Fixed sonar errors

Author: germanosin

api/src/main/java/io/kafbat/ui/service/metrics/scrape/inferred/InferredMetricsScraper.java

@@ -26,6 +26,7 @@ public class InferredMetricsScraper {
   public static final String NODE_ID_TAG = "node_id";
   public static final String TOPIC_TAG = "topic";
   public static final String GROUP_TAG = "group";
+  public static final String PARTITION_TAG = "partition";
   private ScrapedClusterState prevState = null;
 
   public synchronized Mono<InferredMetrics> scrape(ScrapedClusterState newState) {
@@ -130,36 +131,36 @@ private static void fillTopicMetrics(MetricsRegistry registry, ScrapedClusterSta
       state.endOffsets().forEach((partition, endOffset) -> registry.gauge(
           "kafka_topic_partition_next_offset",
           "Current (next) Offset of a Broker at Topic/Partition",
-          List.of(TOPIC_TAG, "partition"),
+          List.of(TOPIC_TAG, PARTITION_TAG),
           List.of(topicName, String.valueOf(partition)),
           endOffset
       ));
       state.startOffsets().forEach((partition, startOffset) -> registry.gauge(
           "kafka_topic_partition_oldest_offset",
           "Oldest Offset of a Broker at Topic/Partition",
-          List.of(TOPIC_TAG, "partition"),
+          List.of(TOPIC_TAG, PARTITION_TAG),
           List.of(topicName, String.valueOf(partition)),
           startOffset
       ));
       state.description().partitions().forEach(p -> {
         registry.gauge(
             "kafka_topic_partition_in_sync_replica",
             "Number of In-Sync Replicas for this Topic/Partition",
-            List.of(TOPIC_TAG, "partition"),
+            List.of(TOPIC_TAG, PARTITION_TAG),
             List.of(topicName, String.valueOf(p.partition())),
             p.isr().size()
         );
         registry.gauge(
             "kafka_topic_partition_replicas",
             "Number of Replicas for this Topic/Partition",
-            List.of(TOPIC_TAG, "partition"),
+            List.of(TOPIC_TAG, PARTITION_TAG),
             List.of(topicName, String.valueOf(p.partition())),
             p.replicas().size()
         );
         registry.gauge(
             "kafka_topic_partition_leader",
             "Leader Broker ID of this Topic/Partition (-1, if no leader)",
-            List.of(TOPIC_TAG, "partition"),
+            List.of(TOPIC_TAG, PARTITION_TAG),
             List.of(topicName, String.valueOf(p.partition())),
             Optional.ofNullable(p.leader()).map(Node::id).orElse(-1)
         );
@@ -212,7 +213,7 @@ private static void fillConsumerGroupsMetrics(MetricsRegistry registry, ScrapedC
         registry.gauge(
             "kafka_consumergroup_current_offset",
             "Current Offset of a ConsumerGroup at Topic/Partition",
-            List.of("consumergroup", TOPIC_TAG, "partition"),
+            List.of("consumergroup", TOPIC_TAG, PARTITION_TAG),
             List.of(groupName, tp.topic(), String.valueOf(tp.partition())),
             committedOffset
         );
@@ -223,7 +224,7 @@ private static void fillConsumerGroupsMetrics(MetricsRegistry registry, ScrapedC
                 registry.gauge(
                     "kafka_consumergroup_lag",
                     "Current Approximate Lag of a ConsumerGroup at Topic/Partition",
-                    List.of("consumergroup", TOPIC_TAG, "partition"),
+                    List.of("consumergroup", TOPIC_TAG, PARTITION_TAG),
                     List.of(groupName, tp.topic(), String.valueOf(tp.partition())),
                     endOffset - committedOffset //TODO: check +-1
                 ));

api/src/main/java/io/kafbat/ui/service/metrics/scrape/jmx/JmxMetricsFormatter.java

@@ -18,7 +18,7 @@ public class JmxMetricsFormatter {
 
   // copied from https://github.com/prometheus/jmx_exporter/blob/b6b811b4aae994e812e902b26dd41f29364c0e2b/collector/src/main/java/io/prometheus/jmx/JmxMBeanPropertyCache.java#L15
   private static final Pattern PROPERTY_PATTERN = Pattern.compile(
-      "([^,=:\\*\\?]+)=(\"(?>[^\\\\\"]*(?:\\\\.)?)*\"|[^,=:\"]*)"
+      "([^,=:\\*\\?]+)=(\"(?:\\\\.|[^\\\\\"])*\"|[^,=:\"]*)"
   );
 
   public static List<RawMetric> constructMetricsList(ObjectName jmxMetric,

api/src/main/java/io/kafbat/ui/service/metrics/scrape/jmx/JmxMetricsRetriever.java

@@ -71,21 +71,35 @@ private void withJmxConnector(String jmxUrl,
                                 MetricsScrapeProperties scrapeProperties,
                                 Consumer<JMXConnector> consumer) {
     var env = prepareJmxEnvAndSetThreadLocal(scrapeProperties);
-    try (JMXConnector connector = JMXConnectorFactory.newJMXConnector(new JMXServiceURL(jmxUrl), env)) {
-      try {
-        connector.connect(env);
-      } catch (Exception exception) {
-        log.error("Error connecting to {}", jmxUrl, exception);
+    JMXServiceURL serviceUrl;
+    try {
+      serviceUrl = new JMXServiceURL(jmxUrl);
+    } catch (java.net.MalformedURLException e) {
+      log.error("Malformed JMX URL: {}", jmxUrl, e);
+      return;
+    }
+    try (JMXConnector connector = JMXConnectorFactory.newJMXConnector(serviceUrl, env)) {
+      if (!tryConnect(connector, env, jmxUrl)) {
         return;
       }
       consumer.accept(connector);
-    } catch (Exception e) {
-      log.error("Error getting jmx metrics from {}", jmxUrl, e);
+    } catch (Exception connectorException) {
+      log.error("Error getting jmx metrics from {}", jmxUrl, connectorException);
     } finally {
       JmxSslSocketFactory.clearThreadLocalContext();
     }
   }
 
+  private boolean tryConnect(JMXConnector connector, Map<String, ?> env, String jmxUrl) {
+    try {
+      connector.connect(env);
+      return true;
+    } catch (Exception connectException) {
+      log.error("Error connecting to {}", jmxUrl, connectException);
+      return false;
+    }
+  }
+
   private Map<String, Object> prepareJmxEnvAndSetThreadLocal(MetricsScrapeProperties scrapeProperties) {
     Map<String, Object> env = new HashMap<>();
     if (isSslJmxEndpoint(scrapeProperties)) {

api/src/main/java/io/kafbat/ui/service/metrics/scrape/prometheus/PrometheusTextFormatParser.java

@@ -39,11 +39,11 @@ public class PrometheusTextFormatParser {
   // Regex to capture metric name, optional labels, value, and optional timestamp.
   // Groups: 1=name, 2=labels (content), 3=value, 4=timestamp
   private static final Pattern METRIC_LINE_PATTERN = Pattern.compile(
-      "^([a-zA-Z_:][a-zA-Z0-9_:]*)" +                        // Metric name
-      "(?:\\{(?>[^}]*)\\})?" +                               // Optional labels (atomic group)
-      "\\s+" +
-      "(-?(?:Inf|NaN|(?:\\d+(?:\\.\\d+)?(?:[eE][+-]?\\d+)?)))" +  // Metric value
-      "(?:\\s+([0-9]+))?$"                                   // Optional timestamp
+      "^([a-zA-Z_:][a-zA-Z0-9_:]*)"                        // Metric name
+      + "(?:\\{(?>[^}]*)\\})?"                               // Optional labels (atomic group)
+      + "\\s+"
+      + "(-?(?:Inf|NaN|(?:\\d+(?:\\.\\d+)?(?:[eE][+-]?\\d+)?)))" // Metric value
+      + "(?:\\s+([0-9]+))?$"                                   // Optional timestamp
   );                // Group 4: Optional timestamp