feat: add support for gRPC client interceptors in ClientConfig

CHANGELOG.md

@@ -1,5 +1,9 @@
 ## 1.9.0 [unreleased]
 
+### Features
+
+1. [#360](https://github.com/InfluxCommunity/influxdb3-java/pull/360): Support passing interceptors to the Flight client.
+
 ## 1.8.0 [2026-02-19]
 
 ### Features

src/main/java/com/influxdb/v3/client/config/ClientConfig.java

@@ -28,6 +28,7 @@
 import java.time.Duration;
 import java.util.Arrays;
 import java.util.HashMap;
+import java.util.List;
 import java.util.Map;
 import java.util.Objects;
 import java.util.Properties;
@@ -36,6 +37,8 @@
 import javax.annotation.Nonnull;
 import javax.annotation.Nullable;
 
+import io.grpc.ClientInterceptor;
+
 import com.influxdb.v3.client.write.WriteOptions;
 import com.influxdb.v3.client.write.WritePrecision;
 
@@ -68,6 +71,7 @@
  *     <li><code>headers</code> - headers to be added to requests</li>
  *     <li><code>sslRootsFilePath</code> - path to the stored certificates file in PEM format</li>
  *     <li><code>disableGRPCCompression</code> - disables the default gRPC compression header</li>
+ *     <li><code>interceptors</code> - list of client interceptors to be used in the query API</li>
  * </ul>
  * <p>
  * If you want to create a client with custom configuration, you can use following code:
@@ -115,6 +119,7 @@ public final class ClientConfig {
     private final Map<String, String> headers;
     private final String sslRootsFilePath;
     private final boolean disableGRPCCompression;
+    private final List<ClientInterceptor> interceptors;
 
     /**
      * Deprecated use {@link #proxyUrl}.
@@ -329,6 +334,16 @@ public boolean getDisableGRPCCompression() {
         return disableGRPCCompression;
     }
 
+    /**
+     * Gets a list of client interceptors.
+     *
+     * @return a list of client interceptors.
+     */
+    @Nullable
+    public List<ClientInterceptor> getInterceptors() {
+        return interceptors;
+    }
+
     /**
      * Validates the configuration properties.
      */
@@ -366,7 +381,8 @@ public boolean equals(final Object o) {
                 && Objects.equals(authenticator, that.authenticator)
                 && Objects.equals(headers, that.headers)
                 && Objects.equals(sslRootsFilePath, that.sslRootsFilePath)
-                && disableGRPCCompression == that.disableGRPCCompression;
+                && disableGRPCCompression == that.disableGRPCCompression
+                && Objects.equals(interceptors, that.interceptors);
     }
 
     @Override
@@ -375,7 +391,7 @@ public int hashCode() {
                 database, writePrecision, gzipThreshold, writeNoSync,
                 timeout, writeTimeout, queryTimeout, allowHttpRedirects, disableServerCertificateValidation,
                 proxy, proxyUrl, authenticator, headers,
-                defaultTags, sslRootsFilePath, disableGRPCCompression);
+                defaultTags, sslRootsFilePath, disableGRPCCompression, interceptors);
     }
 
     @Override
@@ -429,6 +445,7 @@ public static final class Builder {
         private Map<String, String> headers;
         private String sslRootsFilePath;
         private boolean disableGRPCCompression;
+        private List<ClientInterceptor> interceptors;
 
         /**
          * Sets the URL of the InfluxDB server.
@@ -723,6 +740,18 @@ public Builder disableGRPCCompression(final boolean disableGRPCCompression) {
             return this;
         }
 
+        /**
+         *  Sets a list of interceptors to be used for the query API.
+         *
+         * @param interceptors a list of ClientInterceptor
+         * @return this
+         */
+        @Nonnull
+        public Builder interceptors(@Nullable final List<ClientInterceptor> interceptors) {
+            this.interceptors = interceptors;
+            return this;
+        }
+
         /**
          * Build an instance of {@code ClientConfig}.
          *
@@ -897,5 +926,6 @@ private ClientConfig(@Nonnull final Builder builder) {
         headers = builder.headers;
         sslRootsFilePath = builder.sslRootsFilePath;
         disableGRPCCompression = builder.disableGRPCCompression;
+        interceptors = builder.interceptors;
     }
 }

src/main/java/com/influxdb/v3/client/internal/FlightSqlClient.java

@@ -176,6 +176,10 @@ private FlightClient createFlightClient(@Nonnull final ClientConfig config) {
                 .with(Codec.Identity.NONE, false));
         }
 
+        if (config.getInterceptors() != null) {
+            nettyChannelBuilder.intercept(config.getInterceptors());
+        }
+
         return FlightGrpcUtils.createFlightClient(new RootAllocator(Long.MAX_VALUE), nettyChannelBuilder.build());
     }
 

src/test/java/com/influxdb/v3/client/internal/FlightSqlClientTest.java

@@ -24,11 +24,19 @@
 import java.net.InetSocketAddress;
 import java.net.URISyntaxException;
 import java.util.HashMap;
+import java.util.List;
 import java.util.Map;
 import java.util.stream.IntStream;
 import java.util.stream.Stream;
 
+import io.grpc.CallOptions;
+import io.grpc.Channel;
+import io.grpc.ClientCall;
+import io.grpc.ClientInterceptor;
+import io.grpc.ForwardingClientCall;
 import io.grpc.HttpConnectProxiedSocketAddress;
+import io.grpc.Metadata;
+import io.grpc.MethodDescriptor;
 import io.grpc.ProxyDetector;
 import io.grpc.internal.GrpcUtil;
 import org.apache.arrow.flight.CallHeaders;
@@ -108,6 +116,44 @@ public void callHeaders() throws Exception {
         }
     }
 
+    @Test
+    public void setHeaderInInterceptor() throws Exception {
+        ClientInterceptor interceptor = new ClientInterceptor() {
+            @Override
+            public <ReqT, RespT> ClientCall<ReqT, RespT> interceptCall(
+                    final MethodDescriptor<ReqT, RespT> method,
+                    final CallOptions callOptions,
+                    final Channel next
+            ) {
+                ClientCall<ReqT, RespT> call = next.newCall(method, callOptions);
+                return new ForwardingClientCall.SimpleForwardingClientCall<>(call) {
+                    @Override
+                    public void start(final Listener<RespT> responseListener, final Metadata headers) {
+                        Metadata.Key<String> key = Metadata.Key.of(
+                                "some-header",
+                                Metadata.ASCII_STRING_MARSHALLER
+                        );
+                        headers.put(key, "This is from interceptor");
+                        super.start(responseListener, headers);
+                    }
+                };
+            }
+        };
+
+        ClientConfig clientConfig = new ClientConfig.Builder()
+                .host(server.getLocation().getUri().toString())
+                .token("my-token".toCharArray())
+                .interceptors(List.of(interceptor))
+                .build();
+
+        try (FlightSqlClient flightSqlClient = new FlightSqlClient(clientConfig);
+             var data = executeQuery(flightSqlClient, Map.of(), Map.of())) {
+            Assertions.assertThat(data.count()).isEqualTo(rowCount);
+            final Map<String, String> receivedHeaders = headerFactory.getLastInstance().getHeaders();
+            Assertions.assertThat(receivedHeaders.get("some-header")).isEqualTo("This is from interceptor");
+        }
+    }
+
     @Test
     public void callHeadersWithoutToken() throws Exception {
         ClientConfig clientConfig = new ClientConfig.Builder()