diff --git a/xtraplatform-features-graphql/src/main/java/de/ii/xtraplatform/features/graphql/app/AggregateStatsReaderGraphQl.java b/xtraplatform-features-graphql/src/main/java/de/ii/xtraplatform/features/graphql/app/AggregateStatsReaderGraphQl.java
index b438efc4a..68726848c 100644
--- a/xtraplatform-features-graphql/src/main/java/de/ii/xtraplatform/features/graphql/app/AggregateStatsReaderGraphQl.java
+++ b/xtraplatform-features-graphql/src/main/java/de/ii/xtraplatform/features/graphql/app/AggregateStatsReaderGraphQl.java
@@ -8,7 +8,6 @@
 package de.ii.xtraplatform.features.graphql.app;
 
 import de.ii.xtraplatform.crs.domain.BoundingBox;
-import de.ii.xtraplatform.crs.domain.CrsTransformer;
 import de.ii.xtraplatform.crs.domain.CrsTransformerFactory;
 import de.ii.xtraplatform.crs.domain.EpsgCrs;
 import de.ii.xtraplatform.crs.domain.OgcCrs;
@@ -18,20 +17,19 @@
 import de.ii.xtraplatform.streams.domain.Reactive;
 import de.ii.xtraplatform.streams.domain.Reactive.Stream;
 import java.util.List;
+import java.util.Objects;
 import java.util.Optional;
 import org.threeten.extra.Interval;
 
 public class AggregateStatsReaderGraphQl implements AggregateStatsReader<FeatureSchema> {
 
-  private final FeatureMetadata featureMetadata;
-  private final Optional<CrsTransformer> crsTransformer;
-
   public AggregateStatsReaderGraphQl(
       FeatureMetadata featureMetadata,
       CrsTransformerFactory crsTransformerFactory,
       EpsgCrs nativeCrs) {
-    this.featureMetadata = featureMetadata;
-    this.crsTransformer = crsTransformerFactory.getTransformer(OgcCrs.CRS84, nativeCrs, true);
+    Objects.requireNonNull(featureMetadata);
+    Objects.requireNonNull(crsTransformerFactory)
+        .getTransformer(OgcCrs.CRS84, Objects.requireNonNull(nativeCrs), true);
   }
 
   @Override
diff --git a/xtraplatform-features-graphql/src/main/java/de/ii/xtraplatform/features/graphql/app/FeatureProviderGraphQl.java b/xtraplatform-features-graphql/src/main/java/de/ii/xtraplatform/features/graphql/app/FeatureProviderGraphQl.java
index a7ed9bd2e..2f5c995fd 100644
--- a/xtraplatform-features-graphql/src/main/java/de/ii/xtraplatform/features/graphql/app/FeatureProviderGraphQl.java
+++ b/xtraplatform-features-graphql/src/main/java/de/ii/xtraplatform/features/graphql/app/FeatureProviderGraphQl.java
@@ -375,7 +375,6 @@ public Optional<BoundingBox> getSpatialExtent(String typeName) {
           .join();
     } catch (Throwable e) {
       // continue
-      boolean br = true;
     }
 
     return Optional.empty();
diff --git a/xtraplatform-features-graphql/src/main/java/de/ii/xtraplatform/features/graphql/app/FeatureProviderGraphQlFactory.java b/xtraplatform-features-graphql/src/main/java/de/ii/xtraplatform/features/graphql/app/FeatureProviderGraphQlFactory.java
index a5b595941..cc3ba907a 100644
--- a/xtraplatform-features-graphql/src/main/java/de/ii/xtraplatform/features/graphql/app/FeatureProviderGraphQlFactory.java
+++ b/xtraplatform-features-graphql/src/main/java/de/ii/xtraplatform/features/graphql/app/FeatureProviderGraphQlFactory.java
@@ -25,6 +25,7 @@
 import de.ii.xtraplatform.features.graphql.domain.FeatureProviderGraphQlData;
 import de.ii.xtraplatform.features.graphql.domain.ImmutableFeatureProviderGraphQlData;
 import java.util.Map;
+import java.util.Objects;
 import java.util.Optional;
 import java.util.Set;
 import javax.inject.Inject;
@@ -41,7 +42,6 @@ public class FeatureProviderGraphQlFactory
   private static final Logger LOGGER = LoggerFactory.getLogger(FeatureProviderGraphQlFactory.class);
 
   private final Lazy<Set<SchemaFragmentResolver>> schemaResolvers;
-  private final ConnectorFactory connectorFactory;
 
   @Inject
   public FeatureProviderGraphQlFactory(
@@ -50,7 +50,7 @@ public FeatureProviderGraphQlFactory(
       ProviderGraphQlFactoryAssisted providerGraphQlFactoryAssisted) {
     super(providerGraphQlFactoryAssisted);
     this.schemaResolvers = schemaResolvers;
-    this.connectorFactory = connectorFactory;
+    Objects.requireNonNull(connectorFactory);
   }
 
   @Override
diff --git a/xtraplatform-features-graphql/src/main/java/de/ii/xtraplatform/features/graphql/app/FeatureQueryEncoderGraphQl.java b/xtraplatform-features-graphql/src/main/java/de/ii/xtraplatform/features/graphql/app/FeatureQueryEncoderGraphQl.java
index ec9f3a004..8ae46f585 100644
--- a/xtraplatform-features-graphql/src/main/java/de/ii/xtraplatform/features/graphql/app/FeatureQueryEncoderGraphQl.java
+++ b/xtraplatform-features-graphql/src/main/java/de/ii/xtraplatform/features/graphql/app/FeatureQueryEncoderGraphQl.java
@@ -26,6 +26,7 @@
 import java.util.ArrayList;
 import java.util.List;
 import java.util.Map;
+import java.util.Objects;
 import java.util.Optional;
 import java.util.stream.Collectors;
 import java.util.stream.Stream;
@@ -39,7 +40,6 @@ public class FeatureQueryEncoderGraphQl implements FeatureQueryEncoder<String, Q
   private final Map<String, FeatureSchema> featureSchemas;
   private final Map<String, List<FeatureSchema>> sourceSchemas;
   private final GraphQlQueries queryGeneration;
-  private final EpsgCrs nativeCrs;
   private final FilterEncoderGraphQl filterEncoder;
 
   public FeatureQueryEncoderGraphQl(
@@ -52,8 +52,8 @@ public FeatureQueryEncoderGraphQl(
       Cql cql) {
     this.featureSchemas = featureSchemas;
     this.sourceSchemas = sourceSchemas;
+    Objects.requireNonNull(connectionInfo);
     this.queryGeneration = queryGeneration;
-    this.nativeCrs = nativeCrs;
     this.filterEncoder =
         new FilterEncoderGraphQl(nativeCrs, crsTransformerFactory, cql, queryGeneration);
   }
@@ -95,22 +95,16 @@ private String getNestedFields(String sourcePath) {
       return sourcePath;
     }
 
-    String fields = "";
-
     String[] split = sourcePath.split("/");
-    for (int i = split.length - 1; i >= 0; i--) {
-      String elem = split[i];
-      if (!fields.isBlank()) {
-        elem = elem + " " + fields;
-      }
-      if (i > 0) {
-        fields = "{ " + elem + " }";
-      } else {
-        fields = elem;
-      }
+    StringBuilder fields = new StringBuilder(split[split.length - 1]);
+
+    for (int i = split.length - 2; i >= 0; i--) {
+      fields.insert(0, " { ");
+      fields.insert(0, split[i]);
+      fields.append(" }");
     }
 
-    return fields;
+    return fields.toString();
   }
 
   public String getFields(FeatureSchema featureSchema, String indentation) {
@@ -146,7 +140,9 @@ public String encodeFeatureQuery(
 
     String q = String.format(queryTemplate, name + arguments, fields);
 
-    LOGGER.debug("GraphQL Request\n{}", q.replaceAll("\\\\n", "\n"));
+    if (LOGGER.isDebugEnabled()) {
+      LOGGER.debug("GraphQL Request\n{}", q.replaceAll("\\\\n", "\n"));
+    }
 
     return q;
   }
@@ -174,7 +170,7 @@ private List<String> getPaging(int limit, int offset) {
         .map(
             template ->
                 StringTemplateFilters.applyTemplate(
-                    template, (Map.of("value", String.valueOf(limit)))::get))
+                    template, Map.of("value", String.valueOf(limit))::get))
         .ifPresent(arguments::add);
 
     queryGeneration
@@ -184,7 +180,7 @@ private List<String> getPaging(int limit, int offset) {
         .map(
             template ->
                 StringTemplateFilters.applyTemplate(
-                    template, (Map.of("value", String.valueOf(offset)))::get))
+                    template, Map.of("value", String.valueOf(offset))::get))
         .ifPresent(arguments::add);
 
     return arguments;
@@ -212,7 +208,7 @@ private List<String> getFilter(
     String argument =
         StringTemplateFilters.applyTemplate(
             queryGeneration.getCollection().getArguments().getFilter().orElse("{{value}}"),
-            (Map.of("value", filterString))::get);
+            Map.of("value", filterString)::get);
 
     return List.of(argument);
   }
diff --git a/xtraplatform-features-graphql/src/main/java/de/ii/xtraplatform/features/graphql/app/FeatureTokenDecoderGraphQlJson2.java b/xtraplatform-features-graphql/src/main/java/de/ii/xtraplatform/features/graphql/app/FeatureTokenDecoderGraphQlJson2.java
index 95bf8ba0b..3f66fcabb 100644
--- a/xtraplatform-features-graphql/src/main/java/de/ii/xtraplatform/features/graphql/app/FeatureTokenDecoderGraphQlJson2.java
+++ b/xtraplatform-features-graphql/src/main/java/de/ii/xtraplatform/features/graphql/app/FeatureTokenDecoderGraphQlJson2.java
@@ -28,16 +28,12 @@
 import java.util.Objects;
 import java.util.Optional;
 import java.util.stream.Collectors;
-import org.slf4j.Logger;
-import org.slf4j.LoggerFactory;
 
 public class FeatureTokenDecoderGraphQlJson2
     extends FeatureTokenDecoder<
         byte[], FeatureSchema, SchemaMapping, ModifiableContext<FeatureSchema, SchemaMapping>>
     implements Decoder.Pipeline {
 
-  private static final Logger LOGGER =
-      LoggerFactory.getLogger(FeatureTokenDecoderGraphQlJson2.class);
   private static final JsonFactory JSON_FACTORY = new JsonFactory();
 
   private final JsonParser parser;
@@ -47,23 +43,21 @@ public class FeatureTokenDecoderGraphQlJson2
   private final Map<String, SchemaMapping> mappings;
   private final String type;
   private final String wrapper;
-  private final Optional<String> nullValue;
 
-  private boolean started;
-  private int depth = -1;
-  private int featureDepth = 0;
-  private boolean inFeatures = false;
-  private boolean inProperties = false;
-  private boolean isCollection = false;
-  private boolean inErrors = false;
-  private int lastNameIsArrayDepth = 0;
-  private int startArray = 0;
-  private int endArray = 0;
+  private final ParsingState state;
 
   private ModifiableContext<FeatureSchema, SchemaMapping> context;
-  private List<List<String>> arrayPaths;
   private DecoderJsonProperties decoderJsonProperties;
 
+  private static final class ParsingState {
+    boolean started;
+    int featureDepth;
+    boolean inFeatures;
+    boolean inProperties;
+    boolean isCollection;
+    boolean inErrors;
+  }
+
   public FeatureTokenDecoderGraphQlJson2(
       FeatureSchema featureSchema,
       FeatureQuery query,
@@ -80,6 +74,7 @@ public FeatureTokenDecoderGraphQlJson2(
       String type,
       String wrapper,
       Optional<String> nullValue) {
+    super();
     try {
       this.parser = JSON_FACTORY.createNonBlockingByteArrayParser();
     } catch (IOException e) {
@@ -91,7 +86,8 @@ public FeatureTokenDecoderGraphQlJson2(
     this.mappings = mappings;
     this.type = type;
     this.wrapper = wrapper;
-    this.nullValue = nullValue;
+    this.state = new ParsingState();
+    Objects.requireNonNull(nullValue);
   }
 
   @Override
@@ -102,7 +98,7 @@ protected void init() {
             .setMappings(mappings)
             .setQuery(featureQuery);
 
-    this.arrayPaths =
+    List<List<String>> arrayPaths =
         context.mapping().getSchemasByTargetPath().entrySet().stream()
             .filter(entry -> entry.getValue().get(0).isArray())
             .map(entry -> entry.getKey())
@@ -128,7 +124,7 @@ public void onPush(byte[] bytes) {
   }
 
   // for unit tests
-  void parse(String data) throws Exception {
+  void parse(String data) {
     byte[] dataBytes = data.getBytes(StandardCharsets.UTF_8);
     feedInput(dataBytes);
     cleanup();
@@ -147,6 +143,7 @@ private void feedInput(byte[] data) {
     }
   }
 
+  @SuppressWarnings({"PMD.CognitiveComplexity", "PMD.CyclomaticComplexity"})
   public boolean advanceParser() {
 
     boolean feedMeMore = false;
@@ -165,44 +162,44 @@ public boolean advanceParser() {
 
         case START_OBJECT:
         case START_ARRAY:
-          if (!inProperties) {
-            if (inFeatures && context.path().size() == featureDepth) {
-              this.inProperties = true;
-              if (isCollection) {
+          if (!state.inProperties) {
+            if (state.inFeatures && context.path().size() == state.featureDepth) {
+              state.inProperties = true;
+              if (state.isCollection) {
                 startFeature();
               }
-            } else if (!inFeatures && Objects.equals(currentName, wrapper)) {
+            } else if (!state.inFeatures && Objects.equals(currentName, wrapper)) {
               startIfNecessary(nextToken == JsonToken.START_ARRAY);
-            } else if (!inFeatures && Objects.equals(currentName, "errors")) {
-              this.inErrors = true;
+            } else if (!state.inFeatures && Objects.equals(currentName, "errors")) {
+              state.inErrors = true;
             }
             break;
           }
-          feedMeMore = decoderJsonProperties.parse(nextToken, currentName, featureDepth);
+          feedMeMore = decoderJsonProperties.parse(nextToken, currentName, state.featureDepth);
           break;
         case END_OBJECT:
-          if (inProperties && context.path().size() == featureDepth) {
-            this.inProperties = false;
+          if (state.inProperties && context.path().size() == state.featureDepth) {
+            state.inProperties = false;
             getDownstream().onFeatureEnd(context);
-            if (!isCollection) {
+            if (!state.isCollection) {
               getDownstream().onEnd(context);
-              this.inFeatures = false;
+              state.inFeatures = false;
             }
             break;
           }
-          feedMeMore = decoderJsonProperties.parse(nextToken, currentName, featureDepth);
+          feedMeMore = decoderJsonProperties.parse(nextToken, currentName, state.featureDepth);
           break;
         case END_ARRAY:
-          if (!inProperties && context.path().size() == featureDepth) {
+          if (!state.inProperties && context.path().size() == state.featureDepth) {
             getDownstream().onEnd(context);
-            this.inFeatures = false;
+            state.inFeatures = false;
             break;
           }
-          feedMeMore = decoderJsonProperties.parse(nextToken, currentName, featureDepth);
+          feedMeMore = decoderJsonProperties.parse(nextToken, currentName, state.featureDepth);
           break;
         default:
-          if (!inErrors) {
-            feedMeMore = decoderJsonProperties.parse(nextToken, currentName, featureDepth);
+          if (!state.inErrors) {
+            feedMeMore = decoderJsonProperties.parse(nextToken, currentName, state.featureDepth);
             break;
           }
           if (Objects.equals(currentName, "message")) {
@@ -231,10 +228,10 @@ public ModifiableContext<FeatureSchema, SchemaMapping> context() {
   }
 
   private void startIfNecessary(boolean isCollection) {
-    if (!started) {
-      this.started = true;
-      this.inFeatures = true;
-      this.isCollection = isCollection;
+    if (!state.started) {
+      state.started = true;
+      state.inFeatures = true;
+      state.isCollection = isCollection;
 
       if (!isCollection) {
         context.metadata().isSingleFeature(true);
@@ -251,7 +248,7 @@ private void startFeature() {
     context.setIndexes(List.of());
     decoderJsonProperties.reset();
     getDownstream().onFeatureStart(context);
-    this.featureDepth = context.path().size();
-    this.inProperties = true;
+    state.featureDepth = context.path().size();
+    state.inProperties = true;
   }
 }
diff --git a/xtraplatform-features-graphql/src/main/java/de/ii/xtraplatform/features/graphql/app/FilterEncoderGraphQl.java b/xtraplatform-features-graphql/src/main/java/de/ii/xtraplatform/features/graphql/app/FilterEncoderGraphQl.java
index de86ce477..3a91adeb1 100644
--- a/xtraplatform-features-graphql/src/main/java/de/ii/xtraplatform/features/graphql/app/FilterEncoderGraphQl.java
+++ b/xtraplatform-features-graphql/src/main/java/de/ii/xtraplatform/features/graphql/app/FilterEncoderGraphQl.java
@@ -51,14 +51,10 @@
 import java.util.Optional;
 import java.util.function.BiFunction;
 import java.util.stream.Collectors;
-import org.slf4j.Logger;
-import org.slf4j.LoggerFactory;
 
+@SuppressWarnings({"PMD.GodClass", "PMD.TooManyMethods"})
 public class FilterEncoderGraphQl {
 
-  private static final Logger LOGGER = LoggerFactory.getLogger(FilterEncoderGraphQl.class);
-
-  private final Cql cql;
   private final EpsgCrs nativeCrs;
   private final CrsTransformerFactory crsTransformerFactory;
   BiFunction<List<Double>, Optional<EpsgCrs>, List<Double>> coordinatesTransformer;
@@ -71,7 +67,7 @@ public FilterEncoderGraphQl(
       GraphQlQueries queryGeneration) {
     this.nativeCrs = nativeCrs;
     this.crsTransformerFactory = crsTransformerFactory;
-    this.cql = cql;
+    Objects.requireNonNull(cql);
     this.coordinatesTransformer = this::transformCoordinatesIfNecessary;
     this.queryGeneration = queryGeneration;
   }
@@ -82,23 +78,25 @@ public Map<String, String> encode(Cql2Expression filter, FeatureSchema schema) {
 
   private List<Double> transformCoordinatesIfNecessary(
       List<Double> coordinates, Optional<EpsgCrs> sourceCrs) {
+    if (sourceCrs.isEmpty() || Objects.equals(sourceCrs.get(), nativeCrs)) {
+      return coordinates;
+    }
 
-    if (sourceCrs.isPresent() && !Objects.equals(sourceCrs.get(), nativeCrs)) {
-      Optional<CrsTransformer> transformer =
-          crsTransformerFactory.getTransformer(sourceCrs.get(), nativeCrs, true);
-      if (transformer.isPresent()) {
-        double[] transformed =
-            transformer.get().transform(Doubles.toArray(coordinates), coordinates.size() / 2, 2);
-        if (Objects.isNull(transformed)) {
-          throw new IllegalArgumentException(
-              String.format(
-                  "Filter is invalid. Coordinates cannot be transformed: %s", coordinates));
-        }
+    Optional<CrsTransformer> transformer =
+        crsTransformerFactory.getTransformer(sourceCrs.get(), nativeCrs, true);
 
-        return Doubles.asList(transformed);
-      }
+    if (transformer.isEmpty()) {
+      return coordinates;
     }
-    return coordinates;
+
+    double[] transformed =
+        transformer.get().transform(Doubles.toArray(coordinates), coordinates.size() / 2, 2);
+    if (Objects.isNull(transformed)) {
+      throw new IllegalArgumentException(
+          String.format("Filter is invalid. Coordinates cannot be transformed: %s", coordinates));
+    }
+
+    return Doubles.asList(transformed);
   }
 
   // TODO: reverse FeatureSchema for nested mappings?
@@ -106,16 +104,16 @@ private Optional<String> getPrefixedPropertyName(FeatureSchema schema, String pr
     return schema.getProperties().stream()
         .filter(
             featureProperty -> {
-              if (Objects.nonNull(featureProperty.getName())) {
-                if (Objects.equals(
-                    featureProperty.getName().toLowerCase(), property.toLowerCase())) {
-                  return true;
-                }
-                if (Objects.equals(property, ID_PLACEHOLDER) && featureProperty.isId()) {
-                  return true;
-                }
+              String featurePropertyName = featureProperty.getName();
+              if (Objects.isNull(featurePropertyName)) {
+                return false;
               }
-              return false;
+
+              if (featurePropertyName.equalsIgnoreCase(property)) {
+                return true;
+              }
+
+              return Objects.equals(property, ID_PLACEHOLDER) && featureProperty.isId();
             })
         .map(FeatureSchema::getSourcePath)
         .filter(Optional::isPresent)
@@ -195,7 +193,7 @@ public Map<String, String> visit(In in, List<Map<String, String>> children) {
 
       String argument =
           StringTemplateFilters.applyTemplate(
-              template.get(), (Map.of("sourcePath", sourcePath, "value", value))::get);
+              template.get(), Map.of("sourcePath", sourcePath, "value", value)::get);
 
       return fromString(argument);
     }
@@ -248,7 +246,7 @@ public Map<String, String> visit(
         String argument =
             StringTemplateFilters.applyTemplate(
                 queryGeneration.getCollection().getArguments().getBbox().get(),
-                (Map.of("sourcePath", sourcePath, "value", wkt))::get);
+                Map.of("sourcePath", sourcePath, "value", wkt)::get);
 
         return fromString(argument);
       }
@@ -348,7 +346,7 @@ public Map<String, String> visit(Bbox bbox, List<Map<String, String>> children)
       String argument =
           StringTemplateFilters.applyTemplate(
               queryGeneration.getCollection().getArguments().getGeometry().get(),
-              (Map.of("value", wkt))::get,
+              Map.of("value", wkt)::get,
               Map.of("toWkt", java.util.function.Function.identity()));
 
       return fromString(argument);
@@ -401,6 +399,7 @@ static Map<String, String> fromString(String obj) {
     return fromString(obj, false);
   }
 
+  @SuppressWarnings("PMD.CyclomaticComplexity")
   static Map<String, String> fromString(String obj, boolean subField) {
     String separator = subField ? " " : ":";
     String cleaned = obj.trim();
diff --git a/xtraplatform-features-graphql/src/main/java/de/ii/xtraplatform/features/graphql/app/SchemaDeriverGraphQl.java b/xtraplatform-features-graphql/src/main/java/de/ii/xtraplatform/features/graphql/app/SchemaDeriverGraphQl.java
index ab1fdcfea..bb00dc479 100644
--- a/xtraplatform-features-graphql/src/main/java/de/ii/xtraplatform/features/graphql/app/SchemaDeriverGraphQl.java
+++ b/xtraplatform-features-graphql/src/main/java/de/ii/xtraplatform/features/graphql/app/SchemaDeriverGraphQl.java
@@ -46,7 +46,7 @@ public FeatureSchema visit(
                       .map(
                           template ->
                               StringTemplateFilters.applyTemplate(
-                                  template, (Map.of("sourcePath", path))::get))
+                                  template, (String key) -> Map.of("sourcePath", path).get(key)))
                       .map(expr -> FilterEncoderGraphQl.fromString(expr, true))
                       .map(expr -> path + "/" + expr.get(path)));
     } else if (schema.isFeatureRef()) {
diff --git a/xtraplatform-features-graphql/src/main/java/de/ii/xtraplatform/features/graphql/domain/GraphQlQueries.java b/xtraplatform-features-graphql/src/main/java/de/ii/xtraplatform/features/graphql/domain/GraphQlQueries.java
index ffdca6da0..2dc300a7a 100644
--- a/xtraplatform-features-graphql/src/main/java/de/ii/xtraplatform/features/graphql/domain/GraphQlQueries.java
+++ b/xtraplatform-features-graphql/src/main/java/de/ii/xtraplatform/features/graphql/domain/GraphQlQueries.java
@@ -45,7 +45,7 @@ interface SingleQuery {
     String getName();
 
     default String getName(String type) {
-      return StringTemplateFilters.applyTemplate(getName(), (Map.of("type", type))::get);
+      return StringTemplateFilters.applyTemplate(getName(), Map.of("type", type)::get);
     }
 
     /**
@@ -76,7 +76,7 @@ interface CollectionQuery {
     String getName();
 
     default String getName(String type) {
-      return StringTemplateFilters.applyTemplate(getName(), (Map.of("type", type))::get);
+      return StringTemplateFilters.applyTemplate(getName(), Map.of("type", type)::get);
     }
 
     /**
diff --git a/xtraplatform-features-graphql/src/main/java/de/ii/xtraplatform/features/graphql/infra/GraphQlConnectorHttp.java b/xtraplatform-features-graphql/src/main/java/de/ii/xtraplatform/features/graphql/infra/GraphQlConnectorHttp.java
index 5018875b3..46b3c6638 100644
--- a/xtraplatform-features-graphql/src/main/java/de/ii/xtraplatform/features/graphql/infra/GraphQlConnectorHttp.java
+++ b/xtraplatform-features-graphql/src/main/java/de/ii/xtraplatform/features/graphql/infra/GraphQlConnectorHttp.java
@@ -117,14 +117,12 @@ public Optional<Throwable> getConnectionError() {
 
   @Override
   public Reactive.Source<byte[]> getSourceStream(String query) {
-    InputStream inputStream =
+    try (InputStream inputStream =
         httpClient.postAsInputStream(
             connectionInfo.getUri().toString(),
             query.getBytes(StandardCharsets.UTF_8),
             MediaType.APPLICATION_JSON_TYPE,
-            Map.of("Accept", MediaType.APPLICATION_JSON));
-
-    try {
+            Map.of("Accept", MediaType.APPLICATION_JSON))) {
       byte[] bytes = inputStream.readAllBytes();
       LOGGER.debug("Response \n{}", new String(bytes, StandardCharsets.UTF_8));