Fixing propertyType matching for custom conversions

src/main/java/org/springframework/data/neo4j/core/mapping/Neo4jMappingContext.java

@@ -21,6 +21,7 @@
 import java.lang.reflect.Modifier;
 import java.lang.reflect.ParameterizedType;
 import java.lang.reflect.Type;
+import java.lang.reflect.TypeVariable;
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.Collection;
@@ -79,6 +80,7 @@
  *
  * @author Michael J. Simons
  * @author Gerrit Meier
+ * @author Francesco Chicchiriccò
  * @since 6.0
  */
 @API(status = API.Status.STABLE, since = "6.0")
@@ -444,6 +446,7 @@ private <T extends Neo4jPersistentPropertyConverterFactory> T getOrCreateConvert
 		}));
 	}
 
+	@SuppressWarnings("rawtypes")
 	@Nullable Neo4jPersistentPropertyConverter<?> getOptionalCustomConversionsFor(Neo4jPersistentProperty persistentProperty) {
 
 		// Is the annotation present at all?
@@ -468,21 +471,12 @@ private <T extends Neo4jPersistentPropertyConverterFactory> T getOrCreateConvert
 			else {
 				converterClass = customConverter.getClass();
 			}
-			Map<String, Type> typeVariableMap = (converterClass != null)
-					? GenericTypeResolver.getTypeVariableMap(converterClass)
-						.entrySet()
-						.stream()
-						.collect(Collectors.toMap(e -> e.getKey().getName(), Map.Entry::getValue))
-					: Map.of();
-			Type propertyType = null;
-			if (typeVariableMap.containsKey("T")) {
-				propertyType = typeVariableMap.get("T");
-			}
-			else if (typeVariableMap.containsKey("P")) {
-				propertyType = typeVariableMap.get("P");
-			}
-			forCollection = propertyType instanceof ParameterizedType
-					&& persistentProperty.getType().equals(((ParameterizedType) propertyType).getRawType());
+			Map<TypeVariable, Type> typeVariableMap = (converterClass != null)
+					? GenericTypeResolver.getTypeVariableMap(converterClass) : Map.of();
+			forCollection = typeVariableMap.values()
+				.stream()
+				.anyMatch(propertyType -> propertyType instanceof ParameterizedType
+						&& persistentProperty.getType().equals(((ParameterizedType) propertyType).getRawType()));
 		}
 
 		return new NullSafeNeo4jPersistentPropertyConverter<>(customConverter, persistentProperty.isComposite(),

src/test/java/org/springframework/data/neo4j/integration/issues/IssuesIT.java

@@ -205,6 +205,8 @@
 import org.springframework.data.neo4j.integration.issues.gh3092.DynamicLabelChild;
 import org.springframework.data.neo4j.integration.issues.gh3092.DynamicLabelChildRepository;
 import org.springframework.data.neo4j.integration.issues.gh3092.DynamicLabelRoot;
+import org.springframework.data.neo4j.integration.issues.gh3109.NodeWithValueList;
+import org.springframework.data.neo4j.integration.issues.gh3109.NodeWithValueListRepository;
 import org.springframework.data.neo4j.integration.issues.qbe.A;
 import org.springframework.data.neo4j.integration.issues.qbe.ARepository;
 import org.springframework.data.neo4j.integration.issues.qbe.B;
@@ -228,6 +230,7 @@
 
 /**
  * @author Michael J. Simons
+ * @author Francesco Chicchiriccò
  */
 @Neo4jIntegrationTest
 @DisplayNameGeneration(SimpleDisplayNameGeneratorWithTags.class)
@@ -1899,6 +1902,17 @@ void instantiateCorrectEntitiesIfDynamicLabelsAreUsed(@Autowired VehicleReposito
 
 	}
 
+	@Tag("GH-3109")
+	@Test
+	void customConverterForGenericCollection(@Autowired NodeWithValueListRepository repository) {
+		NodeWithValueList entity = new NodeWithValueList();
+		entity.getValueList().add("value1");
+		entity.getValueList().add("value2");
+
+		entity = repository.save(entity);
+		assertThat(entity.getValueList()).containsExactly("value1", "value2");
+	}
+
 	@Configuration
 	@EnableTransactionManagement
 	@EnableNeo4jRepositories(namedQueriesLocation = "more-custom-queries.properties")

src/test/java/org/springframework/data/neo4j/integration/issues/gh3109/NodeWithValueList.java

@@ -0,0 +1,47 @@
+/*
+ * Copyright 2011-present the original author or authors.
+ *
+ * Licensed 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
+ *
+ *      https://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 org.springframework.data.neo4j.integration.issues.gh3109;
+
+import java.util.ArrayList;
+import java.util.List;
+
+import org.springframework.data.neo4j.core.convert.ConvertWith;
+import org.springframework.data.neo4j.core.schema.GeneratedValue;
+import org.springframework.data.neo4j.core.schema.Id;
+import org.springframework.data.neo4j.core.schema.Node;
+
+/**
+ * @author Francesco Chicchiriccò
+ */
+@Node
+public class NodeWithValueList {
+
+	@Id
+	@GeneratedValue
+	private Long id;
+
+	@ConvertWith(converter = StringListConverter.class)
+	private List<String> valueList = new ArrayList<>();
+
+	public Long getId() {
+		return this.id;
+	}
+
+	public List<String> getValueList() {
+		return this.valueList;
+	}
+
+}

src/test/java/org/springframework/data/neo4j/integration/issues/gh3109/NodeWithValueListRepository.java

@@ -0,0 +1,25 @@
+/*
+ * Copyright 2011-present the original author or authors.
+ *
+ * Licensed 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
+ *
+ *      https://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 org.springframework.data.neo4j.integration.issues.gh3109;
+
+import org.springframework.data.neo4j.repository.Neo4jRepository;
+
+/**
+ * @author Francesco Chicchiriccò
+ */
+public interface NodeWithValueListRepository extends Neo4jRepository<NodeWithValueList, Long> {
+
+}

src/test/java/org/springframework/data/neo4j/integration/issues/gh3109/SerializableListConverter.java

@@ -0,0 +1,84 @@
+/*
+ * Copyright 2011-present the original author or authors.
+ *
+ * Licensed 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
+ *
+ *      https://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 org.springframework.data.neo4j.integration.issues.gh3109;
+
+import java.io.Serializable;
+import java.util.ArrayList;
+import java.util.List;
+import java.util.Optional;
+
+import com.fasterxml.jackson.core.type.TypeReference;
+import com.fasterxml.jackson.databind.json.JsonMapper;
+import org.neo4j.driver.Value;
+import org.neo4j.driver.Values;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import org.springframework.data.neo4j.core.convert.Neo4jPersistentPropertyConverter;
+
+/**
+ * @author Francesco Chicchiriccò
+ */
+abstract class SerializableListConverter<T extends Serializable> implements Neo4jPersistentPropertyConverter<List<T>> {
+
+	private static final Logger LOG = LoggerFactory.getLogger(SerializableListConverter.class);
+
+	private static final JsonMapper MAPPER = JsonMapper.builder().findAndAddModules().build();
+
+	private static String serialize(final Object object) {
+		String result = null;
+
+		try {
+			result = MAPPER.writeValueAsString(object);
+		}
+		catch (Exception ex) {
+			LOG.error("During serialization", ex);
+		}
+
+		return result;
+	}
+
+	private static <O extends Object> O deserialize(final String serialized, final TypeReference<O> reference) {
+		O result = null;
+
+		try {
+			result = MAPPER.readValue(serialized, reference);
+		}
+		catch (Exception ex) {
+			LOG.error("During deserialization", ex);
+		}
+
+		return result;
+	}
+
+	protected abstract TypeReference<List<T>> typeRef();
+
+	@Override
+	public Value write(final List<T> source) {
+		return Optional.ofNullable(source)
+			.map(SerializableListConverter::serialize)
+			.map(Values::value)
+			.orElse(Values.value(List.of()));
+	}
+
+	@Override
+	public List<T> read(final Value source) {
+		return Optional.ofNullable(source)
+			.map(data -> deserialize(source.asString(), typeRef()))
+			.orElseGet(ArrayList::new);
+	}
+
+}

src/test/java/org/springframework/data/neo4j/integration/issues/gh3109/StringListConverter.java

@@ -0,0 +1,35 @@
+/*
+ * Copyright 2011-present the original author or authors.
+ *
+ * Licensed 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
+ *
+ *      https://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 org.springframework.data.neo4j.integration.issues.gh3109;
+
+import java.util.List;
+
+import com.fasterxml.jackson.core.type.TypeReference;
+
+/**
+ * @author Francesco Chicchiriccò
+ */
+public class StringListConverter extends SerializableListConverter<String> {
+
+	protected static final TypeReference<List<String>> TYPEREF = new TypeReference<List<String>>() {
+	};
+
+	@Override
+	protected TypeReference<List<String>> typeRef() {
+		return TYPEREF;
+	}
+
+}