javax-servlets/README.md

@@ -1,3 +1,4 @@
 ### Relevant Articles:
 - [Introduction to Java Servlets](http://www.baeldung.com/intro-to-servlets)
 - [An MVC Example with Servlets and JSP](http://www.baeldung.com/mvc-servlet-jsp)
+- [Handling Cookies and a Session in a Java Servlet](http://www.baeldung.com/java-servlet-cookies-session)

jmh/pom.xml

@@ -10,8 +10,9 @@
 
     <parent>
         <groupId>com.baeldung</groupId>
-        <artifactId>parent-modules</artifactId>
+        <artifactId>parent-java</artifactId>
-        <version>1.0.0-SNAPSHOT</version>
+    	<version>0.0.1-SNAPSHOT</version>
+    	<relativePath>../parent-java</relativePath>
     </parent>
 
     <dependencies>
@@ -25,17 +26,6 @@
             <artifactId>jmh-generator-annprocess</artifactId>
             <version>${openjdk.jmh.version}</version>
         </dependency>
-        <dependency>
-            <groupId>junit</groupId>
-            <artifactId>junit</artifactId>
-            <version>${junit.version}</version>
-            <scope>test</scope>
-        </dependency>
-        <dependency>
-            <groupId>com.google.guava</groupId>
-            <artifactId>guava</artifactId>
-            <version>${guava.version}</version>
-        </dependency>
     </dependencies>
 
     <build>

jsf/README.md

@@ -2,3 +2,4 @@
 - [Introduction to JSF Expression Language 3.0](http://www.baeldung.com/jsf-expression-language-el-3)
 - [Introduction to JSF EL 2](http://www.baeldung.com/intro-to-jsf-expression-language)
 - [JavaServer Faces (JSF) with Spring](http://www.baeldung.com/spring-jsf)
+- [Introduction to Primefaces](http://www.baeldung.com/jsf-primefaces)

json/README.md

@@ -4,6 +4,7 @@
 
 ### Relevant Articles:
 - [Introduction to JSON Schema in Java](http://www.baeldung.com/introduction-to-json-schema-in-java)
-- [A Guide to FastJson](http://www.baeldung.com/????????)
+- [A Guide to FastJson](http://www.baeldung.com/fastjson)
 - [Introduction to JSONForms](http://www.baeldung.com/introduction-to-jsonforms)
 - [Introduction to JsonPath](http://www.baeldung.com/guide-to-jayway-jsonpath)
+- [Introduction to JSON-Java (org.json)](http://www.baeldung.com/java-org-json)

jsonb/pom.xml

@@ -34,12 +34,6 @@
             <artifactId>junit-jupiter-api</artifactId>
             <version>${junit.jupiter.version}</version>
         </dependency>
-        <dependency>
-            <groupId>org.junit.jupiter</groupId>
-            <artifactId>junit-jupiter-engine</artifactId>
-            <version>${junit.jupiter.version}</version>
-            <scope>test</scope>
-        </dependency>
         <dependency>
             <groupId>org.junit.platform</groupId>
             <artifactId>junit-platform-surefire-provider</artifactId>

libraries-data/README.md

@@ -3,5 +3,5 @@
 - [Introduction to ORMLite](http://www.baeldung.com/ormlite)
 - [Introduction To Kryo](http://www.baeldung.com/kryo)
 - [Introduction to KafkaStreams in Java](http://www.baeldung.com/java-kafka-streams)
+- [A Guide to Apache Ignite](http://www.baeldung.com/apache-ignite)
 - [Apache Ignite with Spring Data](http://www.baeldung.com/apache-ignite-spring-data)
-

libraries/README.md

@@ -65,7 +65,7 @@
 - [Creating and Configuring Jetty 9 Server in Java](http://www.baeldung.com/jetty-java-programmatic)
 - [Introduction To OpenCSV](http://www.baeldung.com/opencsv)
 - [Introduction to Akka Actors in Java](http://www.baeldung.com/akka-actors-java)
-- [Asynchronous HTTP with async-http-client in Java](https://github.com/eugenp/tutorials/tree/master/libraries)
+- [Asynchronous HTTP with async-http-client in Java](http://www.baeldung.com/async-http-client)
 - [Introduction to Smooks](http://www.baeldung.com/smooks)
 - [WebSockets with AsyncHttpClient](http://www.baeldung.com/async-http-client-websockets)
 - [A Guide to Infinispan in Java](http://www.baeldung.com/infinispan)
@@ -74,7 +74,16 @@
 - [Introduction to Akka Actors in Java](http://www.baeldung.com/akka-actors-java)
 - [A Guide to Apache Commons Collections CollectionUtils](http://www.baeldung.com/apache-commons-collection-utils)
 - [A Guide to Byte Buddy](http://www.baeldung.com/byte-buddy)
+- [Introduction to jOOL](http://www.baeldung.com/jool)
+- [Consumer Driven Contracts with Pact](http://www.baeldung.com/pact-junit-consumer-driven-contracts)
+- [Apache Commons BeanUtils](http://www.baeldung.com/apache-commons-beanutils)
+- [Apache Commons Collections BidiMap](http://www.baeldung.com/commons-collections-bidi-map)
+- [Introduction to Atlassian Fugue](http://www.baeldung.com/java-fugue)
+- [Publish and Receive Messages with Nats Java Client](http://www.baeldung.com/nats-java-client)
 - [Java Concurrency Utility with JCTools](http://www.baeldung.com/java-concurrency-jc-tools)
+- [Apache Commons Collections MapUtils](http://www.baeldung.com/apache-commons-map-utils)
+- [Testing Netty with EmbeddedChannel](http://www.baeldung.com/testing-netty-embedded-channel)
+
 
 The libraries module contains examples related to small libraries that are relatively easy to use and does not require any separate module of its own.
 

libraries/pom.xml

@@ -680,6 +680,12 @@
             <version>${unirest.version}</version>
         </dependency>
 
+        <!-- javalin -->
+        <dependency>
+            <groupId>io.javalin</groupId>
+            <artifactId>javalin</artifactId>
+            <version>1.6.0</version>
+        </dependency>
         <!-- Atlassian Fugue -->
         <dependency>
             <groupId>io.atlassian.fugue</groupId>

libraries/src/main/java/com/baeldung/javalin/JavalinApp.java

@@ -0,0 +1,16 @@
+package com.baeldung.javalin;
+
+import com.baeldung.javalin.User.UserController;
+import io.javalin.Javalin;
+
+public class JavalinApp {
+    public static void main(String[] args) {
+        Javalin app = Javalin.create()
+                .port(7000)
+                .start();
+
+        app.get("/hello", ctx -> ctx.html("Hello, Javalin!"));
+        app.get("/users", UserController.fetchAllUsernames);
+        app.get("/users/:id", UserController.fetchById);
+    }
+}

libraries/src/main/java/com/baeldung/javalin/User/User.java

@@ -0,0 +1,11 @@
+package com.baeldung.javalin.User;
+
+public class User {
+    public final int id;
+    public final String name;
+
+    public User(int id, String name) {
+        this.id = id;
+        this.name = name;
+    }
+}

libraries/src/main/java/com/baeldung/javalin/User/UserController.java

@@ -0,0 +1,24 @@
+package com.baeldung.javalin.User;
+
+import io.javalin.Handler;
+
+import java.util.Objects;
+
+public class UserController {
+    public static Handler fetchAllUsernames = ctx -> {
+        UserDao dao = UserDao.instance();
+        Iterable<String> allUsers = dao.getAllUsernames();
+        ctx.json(allUsers);
+    };
+
+    public static Handler fetchById = ctx -> {
+        int id = Integer.parseInt(Objects.requireNonNull(ctx.param("id")));
+        UserDao dao = UserDao.instance();
+        User user = dao.getUserById(id);
+        if (user == null) {
+            ctx.html("Not Found");
+        } else {
+            ctx.json(user);
+        }
+    };
+}

libraries/src/main/java/com/baeldung/javalin/User/UserDao.java

@@ -0,0 +1,33 @@
+package com.baeldung.javalin.User;
+
+import java.util.Arrays;
+import java.util.List;
+import java.util.Optional;
+import java.util.stream.Collectors;
+
+class UserDao {
+
+    private final List<User> users = Arrays.asList(
+            new User(0, "Steve Rogers"),
+            new User(1, "Tony Stark"),
+            new User(2, "Carol Danvers")
+    );
+
+    private static UserDao userDao = null;
+
+    private UserDao() {
+    }
+
+    static UserDao instance() {
+        if (userDao == null) {
+            userDao = new UserDao();
+        }
+        return userDao;
+    }
+
+    Optional<User> getUserById(int id) { return users.stream().filter(u -> u.id == id).findFirst(); }
+
+    Iterable<String> getAllUsernames() {
+        return users.stream().map(user -> user.name).collect(Collectors.toList());
+    }
+}

logging-modules/README.md

@@ -5,3 +5,4 @@
 
 - [Creating a Custom Logback Appender](http://www.baeldung.com/custom-logback-appender)
 - [Get Log Output in JSON Format](http://www.baeldung.com/java-log-json-output)
+- [A Guide To Logback](http://www.baeldung.com/a-guide-to-logback)

logging-modules/log-mdc/pom.xml

@@ -9,28 +9,22 @@
     <description>tutorial on logging with MDC and NDC</description>
 
     <parent>
-        <groupId>com.baeldung</groupId>
+		<groupId>com.baeldung</groupId>
-        <artifactId>parent-modules</artifactId>
+		<artifactId>parent-spring</artifactId>
-        <version>1.0.0-SNAPSHOT</version>
+		<version>0.0.1-SNAPSHOT</version>
-        <relativePath>../../</relativePath>
+		<relativePath>../../parent-spring</relativePath>
-    </parent>
+	</parent>
 
     <dependencies>
-
-        <dependency>
-            <groupId>org.springframework</groupId>
-            <artifactId>spring-core</artifactId>
-            <version>${springframework.version}</version>
-        </dependency>
         <dependency>
             <groupId>org.springframework</groupId>
             <artifactId>spring-web</artifactId>
-            <version>${springframework.version}</version>
+            <version>${spring.version}</version>
         </dependency>
         <dependency>
             <groupId>org.springframework</groupId>
             <artifactId>spring-webmvc</artifactId>
-            <version>${springframework.version}</version>
+            <version>${spring.version}</version>
         </dependency>
         <dependency>
             <groupId>javax.servlet</groupId>
@@ -79,14 +73,14 @@
         <dependency>
             <groupId>org.springframework</groupId>
             <artifactId>spring-test</artifactId>
-            <version>${springframework.version}</version>
+            <version>${spring.version}</version>
             <scope>test</scope>
         </dependency>
 
     </dependencies>
 
     <properties>
-        <springframework.version>4.3.4.RELEASE</springframework.version>
+        <spring.version>4.3.4.RELEASE</spring.version>
         <log4j.version>1.2.17</log4j.version>
         <log4j2.version>2.7</log4j2.version>
         <disruptor.version>3.3.6</disruptor.version>

logging-modules/log4j2-programmatic-configuration/modify-xml-configuration/pom.xml

@@ -0,0 +1,19 @@
+<?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" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
+	<modelVersion>4.0.0</modelVersion>
+	<parent>
+		<groupId>com.baeldung.log4j2</groupId>
+		<artifactId>log4j2-programmatic-configuration</artifactId>
+		<version>0.0.1-SNAPSHOT</version>
+	</parent>
+	<groupId>com.baeldung.log4j2</groupId>
+	<artifactId>modify-xml-configuration</artifactId>
+	<version>0.0.1-SNAPSHOT</version>
+	<name>modify-xml-configuration</name>
+	<url>http://maven.apache.org</url>
+	<properties>
+		<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
+	</properties>
+</project>

logging-modules/log4j2-programmatic-configuration/modify-xml-configuration/src/main/java/com/baeldung/log4j2/config/CustomXMLConfigurationFactory.java

@@ -0,0 +1,29 @@
+/**
+  This class demonstrates on modifying the loaded xml configuration by
+  extending XMLConfigurationFactory as defined in section 4.4 of 
+  "Programmatic Configuration with Log4j 2"
+**/
+package com.baeldung.log4j2.config;
+
+import org.apache.logging.log4j.core.LoggerContext;
+import org.apache.logging.log4j.core.config.Configuration;
+import org.apache.logging.log4j.core.config.ConfigurationFactory;
+import org.apache.logging.log4j.core.config.ConfigurationSource;
+import org.apache.logging.log4j.core.config.Order;
+import org.apache.logging.log4j.core.config.plugins.Plugin;
+import org.apache.logging.log4j.core.config.xml.XmlConfigurationFactory;
+
+@Plugin(name = "CustomConfigurationFactory", category = ConfigurationFactory.CATEGORY)
+@Order(50)
+public class CustomXMLConfigurationFactory extends XmlConfigurationFactory {
+
+    @Override
+    public Configuration getConfiguration(LoggerContext loggerContext, ConfigurationSource source) {
+        return new MyXMLConfiguration(loggerContext, source);
+    }
+
+    @Override
+    public String[] getSupportedTypes() {
+        return new String[] { ".xml", "*" };
+    }
+}

logging-modules/log4j2-programmatic-configuration/modify-xml-configuration/src/main/java/com/baeldung/log4j2/config/MyXMLConfiguration.java

@@ -0,0 +1,35 @@
+/**
+  This class demonstrates on overriding the configuration loaded through xml
+  as defined in section 4.4 of "Programmatic Configuration with Log4j 2"
+**/
+package com.baeldung.log4j2.config;
+
+import org.apache.logging.log4j.Level;
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.core.Appender;
+import org.apache.logging.log4j.core.Layout;
+import org.apache.logging.log4j.core.LoggerContext;
+import org.apache.logging.log4j.core.appender.FileAppender;
+import org.apache.logging.log4j.core.config.Configuration;
+import org.apache.logging.log4j.core.config.ConfigurationSource;
+import org.apache.logging.log4j.core.config.LoggerConfig;
+import org.apache.logging.log4j.core.config.xml.XmlConfiguration;
+import org.apache.logging.log4j.core.layout.PatternLayout;
+
+public class MyXMLConfiguration extends XmlConfiguration {
+    public MyXMLConfiguration(LoggerContext loggerContext, ConfigurationSource source) {
+        super(loggerContext, source);
+    }
+
+    @Override
+    protected void doConfigure() {
+        super.doConfigure();
+        final LoggerContext ctx = (LoggerContext) LogManager.getContext(false);
+        Configuration config = ctx.getConfiguration();
+        LoggerConfig loggerConfig = config.getLoggerConfig("com");
+        final Layout layout = PatternLayout.createLayout("[%-5level] %d{yyyy-MM-dd HH:mm:ss.SSS} [%t] %c{1} - %msg%n", null, config, null, null, false, false, null, null);
+        Appender appender = FileAppender.createAppender("target/test.log", "false", "false", "File", "true", "false", "false", "4000", layout, null, "false", null, config);
+        loggerConfig.addAppender(appender, Level.DEBUG, null);
+        addAppender(appender);
+    }
+}

logging-modules/log4j2-programmatic-configuration/modify-xml-configuration/src/main/resources/log4j2.xml

@@ -0,0 +1,17 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<Configuration monitorInterval="60">
+	<Appenders>
+		<Console name="console" target="SYSTEM_OUT">
+			<PatternLayout
+				pattern="[%-5level] %d{yyyy-MM-dd HH:mm:ss.SSS} [%t] %c{1} - %msg%n" />
+		</Console>
+	</Appenders>
+	<Loggers>
+		<Logger name="com" additivity="false" level="info">
+			<AppenderRef ref="console" />
+		</Logger>
+		<Root>
+			<AppenderRef ref="console" />
+		</Root>
+	</Loggers>
+</Configuration>

logging-modules/log4j2-programmatic-configuration/modify-xml-configuration/src/test/java/com/baeldung/log4j2/logtest/LogTest.java

@@ -0,0 +1,23 @@
+package com.baeldung.log4j2.logtest;
+
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
+import org.apache.logging.log4j.core.LoggerContext;
+import org.apache.logging.log4j.core.config.plugins.util.PluginManager;
+import org.junit.Test;
+
+
+public class LogTest {
+    static{
+        PluginManager.addPackage("com.baeldung.log4j2.config");
+    }
+    
+    @Test
+    public void simpleProgrammaticConfiguration() {
+        Logger logger = LogManager.getLogger();
+        LoggerContext ctx = (LoggerContext) LogManager.getContext();
+        logger.debug("Debug log message");
+        logger.info("Info log message");
+        logger.error("Error log message");
+    }
+}

logging-modules/log4j2-programmatic-configuration/pom.xml

@@ -0,0 +1,34 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<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>
+	<groupId>com.baeldung.log4j2</groupId>
+	<artifactId>log4j2-programmatic-configuration</artifactId>
+	<version>0.0.1-SNAPSHOT</version>
+	<packaging>pom</packaging>
+	<modules>
+		<module>simple-configuration</module>
+		<module>set-configuration-factory</module>
+		<module>simple-configurator</module>
+		<module>simple-configuration-xml</module>
+		<module>modify-xml-configuration</module>
+	</modules>
+	<dependencies>
+		<dependency>
+			<groupId>junit</groupId>
+			<artifactId>junit</artifactId>
+			<version>4.12</version>
+			<scope>test</scope>
+		</dependency>
+		<dependency>
+			<groupId>org.apache.logging.log4j</groupId>
+			<artifactId>log4j-core</artifactId>
+			<version>2.11.0</version>
+		</dependency>
+		<dependency>
+			<groupId>org.apache.logging.log4j</groupId>
+			<artifactId>log4j-slf4j-impl</artifactId>
+			<version>2.11.0</version>
+		</dependency>
+	</dependencies>
+</project>

logging-modules/log4j2-programmatic-configuration/set-configuration-factory/pom.xml

@@ -0,0 +1,10 @@
+<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>
+	<parent>
+		<groupId>com.baeldung.log4j2</groupId>
+		<artifactId>log4j2-programmatic-configuration</artifactId>
+		<version>0.0.1-SNAPSHOT</version>
+	</parent>
+	<artifactId>set-configuration-factory</artifactId>
+</project>

logging-modules/log4j2-programmatic-configuration/set-configuration-factory/src/main/java/com/baeldung/log4j2/config/CustomConfigurationFactory.java

@@ -0,0 +1,88 @@
+/**
+  This class demonstrates how to build the components of 
+  the configuration factory, as described in Section 3 of 
+  "Programmatic Configuration with Log4j 2"
+**/
+package com.baeldung.log4j2.config;
+
+import java.io.IOException;
+import java.net.URI;
+
+import org.apache.logging.log4j.Level;
+import org.apache.logging.log4j.core.Filter;
+import org.apache.logging.log4j.core.LoggerContext;
+import org.apache.logging.log4j.core.config.Configuration;
+import org.apache.logging.log4j.core.config.ConfigurationFactory;
+import org.apache.logging.log4j.core.config.ConfigurationSource;
+import org.apache.logging.log4j.core.config.builder.api.AppenderComponentBuilder;
+import org.apache.logging.log4j.core.config.builder.api.ComponentBuilder;
+import org.apache.logging.log4j.core.config.builder.api.ConfigurationBuilder;
+import org.apache.logging.log4j.core.config.builder.api.FilterComponentBuilder;
+import org.apache.logging.log4j.core.config.builder.api.LayoutComponentBuilder;
+import org.apache.logging.log4j.core.config.builder.api.LoggerComponentBuilder;
+import org.apache.logging.log4j.core.config.builder.api.RootLoggerComponentBuilder;
+import org.apache.logging.log4j.core.config.builder.impl.BuiltConfiguration;
+
+public class CustomConfigurationFactory extends ConfigurationFactory {
+
+    static Configuration createConfiguration(final String name, ConfigurationBuilder<BuiltConfiguration> builder) {
+        AppenderComponentBuilder console = builder.newAppender("Stdout", "Console");
+        LayoutComponentBuilder layout = builder.newLayout("PatternLayout")
+            .addAttribute("pattern", "%d [%t] %-5level: %msg%n%throwable");
+        console.add(layout);
+        FilterComponentBuilder filter = builder.newFilter("MarkerFilter", Filter.Result.ACCEPT, Filter.Result.DENY);
+        filter.addAttribute("marker", "FLOW");
+        console.add(filter);
+        builder.add(console);
+        ComponentBuilder triggeringPolicies = builder.newComponent("Policies")
+            .addComponent(builder.newComponent("CronTriggeringPolicy")
+                .addAttribute("schedule", "0 0 0 * * ?"))
+            .addComponent(builder.newComponent("SizeBasedTriggeringPolicy")
+                .addAttribute("size", "100M"));
+        AppenderComponentBuilder rollingFile = builder.newAppender("rolling", "RollingFile");
+        rollingFile.addAttribute("fileName", "target/rolling.log");
+        rollingFile.addAttribute("filePattern", "target/archive/rolling-%d{MM-dd-yy}.log.gz");
+        rollingFile.add(layout);
+        rollingFile.addComponent(triggeringPolicies);
+        builder.add(rollingFile);
+        AppenderComponentBuilder file = builder.newAppender("FileSystem", "File");
+        file.addAttribute("fileName", "target/logging.log");
+        file.add(layout);
+        builder.add(file);
+        LoggerComponentBuilder logger = builder.newLogger("com", Level.DEBUG);
+        logger.add(builder.newAppenderRef("Stdout"));
+        logger.add(builder.newAppenderRef("rolling"));
+        logger.add(builder.newAppenderRef("FileSystem"));
+        logger.addAttribute("additivity", false);
+        builder.add(logger);
+        RootLoggerComponentBuilder rootLogger = builder.newRootLogger(Level.ERROR);
+        rootLogger.add(builder.newAppenderRef("Stdout"));
+        rootLogger.add(builder.newAppenderRef("rolling"));
+        rootLogger.add(builder.newAppenderRef("FileSystem"));
+        rootLogger.addAttribute("additivity", false);
+        builder.add(rootLogger);
+        try {
+            builder.writeXmlConfiguration(System.out);
+        } catch (IOException e) {
+            // TODO Auto-generated catch block
+            e.printStackTrace();
+        }
+        return builder.build();
+    }
+
+    public Configuration getConfiguration(final LoggerContext loggerContext, final String name, final URI configLocation) {
+        ConfigurationBuilder<BuiltConfiguration> builder = newConfigurationBuilder();
+        return createConfiguration(name, builder);
+    }
+
+    @Override
+    protected String[] getSupportedTypes() {
+        return new String[] { "*" };
+    }
+
+    @Override
+    public Configuration getConfiguration(LoggerContext loggerContext, ConfigurationSource source) {
+        return getConfiguration(loggerContext, source.toString(), null);
+    }
+
+}

logging-modules/log4j2-programmatic-configuration/set-configuration-factory/src/test/java/com/baeldung/log4j2/logtest/LogTest.java

@@ -0,0 +1,33 @@
+/**
+  This class invokes the configuration factory with static initialization,
+  as defined in section 4.1 of the "Programmatic Configuration with Log4j 2"
+**/
+package com.baeldung.log4j2.logtest;
+
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
+import org.apache.logging.log4j.Marker;
+import org.apache.logging.log4j.MarkerManager;
+import org.apache.logging.log4j.core.config.ConfigurationFactory;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.junit.runners.JUnit4;
+
+import com.baeldung.log4j2.config.CustomConfigurationFactory;
+
+@RunWith(JUnit4.class)
+public class LogTest {
+    static {
+        CustomConfigurationFactory customConfigurationFactory = new CustomConfigurationFactory();
+        ConfigurationFactory.setConfigurationFactory(customConfigurationFactory);
+    }
+
+    @Test
+    public void simpleProgrammaticConfiguration() {
+        Logger logger = LogManager.getLogger();
+        Marker markerContent = MarkerManager.getMarker("FLOW");
+        logger.debug(markerContent, "Debug log message");
+        logger.info(markerContent, "Info log message");
+        logger.error(markerContent, "Error log message");
+    }
+}

logging-modules/log4j2-programmatic-configuration/simple-configuration-xml/pom.xml

@@ -0,0 +1,17 @@
+<?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" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
+	<modelVersion>4.0.0</modelVersion>
+	<parent>
+		<groupId>com.baeldung.log4j2</groupId>
+		<artifactId>log4j2-programmatic-configuration</artifactId>
+		<version>0.0.1-SNAPSHOT</version>
+	</parent>
+	<artifactId>simple-configuration-xml</artifactId>
+	<name>simple-configuration-xml</name>
+	<url>http://maven.apache.org</url>
+	<properties>
+		<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
+	</properties>
+</project>

logging-modules/log4j2-programmatic-configuration/simple-configuration-xml/src/main/resources/log4j2.xml

@@ -0,0 +1,32 @@
+<?xml version="1.0" ?>
+<Configuration>
+	<Appenders>
+		<Console name="Stdout">
+			<PatternLayout pattern="%d [%t] %-5level: %msg%n%throwable" />
+			<MarkerFilter onMatch="ACCEPT" onMismatch="DENY" marker="FLOW" />
+		</Console>
+		<RollingFile name="rolling" fileName="target/rolling.log"
+			filePattern="target/archive/rolling-%d{MM-dd-yy}.log.gz">
+			<PatternLayout pattern="%d [%t] %-5level: %msg%n%throwable" />
+			<Policies>
+				<CronTriggeringPolicy schedule="0 0 0 * * ?" />
+				<SizeBasedTriggeringPolicy size="100M" />
+			</Policies>
+		</RollingFile>
+		<File name="FileSystem" fileName="target/logging.log">
+			<PatternLayout pattern="%d [%t] %-5level: %msg%n%throwable" />
+		</File>
+	</Appenders>
+	<Loggers>
+		<Logger name="com" level="DEBUG" additivity="false">
+			<AppenderRef ref="Stdout" />
+			<AppenderRef ref="rolling" />
+			<AppenderRef ref="FileSystem" />
+		</Logger>
+		<Root level="ERROR" additivity="false">
+			<AppenderRef ref="Stdout" />
+			<AppenderRef ref="rolling" />
+			<AppenderRef ref="FileSystem" />
+		</Root>
+	</Loggers>
+</Configuration>

logging-modules/log4j2-programmatic-configuration/simple-configuration-xml/src/test/java/com/baeldung/log4j2/logtest/LogTest.java

@@ -0,0 +1,30 @@
+/**
+  This class loads the logging configuration from the xml defined in 
+  src/main/resources and uses the same configuration  generated through 
+  programmatic configuration as defined in simple-configuration example.
+**/
+
+package com.baeldung.log4j2.logtest;
+
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
+import org.apache.logging.log4j.Marker;
+import org.apache.logging.log4j.MarkerManager;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.junit.runners.JUnit4;
+
+
+@RunWith(JUnit4.class)
+public class LogTest {
+
+    @Test
+    public void simpleProgrammaticConfiguration(){
+        Logger logger = LogManager.getLogger();
+        Marker markerContent = MarkerManager.getMarker("FLOW");
+        logger.debug(markerContent, "Debug log message");
+        logger.info(markerContent, "Info log message");
+        logger.error(markerContent, "Error log message");
+    }
+
+}

logging-modules/log4j2-programmatic-configuration/simple-configuration/pom.xml

@@ -0,0 +1,10 @@
+<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>
+	<parent>
+		<groupId>com.baeldung.log4j2</groupId>
+		<artifactId>log4j2-programmatic-configuration</artifactId>
+		<version>0.0.1-SNAPSHOT</version>
+	</parent>
+	<artifactId>simple-configuration</artifactId>
+</project>

logging-modules/log4j2-programmatic-configuration/simple-configuration/src/main/java/com/baeldung/log4j2/config/CustomConfigurationFactory.java

@@ -0,0 +1,94 @@
+/**
+  This class demonstrates how to build the components of 
+  the configuration factory, as described in Section 3 of 
+  "Programmatic Configuration with Log4j 2"
+**/
+
+package com.baeldung.log4j2.config;
+
+import java.io.IOException;
+import java.net.URI;
+
+import org.apache.logging.log4j.Level;
+import org.apache.logging.log4j.core.Filter;
+import org.apache.logging.log4j.core.LoggerContext;
+import org.apache.logging.log4j.core.config.Configuration;
+import org.apache.logging.log4j.core.config.ConfigurationFactory;
+import org.apache.logging.log4j.core.config.ConfigurationSource;
+import org.apache.logging.log4j.core.config.Order;
+import org.apache.logging.log4j.core.config.builder.api.AppenderComponentBuilder;
+import org.apache.logging.log4j.core.config.builder.api.ComponentBuilder;
+import org.apache.logging.log4j.core.config.builder.api.ConfigurationBuilder;
+import org.apache.logging.log4j.core.config.builder.api.FilterComponentBuilder;
+import org.apache.logging.log4j.core.config.builder.api.LayoutComponentBuilder;
+import org.apache.logging.log4j.core.config.builder.api.LoggerComponentBuilder;
+import org.apache.logging.log4j.core.config.builder.api.RootLoggerComponentBuilder;
+import org.apache.logging.log4j.core.config.builder.impl.BuiltConfiguration;
+import org.apache.logging.log4j.core.config.plugins.Plugin;
+
+@Plugin(name = "CustomConfigurationFactory", category = ConfigurationFactory.CATEGORY)
+@Order(50)
+public class CustomConfigurationFactory extends ConfigurationFactory {
+
+    static Configuration createConfiguration(final String name, ConfigurationBuilder<BuiltConfiguration> builder) {
+        AppenderComponentBuilder console = builder.newAppender("Stdout", "Console");
+        LayoutComponentBuilder layout = builder.newLayout("PatternLayout")
+            .addAttribute("pattern", "%d [%t] %-5level: %msg%n%throwable");
+        console.add(layout);
+        FilterComponentBuilder filter = builder.newFilter("MarkerFilter", Filter.Result.ACCEPT, Filter.Result.DENY);
+        filter.addAttribute("marker", "FLOW");
+        console.add(filter);
+        builder.add(console);
+        ComponentBuilder triggeringPolicies = builder.newComponent("Policies")
+            .addComponent(builder.newComponent("CronTriggeringPolicy")
+                .addAttribute("schedule", "0 0 0 * * ?"))
+            .addComponent(builder.newComponent("SizeBasedTriggeringPolicy")
+                .addAttribute("size", "100M"));
+        AppenderComponentBuilder rollingFile = builder.newAppender("rolling", "RollingFile");
+        rollingFile.addAttribute("fileName", "target/rolling.log");
+        rollingFile.addAttribute("filePattern", "target/archive/rolling-%d{MM-dd-yy}.log.gz");
+        rollingFile.add(layout);
+        rollingFile.addComponent(triggeringPolicies);
+        builder.add(rollingFile);
+        AppenderComponentBuilder file = builder.newAppender("FileSystem", "File");
+        file.addAttribute("fileName", "target/logging.log");
+        file.add(layout);
+        builder.add(file);
+        LoggerComponentBuilder logger = builder.newLogger("com", Level.DEBUG);
+        logger.add(builder.newAppenderRef("Stdout"));
+        logger.add(builder.newAppenderRef("rolling"));
+        logger.add(builder.newAppenderRef("FileSystem"));
+        logger.addAttribute("additivity", false);
+        builder.add(logger);
+        RootLoggerComponentBuilder rootLogger = builder.newRootLogger(Level.ERROR);
+        rootLogger.add(builder.newAppenderRef("Stdout"));
+        rootLogger.add(builder.newAppenderRef("rolling"));
+        // rootLogger.add(builder.newAppenderRef("syslogAppender"));
+        rootLogger.add(builder.newAppenderRef("FileSystem"));
+        rootLogger.addAttribute("additivity", false);
+        builder.add(rootLogger);
+        try {
+            builder.writeXmlConfiguration(System.out);
+        } catch (IOException e) {
+            // TODO Auto-generated catch block
+            e.printStackTrace();
+        }
+        return builder.build();
+
+    }
+
+    @Override
+    public Configuration getConfiguration(LoggerContext loggerContext, ConfigurationSource source) {
+        return getConfiguration(loggerContext, source.toString(), null);
+    }
+
+    public Configuration getConfiguration(final LoggerContext loggerContext, final String name, final URI configLocation) {
+        ConfigurationBuilder<BuiltConfiguration> builder = newConfigurationBuilder();
+        return createConfiguration(name, builder);
+    }
+
+    @Override
+    protected String[] getSupportedTypes() {
+        return new String[] { "*" };
+    }
+}

logging-modules/log4j2-programmatic-configuration/simple-configuration/src/test/java/com/baeldung/log4j2/logtest/LogTest.java

@@ -0,0 +1,22 @@
+/**
+  This class invokes the configuration factory through the run time property,
+  as defined in section 4.2 of the "Programmatic Configuration with Log4j 2"
+**/
+package com.baeldung.log4j2.logtest;
+
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
+import org.apache.logging.log4j.Marker;
+import org.apache.logging.log4j.MarkerManager;
+import org.junit.Test;
+
+public class LogTest {
+    @Test
+    public void simpleProgrammaticConfiguration() {
+        Logger logger = LogManager.getLogger();
+        Marker markerContent = MarkerManager.getMarker("FLOW");
+        logger.debug(markerContent, "Debug log message");
+        logger.info(markerContent, "Info log message");
+        logger.error(markerContent, "Error log message");
+    }
+}

logging-modules/log4j2-programmatic-configuration/simple-configurator/pom.xml

@@ -0,0 +1,10 @@
+<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>
+	<parent>
+		<groupId>com.baeldung.log4j2</groupId>
+		<artifactId>log4j2-programmatic-configuration</artifactId>
+		<version>0.0.1-SNAPSHOT</version>
+	</parent>
+	<artifactId>simple-configurator</artifactId>
+</project>

logging-modules/log4j2-programmatic-configuration/simple-configurator/src/test/java/com/baeldung/log4j2/configure/LogTest.java

@@ -0,0 +1,40 @@
+/**
+  This class demonstrates how to use ConfigurationBuilderFactory directly, 
+  as described in Section 3 of "Programmatic Configuration with Log4j 2"
+**/
+
+package com.baeldung.log4j2.configure;
+
+import org.apache.logging.log4j.Level;
+import org.apache.logging.log4j.core.appender.ConsoleAppender;
+import org.apache.logging.log4j.core.config.Configurator;
+import org.apache.logging.log4j.core.config.builder.api.AppenderComponentBuilder;
+import org.apache.logging.log4j.core.config.builder.api.ConfigurationBuilder;
+import org.apache.logging.log4j.core.config.builder.api.ConfigurationBuilderFactory;
+import org.apache.logging.log4j.core.config.builder.impl.BuiltConfiguration;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.junit.runners.JUnit4;
+
+import com.baeldung.log4j2.logtest.LogPrinter;
+
+@RunWith(JUnit4.class)
+public class LogTest {
+    @Test
+    public void simpleProgrammaticConfiguration() {
+        ConfigurationBuilder<BuiltConfiguration> builder = ConfigurationBuilderFactory.newConfigurationBuilder();
+        AppenderComponentBuilder console = builder.newAppender("Stdout", "CONSOLE")
+            .addAttribute("target", ConsoleAppender.Target.SYSTEM_OUT);
+        console.add(builder.newLayout("PatternLayout")
+            .addAttribute("pattern", "%d [%t] %-5level: %msg%n%throwable"));
+        builder.add(console);
+        builder.add(builder.newLogger("com", Level.DEBUG)
+            .add(builder.newAppenderRef("Stdout"))
+            .addAttribute("additivity", false));
+        builder.add(builder.newRootLogger(Level.ERROR)
+            .add(builder.newAppenderRef("Stdout")));
+        Configurator.initialize(builder.build());
+        LogPrinter logPrinter = new LogPrinter();
+        logPrinter.printlog();
+    }
+}

logging-modules/log4j2-programmatic-configuration/simple-configurator/src/test/java/com/baeldung/log4j2/logtest/LogPrinter.java

@@ -0,0 +1,15 @@
+package com.baeldung.log4j2.logtest;
+
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
+
+
+public class LogPrinter {
+    private Logger logger = LogManager.getLogger();
+
+    public void printlog() {
+        logger.debug("Debug log message");
+        logger.info("Info log message");
+        logger.error("Error log message");
+    }
+}