set default Java version to 17

Author: FrankHossfeld

malio/pom.xml

@@ -116,8 +116,8 @@
         <artifactId>maven-compiler-plugin</artifactId>
         <version>3.6.1</version>
         <configuration>
-          <source>8</source>
-          <target>8</target>
+          <source>11</source>
+          <target>11</target>
           <showWarnings>true</showWarnings>
           <showDeprecation>true</showDeprecation>
           <meminitial>128m</meminitial>

malio/src/main/java/com/github/nalukit/malio/shared/model/ValidationResult.java

@@ -41,6 +41,6 @@ public void invlidate(String message,
   }
 
   public boolean isValid() {
-    return this.messages.size() == 0;
+    return this.messages.isEmpty();
   }
 }