Fix Maven build of sample-spring-boot

The profile activation by missing files does no support Maven properties.
The directories must be given in plain text. The pom.xml was changed accordingly.

By default activation will only activate a profile if none other profile is active.
Backend selection was therefore migrated to activation by system property.

The documentation was adjusted accordingly.

Author: KarstenSchnitter

README.md

@@ -307,9 +307,11 @@ description about how to apply this feature can be found
 Stacktraces can be logged within one log message. Further details can be found
 [here](https://github.com/SAP/cf-java-logging-support/wiki/Logging-Stack-Traces).
 
-## Sample Application
+## Sample Applications
 
-In order to illustrate how the different features are used, this repository includes a simple application in the  [./sample folder](./sample).
+In order to illustrate how the different features are used, this repository includes two sample applications:
+  * a Jersey implementation in the  [./sample folder](./sample)
+  * a Spring Boot implementaiton in the [./sample-spring-boot folder](./sample-spring-boot)
 
 ## Documentation
 

sample-spring-boot/pom.xml

@@ -105,7 +105,7 @@
 				<filtering>true</filtering>
 			</resource>
 			<resource>
-				<directory>${project.build.directory}/generated-resources/keystore</directory>
+				<directory>${basedir}/target/generated-resources/keystore</directory>
 			</resource>
 		</resources>
 
@@ -130,8 +130,7 @@
 			<id>initialze-keystore</id>
 			<activation>
 				<file>
-					<missing>${project.build.directory}/generated-resources/keystore/token_keystore.jks
-					</missing>
+					<missing>${basedir}/target/generated-resources/keystore/token_keystore.jks</missing>
 				</file>
 			</activation>
 			<build>
@@ -150,8 +149,7 @@
 							</execution>
 						</executions>
 						<configuration>
-							<keystore>${project.build.directory}/generated-resources/keystore/token_keystore.jks
-							</keystore>
+							<keystore>${basedir}/target/generated-resources/keystore/token_keystore.jks</keystore>
 							<storepass>${keystore.token.store_password}</storepass>
 							<keypass>${keystore.token.key_password}</keypass>
 							<alias>${keystore.token.key_alias}</alias>
@@ -169,7 +167,9 @@
 		<profile>
 			<id>logback</id>
 			<activation>
-				<activeByDefault>true</activeByDefault>
+				<property>
+					<name>!log4j2</name>
+				</property>
 			</activation>
 			<dependencies>
 				<dependency>
@@ -186,7 +186,9 @@
 		<profile>
 			<id>log4j2</id>
 			<activation>
-				<activeByDefault>false</activeByDefault>
+				<property>
+					<name>log4j2</name>
+				</property>
 			</activation>
 			<dependencies>
 				<dependency>