fixed many sonar lint findings

.mvn/wrapper/MavenWrapperDownloader.java

@@ -13,6 +13,7 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
+
 import java.net.*;
 import java.io.*;
 import java.nio.channels.*;
@@ -25,7 +26,7 @@ public class MavenWrapperDownloader {
      * Default URL to download the maven-wrapper.jar from, if no 'downloadUrl' is provided.
      */
     private static final String DEFAULT_DOWNLOAD_URL = "https://repo.maven.apache.org/maven2/io/takari/maven-wrapper/"
-        + WRAPPER_VERSION + "/maven-wrapper-" + WRAPPER_VERSION + ".jar";
+            + WRAPPER_VERSION + "/maven-wrapper-" + WRAPPER_VERSION + ".jar";
 
     /**
      * Path to the maven-wrapper.properties file, which might contain a downloadUrl property to
@@ -54,33 +55,22 @@ public static void main(String args[]) {
         // wrapperUrl parameter.
         File mavenWrapperPropertyFile = new File(baseDirectory, MAVEN_WRAPPER_PROPERTIES_PATH);
         String url = DEFAULT_DOWNLOAD_URL;
-        if(mavenWrapperPropertyFile.exists()) {
-            FileInputStream mavenWrapperPropertyFileInputStream = null;
-            try {
+        if (mavenWrapperPropertyFile.exists()) {
+            try (FileInputStream mavenWrapperPropertyFileInputStream = new FileInputStream(mavenWrapperPropertyFile)) {
                 mavenWrapperPropertyFileInputStream = new FileInputStream(mavenWrapperPropertyFile);
                 Properties mavenWrapperProperties = new Properties();
                 mavenWrapperProperties.load(mavenWrapperPropertyFileInputStream);
                 url = mavenWrapperProperties.getProperty(PROPERTY_NAME_WRAPPER_URL, url);
             } catch (IOException e) {
                 System.out.println("- ERROR loading '" + MAVEN_WRAPPER_PROPERTIES_PATH + "'");
-            } finally {
-                try {
-                    if(mavenWrapperPropertyFileInputStream != null) {
-                        mavenWrapperPropertyFileInputStream.close();
-                    }
-                } catch (IOException e) {
-                    // Ignore ...
-                }
             }
         }
         System.out.println("- Downloading from: " + url);
 
         File outputFile = new File(baseDirectory.getAbsolutePath(), MAVEN_WRAPPER_JAR_PATH);
-        if(!outputFile.getParentFile().exists()) {
-            if(!outputFile.getParentFile().mkdirs()) {
-                System.out.println(
-                        "- ERROR creating output directory '" + outputFile.getParentFile().getAbsolutePath() + "'");
-            }
+        if (!outputFile.getParentFile().exists() && !outputFile.getParentFile().mkdirs()) {
+            System.out.println(
+                    "- ERROR creating output directory '" + outputFile.getParentFile().getAbsolutePath() + "'");
         }
         System.out.println("- Downloading to: " + outputFile.getAbsolutePath());
         try {
@@ -106,12 +96,12 @@ protected PasswordAuthentication getPasswordAuthentication() {
             });
         }
         URL website = new URL(urlString);
-        ReadableByteChannel rbc;
-        rbc = Channels.newChannel(website.openStream());
-        FileOutputStream fos = new FileOutputStream(destination);
-        fos.getChannel().transferFrom(rbc, 0, Long.MAX_VALUE);
-        fos.close();
-        rbc.close();
+        try (
+                ReadableByteChannel rbc = Channels.newChannel(website.openStream());
+                FileOutputStream fos = new FileOutputStream(destination)
+        ) {
+            fos.getChannel().transferFrom(rbc, 0, Long.MAX_VALUE);
+        }
     }
 
 }

src/main/java/kafdrop/Kafdrop.java

@@ -43,7 +43,7 @@
 
 @SpringBootApplication
 public class Kafdrop {
-  private final static Logger LOG = LoggerFactory.getLogger(Kafdrop.class);
+  private static final Logger LOG = LoggerFactory.getLogger(Kafdrop.class);
 
   public static void main(String[] args) {
     createApplicationBuilder()
@@ -99,8 +99,7 @@ public void onApplicationEvent(ApplicationEnvironmentPreparedEvent event) {
         try {
           System.setProperty("logging.dir", new File(loggingFile).getParent());
         } catch (Exception ex) {
-          System.err.println("Unable to set up logging.dir from logging.file " + loggingFile + ": " +
-                                 Throwables.getStackTraceAsString(ex));
+          LOG.error("Unable to set up logging.dir from logging.file {}", loggingFile, ex);
         }
       }
       if (environment.containsProperty("debug") &&

src/main/java/kafdrop/config/CorsConfiguration.java

@@ -69,6 +69,7 @@ public Filter corsFilter() {
     return new Filter() {
       @Override
       public void init(FilterConfig filterConfig) {
+        // nothing to init
       }
 
       @Override
@@ -91,6 +92,7 @@ public void doFilter(ServletRequest req, ServletResponse res, FilterChain chain)
 
       @Override
       public void destroy() {
+        // nothing to destroy
       }
     };
   }

src/main/java/kafdrop/config/HealthCheckConfiguration.java

@@ -38,15 +38,15 @@ public HealthCheck(HealthEndpoint healthEndpoint) {
     }
 
     @ManagedAttribute
-    public Map getHealth() {
+    public Map<String, Object> getHealth() {
       final var health = (Health) healthEndpoint.health();
       final var healthMap = new LinkedHashMap<String, Object>();
       healthMap.put("status", getStatus(health));
       healthMap.put("detail", getDetails(health.getDetails()));
       return healthMap;
     }
 
-    private Map getDetails(Map<String, Object> details) {
+    private Map<String, Object> getDetails(Map<String, Object> details) {
       return details.entrySet().stream()
           .collect(Collectors.toMap(Map.Entry::getKey,
                                     e -> {

src/main/java/kafdrop/config/InterceptorConfiguration.java

@@ -22,7 +22,6 @@
 import org.springframework.stereotype.*;
 import org.springframework.web.servlet.*;
 import org.springframework.web.servlet.config.annotation.*;
-import org.springframework.web.servlet.handler.*;
 
 import javax.servlet.http.*;
 
@@ -39,7 +38,7 @@ public void addInterceptors(InterceptorRegistry registry) {
     registry.addInterceptor(new ProfileHandlerInterceptor());
   }
 
-  public class ProfileHandlerInterceptor extends HandlerInterceptorAdapter {
+  public class ProfileHandlerInterceptor implements AsyncHandlerInterceptor {
     @Override
     public void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler, ModelAndView modelAndView) {
       final var activeProfiles = environment.getActiveProfiles();

src/main/java/kafdrop/config/KafkaConfiguration.java

@@ -17,7 +17,7 @@ public final class KafkaConfiguration {
   private static final Logger LOG = LoggerFactory.getLogger(KafkaConfiguration.class);
 
   private String brokerConnect;
-  private Boolean isSecured = false;
+  private boolean isSecured = false;
   private String saslMechanism;
   private String securityProtocol;
   private String truststoreFile;

src/main/java/kafdrop/config/ProtobufDescriptorConfiguration.java

@@ -7,6 +7,7 @@
 import java.util.Arrays;
 import java.util.Collections;
 import java.util.List;
+import java.util.Objects;
 
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
@@ -43,17 +44,10 @@ public List<String> getDescFilesList() {
       File path = new File(directory);
 
       // apply filter for listing only .desc file
-      FilenameFilter filter = new FilenameFilter() {
-
-        @Override
-        public boolean accept(File dir, String name) {
-          return name.endsWith(".desc");
-        }
-
-      };
+      FilenameFilter filter = (dir, name) -> name.endsWith(".desc");
 
       pathnames = path.list(filter);
-      return Arrays.asList(pathnames);
+      return Arrays.asList(Objects.requireNonNull(pathnames));
     }
   }
 }

src/main/java/kafdrop/config/SwaggerConfiguration.java

@@ -18,6 +18,7 @@
 
 package kafdrop.config;
 
+import org.jetbrains.annotations.NotNull;
 import org.springframework.beans.BeansException;
 import org.springframework.beans.factory.config.BeanPostProcessor;
 import org.springframework.boot.autoconfigure.condition.*;
@@ -33,6 +34,7 @@
 
 import java.lang.reflect.Field;
 import java.util.List;
+import java.util.Objects;
 import java.util.function.Predicate;
 import java.util.stream.Collectors;
 
@@ -60,7 +62,7 @@ public Docket swagger() {
   /**
    *  Swagger Predicate for only selecting JSON endpoints.
    */
-  public final class JsonRequestHandlerPredicate implements Predicate<RequestHandler> {
+  public static final class JsonRequestHandlerPredicate implements Predicate<RequestHandler> {
     @Override
     public boolean test(RequestHandler input) {
       return input.produces().contains(MediaType.APPLICATION_JSON);
@@ -70,7 +72,7 @@ public boolean test(RequestHandler input) {
   /**
    *  Swagger Predicate for ignoring {@code /actuator} endpoints.
    */
-  public final class IgnoreDebugPathPredicate implements Predicate<String> {
+  public static final class IgnoreDebugPathPredicate implements Predicate<String> {
     @Override
     public boolean test(String input) {
       return !input.startsWith("/actuator");
@@ -85,7 +87,7 @@ public static BeanPostProcessor springfoxHandlerProviderBeanPostProcessor() {
     return new BeanPostProcessor() {
 
       @Override
-      public Object postProcessAfterInitialization(Object bean, String beanName) throws BeansException {
+      public Object postProcessAfterInitialization(@NotNull Object bean, @NotNull String beanName) throws BeansException {
         if (bean instanceof WebMvcRequestHandlerProvider || bean instanceof WebFluxRequestHandlerProvider) {
           customizeSpringfoxHandlerMappings(getHandlerMappings(bean));
         }
@@ -104,7 +106,7 @@ private <T extends RequestMappingInfoHandlerMapping> void customizeSpringfoxHand
       private List<RequestMappingInfoHandlerMapping> getHandlerMappings(Object bean) {
         try {
           Field field = ReflectionUtils.findField(bean.getClass(), "handlerMappings");
-          field.setAccessible(true);
+          Objects.requireNonNull(field).setAccessible(true);
           return (List<RequestMappingInfoHandlerMapping>) field.get(bean);
         } catch (IllegalArgumentException | IllegalAccessException e) {
           throw new IllegalStateException(e);

src/main/java/kafdrop/controller/AclController.java

@@ -26,8 +26,8 @@
 import org.springframework.http.MediaType;
 import org.springframework.stereotype.Controller;
 import org.springframework.ui.Model;
+import org.springframework.web.bind.annotation.GetMapping;
 import org.springframework.web.bind.annotation.RequestMapping;
-import org.springframework.web.bind.annotation.RequestMethod;
 import org.springframework.web.bind.annotation.ResponseBody;
 
 import java.util.List;
@@ -52,7 +52,7 @@ public String acls(Model model) {
   @ApiResponses(value = {
       @ApiResponse(code = 200, message = "Success", response = String.class, responseContainer = "List")
   })
-  @RequestMapping(path = "/acl", produces = MediaType.APPLICATION_JSON_VALUE, method = RequestMethod.GET)
+  @GetMapping(path = "/acl", produces = MediaType.APPLICATION_JSON_VALUE)
   public @ResponseBody List<AclVO> getAllTopics() {
     return kafkaMonitor.getAcls();
   }

src/main/java/kafdrop/controller/BasicErrorController.java

@@ -1,5 +1,7 @@
 package kafdrop.controller;
 
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
 import org.springframework.boot.autoconfigure.web.servlet.error.*;
 import org.springframework.boot.web.error.ErrorAttributeOptions;
 import org.springframework.boot.web.servlet.error.*;
@@ -12,14 +14,16 @@
 
 @Controller
 public final class BasicErrorController extends AbstractErrorController {
+  private static final Logger LOG = LoggerFactory.getLogger(BasicErrorController.class);
+
   public BasicErrorController(ErrorAttributes errorAttributes) {
     super(errorAttributes);
   }
 
   @RequestMapping("/error")
   public ModelAndView handleError(HttpServletRequest request) {
     final var error = getErrorAttributes(request, ErrorAttributeOptions.of(ErrorAttributeOptions.Include.STACK_TRACE));
-    System.out.println("errorAtts: " + error);
+    LOG.info("errorAtts: {}", error);
     final var model = Map.of("error", error);
     return new ModelAndView("error", model);
   }

src/main/java/kafdrop/controller/BrokerController.java

@@ -49,7 +49,7 @@ public String brokerDetails(@PathVariable("id") int brokerId, Model model) {
       @ApiResponse(code = 200, message = "Success", response = BrokerVO.class),
       @ApiResponse(code = 404, message = "Invalid Broker ID")
   })
-  @RequestMapping(path = "/broker/{id}", produces = MediaType.APPLICATION_JSON_VALUE, method = RequestMethod.GET)
+  @GetMapping(path = "/broker/{id}", produces = MediaType.APPLICATION_JSON_VALUE)
   public @ResponseBody BrokerVO brokerDetailsJson(@PathVariable("id") int brokerId) {
     return kafkaMonitor.getBroker(brokerId).orElseThrow(() -> new BrokerNotFoundException("No such broker " + brokerId));
   }
@@ -58,7 +58,7 @@ public String brokerDetails(@PathVariable("id") int brokerId, Model model) {
   @ApiResponses(value = {
       @ApiResponse(code = 200, message = "Success", response = BrokerVO.class)
   })
-  @RequestMapping(path = "/broker", produces = MediaType.APPLICATION_JSON_VALUE, method = RequestMethod.GET)
+  @GetMapping(path = "/broker", produces = MediaType.APPLICATION_JSON_VALUE)
   public @ResponseBody List<BrokerVO> brokerDetailsJson() {
     return kafkaMonitor.getBrokers();
   }

src/main/java/kafdrop/controller/ClusterController.java

@@ -30,7 +30,6 @@
 import org.springframework.ui.*;
 import org.springframework.web.bind.annotation.*;
 
-import java.time.*;
 import java.util.*;
 import java.util.stream.*;
 
@@ -93,7 +92,7 @@ public String clusterInfo(Model model,
   @ApiResponses(value = {
       @ApiResponse(code = 200, message = "Success", response = ClusterInfoVO.class)
   })
-  @RequestMapping(path = "/", produces = MediaType.APPLICATION_JSON_VALUE, method = RequestMethod.GET)
+  @GetMapping(path = "/", produces = MediaType.APPLICATION_JSON_VALUE)
   public @ResponseBody ClusterInfoVO getCluster() {
     final var vo = new ClusterInfoVO();
     vo.brokers = kafkaMonitor.getBrokers();
@@ -112,6 +111,7 @@ public String brokerNotFound(Model model) {
   @ResponseStatus(HttpStatus.OK)
   @RequestMapping("/health_check")
   public void healthCheck() {
+    // only http code shall be checked
   }
 
   /**

src/main/java/kafdrop/controller/ConsumerController.java

@@ -51,7 +51,7 @@ public String consumerDetail(@PathVariable("groupId") String groupId, Model mode
       @ApiResponse(code = 200, message = "Success", response = ConsumerVO.class),
       @ApiResponse(code = 404, message = "Invalid consumer group")
   })
-  @RequestMapping(path = "/{groupId:.+}", produces = MediaType.APPLICATION_JSON_VALUE, method = RequestMethod.GET)
+  @GetMapping(path = "/{groupId:.+}", produces = MediaType.APPLICATION_JSON_VALUE)
   public @ResponseBody ConsumerVO getConsumer(@PathVariable("groupId") String groupId) throws ConsumerNotFoundException {
     final var topicVos = kafkaMonitor.getTopics();
     final var consumer = kafkaMonitor.getConsumers(topicVos)

src/main/java/kafdrop/controller/MessageController.java

@@ -36,8 +36,6 @@
 import org.springframework.web.bind.annotation.GetMapping;
 import org.springframework.web.bind.annotation.ModelAttribute;
 import org.springframework.web.bind.annotation.PathVariable;
-import org.springframework.web.bind.annotation.RequestMapping;
-import org.springframework.web.bind.annotation.RequestMethod;
 import org.springframework.web.bind.annotation.RequestParam;
 import org.springframework.web.bind.annotation.ResponseBody;
 
@@ -210,7 +208,7 @@ private MessageFormat getSelectedMessageFormat(String format) {
       @ApiResponse(code = 200, message = "Success", response = List.class),
       @ApiResponse(code = 404, message = "Invalid topic name")
   })
-  @RequestMapping(method = RequestMethod.GET, value = "/topic/{name:.+}/messages", produces = MediaType.APPLICATION_JSON_VALUE)
+  @GetMapping(value = "/topic/{name:.+}/messages", produces = MediaType.APPLICATION_JSON_VALUE)
   public @ResponseBody
   List<Object> getPartitionOrMessages(
       @PathVariable("name") String topicName,
@@ -264,10 +262,10 @@ private MessageDeserializer getDeserializer(String topicName, MessageFormat form
       // filter the input file name
 
       final var descFileName = descFile.replace(".desc", "")
-          .replaceAll("\\.", "")
-          .replaceAll("/", "");
+          .replace(".", "")
+          .replace("/", "");
       final var fullDescFile = protobufProperties.getDirectory() + File.separator + descFileName + ".desc";
-      deserializer = new ProtobufMessageDeserializer(topicName, fullDescFile, msgTypeName);
+      deserializer = new ProtobufMessageDeserializer(fullDescFile, msgTypeName);
     } else if (format == MessageFormat.PROTOBUF) {
       final var schemaRegistryUrl = schemaRegistryProperties.getConnect();
       final var schemaRegistryAuth = schemaRegistryProperties.getAuth();