Merge branch 'master' of https://github.com/eugenp/tutorials

akka-http/pom.xml

@@ -1,8 +1,7 @@
 <?xml version="1.0" encoding="UTF-8"?>
-<project
+<project xmlns="http://maven.apache.org/POM/4.0.0"
-    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd"
+    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
-    xmlns="http://maven.apache.org/POM/4.0.0"
+    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
-    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
     <modelVersion>4.0.0</modelVersion>
     <artifactId>akka-http</artifactId>
     <name>akka-http</name>
@@ -38,8 +37,6 @@
     </dependencies>
 
     <properties>
-        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
-        <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
         <akka.http.version>10.0.11</akka.http.version>
         <akka.stream.version>2.5.11</akka.stream.version>
     </properties>

akka-streams/pom.xml

@@ -1,6 +1,5 @@
 <?xml version="1.0" encoding="UTF-8"?>
-<project
+<project xmlns="http://maven.apache.org/POM/4.0.0"
-    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>

algorithms-genetic/pom.xml

@@ -1,6 +1,5 @@
 <?xml version="1.0" encoding="UTF-8"?>
-<project
+<project xmlns="http://maven.apache.org/POM/4.0.0"
-    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>
@@ -44,18 +43,6 @@
         </dependency>
     </dependencies>
 
-    <build>
-        <pluginManagement>
-            <plugins>
-                <plugin>
-                    <groupId>org.codehaus.mojo</groupId>
-                    <artifactId>exec-maven-plugin</artifactId>
-                    <version>${exec-maven-plugin.version}</version>
-                </plugin>
-            </plugins>
-        </pluginManagement>
-    </build>
-
     <properties>
         <commons-math3.version>3.6.1</commons-math3.version>
         <io.jenetics.version>3.7.0</io.jenetics.version>

algorithms-miscellaneous-1/pom.xml

@@ -1,6 +1,5 @@
 <?xml version="1.0" encoding="UTF-8"?>
-<project
+<project xmlns="http://maven.apache.org/POM/4.0.0"
-    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>
@@ -49,18 +48,6 @@
         </dependency>
     </dependencies>
 
-    <build>
-        <pluginManagement>
-            <plugins>
-                <plugin>
-                    <groupId>org.codehaus.mojo</groupId>
-                    <artifactId>exec-maven-plugin</artifactId>
-                    <version>${exec-maven-plugin.version}</version>
-                </plugin>
-            </plugins>
-        </pluginManagement>
-    </build>
-
     <reporting>
         <plugins>
             <plugin>

algorithms-miscellaneous-2/pom.xml

@@ -1,6 +1,5 @@
 <?xml version="1.0" encoding="UTF-8"?>
-<project
+<project xmlns="http://maven.apache.org/POM/4.0.0"
-    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>
@@ -54,18 +53,6 @@
         </dependency>
     </dependencies>
 
-    <build>
-        <pluginManagement>
-            <plugins>
-                <plugin>
-                    <groupId>org.codehaus.mojo</groupId>
-                    <artifactId>exec-maven-plugin</artifactId>
-                    <version>${exec-maven-plugin.version}</version>
-                </plugin>
-            </plugins>
-        </pluginManagement>
-    </build>
-
     <reporting>
         <plugins>
             <plugin>

algorithms-miscellaneous-3/pom.xml

@@ -1,6 +1,5 @@
 <?xml version="1.0" encoding="UTF-8"?>
-<project
+<project xmlns="http://maven.apache.org/POM/4.0.0"
-    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>
@@ -74,25 +73,11 @@
         </dependency>
     </dependencies>
 
-    <build>
-        <pluginManagement>
-            <plugins>
-                <plugin>
-                    <groupId>org.codehaus.mojo</groupId>
-                    <artifactId>exec-maven-plugin</artifactId>
-                    <version>${exec-maven-plugin.version}</version>
-                </plugin>
-            </plugins>
-        </pluginManagement>
-    </build>
-
     <properties>
         <org.assertj.core.version>3.9.0</org.assertj.core.version>
         <commons-collections4.version>4.3</commons-collections4.version>
         <guava.version>28.0-jre</guava.version>
         <retrofit.version>2.6.0</retrofit.version>
-        <jmh-core.version>1.19</jmh-core.version>
-        <jmh-generator.version>1.19</jmh-generator.version>
         <commons.lang3.version>3.8.1</commons.lang3.version>
         <JUnitParams.version>1.1.0</JUnitParams.version>
     </properties>

algorithms-miscellaneous-4/pom.xml

@@ -1,6 +1,5 @@
 <?xml version="1.0" encoding="UTF-8"?>
-<project
+<project xmlns="http://maven.apache.org/POM/4.0.0"
-    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>
@@ -34,18 +33,6 @@
         </dependency>
     </dependencies>
 
-    <build>
-        <pluginManagement>
-            <plugins>
-                <plugin>
-                    <groupId>org.codehaus.mojo</groupId>
-                    <artifactId>exec-maven-plugin</artifactId>
-                    <version>${exec-maven-plugin.version}</version>
-                </plugin>
-            </plugins>
-        </pluginManagement>
-    </build>
-
     <properties>
         <org.assertj.core.version>3.9.0</org.assertj.core.version>
         <guava.version>27.0.1-jre</guava.version>

algorithms-miscellaneous-5/pom.xml

@@ -1,6 +1,5 @@
 <?xml version="1.0" encoding="UTF-8"?>
-<project
+<project xmlns="http://maven.apache.org/POM/4.0.0"
-    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>
@@ -49,18 +48,6 @@
         </dependency>
     </dependencies>
 
-    <build>
-        <pluginManagement>
-            <plugins>
-                <plugin>
-                    <groupId>org.codehaus.mojo</groupId>
-                    <artifactId>exec-maven-plugin</artifactId>
-                    <version>${exec-maven-plugin.version}</version>
-                </plugin>
-            </plugins>
-        </pluginManagement>
-    </build>
-
     <properties>
         <tradukisto.version>1.0.1</tradukisto.version>
         <org.assertj.core.version>3.9.0</org.assertj.core.version>

algorithms-miscellaneous-5/src/main/java/com/baeldung/algorithms/maximumsubarray/KadaneAlgorithm.java

@@ -13,22 +13,22 @@ public class KadaneAlgorithm {
         int start = 0;
         int end = 0;
 
-        int maxSoFar = 0, maxEndingHere = 0;
+        int maxSoFar = arr[0], maxEndingHere = arr[0];
-
         for (int i = 0; i < size; i++) {
 
             if (arr[i] > maxEndingHere + arr[i]) {
                 start = i;
                 maxEndingHere = arr[i];
-            } else
+            } else {
                 maxEndingHere = maxEndingHere + arr[i];
+            }
 
             if (maxSoFar < maxEndingHere) {
                 maxSoFar = maxEndingHere;
                 end = i;
             }
         }
-        logger.info("Found Maximum Subarray between {} and {}", start, end);
+        logger.info("Found Maximum Subarray between {} and {}", Math.min(start, end), end);
         return maxSoFar;
     }
 }

algorithms-miscellaneous-5/src/test/java/com/baeldung/algorithms/maximumsubarray/KadaneAlgorithmUnitTest.java

@@ -16,4 +16,15 @@ class KadaneAlgorithmUnitTest {
         //then
         assertEquals(6, maxSum);
     }
+
+    @Test
+    void givenArrayWithAllNegativeNumbersWhenMaximumSubarrayThenReturnsExpectedResult() {
+        //given
+        int[] arr = new int[] { -8, -7, -5, -4, -3, -1, -2 };
+        //when
+        KadaneAlgorithm algorithm = new KadaneAlgorithm();
+        int maxSum = algorithm.maxSubArraySum(arr);
+        //then
+        assertEquals(-1, maxSum);
+    }
 }

algorithms-miscellaneous-6/pom.xml

@@ -1,5 +1,6 @@
 <?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"
+<project xmlns="http://maven.apache.org/POM/4.0.0"
+    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
     xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
     <modelVersion>4.0.0</modelVersion>
     <artifactId>algorithms-miscellaneous-6</artifactId>

algorithms-searching/pom.xml

@@ -1,6 +1,5 @@
 <?xml version="1.0" encoding="UTF-8"?>
-<project
+<project xmlns="http://maven.apache.org/POM/4.0.0"
-    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>

algorithms-sorting-2/pom.xml

@@ -1,5 +1,4 @@
-<project
+<project xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
-    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
     xmlns="http://maven.apache.org/POM/4.0.0"
     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>
@@ -44,18 +43,6 @@
         </dependency>
     </dependencies>
 
-    <build>
-        <pluginManagement>
-            <plugins>
-                <plugin>
-                    <groupId>org.codehaus.mojo</groupId>
-                    <artifactId>exec-maven-plugin</artifactId>
-                    <version>${exec-maven-plugin.version}</version>
-                </plugin>
-            </plugins>
-        </pluginManagement>
-    </build>
-
     <properties>
         <commons-math3.version>3.6.1</commons-math3.version>
         <org.assertj.core.version>3.9.0</org.assertj.core.version>

algorithms-sorting/pom.xml

@@ -1,6 +1,5 @@
 <?xml version="1.0" encoding="UTF-8"?>
-<project
+<project xmlns="http://maven.apache.org/POM/4.0.0"
-    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>
@@ -45,18 +44,6 @@
         </dependency>
     </dependencies>
 
-    <build>
-        <pluginManagement>
-            <plugins>
-                <plugin>
-                    <groupId>org.codehaus.mojo</groupId>
-                    <artifactId>exec-maven-plugin</artifactId>
-                    <version>${exec-maven-plugin.version}</version>
-                </plugin>
-            </plugins>
-        </pluginManagement>
-    </build>
-
     <properties>
         <commons-math3.version>3.6.1</commons-math3.version>
         <org.assertj.core.version>3.9.0</org.assertj.core.version>

animal-sniffer-mvn-plugin/pom.xml

@@ -1,6 +1,5 @@
 <?xml version="1.0" encoding="UTF-8"?>
-<project
+<project xmlns="http://maven.apache.org/POM/4.0.0"
-    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/maven-v4_0_0.xsd">
     <modelVersion>4.0.0</modelVersion>

annotations/annotation-processing/pom.xml

@@ -1,6 +1,5 @@
 <?xml version="1.0" encoding="UTF-8"?>
-<project
+<project xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
-    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
     xmlns="http://maven.apache.org/POM/4.0.0"
     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>

annotations/annotation-user/pom.xml

@@ -1,6 +1,5 @@
 <?xml version="1.0" encoding="UTF-8"?>
-<project
+<project xmlns="http://maven.apache.org/POM/4.0.0"
-    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>

annotations/pom.xml

@@ -1,6 +1,5 @@
 <?xml version="1.0" encoding="UTF-8"?>
-<project
+<project xmlns="http://maven.apache.org/POM/4.0.0"
-    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>

antlr/pom.xml

@@ -1,6 +1,5 @@
 <?xml version="1.0" encoding="UTF-8"?>
-<project
+<project xmlns="http://maven.apache.org/POM/4.0.0"
-    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/maven-v4_0_0.xsd">
     <modelVersion>4.0.0</modelVersion>

apache-cxf/cxf-aegis/pom.xml

@@ -1,6 +1,5 @@
 <?xml version="1.0" encoding="UTF-8"?>
-<project
+<project xmlns="http://maven.apache.org/POM/4.0.0"
-    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/maven-v4_0_0.xsd">
     <modelVersion>4.0.0</modelVersion>

apache-cxf/cxf-introduction/pom.xml

@@ -1,6 +1,5 @@
 <?xml version="1.0" encoding="UTF-8"?>
-<project
+<project xmlns="http://maven.apache.org/POM/4.0.0"
-    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/maven-v4_0_0.xsd">
     <modelVersion>4.0.0</modelVersion>

apache-cxf/cxf-jaxrs-implementation/pom.xml

@@ -1,6 +1,5 @@
 <?xml version="1.0" encoding="UTF-8"?>
-<project
+<project xmlns="http://maven.apache.org/POM/4.0.0"
-    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/maven-v4_0_0.xsd">
     <modelVersion>4.0.0</modelVersion>

apache-cxf/cxf-spring/pom.xml

@@ -1,6 +1,5 @@
 <?xml version="1.0" encoding="UTF-8"?>
-<project
+<project xmlns="http://maven.apache.org/POM/4.0.0"
-    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/maven-v4_0_0.xsd">
     <modelVersion>4.0.0</modelVersion>

apache-cxf/pom.xml

@@ -1,6 +1,5 @@
 <?xml version="1.0" encoding="UTF-8"?>
-<project
+<project xmlns="http://maven.apache.org/POM/4.0.0"
-    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>
@@ -30,7 +29,6 @@
                 <plugin>
                     <groupId>org.codehaus.mojo</groupId>
                     <artifactId>exec-maven-plugin</artifactId>
-                    <version>${exec-maven-plugin.version}</version>
                 </plugin>
             </plugins>
         </pluginManagement>

apache-cxf/sse-jaxrs/pom.xml

@@ -1,6 +1,5 @@
 <?xml version="1.0" encoding="UTF-8"?>
-<project
+<project xmlns="http://maven.apache.org/POM/4.0.0"
-    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>

apache-cxf/sse-jaxrs/sse-jaxrs-client/pom.xml

@@ -1,6 +1,5 @@
 <?xml version="1.0" encoding="UTF-8"?>
-<project
+<project xmlns="http://maven.apache.org/POM/4.0.0"
-    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>

apache-cxf/sse-jaxrs/sse-jaxrs-server/pom.xml

@@ -1,6 +1,5 @@
 <?xml version="1.0" encoding="UTF-8"?>
-<project
+<project xmlns="http://maven.apache.org/POM/4.0.0"
-    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>

apache-libraries/pom.xml

@@ -1,5 +1,6 @@
 <?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"
+<project xmlns="http://maven.apache.org/POM/4.0.0"
+    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
     xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
     <modelVersion>4.0.0</modelVersion>
     <artifactId>apache-libraries</artifactId>
@@ -29,7 +30,6 @@
             <artifactId>avro-maven-plugin</artifactId>
             <version>${avro.version}</version>
         </dependency>
-
         <!-- beam -->
         <dependency>
             <groupId>org.apache.beam</groupId>
@@ -43,7 +43,6 @@
             <version>${beam.version}</version>
             <scope>runtime</scope>
         </dependency>
-
         <!-- bval -->
         <dependency>
             <groupId>org.apache.bval</groupId>
@@ -60,7 +59,6 @@
             <artifactId>bval-extras</artifactId>
             <version>${bval.version}</version>
         </dependency>
-
         <!-- meecrowave -->
         <dependency>
             <groupId>org.apache.meecrowave</groupId>
@@ -84,14 +82,12 @@
             <version>${meecrowave-junit.version}</version>
             <scope>test</scope>
         </dependency>
-        
         <!-- opennlp -->
         <dependency>
             <groupId>org.apache.opennlp</groupId>
             <artifactId>opennlp-tools</artifactId>
             <version>${opennlp.opennlp-tools.version}</version>
         </dependency>
-        
         <!-- pulsar -->
         <dependency>
             <groupId>org.apache.pulsar</groupId>
@@ -99,14 +95,12 @@
             <version>${pulsar-client.version}</version>
             <scope>compile</scope>
         </dependency>
-        
         <!-- zookeeper -->
         <dependency>
             <groupId>org.apache.zookeeper</groupId>
             <artifactId>zookeeper</artifactId>
             <version>${zookeeper.version}</version>
         </dependency>
-        
         <!-- curator -->
         <dependency>
             <groupId>org.apache.curator</groupId>
@@ -145,21 +139,18 @@
             <version>${avaitility.version}</version>
             <scope>test</scope>
         </dependency>
-        
         <!-- geode -->
         <dependency>
             <groupId>org.apache.geode</groupId>
             <artifactId>geode-core</artifactId>
             <version>${geode.core}</version>
         </dependency>
-        
         <!-- solr -->
         <dependency>
             <groupId>org.apache.solr</groupId>
             <artifactId>solr-solrj</artifactId>
             <version>${solr.solr-solrj.version}</version>
         </dependency>
-        
         <!-- common -->
         <dependency>
             <groupId>org.assertj</groupId>

apache-libraries/src/test/java/com/baeldung/avro/util/serealization/AvroSerealizerDeSerealizerIntegrationTest.java

@@ -13,7 +13,7 @@ import java.util.Objects;
 
 import static org.junit.Assert.*;
 
-public class AvroSerealizerDeSerealizerUnitTest {
+public class AvroSerealizerDeSerealizerIntegrationTest {
 
     AvroSerealizer serealizer;
     AvroDeSerealizer deSerealizer;

apache-libraries/src/test/java/com/baeldung/meecrowave/ArticleEndpointsIntegrationTest.java

@@ -17,7 +17,7 @@ import okhttp3.Request;
 import okhttp3.Response;
 
 @RunWith(MonoMeecrowave.Runner.class)
-public class ArticleEndpointsUnitTest {
+public class ArticleEndpointsIntegrationTest {
     
     @ConfigurationInject
     private Meecrowave.Builder config;

apache-olingo/olingo2/pom.xml

@@ -1,6 +1,5 @@
 <?xml version="1.0" encoding="UTF-8"?>
-<project
+<project xmlns="http://maven.apache.org/POM/4.0.0"
-    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>
@@ -40,7 +39,6 @@
             <artifactId>spring-boot-starter-test</artifactId>
             <scope>test</scope>
         </dependency>
-
         <!-- Olingo 2 Dependencies -->
         <dependency>
             <groupId>org.apache.olingo</groupId>

apache-poi/README.md

@@ -11,3 +11,4 @@ This module contains articles about Apache POI
 - [Get String Value of Excel Cell with Apache POI](https://www.baeldung.com/java-apache-poi-cell-string-value)
 - [Read Excel Cell Value Rather Than Formula With Apache POI](https://www.baeldung.com/apache-poi-read-cell-value-formula)
 - [Setting Formulas in Excel with Apache POI](https://www.baeldung.com/java-apache-poi-set-formulas)
+- [Insert a Row in Excel Using Apache POI](https://www.baeldung.com/apache-poi-insert-excel-row)

apache-poi/pom.xml

@@ -1,6 +1,5 @@
 <?xml version="1.0" encoding="UTF-8"?>
-<project
+<project xmlns="http://maven.apache.org/POM/4.0.0"
-    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>

apache-poi/src/test/java/com/baeldung/poi/excel/insert/ExcelInsertRowUnitTest.java

@@ -0,0 +1,50 @@
+package com.baeldung.poi.excel.insert;
+
+import org.apache.poi.ss.usermodel.Sheet;
+import org.apache.poi.ss.usermodel.Workbook;
+import org.apache.poi.xssf.usermodel.XSSFWorkbook;
+import org.junit.Before;
+import org.junit.Test;
+import org.junit.jupiter.api.Assertions;
+
+import java.io.File;
+import java.io.FileOutputStream;
+import java.io.IOException;
+import java.net.URISyntaxException;
+import java.nio.file.Paths;
+
+public class ExcelInsertRowUnitTest {
+    private static final String FILE_NAME = "test.xlsx";
+    private static final String NEW_FILE_NAME = "new_test.xlsx";
+    private String fileLocation;
+
+    @Before
+    public void setup() throws URISyntaxException {
+        fileLocation = Paths.get(ClassLoader.getSystemResource(FILE_NAME).toURI()).toString();
+    }
+
+    @Test
+    public void givenWorkbook_whenInsertRowBetween_thenRowCreated() throws IOException {
+        int startRow = 2;
+        int rowNumber = 1;
+        Workbook workbook = new XSSFWorkbook(fileLocation);
+        Sheet sheet = workbook.getSheetAt(0);
+        int lastRow = sheet.getLastRowNum();
+        if (lastRow < startRow) {
+            sheet.createRow(startRow);
+        }
+        sheet.shiftRows(startRow, lastRow, rowNumber, true, true);
+        sheet.createRow(startRow);
+        FileOutputStream outputStream = new FileOutputStream(NEW_FILE_NAME);
+        workbook.write(outputStream);
+        File file = new File(NEW_FILE_NAME);
+
+        final int expectedRowResult = 5;
+        Assertions.assertEquals(expectedRowResult, workbook.getSheetAt(0).getLastRowNum());
+
+        outputStream.close();
+        file.delete();
+        workbook.close();
+    }
+
+}

apache-rocketmq/pom.xml

@@ -1,6 +1,5 @@
 <?xml version="1.0" encoding="UTF-8"?>
-<project
+<project xmlns="http://maven.apache.org/POM/4.0.0"
-    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>

apache-shiro/pom.xml

@@ -1,6 +1,5 @@
 <?xml version="1.0" encoding="UTF-8"?>
-<project
+<project xmlns="http://maven.apache.org/POM/4.0.0"
-    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>

apache-spark/pom.xml

@@ -1,6 +1,5 @@
 <?xml version="1.0" encoding="UTF-8"?>
-<project
+<project xmlns="http://maven.apache.org/POM/4.0.0"
-    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>

apache-tapestry/pom.xml

@@ -1,8 +1,7 @@
 <?xml version="1.0" encoding="UTF-8"?>
-<project
+<project xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
-    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd"
+    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/maven-v4_0_0.xsd">
-    xmlns="http://maven.apache.org/POM/4.0.0">
     <modelVersion>4.0.0</modelVersion>
     <groupId>com.baeldung</groupId>
     <artifactId>apache-tapestry</artifactId>
@@ -12,45 +11,43 @@
 
     <dependencies>
         <!-- To set up an application with a database, change the artifactId below to tapestry-hibernate, 
-        and add a dependency on your JDBC driver. You'll also need to add Hibernate configuration files, such as hibernate.cfg.xml. -->
+            and add a dependency on your JDBC driver. You'll also need to add Hibernate configuration files, such 
+            as hibernate.cfg.xml. -->
         <dependency>
             <groupId>org.apache.tapestry</groupId>
             <artifactId>tapestry-core</artifactId>
             <version>${tapestry-release-version}</version>
         </dependency>
-
         <!-- Include the Log4j implementation for the SLF4J logging framework -->
         <dependency>
             <groupId>org.slf4j</groupId>
             <artifactId>slf4j-log4j12</artifactId>
             <version>${slf4j-release-version}</version>
         </dependency>
-
         <dependency>
             <groupId>org.apache.tapestry</groupId>
             <artifactId>tapestry-webresources</artifactId>
             <version>${tapestry-release-version}</version>
         </dependency>
-
         <!-- Uncomment this to add support for file uploads: -->
-        <!-- <dependency> <groupId>org.apache.tapestry</groupId> <artifactId>tapestry-upload</artifactId> <version>${tapestry-release-version}</version> </dependency> -->
+        <!-- <dependency> <groupId>org.apache.tapestry</groupId> <artifactId>tapestry-upload</artifactId> 
+            <version>${tapestry-release-version}</version> </dependency> -->
 
-        <!-- A dependency on either JUnit or TestNG is required, or the surefire plugin (which runs the tests) will fail, preventing Maven from packaging the WAR. Tapestry includes 
+        <!-- A dependency on either JUnit or TestNG is required, or the surefire plugin (which runs the 
-            a large number of testing facilities designed for use with TestNG (http://testng.org/), so it's recommended. -->
+            tests) will fail, preventing Maven from packaging the WAR. Tapestry includes a large number of testing 
+            facilities designed for use with TestNG (http://testng.org/), so it's recommended. -->
         <dependency>
             <groupId>org.testng</groupId>
             <artifactId>testng</artifactId>
             <version>${testng-release-version}</version>
             <scope>test</scope>
         </dependency>
-
         <dependency>
             <groupId>org.apache.tapestry</groupId>
             <artifactId>tapestry-test</artifactId>
             <version>${tapestry-release-version}</version>
             <scope>test</scope>
         </dependency>
-
         <!-- Provided by the servlet container, but sometimes referenced in the application code. -->
         <dependency>
             <groupId>javax.servlet</groupId>
@@ -58,7 +55,6 @@
             <version>${servlet-api-release-version}</version>
             <scope>provided</scope>
         </dependency>
-
         <!-- Provide dependency to the Tapestry javadoc taglet which replaces the Maven component report -->
         <dependency>
             <groupId>org.apache.tapestry</groupId>
@@ -101,7 +97,8 @@
                 <configuration>
                     <!-- Log to the console. -->
                     <requestLog implementation="org.mortbay.jetty.NCSARequestLog">
-                        <!-- This doesn't do anything for Jetty, but is a workaround for a Maven bug that prevents the requestLog from being set. -->
+                        <!-- This doesn't do anything for Jetty, but is a workaround for a Maven bug 
+                            that prevents the requestLog from being set. -->
                         <append>true</append>
                     </requestLog>
                     <systemProperties>
@@ -123,7 +120,8 @@
             <url>http://repository.jboss.org/nexus/content/groups/public/</url>
         </repository>
 
-        <!-- This repository is only needed when the Tapestry version is a preview release, rather than a final release. -->
+        <!-- This repository is only needed when the Tapestry version is a preview release, rather than 
+            a final release. -->
         <repository>
             <id>apache-staging</id>
             <url>https://repository.apache.org/content/groups/staging/</url>

apache-thrift/pom.xml

@@ -1,6 +1,5 @@
 <?xml version="1.0" encoding="UTF-8"?>
-<project
+<project xmlns="http://maven.apache.org/POM/4.0.0"
-    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>
@@ -27,7 +26,6 @@
                 </exclusion>
             </exclusions>
         </dependency>
-
         <dependency>
             <groupId>org.slf4j</groupId>
             <artifactId>slf4j-simple</artifactId>

apache-tika/pom.xml

@@ -1,6 +1,5 @@
 <?xml version="1.0" encoding="UTF-8"?>
-<project
+<project xmlns="http://maven.apache.org/POM/4.0.0"
-    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>

apache-velocity/pom.xml

@@ -1,6 +1,5 @@
 <?xml version="1.0" encoding="UTF-8"?>
-<project
+<project xmlns="http://maven.apache.org/POM/4.0.0"
-    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/maven-v4_0_0.xsd">
     <modelVersion>4.0.0</modelVersion>

asciidoctor/pom.xml

@@ -1,6 +1,5 @@
 <?xml version="1.0" encoding="UTF-8"?>
-<project
+<project xmlns="http://maven.apache.org/POM/4.0.0"
-    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>

asm/pom.xml

@@ -1,6 +1,5 @@
 <?xml version="1.0" encoding="UTF-8"?>
-<project
+<project xmlns="http://maven.apache.org/POM/4.0.0"
-    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>

atomix/pom.xml

@@ -1,6 +1,5 @@
 <?xml version="1.0" encoding="UTF-8"?>
-<project
+<project xmlns="http://maven.apache.org/POM/4.0.0"
-    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>

aws-app-sync/pom.xml

@@ -1,5 +1,6 @@
 <?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"
+<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 https://maven.apache.org/xsd/maven-4.0.0.xsd">
     <modelVersion>4.0.0</modelVersion>
     <artifactId>aws-app-sync</artifactId>
@@ -14,12 +15,10 @@
     </parent>
 
     <dependencies>
-
         <dependency>
             <groupId>org.springframework.boot</groupId>
             <artifactId>spring-boot-starter-web</artifactId>
         </dependency>
-
         <dependency>
             <groupId>org.springframework.boot</groupId>
             <artifactId>spring-boot-starter-test</artifactId>

aws-lambda/lambda/pom.xml

@@ -1,12 +1,11 @@
 <?xml version="1.0" encoding="UTF-8"?>
-<project
+<project xmlns="http://maven.apache.org/POM/4.0.0"
-    xmlns="http://maven.apache.org/POM/4.0.0"
     xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
     xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
     <modelVersion>4.0.0</modelVersion>
-    <artifactId>aws-lambda-examples</artifactId>
+    <artifactId>lambda</artifactId>
     <version>0.1.0-SNAPSHOT</version>
-    <name>aws-lambda-examples</name>
+    <name>lambda</name>
     <packaging>jar</packaging>
 
     <parent>

aws-lambda/pom.xml

@@ -1,6 +1,5 @@
 <?xml version="1.0" encoding="UTF-8"?>
-<project
+<project xmlns="http://maven.apache.org/POM/4.0.0"
-    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>

aws-lambda/shipping-tracker/ShippingFunction/pom.xml

@@ -1,16 +1,12 @@
-<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+<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/maven-v4_0_0.xsd">
     <modelVersion>4.0.0</modelVersion>
     <groupId>com.baeldung</groupId>
     <artifactId>ShippingFunction</artifactId>
     <version>1.0</version>
     <packaging>jar</packaging>
-    <name>Shipping Tracker Lambda Function</name>
+    <name>ShippingFunction</name>
-    <properties>
-        <maven.compiler.source>1.8</maven.compiler.source>
-        <maven.compiler.target>1.8</maven.compiler.target>
-        <hibernate.version>5.4.21.Final</hibernate.version>
-    </properties>
 
     <dependencies>
         <dependency>
@@ -70,4 +66,11 @@
             </plugin>
         </plugins>
     </build>
+
+    <properties>
+        <maven.compiler.source>1.8</maven.compiler.source>
+        <maven.compiler.target>1.8</maven.compiler.target>
+        <hibernate.version>5.4.21.Final</hibernate.version>
+    </properties>
+
 </project>

aws-reactive/pom.xml

@@ -1,9 +1,12 @@
 <?xml version="1.0" encoding="UTF-8"?>
-<project
+<project xmlns="http://maven.apache.org/POM/4.0.0"
-    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 https://maven.apache.org/xsd/maven-4.0.0.xsd">
     <modelVersion>4.0.0</modelVersion>
+    <artifactId>aws-reactive</artifactId>
+    <version>0.0.1-SNAPSHOT</version>
+    <name>aws-reactive</name>
+    <description>AWS Reactive Sample</description>
 
     <parent>
         <groupId>com.baeldung</groupId>
@@ -11,14 +14,8 @@
         <version>1.0.0-SNAPSHOT</version>
     </parent>
 
-    <artifactId>aws-reactive</artifactId>
-    <version>0.0.1-SNAPSHOT</version>
-    <name>aws-reactive</name>
-    <description>AWS Reactive Sample</description>
-
     <dependencyManagement>
         <dependencies>
-
             <dependency>
                 <!-- Import dependency management from Spring Boot -->
                 <groupId>org.springframework.boot</groupId>
@@ -27,7 +24,6 @@
                 <type>pom</type>
                 <scope>import</scope>
             </dependency>
-
             <dependency>
                 <groupId>software.amazon.awssdk</groupId>
                 <artifactId>bom</artifactId>
@@ -43,20 +39,16 @@
             <groupId>org.springframework.boot</groupId>
             <artifactId>spring-boot-starter-webflux</artifactId>
         </dependency>
-
         <dependency>
             <groupId>software.amazon.awssdk</groupId>
             <artifactId>s3</artifactId>
             <scope>compile</scope>
         </dependency>
-
         <dependency>
             <artifactId>netty-nio-client</artifactId>
             <groupId>software.amazon.awssdk</groupId>
             <scope>compile</scope>
         </dependency>
-
-
         <dependency>
             <groupId>org.springframework.boot</groupId>
             <artifactId>spring-boot-starter-test</artifactId>
@@ -68,8 +60,6 @@
                 </exclusion>
             </exclusions>
         </dependency>
-
-
         <dependency>
             <groupId>io.projectreactor</groupId>
             <artifactId>reactor-test</artifactId>
@@ -100,7 +90,6 @@
     </build>
 
     <properties>
-        <java.version>1.8</java.version>
         <spring.version>2.2.1.RELEASE</spring.version>
         <awssdk.version>2.10.27</awssdk.version>
     </properties>

aws/pom.xml

@@ -1,6 +1,5 @@
 <?xml version="1.0" encoding="UTF-8"?>
-<project
+<project xmlns="http://maven.apache.org/POM/4.0.0"
-    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>

axon/README.md

@@ -5,3 +5,4 @@ This module contains articles about Axon
 ### Relevant articles
 
 - [A Guide to the Axon Framework](https://www.baeldung.com/axon-cqrs-event-sourcing)
+- [Multi-Entity Aggregates in Axon](https://www.baeldung.com/java-axon-multi-entity-aggregates)

axon/pom.xml

@@ -1,6 +1,5 @@
 <?xml version="1.0" encoding="UTF-8"?>
-<project
+<project xmlns="http://maven.apache.org/POM/4.0.0"
-    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>
@@ -15,36 +14,41 @@
         <relativePath>../parent-boot-2</relativePath>
     </parent>
 
+    <dependencyManagement>
+        <dependencies>
+            <dependency>
+                <groupId>org.axonframework</groupId>
+                <artifactId>axon-bom</artifactId>
+                <version>4.5.0</version>
+                <type>pom</type>
+                <scope>import</scope>
+            </dependency>
+        </dependencies>
+    </dependencyManagement>
+
     <dependencies>
         <dependency>
             <groupId>org.axonframework</groupId>
             <artifactId>axon-spring-boot-starter</artifactId>
-            <version>${axon.version}</version>
         </dependency>
-
         <dependency>
             <groupId>org.axonframework</groupId>
             <artifactId>axon-test</artifactId>
-            <version>${axon.version}</version>
             <scope>test</scope>
         </dependency>
-
         <dependency>
             <groupId>org.springframework.boot</groupId>
             <artifactId>spring-boot-autoconfigure</artifactId>
             <scope>compile</scope>
         </dependency>
-
         <dependency>
             <groupId>org.springframework.boot</groupId>
             <artifactId>spring-boot-starter-web</artifactId>
         </dependency>
-
         <dependency>
             <groupId>org.springframework.boot</groupId>
             <artifactId>spring-boot-starter-data-jpa</artifactId>
         </dependency>
-
         <dependency>
             <groupId>com.h2database</groupId>
             <artifactId>h2</artifactId>
@@ -52,8 +56,4 @@
         </dependency>
     </dependencies>
 
-    <properties>
-        <axon.version>4.1.2</axon.version>
-    </properties>
-
 </project>

axon/src/main/java/com/baeldung/axon/commandmodel/OrderAggregate.java

@@ -1,59 +0,0 @@
-package com.baeldung.axon.commandmodel;
-
-import static org.axonframework.modelling.command.AggregateLifecycle.apply;
-
-import org.axonframework.commandhandling.CommandHandler;
-import org.axonframework.eventsourcing.EventSourcingHandler;
-import org.axonframework.modelling.command.AggregateIdentifier;
-import org.axonframework.spring.stereotype.Aggregate;
-
-import com.baeldung.axon.coreapi.commands.ConfirmOrderCommand;
-import com.baeldung.axon.coreapi.commands.PlaceOrderCommand;
-import com.baeldung.axon.coreapi.commands.ShipOrderCommand;
-import com.baeldung.axon.coreapi.events.OrderConfirmedEvent;
-import com.baeldung.axon.coreapi.events.OrderPlacedEvent;
-import com.baeldung.axon.coreapi.events.OrderShippedEvent;
-import com.baeldung.axon.coreapi.exceptions.UnconfirmedOrderException;
-
-@Aggregate
-public class OrderAggregate {
-
-    @AggregateIdentifier
-    private String orderId;
-    private boolean orderConfirmed;
-
-    @CommandHandler
-    public OrderAggregate(PlaceOrderCommand command) {
-        apply(new OrderPlacedEvent(command.getOrderId(), command.getProduct()));
-    }
-
-    @CommandHandler
-    public void handle(ConfirmOrderCommand command) {
-        apply(new OrderConfirmedEvent(orderId));
-    }
-
-    @CommandHandler
-    public void handle(ShipOrderCommand command) {
-        if (!orderConfirmed) {
-            throw new UnconfirmedOrderException();
-        }
-
-        apply(new OrderShippedEvent(orderId));
-    }
-
-    @EventSourcingHandler
-    public void on(OrderPlacedEvent event) {
-        this.orderId = event.getOrderId();
-        this.orderConfirmed = false;
-    }
-
-    @EventSourcingHandler
-    public void on(OrderConfirmedEvent event) {
-        this.orderConfirmed = true;
-    }
-
-    protected OrderAggregate() {
-        // Required by Axon to build a default Aggregate prior to Event Sourcing
-    }
-
-}

axon/src/main/java/com/baeldung/axon/commandmodel/order/OrderAggregate.java

@@ -0,0 +1,98 @@
+package com.baeldung.axon.commandmodel.order;
+
+import com.baeldung.axon.coreapi.commands.AddProductCommand;
+import com.baeldung.axon.coreapi.commands.ConfirmOrderCommand;
+import com.baeldung.axon.coreapi.commands.CreateOrderCommand;
+import com.baeldung.axon.coreapi.commands.ShipOrderCommand;
+import com.baeldung.axon.coreapi.events.OrderConfirmedEvent;
+import com.baeldung.axon.coreapi.events.OrderCreatedEvent;
+import com.baeldung.axon.coreapi.events.OrderShippedEvent;
+import com.baeldung.axon.coreapi.events.ProductAddedEvent;
+import com.baeldung.axon.coreapi.events.ProductRemovedEvent;
+import com.baeldung.axon.coreapi.exceptions.DuplicateOrderLineException;
+import com.baeldung.axon.coreapi.exceptions.OrderAlreadyConfirmedException;
+import com.baeldung.axon.coreapi.exceptions.UnconfirmedOrderException;
+import org.axonframework.commandhandling.CommandHandler;
+import org.axonframework.eventsourcing.EventSourcingHandler;
+import org.axonframework.modelling.command.AggregateIdentifier;
+import org.axonframework.modelling.command.AggregateMember;
+import org.axonframework.spring.stereotype.Aggregate;
+
+import java.util.HashMap;
+import java.util.Map;
+
+import static org.axonframework.modelling.command.AggregateLifecycle.apply;
+
+@Aggregate
+public class OrderAggregate {
+
+    @AggregateIdentifier
+    private String orderId;
+    private boolean orderConfirmed;
+
+    @AggregateMember
+    private Map<String, OrderLine> orderLines;
+
+    @CommandHandler
+    public OrderAggregate(CreateOrderCommand command) {
+        apply(new OrderCreatedEvent(command.getOrderId()));
+    }
+
+    @CommandHandler
+    public void handle(AddProductCommand command) {
+        if (orderConfirmed) {
+            throw new OrderAlreadyConfirmedException(orderId);
+        }
+
+        String productId = command.getProductId();
+        if (orderLines.containsKey(productId)) {
+            throw new DuplicateOrderLineException(productId);
+        }
+        apply(new ProductAddedEvent(orderId, productId));
+    }
+
+    @CommandHandler
+    public void handle(ConfirmOrderCommand command) {
+        if (orderConfirmed) {
+            return;
+        }
+
+        apply(new OrderConfirmedEvent(orderId));
+    }
+
+    @CommandHandler
+    public void handle(ShipOrderCommand command) {
+        if (!orderConfirmed) {
+            throw new UnconfirmedOrderException();
+        }
+
+        apply(new OrderShippedEvent(orderId));
+    }
+
+    @EventSourcingHandler
+    public void on(OrderCreatedEvent event) {
+        this.orderId = event.getOrderId();
+        this.orderConfirmed = false;
+        this.orderLines = new HashMap<>();
+    }
+
+    @EventSourcingHandler
+    public void on(OrderConfirmedEvent event) {
+        this.orderConfirmed = true;
+    }
+
+    @EventSourcingHandler
+    public void on(ProductAddedEvent event) {
+        String productId = event.getProductId();
+        this.orderLines.put(productId, new OrderLine(productId));
+    }
+
+    @EventSourcingHandler
+    public void on(ProductRemovedEvent event) {
+        this.orderLines.remove(event.getProductId());
+    }
+
+    protected OrderAggregate() {
+        // Required by Axon to build a default Aggregate prior to Event Sourcing
+    }
+}

axon/src/main/java/com/baeldung/axon/commandmodel/order/OrderLine.java

@@ -0,0 +1,83 @@
+package com.baeldung.axon.commandmodel.order;
+
+import com.baeldung.axon.coreapi.commands.DecrementProductCountCommand;
+import com.baeldung.axon.coreapi.commands.IncrementProductCountCommand;
+import com.baeldung.axon.coreapi.events.OrderConfirmedEvent;
+import com.baeldung.axon.coreapi.events.ProductCountDecrementedEvent;
+import com.baeldung.axon.coreapi.events.ProductCountIncrementedEvent;
+import com.baeldung.axon.coreapi.events.ProductRemovedEvent;
+import com.baeldung.axon.coreapi.exceptions.OrderAlreadyConfirmedException;
+import org.axonframework.commandhandling.CommandHandler;
+import org.axonframework.eventsourcing.EventSourcingHandler;
+import org.axonframework.modelling.command.EntityId;
+
+import java.util.Objects;
+
+import static org.axonframework.modelling.command.AggregateLifecycle.apply;
+
+public class OrderLine {
+
+    @EntityId
+    private final String productId;
+    private Integer count;
+    private boolean orderConfirmed;
+
+    public OrderLine(String productId) {
+        this.productId = productId;
+        this.count = 1;
+    }
+
+    @CommandHandler
+    public void handle(IncrementProductCountCommand command) {
+        if (orderConfirmed) {
+            throw new OrderAlreadyConfirmedException(command.getOrderId());
+        }
+
+        apply(new ProductCountIncrementedEvent(command.getOrderId(), productId));
+    }
+
+    @CommandHandler
+    public void handle(DecrementProductCountCommand command) {
+        if (orderConfirmed) {
+            throw new OrderAlreadyConfirmedException(command.getOrderId());
+        }
+
+        if (count <= 1) {
+            apply(new ProductRemovedEvent(command.getOrderId(), productId));
+        } else {
+            apply(new ProductCountDecrementedEvent(command.getOrderId(), productId));
+        }
+    }
+
+    @EventSourcingHandler
+    public void on(ProductCountIncrementedEvent event) {
+        this.count++;
+    }
+
+    @EventSourcingHandler
+    public void on(ProductCountDecrementedEvent event) {
+        this.count--;
+    }
+
+    @EventSourcingHandler
+    public void on(OrderConfirmedEvent event) {
+        this.orderConfirmed = true;
+    }
+
+    @Override
+    public boolean equals(Object o) {
+        if (this == o) {
+            return true;
+        }
+        if (o == null || getClass() != o.getClass()) {
+            return false;
+        }
+        OrderLine orderLine = (OrderLine) o;
+        return Objects.equals(productId, orderLine.productId) && Objects.equals(count, orderLine.count);
+    }
+
+    @Override
+    public int hashCode() {
+        return Objects.hash(productId, count);
+    }
+}

axon/src/main/java/com/baeldung/axon/coreapi/commands/AddProductCommand.java

@@ -0,0 +1,50 @@
+package com.baeldung.axon.coreapi.commands;
+
+import org.axonframework.modelling.command.TargetAggregateIdentifier;
+
+import java.util.Objects;
+
+public class AddProductCommand {
+
+    @TargetAggregateIdentifier
+    private final String orderId;
+    private final String productId;
+
+    public AddProductCommand(String orderId, String productId) {
+        this.orderId = orderId;
+        this.productId = productId;
+    }
+
+    public String getOrderId() {
+        return orderId;
+    }
+
+    public String getProductId() {
+        return productId;
+    }
+
+    @Override
+    public boolean equals(Object o) {
+        if (this == o) {
+            return true;
+        }
+        if (o == null || getClass() != o.getClass()) {
+            return false;
+        }
+        AddProductCommand that = (AddProductCommand) o;
+        return Objects.equals(orderId, that.orderId) && Objects.equals(productId, that.productId);
+    }
+
+    @Override
+    public int hashCode() {
+        return Objects.hash(orderId, productId);
+    }
+
+    @Override
+    public String toString() {
+        return "AddProductCommand{" +
+                "orderId='" + orderId + '\'' +
+                ", productId='" + productId + '\'' +
+                '}';
+    }
+}

axon/src/main/java/com/baeldung/axon/coreapi/commands/CreateOrderCommand.java

@@ -0,0 +1,43 @@
+package com.baeldung.axon.coreapi.commands;
+
+import org.axonframework.modelling.command.TargetAggregateIdentifier;
+
+import java.util.Objects;
+
+public class CreateOrderCommand {
+
+    @TargetAggregateIdentifier
+    private final String orderId;
+
+    public CreateOrderCommand(String orderId) {
+        this.orderId = orderId;
+    }
+
+    public String getOrderId() {
+        return orderId;
+    }
+
+    @Override
+    public boolean equals(Object o) {
+        if (this == o) {
+            return true;
+        }
+        if (o == null || getClass() != o.getClass()) {
+            return false;
+        }
+        CreateOrderCommand that = (CreateOrderCommand) o;
+        return Objects.equals(orderId, that.orderId);
+    }
+
+    @Override
+    public int hashCode() {
+        return Objects.hash(orderId);
+    }
+
+    @Override
+    public String toString() {
+        return "CreateOrderCommand{" +
+                "orderId='" + orderId + '\'' +
+                '}';
+    }
+}

axon/src/main/java/com/baeldung/axon/coreapi/commands/DecrementProductCountCommand.java

@@ -0,0 +1,50 @@
+package com.baeldung.axon.coreapi.commands;
+
+import org.axonframework.modelling.command.TargetAggregateIdentifier;
+
+import java.util.Objects;
+
+public class DecrementProductCountCommand {
+
+    @TargetAggregateIdentifier
+    private final String orderId;
+    private final String productId;
+
+    public DecrementProductCountCommand(String orderId, String productId) {
+        this.orderId = orderId;
+        this.productId = productId;
+    }
+
+    public String getOrderId() {
+        return orderId;
+    }
+
+    public String getProductId() {
+        return productId;
+    }
+
+    @Override
+    public boolean equals(Object o) {
+        if (this == o) {
+            return true;
+        }
+        if (o == null || getClass() != o.getClass()) {
+            return false;
+        }
+        DecrementProductCountCommand that = (DecrementProductCountCommand) o;
+        return Objects.equals(orderId, that.orderId) && Objects.equals(productId, that.productId);
+    }
+
+    @Override
+    public int hashCode() {
+        return Objects.hash(orderId, productId);
+    }
+
+    @Override
+    public String toString() {
+        return "DecrementProductCountCommand{" +
+                "orderId='" + orderId + '\'' +
+                ", productId='" + productId + '\'' +
+                '}';
+    }
+}

axon/src/main/java/com/baeldung/axon/coreapi/commands/IncrementProductCountCommand.java

@@ -0,0 +1,50 @@
+package com.baeldung.axon.coreapi.commands;
+
+import org.axonframework.modelling.command.TargetAggregateIdentifier;
+
+import java.util.Objects;
+
+public class IncrementProductCountCommand {
+
+    @TargetAggregateIdentifier
+    private final String orderId;
+    private final String productId;
+
+    public IncrementProductCountCommand(String orderId, String productId) {
+        this.orderId = orderId;
+        this.productId = productId;
+    }
+
+    public String getOrderId() {
+        return orderId;
+    }
+
+    public String getProductId() {
+        return productId;
+    }
+
+    @Override
+    public boolean equals(Object o) {
+        if (this == o) {
+            return true;
+        }
+        if (o == null || getClass() != o.getClass()) {
+            return false;
+        }
+        IncrementProductCountCommand that = (IncrementProductCountCommand) o;
+        return Objects.equals(orderId, that.orderId) && Objects.equals(productId, that.productId);
+    }
+
+    @Override
+    public int hashCode() {
+        return Objects.hash(orderId, productId);
+    }
+
+    @Override
+    public String toString() {
+        return "IncrementProductCountCommand{" +
+                "orderId='" + orderId + '\'' +
+                ", productId='" + productId + '\'' +
+                '}';
+    }
+}

axon/src/main/java/com/baeldung/axon/coreapi/commands/PlaceOrderCommand.java

@@ -1,51 +0,0 @@
-package com.baeldung.axon.coreapi.commands;
-
-import java.util.Objects;
-
-import org.axonframework.modelling.command.TargetAggregateIdentifier;
-
-public class PlaceOrderCommand {
-
-    @TargetAggregateIdentifier
-    private final String orderId;
-    private final String product;
-
-    public PlaceOrderCommand(String orderId, String product) {
-        this.orderId = orderId;
-        this.product = product;
-    }
-
-    public String getOrderId() {
-        return orderId;
-    }
-
-    public String getProduct() {
-        return product;
-    }
-
-    @Override
-    public int hashCode() {
-        return Objects.hash(orderId, product);
-    }
-
-    @Override
-    public boolean equals(Object obj) {
-        if (this == obj) {
-            return true;
-        }
-        if (obj == null || getClass() != obj.getClass()) {
-            return false;
-        }
-        final PlaceOrderCommand other = (PlaceOrderCommand) obj;
-        return Objects.equals(this.orderId, other.orderId)
-                && Objects.equals(this.product, other.product);
-    }
-
-    @Override
-    public String toString() {
-        return "PlaceOrderCommand{" +
-                "orderId='" + orderId + '\'' +
-                ", product='" + product + '\'' +
-                '}';
-    }
-}

axon/src/main/java/com/baeldung/axon/coreapi/events/OrderCreatedEvent.java

@@ -0,0 +1,40 @@
+package com.baeldung.axon.coreapi.events;
+
+import java.util.Objects;
+
+public class OrderCreatedEvent {
+
+    private final String orderId;
+
+    public OrderCreatedEvent(String orderId) {
+        this.orderId = orderId;
+    }
+
+    public String getOrderId() {
+        return orderId;
+    }
+
+    @Override
+    public boolean equals(Object o) {
+        if (this == o) {
+            return true;
+        }
+        if (o == null || getClass() != o.getClass()) {
+            return false;
+        }
+        OrderCreatedEvent that = (OrderCreatedEvent) o;
+        return Objects.equals(orderId, that.orderId);
+    }
+
+    @Override
+    public int hashCode() {
+        return Objects.hash(orderId);
+    }
+
+    @Override
+    public String toString() {
+        return "OrderCreatedEvent{" +
+                "orderId='" + orderId + '\'' +
+                '}';
+    }
+}

axon/src/main/java/com/baeldung/axon/coreapi/events/OrderPlacedEvent.java

@@ -1,48 +0,0 @@
-package com.baeldung.axon.coreapi.events;
-
-import java.util.Objects;
-
-public class OrderPlacedEvent {
-
-    private final String orderId;
-    private final String product;
-
-    public OrderPlacedEvent(String orderId, String product) {
-        this.orderId = orderId;
-        this.product = product;
-    }
-
-    public String getOrderId() {
-        return orderId;
-    }
-
-    public String getProduct() {
-        return product;
-    }
-
-    @Override
-    public int hashCode() {
-        return Objects.hash(orderId, product);
-    }
-
-    @Override
-    public boolean equals(Object obj) {
-        if (this == obj) {
-            return true;
-        }
-        if (obj == null || getClass() != obj.getClass()) {
-            return false;
-        }
-        final OrderPlacedEvent other = (OrderPlacedEvent) obj;
-        return Objects.equals(this.orderId, other.orderId)
-                && Objects.equals(this.product, other.product);
-    }
-
-    @Override
-    public String toString() {
-        return "OrderPlacedEvent{" +
-                "orderId='" + orderId + '\'' +
-                ", product='" + product + '\'' +
-                '}';
-    }
-}

axon/src/main/java/com/baeldung/axon/coreapi/events/ProductAddedEvent.java

@@ -0,0 +1,47 @@
+package com.baeldung.axon.coreapi.events;
+
+import java.util.Objects;
+
+public class ProductAddedEvent {
+
+    private final String orderId;
+    private final String productId;
+
+    public ProductAddedEvent(String orderId, String productId) {
+        this.orderId = orderId;
+        this.productId = productId;
+    }
+
+    public String getOrderId() {
+        return orderId;
+    }
+
+    public String getProductId() {
+        return productId;
+    }
+
+    @Override
+    public boolean equals(Object o) {
+        if (this == o) {
+            return true;
+        }
+        if (o == null || getClass() != o.getClass()) {
+            return false;
+        }
+        ProductAddedEvent that = (ProductAddedEvent) o;
+        return Objects.equals(orderId, that.orderId) && Objects.equals(productId, that.productId);
+    }
+
+    @Override
+    public int hashCode() {
+        return Objects.hash(orderId, productId);
+    }
+
+    @Override
+    public String toString() {
+        return "ProductAddedEvent{" +
+                "orderId='" + orderId + '\'' +
+                ", productId='" + productId + '\'' +
+                '}';
+    }
+}

axon/src/main/java/com/baeldung/axon/coreapi/events/ProductCountDecrementedEvent.java

@@ -0,0 +1,47 @@
+package com.baeldung.axon.coreapi.events;
+
+import java.util.Objects;
+
+public class ProductCountDecrementedEvent {
+
+    private final String orderId;
+    private final String productId;
+
+    public ProductCountDecrementedEvent(String orderId, String productId) {
+        this.orderId = orderId;
+        this.productId = productId;
+    }
+
+    public String getOrderId() {
+        return orderId;
+    }
+
+    public String getProductId() {
+        return productId;
+    }
+
+    @Override
+    public boolean equals(Object o) {
+        if (this == o) {
+            return true;
+        }
+        if (o == null || getClass() != o.getClass()) {
+            return false;
+        }
+        ProductCountDecrementedEvent that = (ProductCountDecrementedEvent) o;
+        return Objects.equals(orderId, that.orderId) && Objects.equals(productId, that.productId);
+    }
+
+    @Override
+    public int hashCode() {
+        return Objects.hash(orderId, productId);
+    }
+
+    @Override
+    public String toString() {
+        return "ProductCountDecrementedEvent{" +
+                "orderId='" + orderId + '\'' +
+                ", productId='" + productId + '\'' +
+                '}';
+    }
+}

axon/src/main/java/com/baeldung/axon/coreapi/events/ProductCountIncrementedEvent.java

@@ -0,0 +1,47 @@
+package com.baeldung.axon.coreapi.events;
+
+import java.util.Objects;
+
+public class ProductCountIncrementedEvent {
+
+    private final String orderId;
+    private final String productId;
+
+    public ProductCountIncrementedEvent(String orderId, String productId) {
+        this.orderId = orderId;
+        this.productId = productId;
+    }
+
+    public String getOrderId() {
+        return orderId;
+    }
+
+    public String getProductId() {
+        return productId;
+    }
+
+    @Override
+    public boolean equals(Object o) {
+        if (this == o) {
+            return true;
+        }
+        if (o == null || getClass() != o.getClass()) {
+            return false;
+        }
+        ProductCountIncrementedEvent that = (ProductCountIncrementedEvent) o;
+        return Objects.equals(orderId, that.orderId) && Objects.equals(productId, that.productId);
+    }
+
+    @Override
+    public int hashCode() {
+        return Objects.hash(orderId, productId);
+    }
+
+    @Override
+    public String toString() {
+        return "ProductCountIncrementedEvent{" +
+                "orderId='" + orderId + '\'' +
+                ", productId='" + productId + '\'' +
+                '}';
+    }
+}

axon/src/main/java/com/baeldung/axon/coreapi/events/ProductRemovedEvent.java

@@ -0,0 +1,47 @@
+package com.baeldung.axon.coreapi.events;
+
+import java.util.Objects;
+
+public class ProductRemovedEvent {
+
+    private final String orderId;
+    private final String productId;
+
+    public ProductRemovedEvent(String orderId, String productId) {
+        this.orderId = orderId;
+        this.productId = productId;
+    }
+
+    public String getOrderId() {
+        return orderId;
+    }
+
+    public String getProductId() {
+        return productId;
+    }
+
+    @Override
+    public boolean equals(Object o) {
+        if (this == o) {
+            return true;
+        }
+        if (o == null || getClass() != o.getClass()) {
+            return false;
+        }
+        ProductRemovedEvent that = (ProductRemovedEvent) o;
+        return Objects.equals(orderId, that.orderId) && Objects.equals(productId, that.productId);
+    }
+
+    @Override
+    public int hashCode() {
+        return Objects.hash(orderId, productId);
+    }
+
+    @Override
+    public String toString() {
+        return "ProductRemovedEvent{" +
+                "orderId='" + orderId + '\'' +
+                ", productId='" + productId + '\'' +
+                '}';
+    }
+}

axon/src/main/java/com/baeldung/axon/coreapi/exceptions/DuplicateOrderLineException.java

@@ -0,0 +1,8 @@
+package com.baeldung.axon.coreapi.exceptions;
+
+public class DuplicateOrderLineException extends IllegalStateException {
+
+    public DuplicateOrderLineException(String productId) {
+        super("Cannot duplicate order line for product identifier [" + productId + "]");
+    }
+}

axon/src/main/java/com/baeldung/axon/coreapi/exceptions/OrderAlreadyConfirmedException.java

@@ -0,0 +1,8 @@
+package com.baeldung.axon.coreapi.exceptions;
+
+public class OrderAlreadyConfirmedException extends IllegalStateException {
+
+    public OrderAlreadyConfirmedException(String orderId) {
+        super("Cannot perform operation because order [" + orderId + "] is already confirmed.");
+    }
+}

axon/src/main/java/com/baeldung/axon/coreapi/queries/Order.java

@@ -0,0 +1,83 @@
+package com.baeldung.axon.coreapi.queries;
+
+import java.util.HashMap;
+import java.util.Map;
+import java.util.Objects;
+
+public class Order {
+
+    private final String orderId;
+    private final Map<String, Integer> products;
+    private OrderStatus orderStatus;
+
+    public Order(String orderId) {
+        this.orderId = orderId;
+        this.products = new HashMap<>();
+        orderStatus = OrderStatus.CREATED;
+    }
+
+    public String getOrderId() {
+        return orderId;
+    }
+
+    public Map<String, Integer> getProducts() {
+        return products;
+    }
+
+    public OrderStatus getOrderStatus() {
+        return orderStatus;
+    }
+
+    public void addProduct(String productId) {
+        products.putIfAbsent(productId, 1);
+    }
+
+    public void incrementProductInstance(String productId) {
+        products.computeIfPresent(productId, (id, count) -> ++count);
+    }
+
+    public void decrementProductInstance(String productId) {
+        products.computeIfPresent(productId, (id, count) -> --count);
+    }
+
+
+    public void removeProduct(String productId) {
+        products.remove(productId);
+    }
+
+    public void setOrderConfirmed() {
+        this.orderStatus = OrderStatus.CONFIRMED;
+    }
+
+    public void setOrderShipped() {
+        this.orderStatus = OrderStatus.SHIPPED;
+    }
+
+    @Override
+    public boolean equals(Object o) {
+        if (this == o) {
+            return true;
+        }
+        if (o == null || getClass() != o.getClass()) {
+            return false;
+        }
+        Order that = (Order) o;
+        return Objects.equals(orderId, that.orderId)
+                && Objects.equals(products, that.products)
+                && orderStatus == that.orderStatus;
+    }
+
+    @Override
+    public int hashCode() {
+        return Objects.hash(orderId, products, orderStatus);
+    }
+
+    @Override
+    public String toString() {
+        return "Order{" +
+                "orderId='" + orderId + '\'' +
+                ", products=" + products +
+                ", orderStatus=" + orderStatus +
+                '}';
+    }
+}

axon/src/main/java/com/baeldung/axon/coreapi/queries/OrderStatus.java

@@ -2,6 +2,5 @@ package com.baeldung.axon.coreapi.queries;
 
 public enum OrderStatus {
 
-    PLACED, CONFIRMED, SHIPPED
+    CREATED, CONFIRMED, SHIPPED
-
 }

axon/src/main/java/com/baeldung/axon/coreapi/queries/OrderedProduct.java

@@ -1,64 +0,0 @@
-package com.baeldung.axon.coreapi.queries;
-
-import java.util.Objects;
-
-public class OrderedProduct {
-
-    private final String orderId;
-    private final String product;
-    private OrderStatus orderStatus;
-
-    public OrderedProduct(String orderId, String product) {
-        this.orderId = orderId;
-        this.product = product;
-        orderStatus = OrderStatus.PLACED;
-    }
-
-    public String getOrderId() {
-        return orderId;
-    }
-
-    public String getProduct() {
-        return product;
-    }
-
-    public OrderStatus getOrderStatus() {
-        return orderStatus;
-    }
-
-    public void setOrderConfirmed() {
-        this.orderStatus = OrderStatus.CONFIRMED;
-    }
-
-    public void setOrderShipped() {
-        this.orderStatus = OrderStatus.SHIPPED;
-    }
-
-    @Override
-    public int hashCode() {
-        return Objects.hash(orderId, product, orderStatus);
-    }
-
-    @Override
-    public boolean equals(Object obj) {
-        if (this == obj) {
-            return true;
-        }
-        if (obj == null || getClass() != obj.getClass()) {
-            return false;
-        }
-        final OrderedProduct other = (OrderedProduct) obj;
-        return Objects.equals(this.orderId, other.orderId)
-                && Objects.equals(this.product, other.product)
-                && Objects.equals(this.orderStatus, other.orderStatus);
-    }
-
-    @Override
-    public String toString() {
-        return "OrderedProduct{" +
-                "orderId='" + orderId + '\'' +
-                ", product='" + product + '\'' +
-                ", orderStatus=" + orderStatus +
-                '}';
-    }
-}

axon/src/main/java/com/baeldung/axon/gui/OrderRestEndpoint.java

@@ -1,20 +1,24 @@
 package com.baeldung.axon.gui;
 
-import java.util.List;
+import com.baeldung.axon.coreapi.commands.AddProductCommand;
-import java.util.UUID;
+import com.baeldung.axon.coreapi.commands.ConfirmOrderCommand;
-
+import com.baeldung.axon.coreapi.commands.CreateOrderCommand;
+import com.baeldung.axon.coreapi.commands.DecrementProductCountCommand;
+import com.baeldung.axon.coreapi.commands.IncrementProductCountCommand;
+import com.baeldung.axon.coreapi.commands.ShipOrderCommand;
+import com.baeldung.axon.coreapi.queries.FindAllOrderedProductsQuery;
+import com.baeldung.axon.coreapi.queries.Order;
 import org.axonframework.commandhandling.gateway.CommandGateway;
 import org.axonframework.messaging.responsetypes.ResponseTypes;
 import org.axonframework.queryhandling.QueryGateway;
 import org.springframework.web.bind.annotation.GetMapping;
+import org.springframework.web.bind.annotation.PathVariable;
 import org.springframework.web.bind.annotation.PostMapping;
 import org.springframework.web.bind.annotation.RestController;
 
-import com.baeldung.axon.coreapi.commands.ConfirmOrderCommand;
+import java.util.List;
-import com.baeldung.axon.coreapi.commands.PlaceOrderCommand;
+import java.util.UUID;
-import com.baeldung.axon.coreapi.commands.ShipOrderCommand;
+import java.util.concurrent.CompletableFuture;
-import com.baeldung.axon.coreapi.queries.FindAllOrderedProductsQuery;
-import com.baeldung.axon.coreapi.queries.OrderedProduct;
 
 @RestController
 public class OrderRestEndpoint {
@@ -28,25 +32,63 @@ public class OrderRestEndpoint {
     }
 
     @PostMapping("/ship-order")
-    public void shipOrder() {
+    public CompletableFuture<Void> shipOrder() {
         String orderId = UUID.randomUUID().toString();
-        commandGateway.send(new PlaceOrderCommand(orderId, "Deluxe Chair"));
+        return commandGateway.send(new CreateOrderCommand(orderId))
-        commandGateway.send(new ConfirmOrderCommand(orderId));
+                             .thenCompose(result -> commandGateway.send(new AddProductCommand(orderId, "Deluxe Chair")))
-        commandGateway.send(new ShipOrderCommand(orderId));
+                             .thenCompose(result -> commandGateway.send(new ConfirmOrderCommand(orderId)))
+                             .thenCompose(result -> commandGateway.send(new ShipOrderCommand(orderId)));
     }
 
     @PostMapping("/ship-unconfirmed-order")
-    public void shipUnconfirmedOrder() {
+    public CompletableFuture<Void> shipUnconfirmedOrder() {
         String orderId = UUID.randomUUID().toString();
-        commandGateway.send(new PlaceOrderCommand(orderId, "Deluxe Chair"));
+        return commandGateway.send(new CreateOrderCommand(orderId))
+                             .thenCompose(result -> commandGateway.send(new AddProductCommand(orderId, "Deluxe Chair")))
                              // This throws an exception, as an Order cannot be shipped if it has not been confirmed yet.
-        commandGateway.send(new ShipOrderCommand(orderId));
+                             .thenCompose(result -> commandGateway.send(new ShipOrderCommand(orderId)));
+    }
+
+    @PostMapping("/order")
+    public CompletableFuture<String> createOrder() {
+        return createOrder(UUID.randomUUID().toString());
+    }
+
+    @PostMapping("/order/{order-id}")
+    public CompletableFuture<String> createOrder(@PathVariable("order-id") String orderId) {
+        return commandGateway.send(new CreateOrderCommand(orderId));
+    }
+
+    @PostMapping("/order/{order-id}/product/{product-id}")
+    public CompletableFuture<Void> addProduct(@PathVariable("order-id") String orderId,
+                                              @PathVariable("product-id") String productId) {
+        return commandGateway.send(new AddProductCommand(orderId, productId));
+    }
+
+    @PostMapping("/order/{order-id}/product/{product-id}/increment")
+    public CompletableFuture<Void> incrementProduct(@PathVariable("order-id") String orderId,
+                                                    @PathVariable("product-id") String productId) {
+        return commandGateway.send(new IncrementProductCountCommand(orderId, productId));
+    }
+
+    @PostMapping("/order/{order-id}/product/{product-id}/decrement")
+    public CompletableFuture<Void> decrementProduct(@PathVariable("order-id") String orderId,
+                                                    @PathVariable("product-id") String productId) {
+        return commandGateway.send(new DecrementProductCountCommand(orderId, productId));
+    }
+
+    @PostMapping("/order/{order-id}/confirm")
+    public CompletableFuture<Void> confirmOrder(@PathVariable("order-id") String orderId) {
+        return commandGateway.send(new ConfirmOrderCommand(orderId));
+    }
+
+    @PostMapping("/order/{order-id}/ship")
+    public CompletableFuture<Void> shipOrder(@PathVariable("order-id") String orderId) {
+        return commandGateway.send(new ShipOrderCommand(orderId));
     }
 
     @GetMapping("/all-orders")
-    public List<OrderedProduct> findAllOrderedProducts() {
+    public CompletableFuture<List<Order>> findAllOrders() {
-        return queryGateway.query(new FindAllOrderedProductsQuery(), ResponseTypes.multipleInstancesOf(OrderedProduct.class))
+        return queryGateway.query(new FindAllOrderedProductsQuery(), ResponseTypes.multipleInstancesOf(Order.class));
-                           .join();
     }
-
 }

axon/src/main/java/com/baeldung/axon/querymodel/OrderedProductsEventHandler.java

@@ -1,52 +0,0 @@
-package com.baeldung.axon.querymodel;
-
-import java.util.ArrayList;
-import java.util.HashMap;
-import java.util.List;
-import java.util.Map;
-
-import org.axonframework.config.ProcessingGroup;
-import org.axonframework.eventhandling.EventHandler;
-import org.axonframework.queryhandling.QueryHandler;
-import org.springframework.stereotype.Service;
-
-import com.baeldung.axon.coreapi.events.OrderConfirmedEvent;
-import com.baeldung.axon.coreapi.events.OrderPlacedEvent;
-import com.baeldung.axon.coreapi.events.OrderShippedEvent;
-import com.baeldung.axon.coreapi.queries.FindAllOrderedProductsQuery;
-import com.baeldung.axon.coreapi.queries.OrderedProduct;
-
-@Service
-@ProcessingGroup("ordered-products")
-public class OrderedProductsEventHandler {
-
-    private final Map<String, OrderedProduct> orderedProducts = new HashMap<>();
-
-    @EventHandler
-    public void on(OrderPlacedEvent event) {
-        String orderId = event.getOrderId();
-        orderedProducts.put(orderId, new OrderedProduct(orderId, event.getProduct()));
-    }
-
-    @EventHandler
-    public void on(OrderConfirmedEvent event) {
-        orderedProducts.computeIfPresent(event.getOrderId(), (orderId, orderedProduct) -> {
-            orderedProduct.setOrderConfirmed();
-            return orderedProduct;
-        });
-    }
-
-    @EventHandler
-    public void on(OrderShippedEvent event) {
-        orderedProducts.computeIfPresent(event.getOrderId(), (orderId, orderedProduct) -> {
-            orderedProduct.setOrderShipped();
-            return orderedProduct;
-        });
-    }
-
-    @QueryHandler
-    public List<OrderedProduct> handle(FindAllOrderedProductsQuery query) {
-        return new ArrayList<>(orderedProducts.values());
-    }
-
-}

axon/src/main/java/com/baeldung/axon/querymodel/OrdersEventHandler.java

@@ -0,0 +1,86 @@
+package com.baeldung.axon.querymodel;
+
+import com.baeldung.axon.coreapi.events.OrderConfirmedEvent;
+import com.baeldung.axon.coreapi.events.OrderCreatedEvent;
+import com.baeldung.axon.coreapi.events.OrderShippedEvent;
+import com.baeldung.axon.coreapi.events.ProductAddedEvent;
+import com.baeldung.axon.coreapi.events.ProductCountDecrementedEvent;
+import com.baeldung.axon.coreapi.events.ProductCountIncrementedEvent;
+import com.baeldung.axon.coreapi.events.ProductRemovedEvent;
+import com.baeldung.axon.coreapi.queries.FindAllOrderedProductsQuery;
+import com.baeldung.axon.coreapi.queries.Order;
+import org.axonframework.config.ProcessingGroup;
+import org.axonframework.eventhandling.EventHandler;
+import org.axonframework.queryhandling.QueryHandler;
+import org.springframework.stereotype.Service;
+
+import java.util.ArrayList;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+
+@Service
+@ProcessingGroup("orders")
+public class OrdersEventHandler {
+
+    private final Map<String, Order> orders = new HashMap<>();
+
+    @EventHandler
+    public void on(OrderCreatedEvent event) {
+        String orderId = event.getOrderId();
+        orders.put(orderId, new Order(orderId));
+    }
+
+    @EventHandler
+    public void on(ProductAddedEvent event) {
+        orders.computeIfPresent(event.getOrderId(), (orderId, order) -> {
+            order.addProduct(event.getProductId());
+            return order;
+        });
+    }
+
+    @EventHandler
+    public void on(ProductCountIncrementedEvent event) {
+        orders.computeIfPresent(event.getOrderId(), (orderId, order) -> {
+            order.incrementProductInstance(event.getProductId());
+            return order;
+        });
+    }
+
+    @EventHandler
+    public void on(ProductCountDecrementedEvent event) {
+        orders.computeIfPresent(event.getOrderId(), (orderId, order) -> {
+            order.decrementProductInstance(event.getProductId());
+            return order;
+        });
+    }
+
+    @EventHandler
+    public void on(ProductRemovedEvent event) {
+        orders.computeIfPresent(event.getOrderId(), (orderId, order) -> {
+            order.removeProduct(event.getProductId());
+            return order;
+        });
+    }
+
+    @EventHandler
+    public void on(OrderConfirmedEvent event) {
+        orders.computeIfPresent(event.getOrderId(), (orderId, order) -> {
+            order.setOrderConfirmed();
+            return order;
+        });
+    }
+
+    @EventHandler
+    public void on(OrderShippedEvent event) {
+        orders.computeIfPresent(event.getOrderId(), (orderId, order) -> {
+            order.setOrderShipped();
+            return order;
+        });
+    }
+
+    @QueryHandler
+    public List<Order> handle(FindAllOrderedProductsQuery query) {
+        return new ArrayList<>(orders.values());
+    }
+}

axon/src/main/resources/order-api.http

@@ -1,11 +1,37 @@
+### Create Order, Add Product, Confirm and Ship Order
+
 POST http://localhost:8080/ship-order
 
-###
+### Create Order, Add Product and Ship Order
 
 POST http://localhost:8080/ship-unconfirmed-order
 
-###
+### Retrieve all existing Orders
 
 GET http://localhost:8080/all-orders
 
+### Create Order with id 666a1661-474d-4046-8b12-8b5896312768
+
+POST http://localhost:8080/order/666a1661-474d-4046-8b12-8b5896312768
+
+### Add Product a6aa01eb-4e38-4dfb-b53b-b5b82961fbf3 to Order 666a1661-474d-4046-8b12-8b5896312768
+
+POST http://localhost:8080/order/666a1661-474d-4046-8b12-8b5896312768/product/a6aa01eb-4e38-4dfb-b53b-b5b82961fbf3
+
+### Increment Product a6aa01eb-4e38-4dfb-b53b-b5b82961fbf3 to Order 666a1661-474d-4046-8b12-8b5896312768
+
+POST http://localhost:8080/order/666a1661-474d-4046-8b12-8b5896312768/product/a6aa01eb-4e38-4dfb-b53b-b5b82961fbf3/increment
+
+### Decrement Product a6aa01eb-4e38-4dfb-b53b-b5b82961fbf3 to Order 666a1661-474d-4046-8b12-8b5896312768
+
+POST http://localhost:8080/order/666a1661-474d-4046-8b12-8b5896312768/product/a6aa01eb-4e38-4dfb-b53b-b5b82961fbf3/decrement
+
+### Confirm Order 666a1661-474d-4046-8b12-8b5896312768
+
+POST http://localhost:8080/order/666a1661-474d-4046-8b12-8b5896312768/confirm
+
+### Ship Order 666a1661-474d-4046-8b12-8b5896312768
+
+POST http://localhost:8080/order/666a1661-474d-4046-8b12-8b5896312768/ship
+
 ###

axon/src/test/java/com/baeldung/axon/commandmodel/OrderAggregateUnitTest.java

@@ -1,62 +1,139 @@
 package com.baeldung.axon.commandmodel;
 
-import java.util.UUID;
+import com.baeldung.axon.commandmodel.order.OrderAggregate;
-
+import com.baeldung.axon.coreapi.commands.AddProductCommand;
+import com.baeldung.axon.coreapi.commands.ConfirmOrderCommand;
+import com.baeldung.axon.coreapi.commands.CreateOrderCommand;
+import com.baeldung.axon.coreapi.commands.DecrementProductCountCommand;
+import com.baeldung.axon.coreapi.commands.IncrementProductCountCommand;
+import com.baeldung.axon.coreapi.commands.ShipOrderCommand;
+import com.baeldung.axon.coreapi.events.OrderConfirmedEvent;
+import com.baeldung.axon.coreapi.events.OrderCreatedEvent;
+import com.baeldung.axon.coreapi.events.OrderShippedEvent;
+import com.baeldung.axon.coreapi.events.ProductAddedEvent;
+import com.baeldung.axon.coreapi.events.ProductCountDecrementedEvent;
+import com.baeldung.axon.coreapi.events.ProductCountIncrementedEvent;
+import com.baeldung.axon.coreapi.events.ProductRemovedEvent;
+import com.baeldung.axon.coreapi.exceptions.DuplicateOrderLineException;
+import com.baeldung.axon.coreapi.exceptions.OrderAlreadyConfirmedException;
 import com.baeldung.axon.coreapi.exceptions.UnconfirmedOrderException;
 import org.axonframework.test.aggregate.AggregateTestFixture;
 import org.axonframework.test.aggregate.FixtureConfiguration;
-import org.junit.*;
+import org.axonframework.test.matchers.Matchers;
+import org.junit.jupiter.api.*;
 
-import com.baeldung.axon.coreapi.commands.ConfirmOrderCommand;
+import java.util.UUID;
-import com.baeldung.axon.coreapi.commands.PlaceOrderCommand;
-import com.baeldung.axon.coreapi.commands.ShipOrderCommand;
-import com.baeldung.axon.coreapi.events.OrderConfirmedEvent;
-import com.baeldung.axon.coreapi.events.OrderPlacedEvent;
-import com.baeldung.axon.coreapi.events.OrderShippedEvent;
 
-public class OrderAggregateUnitTest {
+class OrderAggregateUnitTest {
+
+    private static final String ORDER_ID = UUID.randomUUID().toString();
+    private static final String PRODUCT_ID = UUID.randomUUID().toString();
 
     private FixtureConfiguration<OrderAggregate> fixture;
 
-    @Before
+    @BeforeEach
-    public void setUp() {
+    void setUp() {
         fixture = new AggregateTestFixture<>(OrderAggregate.class);
     }
 
     @Test
-    public void giveNoPriorActivity_whenPlaceOrderCommand_thenShouldPublishOrderPlacedEvent() {
+    void giveNoPriorActivity_whenCreateOrderCommand_thenShouldPublishOrderCreatedEvent() {
-        String orderId = UUID.randomUUID().toString();
-        String product = "Deluxe Chair";
         fixture.givenNoPriorActivity()
-               .when(new PlaceOrderCommand(orderId, product))
+               .when(new CreateOrderCommand(ORDER_ID))
-               .expectEvents(new OrderPlacedEvent(orderId, product));
+               .expectEvents(new OrderCreatedEvent(ORDER_ID));
     }
 
     @Test
-    public void givenOrderPlacedEvent_whenConfirmOrderCommand_thenShouldPublishOrderConfirmedEvent() {
+    void givenOrderCreatedEvent_whenAddProductCommand_thenShouldPublishProductAddedEvent() {
-        String orderId = UUID.randomUUID().toString();
+        fixture.given(new OrderCreatedEvent(ORDER_ID))
-        String product = "Deluxe Chair";
+               .when(new AddProductCommand(ORDER_ID, PRODUCT_ID))
-        fixture.given(new OrderPlacedEvent(orderId, product))
+               .expectEvents(new ProductAddedEvent(ORDER_ID, PRODUCT_ID));
-               .when(new ConfirmOrderCommand(orderId))
-               .expectEvents(new OrderConfirmedEvent(orderId));
     }
 
     @Test
-    public void givenOrderPlacedEvent_whenShipOrderCommand_thenShouldThrowUnconfirmedOrderException() {
+    void givenOrderCreatedEventAndProductAddedEvent_whenAddProductCommandForSameProductId_thenShouldThrowDuplicateOrderLineException() {
-        String orderId = UUID.randomUUID().toString();
+        fixture.given(new OrderCreatedEvent(ORDER_ID), new ProductAddedEvent(ORDER_ID, PRODUCT_ID))
-        String product = "Deluxe Chair";
+               .when(new AddProductCommand(ORDER_ID, PRODUCT_ID))
-        fixture.given(new OrderPlacedEvent(orderId, product))
+               .expectException(DuplicateOrderLineException.class)
-               .when(new ShipOrderCommand(orderId))
+               .expectExceptionMessage(Matchers.predicate(message -> ((String) message).contains(PRODUCT_ID)));
+    }
+
+    @Test
+    void givenOrderCreatedEventAndProductAddedEvent_whenIncrementProductCountCommand_thenShouldPublishProductCountIncrementedEvent() {
+        fixture.given(new OrderCreatedEvent(ORDER_ID), new ProductAddedEvent(ORDER_ID, PRODUCT_ID))
+               .when(new IncrementProductCountCommand(ORDER_ID, PRODUCT_ID))
+               .expectEvents(new ProductCountIncrementedEvent(ORDER_ID, PRODUCT_ID));
+    }
+
+    @Test
+    void givenOrderCreatedEventProductAddedEventAndProductCountIncrementedEvent_whenDecrementProductCountCommand_thenShouldPublishProductCountDecrementedEvent() {
+        fixture.given(new OrderCreatedEvent(ORDER_ID),
+                      new ProductAddedEvent(ORDER_ID, PRODUCT_ID),
+                      new ProductCountIncrementedEvent(ORDER_ID, PRODUCT_ID))
+               .when(new DecrementProductCountCommand(ORDER_ID, PRODUCT_ID))
+               .expectEvents(new ProductCountDecrementedEvent(ORDER_ID, PRODUCT_ID));
+    }
+
+    @Test
+    void givenOrderCreatedEventAndProductAddedEvent_whenDecrementProductCountCommand_thenShouldPublishProductRemovedEvent() {
+        fixture.given(new OrderCreatedEvent(ORDER_ID), new ProductAddedEvent(ORDER_ID, PRODUCT_ID))
+               .when(new DecrementProductCountCommand(ORDER_ID, PRODUCT_ID))
+               .expectEvents(new ProductRemovedEvent(ORDER_ID, PRODUCT_ID));
+    }
+
+    @Test
+    void givenOrderCreatedEvent_whenConfirmOrderCommand_thenShouldPublishOrderConfirmedEvent() {
+        fixture.given(new OrderCreatedEvent(ORDER_ID))
+               .when(new ConfirmOrderCommand(ORDER_ID))
+               .expectEvents(new OrderConfirmedEvent(ORDER_ID));
+    }
+
+    @Test
+    void givenOrderCreatedEventAndOrderConfirmedEvent_whenConfirmOrderCommand_thenExpectNoEvents() {
+        fixture.given(new OrderCreatedEvent(ORDER_ID), new OrderConfirmedEvent(ORDER_ID))
+               .when(new ConfirmOrderCommand(ORDER_ID))
+               .expectNoEvents();
+    }
+
+    @Test
+    void givenOrderCreatedEvent_whenShipOrderCommand_thenShouldThrowUnconfirmedOrderException() {
+        fixture.given(new OrderCreatedEvent(ORDER_ID))
+               .when(new ShipOrderCommand(ORDER_ID))
                .expectException(UnconfirmedOrderException.class);
     }
 
     @Test
-    public void givenOrderPlacedEventAndOrderConfirmedEvent_whenShipOrderCommand_thenShouldPublishOrderShippedEvent() {
+    void givenOrderCreatedEventAndOrderConfirmedEvent_whenShipOrderCommand_thenShouldPublishOrderShippedEvent() {
-        String orderId = UUID.randomUUID().toString();
+        fixture.given(new OrderCreatedEvent(ORDER_ID), new OrderConfirmedEvent(ORDER_ID))
-        String product = "Deluxe Chair";
+               .when(new ShipOrderCommand(ORDER_ID))
-        fixture.given(new OrderPlacedEvent(orderId, product), new OrderConfirmedEvent(orderId))
+               .expectEvents(new OrderShippedEvent(ORDER_ID));
-               .when(new ShipOrderCommand(orderId))
-               .expectEvents(new OrderShippedEvent(orderId));
     }
 
+    @Test
+    void givenOrderCreatedEventProductAndOrderConfirmedEvent_whenAddProductCommand_thenShouldThrowOrderAlreadyConfirmedException() {
+        fixture.given(new OrderCreatedEvent(ORDER_ID), new OrderConfirmedEvent(ORDER_ID))
+               .when(new AddProductCommand(ORDER_ID, PRODUCT_ID))
+               .expectException(OrderAlreadyConfirmedException.class)
+               .expectExceptionMessage(Matchers.predicate(message -> ((String) message).contains(ORDER_ID)));
+    }
+
+    @Test
+    void givenOrderCreatedEventProductAddedEventAndOrderConfirmedEvent_whenIncrementProductCountCommand_thenShouldThrowOrderAlreadyConfirmedException() {
+        fixture.given(new OrderCreatedEvent(ORDER_ID),
+                      new ProductAddedEvent(ORDER_ID, PRODUCT_ID),
+                      new OrderConfirmedEvent(ORDER_ID))
+               .when(new IncrementProductCountCommand(ORDER_ID, PRODUCT_ID))
+               .expectException(OrderAlreadyConfirmedException.class)
+               .expectExceptionMessage(Matchers.predicate(message -> ((String) message).contains(ORDER_ID)));
+    }
+
+    @Test
+    void givenOrderCreatedEventProductAddedEventAndOrderConfirmedEvent_whenDecrementProductCountCommand_thenShouldThrowOrderAlreadyConfirmedException() {
+        fixture.given(new OrderCreatedEvent(ORDER_ID),
+                      new ProductAddedEvent(ORDER_ID, PRODUCT_ID),
+                      new OrderConfirmedEvent(ORDER_ID))
+               .when(new DecrementProductCountCommand(ORDER_ID, PRODUCT_ID))
+               .expectException(OrderAlreadyConfirmedException.class)
+               .expectExceptionMessage(Matchers.predicate(message -> ((String) message).contains(ORDER_ID)));
+    }
 }

azure/pom.xml

@@ -1,6 +1,5 @@
 <?xml version="1.0" encoding="UTF-8"?>
-<project
+<project xmlns="http://maven.apache.org/POM/4.0.0"
-    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>
@@ -22,24 +21,20 @@
             <groupId>org.springframework.boot</groupId>
             <artifactId>spring-boot-starter-web</artifactId>
         </dependency>
-
         <dependency>
             <groupId>org.springframework.boot</groupId>
             <artifactId>spring-boot-starter-tomcat</artifactId>
             <scope>provided</scope>
         </dependency>
-
         <dependency>
             <groupId>org.springframework.boot</groupId>
             <artifactId>spring-boot-starter-data-jpa</artifactId>
         </dependency>
-
         <dependency>
             <groupId>com.h2database</groupId>
             <artifactId>h2</artifactId>
             <scope>runtime</scope>
         </dependency>
-
         <dependency>
             <groupId>mysql</groupId>
             <artifactId>mysql-connector-java</artifactId>

bazel/bazelapp/pom.xml

@@ -1,6 +1,5 @@
 <?xml version="1.0" encoding="UTF-8"?>
-<project
+<project xmlns="http://maven.apache.org/POM/4.0.0"
-    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>

bazel/bazelgreeting/pom.xml

@@ -1,6 +1,5 @@
 <?xml version="1.0" encoding="UTF-8"?>
-<project
+<project xmlns="http://maven.apache.org/POM/4.0.0"
-    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>

bazel/pom.xml

@@ -1,6 +1,5 @@
 <?xml version="1.0" encoding="UTF-8"?>
-<project
+<project xmlns="http://maven.apache.org/POM/4.0.0"
-    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>

blade/pom.xml

@@ -1,6 +1,5 @@
 <?xml version="1.0" encoding="UTF-8"?>
-<project
+<project xmlns="http://maven.apache.org/POM/4.0.0"
-    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/maven-v4_0_0.xsd">
     <modelVersion>4.0.0</modelVersion>
@@ -19,19 +18,16 @@
             <artifactId>blade-mvc</artifactId>
             <version>${blade-mvc.version}</version>
         </dependency>
-
         <dependency>
             <groupId>org.webjars</groupId>
             <artifactId>bootstrap</artifactId>
             <version>${bootstrap.version}</version>
         </dependency>
-
         <dependency>
             <groupId>org.apache.commons</groupId>
             <artifactId>commons-lang3</artifactId>
             <version>${commons-lang3.version}</version>
         </dependency>
-
         <!-- PROVIDED -->
         <dependency>
             <groupId>org.projectlombok</groupId>
@@ -39,7 +35,6 @@
             <version>${lombok.version}</version>
             <scope>provided</scope>
         </dependency>
-
         <!-- TEST -->
         <dependency>
             <groupId>org.assertj</groupId>
@@ -111,7 +106,6 @@
                             </arguments>
                         </configuration>
                     </execution>
-
                     <!--Stop all processes in reverse order -->
                     <execution>
                         <id>stop-all</id>
@@ -122,7 +116,6 @@
                     </execution>
                 </executions>
             </plugin>
-
             <plugin>
                 <artifactId>maven-assembly-plugin</artifactId>
                 <version>${assembly.plugin.version}</version>

bootique/pom.xml

@@ -1,6 +1,5 @@
 <?xml version="1.0" encoding="UTF-8"?>
-<project
+<project xmlns="http://maven.apache.org/POM/4.0.0"
-    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/maven-v4_0_0.xsd">
     <modelVersion>4.0.0</modelVersion>

cdi/pom.xml

@@ -1,6 +1,5 @@
 <?xml version="1.0" encoding="UTF-8"?>
-<project
+<project xmlns="http://maven.apache.org/POM/4.0.0"
-        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>

checker-plugin/pom.xml

@@ -1,6 +1,5 @@
 <?xml version="1.0" encoding="UTF-8"?>
-<project
+<project xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
-    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
     xmlns="http://maven.apache.org/POM/4.0.0"
     xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
     <modelVersion>4.0.0</modelVersion>
@@ -69,7 +68,6 @@
                         <!-- location of the annotated JDK, which comes from a Maven dependency -->
                         <arg>-Xbootclasspath/p:${annotatedJdk}</arg>
                         <!-- -->
-
                         <!-- Uncomment the following line to use the type annotations compiler. -->
                         <!-- <arg>-J-Xbootclasspath/p:${typeAnnotationsJavac}</arg> -->
                         <!-- Uncomment the following line to turn type-checking warnings into errors. -->

cloud-foundry-uaa/cf-uaa-oauth2-client/pom.xml

@@ -1,6 +1,5 @@
 <?xml version="1.0" encoding="UTF-8"?>
-<project
+<project xmlns="http://maven.apache.org/POM/4.0.0"
-    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>

cloud-foundry-uaa/cf-uaa-oauth2-resource-server/pom.xml

@@ -1,6 +1,5 @@
 <?xml version="1.0" encoding="UTF-8"?>
-<project
+<project xmlns="http://maven.apache.org/POM/4.0.0"
-    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>

code-generation/pom.xml

@@ -1,6 +1,5 @@
 <?xml version="1.0" encoding="UTF-8"?>
-<project
+<project xmlns="http://maven.apache.org/POM/4.0.0"
-    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/maven-v4_0_0.xsd">
     <modelVersion>4.0.0</modelVersion>
@@ -43,7 +42,6 @@
             <version>${auto-service.version}</version>
             <optional>true</optional>
         </dependency>
-
         <dependency>
             <groupId>com.google.inject</groupId>
             <artifactId>guice</artifactId>

core-groovy-2/pom.xml

@@ -1,6 +1,5 @@
 <?xml version="1.0" encoding="UTF-8"?>
-<project
+<project xmlns="http://maven.apache.org/POM/4.0.0"
-    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>
@@ -115,7 +114,6 @@
             </plugin>
             <plugin>
                 <artifactId>maven-surefire-plugin</artifactId>
-                <version>${surefire.plugin.version}</version>
                 <configuration>
                     <useFile>false</useFile>
                     <includes>
@@ -186,10 +184,8 @@
         <logback.version>1.2.3</logback.version>
         <groovy.version>2.5.7</groovy.version>
         <assembly.plugin.version>3.1.0</assembly.plugin.version>
-        <surefire.plugin.version>2.20.1</surefire.plugin.version>
         <compiler.plugin.version>3.8.0</compiler.plugin.version>
         <groovy.compiler.version>3.3.0-01</groovy.compiler.version>
     </properties>
 
 </project>
-

core-groovy-collections/pom.xml

@@ -1,6 +1,5 @@
 <?xml version="1.0" encoding="UTF-8"?>
-<project
+<project xmlns="http://maven.apache.org/POM/4.0.0"
-    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>
@@ -101,7 +100,6 @@
             </plugin>
             <plugin>
                 <artifactId>maven-surefire-plugin</artifactId>
-                <version>${surefire.plugin.version}</version>
                 <configuration>
                     <useFile>false</useFile>
                     <includes>
@@ -128,8 +126,6 @@
         <hsqldb.version>2.4.0</hsqldb.version>
         <spock-core.version>1.1-groovy-2.4</spock-core.version>
         <gmavenplus-plugin.version>1.6</gmavenplus-plugin.version>
-        <surefire.plugin.version>2.20.1</surefire.plugin.version>
     </properties>
 
 </project>
-

core-groovy-strings/pom.xml

@@ -1,6 +1,5 @@
 <?xml version="1.0" encoding="UTF-8"?>
-<project
+<project xmlns="http://maven.apache.org/POM/4.0.0"
-    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>

core-groovy/pom.xml

@@ -1,6 +1,5 @@
 <?xml version="1.0" encoding="UTF-8"?>
-<project
+<project xmlns="http://maven.apache.org/POM/4.0.0"
-    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>
@@ -120,4 +119,3 @@
     </properties>
 
 </project>
-

core-java-modules/core-java-10/README.md

@@ -11,3 +11,4 @@ This module contains articles about Java 10 core features
 - [Copying Sets in Java](https://www.baeldung.com/java-copy-sets)
 - [Converting between a List and a Set in Java](https://www.baeldung.com/convert-list-to-set-and-set-to-list)
 - [Java IndexOutOfBoundsException “Source Does Not Fit in Dest”](https://www.baeldung.com/java-indexoutofboundsexception)
+- [Collect a Java Stream to an Immutable Collection](https://www.baeldung.com/java-stream-immutable-collection)

core-java-modules/core-java-10/pom.xml

@@ -1,6 +1,5 @@
 <?xml version="1.0" encoding="UTF-8"?>
-<project
+<project xmlns="http://maven.apache.org/POM/4.0.0"
-        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>

core-java-modules/core-java-10/src/test/java/com/baeldung/java10/streams/StreamToImmutableJava10UnitTest.java

@@ -0,0 +1,20 @@
+package com.baeldung.java10.streams;
+
+import static java.util.stream.Collectors.toUnmodifiableList;
+
+import java.util.Arrays;
+import java.util.List;
+
+import org.junit.Test;
+
+public class StreamToImmutableJava10UnitTest {
+
+    @Test
+    public void whenUsingCollectorsToUnmodifiableList_thenSuccess() {
+        List<String> givenList = Arrays.asList("a", "b", "c");
+        List<String> result = givenList.stream()
+            .collect(toUnmodifiableList());
+
+        System.out.println(result.getClass());
+    }
+}

core-java-modules/core-java-11-2/pom.xml

@@ -1,6 +1,5 @@
 <?xml version="1.0" encoding="UTF-8"?>
-<project
+<project xmlns="http://maven.apache.org/POM/4.0.0"
-        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>
@@ -51,6 +50,11 @@
             <version>${junit.jupiter.version}</version>
             <scope>test</scope>
         </dependency>
+        <dependency>
+            <groupId>org.apache.commons</groupId>
+            <artifactId>commons-lang3</artifactId>
+            <version>${commons-lang3.version}</version>
+        </dependency>
     </dependencies>
 
     <build>
@@ -74,6 +78,7 @@
         <junit.jupiter.version>5.7.0</junit.jupiter.version>
         <assertj.version>3.17.2</assertj.version>
         <mockserver.version>5.11.1</mockserver.version>
+        <commons-lang3.version>3.12.0</commons-lang3.version>
     </properties>
 
 </project>

core-java-modules/core-java-11-2/src/test/java/com/baeldung/version/VersionUnitTest.java

@@ -0,0 +1,48 @@
+package com.baeldung.version;
+
+import org.apache.commons.lang3.SystemUtils;
+import org.assertj.core.api.Assertions;
+import org.junit.jupiter.api.Disabled;
+import org.junit.jupiter.api.Test;
+
+public class VersionUnitTest {
+
+    @Test
+    public void givenJava_whenUsingRuntime_thenGetVersion() {
+        String expectedVersion = "11";
+        Runtime.Version runtimeVersion = Runtime.version();
+        String version = String.valueOf(runtimeVersion.version().get(0));
+        Assertions.assertThat(version).isEqualTo(expectedVersion);
+    }
+
+    @Test
+    @Disabled("Only valid for Java 8 and lower")
+    public void givenJava_whenUsingCommonsLang_thenGetVersion() {
+        int expectedVersion = 8;
+        String[] versionElements = SystemUtils.JAVA_SPECIFICATION_VERSION.split("\\.");
+        int discard = Integer.parseInt(versionElements[0]);
+        int version;
+        if (discard == 1) {
+            version = Integer.parseInt(versionElements[1]);
+        } else {
+            version = discard;
+        }
+        Assertions.assertThat(version).isEqualTo(expectedVersion);
+    }
+
+    @Test
+    @Disabled("Only valid for Java 8 and lower")
+    public void givenJava_whenUsingSystemProp_thenGetVersion() {
+        int expectedVersion = 8;
+        String[] versionElements = System.getProperty("java.version").split("\\.");
+        int discard = Integer.parseInt(versionElements[0]);
+        int version;
+        if (discard == 1) {
+            version = Integer.parseInt(versionElements[1]);
+        } else {
+            version = discard;
+        }
+        Assertions.assertThat(version).isEqualTo(expectedVersion);
+    }
+}
+

core-java-modules/core-java-11/pom.xml

@@ -1,6 +1,5 @@
 <?xml version="1.0" encoding="UTF-8"?>
-<project
+<project xmlns="http://maven.apache.org/POM/4.0.0"
-    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>
@@ -32,12 +31,12 @@
         <dependency>
             <groupId>org.openjdk.jmh</groupId>
             <artifactId>jmh-core</artifactId>
-            <version>${jmh.version}</version>
+            <version>${jmh-core.version}</version>
         </dependency>
         <dependency>
             <groupId>org.openjdk.jmh</groupId>
             <artifactId>jmh-generator-annprocess</artifactId>
-            <version>${jmh.version}</version>
+            <version>${jmh-generator.version}</version>
             <scope>provided</scope>
         </dependency>
         <dependency>
@@ -76,10 +75,12 @@
                         <configuration>
                             <finalName>${uberjar.name}</finalName>
                             <transformers>
-                                <transformer implementation="org.apache.maven.plugins.shade.resource.ManifestResourceTransformer">
+                                <transformer
+                                    implementation="org.apache.maven.plugins.shade.resource.ManifestResourceTransformer">
                                     <mainClass>org.openjdk.jmh.Main</mainClass>
                                 </transformer>
-                                <transformer implementation="org.apache.maven.plugins.shade.resource.ServicesResourceTransformer" />
+                                <transformer
+                                    implementation="org.apache.maven.plugins.shade.resource.ServicesResourceTransformer" />
                             </transformers>
                             <filters>
                                 <filter>
@@ -105,7 +106,6 @@
         <guava.version>27.1-jre</guava.version>
         <assertj.version>3.11.1</assertj.version>
         <uberjar.name>benchmarks</uberjar.name>
-        <jmh.version>1.22</jmh.version>
         <eclipse.collections.version>10.0.0</eclipse.collections.version>
         <shade.plugin.version>3.2.4</shade.plugin.version>
     </properties>

core-java-modules/core-java-12/pom.xml

@@ -1,6 +1,5 @@
 <?xml version="1.0" encoding="UTF-8"?>
-<project
+<project xmlns="http://maven.apache.org/POM/4.0.0"
-    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>

core-java-modules/core-java-13/pom.xml

@@ -1,6 +1,5 @@
 <?xml version="1.0" encoding="UTF-8"?>
-<project
+<project xmlns="http://maven.apache.org/POM/4.0.0"
-    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>

core-java-modules/core-java-14/pom.xml

@@ -1,6 +1,5 @@
 <?xml version="1.0" encoding="UTF-8"?>
-<project
+<project xmlns="http://maven.apache.org/POM/4.0.0"
-    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>
@@ -15,6 +14,7 @@
         <version>1.0.0-SNAPSHOT</version>
         <relativePath>../../</relativePath>
     </parent>
+    
     <dependencies>
         <dependency>
             <groupId>org.assertj</groupId>
@@ -35,6 +35,7 @@
             <scope>test</scope>
         </dependency>
     </dependencies>
+    
     <build>
         <plugins>
             <plugin>