Feature/fix sonar warnings (#1226)

* Fixed sonar warnings

- "Cognitive Complexity"
- "Do not use replaceAll when not using a regex"
- java:S5869 - Character classes in regular expressions should not contain the same character twice
- Improved bad name
- Typos
- reduced code duplications
- Replaced hand-made wait-utility with Awaitility
- Log messages
- Duplicate code
- Typos
- Removed Thread.sleep, instead relaxed check condition
- Removed use of deprecated API
- Removed use of deprecated API
- Added supress-warnings as I do not see a better way to write the tests
- Removed Thread.sleep / redundant functionality to Awaitility
- Fixed other warnings (use isZero, isEmpty, hasToString)
- Removed/Reduced duplicate code
- Added generics
- Fixed asserts
- removed: field.setAccessible(true) actually should not be needed for public static fields!
- Too long constructor passes arguments in wrong order - how surprisingly...
- Clean-up use of varargs arguments
- Fixed regex
- Fixed typos and other minor stuff
- Making public constructors protected in abstract classes
- Swapped expected and asserted argument
- volatile not enough for syncing threads
- volatile not enough for syncing threads
- out-commented code
- Made regex not-greedy, added tests for verification
- Avoid exposure of thread-local member var

Signed-off-by: Peter Vigier <Peter.Vigier@bosch.io>

* Fixed Sonar warnings

* License header fix

Signed-off-by: Peter Vigier <Peter.Vigier@bosch.io>

* License header fix #2

Signed-off-by: Peter Vigier <Peter.Vigier@bosch.io>

* Fixing review findings

Signed-off-by: Peter Vigier <Peter.Vigier@bosch.io>

* Fixing tests

- Fixed '&' usage in javadoc and typos
- Fixing some warnings

Signed-off-by: Peter Vigier <Peter.Vigier@bosch.io>

hawkbit-rest/hawkbit-rest-core/src/main/java/org/eclipse/hawkbit/rest/RestConfiguration.java

@@ -74,9 +74,9 @@ public class RestConfiguration {
      *         filter in the filter chain
      */
     @Bean
-    FilterRegistrationBean eTagFilter() {
+    FilterRegistrationBean<ExcludePathAwareShallowETagFilter> eTagFilter() {
 
-        final FilterRegistrationBean filterRegBean = new FilterRegistrationBean();
+        final FilterRegistrationBean<ExcludePathAwareShallowETagFilter> filterRegBean = new FilterRegistrationBean<>();
         // Exclude the URLs for downloading artifacts, so no eTag is generated
         // in the ShallowEtagHeaderFilter, just using the SH1 hash of the
         // artifact itself as 'ETag', because otherwise the file will be copied

hawkbit-rest/hawkbit-rest-core/src/main/java/org/eclipse/hawkbit/rest/util/FileStreamingUtil.java

@@ -151,7 +151,7 @@ public final class FileStreamingUtil {
             LOG.debug("range header for filename ({}) is: {}", filename, range);
 
             // Range header matches"bytes=n-n,n-n,n-n..."
-            if (!range.matches("^bytes=\\d*-\\d*(,\\d*-\\d*)*$")) {
+            if (!range.matches("^bytes=\\d*-\\d*(,\\d*-\\d*)*+$")) {
                 response.setHeader(HttpHeaders.CONTENT_RANGE, "bytes */" + length);
                 LOG.debug("range header for filename ({}) is not satisfiable: ", filename);
                 return new ResponseEntity<>(HttpStatus.REQUESTED_RANGE_NOT_SATISFIABLE);