BAEL-9709 Fix start of Boot projects with parent-boot-2 parent

-Added placeholder {start-class} tag in parent-boot-2's spring-boot-maven-plugin so that any child that has a {start-class} automatically is benefited from this plugin and wil help that child class to run
-Fix startup issues of few spring boot 2 projects

parent-boot-2/pom.xml

@@ -42,6 +42,9 @@
 					<groupId>org.springframework.boot</groupId>
 					<artifactId>spring-boot-maven-plugin</artifactId>
 					<version>${spring-boot.version}</version>
+					<configuration>
+						<mainClass>${start-class}</mainClass>
+					</configuration>
 				</plugin>
 			</plugins>
 		</pluginManagement>

spring-all/pom.xml

@@ -1,7 +1,6 @@
 <project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
     xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
     <modelVersion>4.0.0</modelVersion>
-    <groupId>com.baeldung</groupId>
     <artifactId>spring-all</artifactId>
     <version>0.1-SNAPSHOT</version>
     <name>spring-all</name>

spring-boot-h2/spring-boot-h2-database/pom.xml

@@ -23,7 +23,7 @@
         <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
         <java.version>1.8</java.version>
         <!-- The main class to start by executing java -jar -->
-        <start-class>com.mycorp.starter.HelloWorldApplication</start-class>
+        <start-class>com.baeldung.h2db.demo.server.SpringBootApp</start-class>
     </properties>
 
     <dependencies>

spring-boot-mvc/pom.xml

@@ -23,7 +23,7 @@
 			<groupId>org.apache.tomcat.embed</groupId>
 			<artifactId>tomcat-embed-jasper</artifactId>
 		</dependency>
-		<!--JSF-->
+		<!--JSF -->
 		<dependency>
 			<groupId>org.glassfish</groupId>
 			<artifactId>javax.faces</artifactId>
@@ -47,6 +47,15 @@
 			<artifactId>rome</artifactId>
 			<version>${rome.version}</version>
 		</dependency>
+
+		<dependency>
+			<groupId>org.hibernate.validator</groupId>
+			<artifactId>hibernate-validator</artifactId>
+		</dependency>
+		<dependency>
+			<groupId>javax.validation</groupId>
+			<artifactId>validation-api</artifactId>
+		</dependency>
 	</dependencies>
 
 	<build>

spring-boot/pom.xml

@@ -1,9 +1,7 @@
 <project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
     xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
     <modelVersion>4.0.0</modelVersion>
-    <groupId>com.baeldung</groupId>
     <artifactId>spring-boot</artifactId>
-    <version>0.0.1-SNAPSHOT</version>
     <packaging>war</packaging>
     <name>spring-boot</name>
     <description>This is simple boot application for Spring boot actuator test</description>
@@ -159,6 +157,11 @@
             <version>1.1.16</version>
             <scope>compile</scope>
         </dependency>
+        
+        <dependency>
+        	<groupId>javax.validation</groupId>
+        	<artifactId>validation-api</artifactId>
+        </dependency>
     </dependencies>
 
     <build>
@@ -234,7 +237,6 @@
         <graphql-spring-boot-starter.version>3.6.0</graphql-spring-boot-starter.version>
         <graphql-java-tools.version>3.2.0</graphql-java-tools.version>
         <guava.version>18.0</guava.version>
-		<junit-platform.version>1.2.0</junit-platform.version>
 		<git-commit-id-plugin.version>2.2.4</git-commit-id-plugin.version>
     </properties>
 

spring-security-mvc-boot/pom.xml

@@ -220,7 +220,7 @@
 
 
     <properties>
-        <start-class>org.baeldung.Application</start-class>
+        <start-class>org.baeldung.custom.Application</start-class>
         <!--If you want to run the example with the voters comment the tag 
             above and uncomment the one below -->
         <!--<start-class>org.baeldung.voter.VoterApplication</start-class> -->