Set the java version of the modules to 11

Author: Soroosh Sarabadani

Diff for: operator-framework/pom.xml

@@ -16,9 +16,9 @@
     <packaging>jar</packaging>
 
     <properties>
-        <java.version>8</java.version>
-        <maven.compiler.source>1.8</maven.compiler.source>
-        <maven.compiler.target>1.8</maven.compiler.target>
+        <java.version>11</java.version>
+        <maven.compiler.source>11</maven.compiler.source>
+        <maven.compiler.target>11</maven.compiler.target>
     </properties>
 
     <build>

Diff for: samples/common/pom.xml

@@ -15,9 +15,9 @@
     <packaging>jar</packaging>
 
     <properties>
-        <java.version>8</java.version>
-        <maven.compiler.source>1.8</maven.compiler.source>
-        <maven.compiler.target>1.8</maven.compiler.target>
+        <java.version>11</java.version>
+        <maven.compiler.source>11</maven.compiler.source>
+        <maven.compiler.target>11</maven.compiler.target>
     </properties>
 
     <dependencies>

Diff for: samples/mysql-schema/README.md

@@ -23,7 +23,7 @@ use it as is with real databases.
 ### Try 
 
 To try how the operator works you will need the following:
-* JDK installed (minimum version 8, tested with 1.8, 12, 13)
+* JDK installed (minimum version 11, tested with 11 and 15)
 * Maven installed (tested with 3.6.3)
 * A working Kubernetes cluster (tested with v1.15.9-gke.24)
 * kubectl installed (tested with v1.15.5)

Diff for: samples/mysql-schema/pom.xml

@@ -15,9 +15,9 @@
     <packaging>jar</packaging>
 
     <properties>
-        <java.version>8</java.version>
-        <maven.compiler.source>1.8</maven.compiler.source>
-        <maven.compiler.target>1.8</maven.compiler.target>
+        <java.version>11</java.version>
+        <maven.compiler.source>11</maven.compiler.source>
+        <maven.compiler.target>11</maven.compiler.target>
     </properties>
 
     <dependencies>

Diff for: samples/pure-java/pom.xml

@@ -15,9 +15,9 @@
     <packaging>jar</packaging>
 
     <properties>
-        <java.version>8</java.version>
-        <maven.compiler.source>1.8</maven.compiler.source>
-        <maven.compiler.target>1.8</maven.compiler.target>
+        <java.version>11</java.version>
+        <maven.compiler.source>11</maven.compiler.source>
+        <maven.compiler.target>11</maven.compiler.target>
     </properties>
 
     <dependencies>

Diff for: samples/spring-boot-auto-config/pom.xml

@@ -15,9 +15,9 @@
     <packaging>jar</packaging>
 
     <properties>
-        <java.version>8</java.version>
-        <maven.compiler.source>1.8</maven.compiler.source>
-        <maven.compiler.target>1.8</maven.compiler.target>
+        <java.version>11</java.version>
+        <maven.compiler.source>11</maven.compiler.source>
+        <maven.compiler.target>11</maven.compiler.target>
     </properties>
 
     <dependencies>

Diff for: samples/spring-boot-plain/pom.xml

@@ -15,9 +15,9 @@
     <packaging>jar</packaging>
 
     <properties>
-        <java.version>8</java.version>
-        <maven.compiler.source>1.8</maven.compiler.source>
-        <maven.compiler.target>1.8</maven.compiler.target>
+        <java.version>11</java.version>
+        <maven.compiler.source>11</maven.compiler.source>
+        <maven.compiler.target>11</maven.compiler.target>
     </properties>
 
     <dependencies>

Diff for: samples/tomcat/pom.xml

@@ -18,9 +18,9 @@
     <properties>
         <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
         <java-operator-sdk.version>1.3.0</java-operator-sdk.version>
-        <java.version>8</java.version>
-        <maven.compiler.source>1.8</maven.compiler.source>
-        <maven.compiler.target>1.8</maven.compiler.target>
+        <java.version>11</java.version>
+        <maven.compiler.source>11</maven.compiler.source>
+        <maven.compiler.target>11</maven.compiler.target>
         <jib-maven-plugin.version>2.5.2</jib-maven-plugin.version>
     </properties>
 

Diff for: samples/webserver/pom.xml

@@ -15,9 +15,9 @@
     <packaging>jar</packaging>
 
     <properties>
-        <java.version>8</java.version>
-        <maven.compiler.source>1.8</maven.compiler.source>
-        <maven.compiler.target>1.8</maven.compiler.target>
+        <java.version>11</java.version>
+        <maven.compiler.source>11</maven.compiler.source>
+        <maven.compiler.target>11</maven.compiler.target>
     </properties>
 
     <dependencies>

Diff for: spring-boot-starter/pom.xml

@@ -15,9 +15,9 @@
     <packaging>jar</packaging>
 
     <properties>
-        <java.version>8</java.version>
-        <maven.compiler.source>1.8</maven.compiler.source>
-        <maven.compiler.target>1.8</maven.compiler.target>
+        <java.version>11</java.version>
+        <maven.compiler.source>11</maven.compiler.source>
+        <maven.compiler.target>11</maven.compiler.target>
     </properties>
 
     <build>