Improve checkstyle rules with header and unused imports

.checkstyle/HEADER

@@ -0,0 +1,18 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */

.checkstyle/checkstyle.xml

@@ -2,20 +2,6 @@
 <!DOCTYPE module PUBLIC
         "-//Checkstyle//DTD Checkstyle Configuration 1.3//EN"
         "https://checkstyle.org/dtds/configuration_1_3.dtd">
-
-<!--
-    Checkstyle configuration that checks the Google coding conventions from Google Java Style
-    that can be found at https://google.github.io/styleguide/javaguide.html
-
-    Checkstyle is very configurable. Be sure to read the documentation at
-    http://checkstyle.org (or in your downloaded distribution).
-
-    To completely disable a check, just comment it out or delete it from the file.
-    To suppress certain violations please review suppression filters.
-
-    Authors: Max Vetrenko, Ruslan Diachenko, Roman Ivanov.
- -->
-
 <module name="Checker">
     <module name="SuppressWarningsFilter"/>
 
@@ -24,20 +10,21 @@
     <property name="severity" value="warning"/>
 
     <property name="fileExtensions" value="java, properties, xml"/>
-    <!-- Excludes all 'module-info.java' files              -->
-    <!-- See https://checkstyle.org/filefilters/index.html -->
+
+    <module name="Header">
+        <property name="headerFile" value="${config_loc}/HEADER"/>
+    </module>
+
     <module name="BeforeExecutionExclusionFileFilter">
         <property name="fileNamePattern" value="module\-info\.java$"/>
     </module>
-    <!-- https://checkstyle.org/filters/suppressionfilter.html -->
+
     <module name="SuppressionFilter">
         <property name="file" value="${org.checkstyle.google.suppressionfilter.config}"
                   default="checkstyle-suppressions.xml"/>
         <property name="optional" value="true"/>
     </module>
 
-    <!-- Checks for whitespace                               -->
-    <!-- See http://checkstyle.org/checks/whitespace/index.html -->
     <module name="FileTabCharacter">
         <property name="eachLine" value="true"/>
     </module>
@@ -49,7 +36,15 @@
     </module>
 
     <module name="TreeWalker">
+        <module name="UnusedImports"/>
+        <module name="RedundantImport"/>
+        <module name="SimplifyBooleanExpression"/>
+        <module name="SimplifyBooleanReturn"/>
         <module name="OuterTypeFilename"/>
+        <module name="UnnecessaryParentheses">
+            <property name="tokens"
+                      value="IDENT, NUM_DOUBLE, LAMBDA, TEXT_BLOCK_LITERAL_BEGIN, UNARY_MINUS, UNARY_PLUS, INC, DEC, POST_INC, POST_DEC"/>
+        </module>
         <module name="IllegalTokenText">
             <property name="tokens" value="STRING_LITERAL, CHAR_LITERAL"/>
             <property name="format"
@@ -96,7 +91,7 @@
             <property name="tokens"
                       value="CLASS_DEF, METHOD_DEF, CTOR_DEF, LITERAL_FOR, LITERAL_WHILE, STATIC_INIT,
                     INSTANCE_INIT, ANNOTATION_DEF, ENUM_DEF, INTERFACE_DEF, RECORD_DEF,
-                    COMPACT_CTOR_DEF"/>
+                    COMPACT_CTOR_DEF, LITERAL_SWITCH"/>
         </module>
         <module name="SuppressionXpathSingleFilter">
             <!-- suppresion is required till https://github.com/checkstyle/checkstyle/issues/7541 -->
@@ -379,4 +374,4 @@
             <property name="influenceFormat" value="1"/>
         </module>
     </module>
-</module>
+</module>

.github/workflows/hotfix.yml

@@ -9,6 +9,7 @@ on:
 
 jobs:
   create-branch:
+    name: Create Branch
     runs-on: ubuntu-latest
     if: github.ref == 'refs/heads/main'
     steps:
@@ -18,7 +19,7 @@ jobs:
           fetch-depth: 0
           token: ${{ secrets.CI_CD_TOKEN }}
 
-      - name: Create hotfix branch
+      - name: Create branch
         run: |
           START_TAG=v${{ github.event.inputs.tag_version }}
           echo "Start from tag $START_TAG"

.github/workflows/pull_request.yml

@@ -8,6 +8,7 @@ on:
 
 jobs:
   build:
+    name: Build
     runs-on: ubuntu-latest
     steps:
       - name: Checkout project

.github/workflows/push_master.yml

@@ -7,6 +7,7 @@ on:
 
 jobs:
   build:
+    name: Build
     runs-on: ubuntu-latest
     steps:
       - name: Docker login

.github/workflows/release.yml

@@ -7,6 +7,7 @@ on:
 
 jobs:
   build:
+    name: Release
     runs-on: ubuntu-latest
     steps:
       - name: Docker login

.github/workflows/tag.yml

@@ -9,6 +9,7 @@ on:
 
 jobs:
   tag:
+    name: Tag
     runs-on: ubuntu-latest
     if: github.ref == 'refs/heads/master' || startsWith(github.ref, 'refs/heads/hotfix/v')
     steps:

build.gradle

@@ -126,10 +126,11 @@ test {
 }
 
 checkstyle {
-    toolVersion = '10.12.3'
+    toolVersion = '10.12.4'
     configFile = file(".checkstyle/checkstyle.xml")
     ignoreFailures = false
     maxErrors = 0
     maxWarnings = 0
+    configDirectory = file(".checkstyle")
 }
 

src/main/java/com/michelin/ns4kafka/Application.java

@@ -1,3 +1,22 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
 package com.michelin.ns4kafka;
 
 import io.micronaut.openapi.annotation.OpenAPIInclude;

src/main/java/com/michelin/ns4kafka/controller/AkhqClaimProviderController.java

@@ -1,3 +1,22 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
 package com.michelin.ns4kafka.controller;
 
 import com.michelin.ns4kafka.model.AccessControlEntry;

src/main/java/com/michelin/ns4kafka/controller/ApiResourcesController.java

@@ -1,3 +1,22 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
 package com.michelin.ns4kafka.controller;
 
 import com.michelin.ns4kafka.repository.RoleBindingRepository;

src/main/java/com/michelin/ns4kafka/controller/ConnectorController.java

@@ -1,3 +1,22 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
 package com.michelin.ns4kafka.controller;
 
 import static com.michelin.ns4kafka.util.FormatErrorUtils.invalidOwner;
@@ -223,9 +242,9 @@ public Mono<HttpResponse<List<Connector>>> bulkDelete(String namespace,
 
         // Validate ownership
         List<String> validationErrors = connectors.stream()
-                .filter(connector -> !connectorService.isNamespaceOwnerOfConnect(ns, connector.getMetadata().getName()))
-                .map(connector -> invalidOwner(connector.getMetadata().getName()))
-                .toList();
+            .filter(connector -> !connectorService.isNamespaceOwnerOfConnect(ns, connector.getMetadata().getName()))
+            .map(connector -> invalidOwner(connector.getMetadata().getName()))
+            .toList();
 
         if (!validationErrors.isEmpty()) {
             return Mono.error(new ResourceValidationException(CONNECTOR, name, validationErrors));
@@ -240,11 +259,11 @@ public Mono<HttpResponse<List<Connector>>> bulkDelete(String namespace,
         }
 
         return Flux.fromIterable(connectors)
-                .flatMap(connector -> {
-                    sendEventLog(connector, ApplyStatus.deleted, connector.getSpec(), null, EMPTY_STRING);
-                    return connectorService.delete(ns, connector);
-                })
-                .then(Mono.just(HttpResponse.ok(connectors)));
+            .flatMap(connector -> {
+                sendEventLog(connector, ApplyStatus.deleted, connector.getSpec(), null, EMPTY_STRING);
+                return connectorService.delete(ns, connector);
+            })
+            .then(Mono.just(HttpResponse.ok(connectors)));
     }
 
     /**

src/main/java/com/michelin/ns4kafka/controller/ConsumerGroupController.java

@@ -1,3 +1,22 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
 package com.michelin.ns4kafka.controller;
 
 import static com.michelin.ns4kafka.util.FormatErrorUtils.invalidConsumerGroupOperation;

src/main/java/com/michelin/ns4kafka/controller/ExceptionHandlerController.java

@@ -1,3 +1,22 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
 package com.michelin.ns4kafka.controller;
 
 import com.michelin.ns4kafka.model.Status;

src/main/java/com/michelin/ns4kafka/controller/NamespaceController.java

@@ -1,3 +1,22 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
 package com.michelin.ns4kafka.controller;
 
 import static com.michelin.ns4kafka.util.FormatErrorUtils.invalidImmutableValue;