suggestions from SonarLint

src/main/java/eu/dnetlib/dhp/schema/action/AtomicActionDeserializer.java

@@ -4,7 +4,6 @@ package eu.dnetlib.dhp.schema.action;
 import java.io.IOException;
 
 import com.fasterxml.jackson.core.JsonParser;
-import com.fasterxml.jackson.core.JsonProcessingException;
 import com.fasterxml.jackson.databind.DeserializationContext;
 import com.fasterxml.jackson.databind.JsonDeserializer;
 import com.fasterxml.jackson.databind.JsonNode;
@@ -12,10 +11,11 @@ import com.fasterxml.jackson.databind.ObjectMapper;
 
 import eu.dnetlib.dhp.schema.oaf.Oaf;
 
-public class AtomicActionDeserializer extends JsonDeserializer {
+public class AtomicActionDeserializer<T extends Oaf> extends JsonDeserializer<AtomicAction<T>> {
 
 	@Override
-	public Object deserialize(JsonParser jp, DeserializationContext ctxt)
+	@SuppressWarnings("unchecked")
+	public AtomicAction<T> deserialize(JsonParser jp, DeserializationContext ctxt)
 		throws IOException {
 		JsonNode node = jp.getCodec().readTree(jp);
 		String classTag = node.get("clazz").asText();
@@ -23,8 +23,9 @@ public class AtomicActionDeserializer extends JsonDeserializer {
 		ObjectMapper mapper = new ObjectMapper();
 
 		try {
-			final Class<?> clazz = Class.forName(classTag);
-			return new AtomicAction(clazz, (Oaf) mapper.readValue(payload.toString(), clazz));
+			final Class<T> clazz = (Class<T>) Class.forName(classTag);
+			final T oaf = mapper.readValue(payload.toString(), clazz);
+			return new AtomicAction(clazz, oaf);
 		} catch (ClassNotFoundException e) {
 			throw new IOException(e);
 		}

src/main/java/eu/dnetlib/dhp/schema/common/AccessRightComparator.java

@@ -3,7 +3,6 @@ package eu.dnetlib.dhp.schema.common;
 
 import java.util.Comparator;
 
-import eu.dnetlib.dhp.schema.oaf.AccessRight;
 import eu.dnetlib.dhp.schema.oaf.Qualifier;
 
 public class AccessRightComparator<T extends Qualifier> implements Comparator<T> {

src/main/java/eu/dnetlib/dhp/schema/common/ModelConstants.java

@@ -8,6 +8,8 @@ import eu.dnetlib.dhp.schema.oaf.Qualifier;
 
 public class ModelConstants {
 
+	private ModelConstants() {}
+
 	public static final String ORCID = "orcid";
 	public static final String ORCID_PENDING = "orcid_pending";
 	public static final String ORCID_CLASSNAME = "Open Researcher and Contributor ID";

src/main/java/eu/dnetlib/dhp/schema/common/ModelSupport.java

@@ -7,13 +7,14 @@ import java.nio.charset.StandardCharsets;
 import java.security.MessageDigest;
 import java.security.NoSuchAlgorithmException;
 import java.text.ParseException;
-import java.time.format.DateTimeParseException;
-import java.util.*;
+import java.util.Date;
+import java.util.Map;
+import java.util.Objects;
+import java.util.Optional;
 import java.util.function.Function;
 
 import org.apache.commons.codec.binary.Hex;
 import org.apache.commons.lang3.StringUtils;
-import org.apache.commons.lang3.time.DateUtils;
 
 import com.github.sisyphsu.dateparser.DateParserUtils;
 import com.google.common.collect.Maps;

src/main/java/eu/dnetlib/dhp/schema/dump/oaf/Author.java

@@ -2,7 +2,6 @@
 package eu.dnetlib.dhp.schema.dump.oaf;
 
 import java.io.Serializable;
-import java.util.List;
 
 /**
  * Used to represent the generic author of the result. It has six parameters: - name of type String to store the given

src/main/java/eu/dnetlib/dhp/schema/dump/oaf/Container.java

@@ -2,7 +2,6 @@
 package eu.dnetlib.dhp.schema.dump.oaf;
 
 import java.io.Serializable;
-import java.util.Objects;
 
 /**
  * To store information about the conference or journal where the result has been presented or published. It contains

src/main/java/eu/dnetlib/dhp/schema/dump/oaf/Qualifier.java

@@ -3,10 +3,6 @@ package eu.dnetlib.dhp.schema.dump.oaf;
 
 import java.io.Serializable;
 
-import org.apache.commons.lang3.StringUtils;
-
-import com.fasterxml.jackson.annotation.JsonIgnore;
-
 /**
  * To represent the information described by a code and a value It has two parameters: - code to store the code
  * (generally the classid of the eu.dnetlib.dhp.schema.oaf.Qualifier element) - label to store the label (generally the

src/main/java/eu/dnetlib/dhp/schema/dump/oaf/Result.java

@@ -4,8 +4,6 @@ package eu.dnetlib.dhp.schema.dump.oaf;
 import java.io.Serializable;
 import java.util.List;
 
-import eu.dnetlib.dhp.schema.dump.oaf.community.Project;
-
 /**
  * To represent the dumped result. It will be extended in the dump for Research Communities - Research
  * Initiative/Infrastructures. It has the following parameters: - author of type

src/main/java/eu/dnetlib/dhp/schema/dump/oaf/community/Context.java

@@ -3,6 +3,8 @@ package eu.dnetlib.dhp.schema.dump.oaf.community;
 
 import java.util.List;
 import java.util.Objects;
+import java.util.Optional;
+import java.util.stream.Collectors;
 
 import eu.dnetlib.dhp.schema.dump.oaf.Provenance;
 import eu.dnetlib.dhp.schema.dump.oaf.Qualifier;
@@ -32,9 +34,13 @@ public class Context extends Qualifier {
 
 	@Override
 	public int hashCode() {
-		String provenance = "";
-		this.provenance.forEach(p -> provenance.concat(p.toString()));
-		return Objects.hash(getCode(), getLabel(), provenance);
+		final String p = Optional.ofNullable(getProvenance())
+				.map(prov -> prov.stream()
+						.map(Provenance::toString)
+						.collect(Collectors.joining()))
+				.orElse("");
+
+		return Objects.hash(getCode(), getLabel(), p);
 	}
 
 }

src/main/java/eu/dnetlib/dhp/schema/dump/oaf/community/Funder.java

@@ -1,8 +1,6 @@
 
 package eu.dnetlib.dhp.schema.dump.oaf.community;
 
-import java.io.Serializable;
-
 /**
  * To store information about the funder funding the project related to the result. It has the following parameters: -
  * shortName of type String to store the funder short name (e.c. AKA). - name of type String to store the funder name

src/main/java/eu/dnetlib/dhp/schema/dump/oaf/community/Project.java

@@ -1,8 +1,6 @@
 
 package eu.dnetlib.dhp.schema.dump.oaf.community;
 
-import java.io.Serializable;
-
 import eu.dnetlib.dhp.schema.dump.oaf.Provenance;
 
 /**

src/main/java/eu/dnetlib/dhp/schema/dump/oaf/graph/Datasource.java

@@ -6,7 +6,6 @@ import java.util.List;
 
 import eu.dnetlib.dhp.schema.dump.oaf.Container;
 import eu.dnetlib.dhp.schema.dump.oaf.ControlledField;
-import eu.dnetlib.dhp.schema.dump.oaf.KeyValue;
 
 /**
  * To store information about the datasource OpenAIRE collects information from. It contains the following parameters: -

src/main/java/eu/dnetlib/dhp/schema/dump/oaf/graph/Funder.java

@@ -1,8 +1,6 @@
 
 package eu.dnetlib.dhp.schema.dump.oaf.graph;
 
-import java.io.Serializable;
-
 /**
  * To store information about the funder funding the project related to the result. It extends
  * eu.dnetlib.dhp.schema.dump.oaf.Funder with the following parameter: - - private

src/main/java/eu/dnetlib/dhp/schema/dump/oaf/graph/Granted.java

@@ -2,7 +2,6 @@
 package eu.dnetlib.dhp.schema.dump.oaf.graph;
 
 import java.io.Serializable;
-import java.util.Optional;
 
 /**
  * To describe the funded amount. It has the following parameters: - private String currency to store the currency of

src/main/java/eu/dnetlib/dhp/schema/dump/oaf/graph/Organization.java

@@ -5,10 +5,7 @@ import java.io.Serializable;
 import java.util.List;
 
 import eu.dnetlib.dhp.schema.dump.oaf.ControlledField;
-import eu.dnetlib.dhp.schema.dump.oaf.Country;
-import eu.dnetlib.dhp.schema.dump.oaf.KeyValue;
 import eu.dnetlib.dhp.schema.dump.oaf.Qualifier;
-import eu.dnetlib.dhp.schema.dump.oaf.community.Project;
 
 /**
  * To represent the generic organizaiton. It has the following parameters: - private String legalshortname to store the

src/main/java/eu/dnetlib/dhp/schema/oaf/AccessRight.java

@@ -18,6 +18,7 @@ public class AccessRight extends Qualifier {
 		this.openAccessRoute = openAccessRoute;
 	}
 
+	@Override
 	public String toComparableString() {
 		String s = super.toComparableString();
 		return Optional

src/main/java/eu/dnetlib/dhp/schema/oaf/OafEntity.java

@@ -96,7 +96,8 @@ public abstract class OafEntity extends Oaf implements Serializable {
 			oaiprovenance = e.getOaiprovenance();
 	}
 
-	protected <T> List<T> mergeLists(final List<T>... lists) {
+	@SafeVarargs
+	protected final <T> List<T> mergeLists(final List<T>... lists) {
 
 		return Arrays
 			.stream(lists)

src/main/java/eu/dnetlib/dhp/schema/oaf/Project.java

@@ -348,10 +348,6 @@ public class Project extends OafEntity implements Serializable {
 			: contactemail;
 		summary = p.getSummary() != null && compareTrust(this, e) < 0 ? p.getSummary() : summary;
 		currency = p.getCurrency() != null && compareTrust(this, e) < 0 ? p.getCurrency() : currency;
-//		totalcost = p.getTotalcost() != null && compareTrust(this, e) < 0 ? p.getTotalcost() : totalcost;
-//		fundedamount = p.getFundedamount() != null && compareTrust(this, e) < 0
-//			? p.getFundedamount()
-//			: fundedamount;
 
 		if (p.getH2020topiccode() != null && StringUtils.isEmpty(h2020topiccode)){
 			h2020topiccode = p.getH2020topiccode();

src/main/java/eu/dnetlib/dhp/schema/oaf/Relation.java

@@ -4,9 +4,9 @@ package eu.dnetlib.dhp.schema.oaf;
 import static com.google.common.base.Preconditions.checkArgument;
 
 import java.text.ParseException;
-import java.util.*;
-import java.util.stream.Collectors;
-import java.util.stream.Stream;
+import java.util.ArrayList;
+import java.util.List;
+import java.util.Objects;
 
 import eu.dnetlib.dhp.schema.common.ModelSupport;
 

src/main/java/eu/dnetlib/dhp/schema/oaf/Result.java

@@ -349,10 +349,10 @@ public class Result extends OafEntity implements Serializable {
 	private StructuredProperty getMainTitle(List<StructuredProperty> titles) {
 		// need to check if the list of titles contains more than 1 main title? (in that case, we should chose which
 		// main title select in the list)
-		for (StructuredProperty title : titles) {
-			if (title.getQualifier() != null && title.getQualifier().getClassid() != null)
-				if (title.getQualifier().getClassid().equals("main title"))
-					return title;
+		for (StructuredProperty t : titles) {
+			if (t.getQualifier() != null && t.getQualifier().getClassid() != null)
+				if (t.getQualifier().getClassid().equals("main title"))
+					return t;
 		}
 		return null;
 	}

src/main/java/eu/dnetlib/dhp/schema/oaf/StructuredProperty.java

@@ -8,8 +8,6 @@ import java.util.stream.Stream;
 
 import org.apache.commons.lang3.StringUtils;
 
-import com.google.common.base.Joiner;
-
 public class StructuredProperty implements Serializable {
 
 	private String value;

src/main/java/eu/dnetlib/dhp/schema/oaf/utils/CleaningFunctions.java

@@ -22,6 +22,8 @@ public class CleaningFunctions {
 		PID_BLACKLIST.add("na");
 	}
 
+	private CleaningFunctions() {}
+
 	/**
 	 * Utility method that filter PID values on a per-type basis.
 	 * @param s the PID whose value will be checked.

src/main/java/eu/dnetlib/dhp/schema/oaf/utils/IdentifierFactory.java

@@ -120,7 +120,7 @@ public class IdentifierFactory implements Serializable {
 		return pids
 			.values()
 			.stream()
-			.flatMap(s -> s.stream())
+			.flatMap(Set::stream)
 			.min(new PidComparator<>(entity))
 			.map(
 				min -> Optional
@@ -140,8 +140,7 @@ public class IdentifierFactory implements Serializable {
 		if (entity instanceof Result) {
 			return Optional
 				.ofNullable(((Result) entity).getInstance())
-				.map(
-					instance -> mapPids(instance))
+				.map(IdentifierFactory::mapPids)
 				.orElse(new HashMap<>());
 		} else {
 			return entity
@@ -247,7 +246,6 @@ public class IdentifierFactory implements Serializable {
 			md.update(s.getBytes(StandardCharsets.UTF_8));
 			return new String(Hex.encodeHex(md.digest()));
 		} catch (final Exception e) {
-			System.err.println("Error creating id");
 			return null;
 		}
 	}

src/main/java/eu/dnetlib/dhp/schema/oaf/utils/ModelHardLimits.java

@@ -3,6 +3,8 @@ package eu.dnetlib.dhp.schema.oaf.utils;
 
 public class ModelHardLimits {
 
+	private ModelHardLimits() {}
+
 	public static final String LAYOUT = "index";
 	public static final String INTERPRETATION = "openaire";
 	public static final String SEPARATOR = "-";

src/main/java/eu/dnetlib/dhp/schema/oaf/utils/PidBlacklistProvider.java

@@ -34,4 +34,6 @@ public class PidBlacklistProvider {
 			.orElse(new HashSet<>());
 	}
 
+	private PidBlacklistProvider() {}
+
 }

src/main/java/eu/dnetlib/dhp/schema/oaf/utils/ResultTypeComparator.java

@@ -9,6 +9,7 @@ import java.util.Optional;
 import java.util.stream.Collectors;
 
 import eu.dnetlib.dhp.schema.common.ModelConstants;
+import eu.dnetlib.dhp.schema.oaf.KeyValue;
 import eu.dnetlib.dhp.schema.oaf.Result;
 
 public class ResultTypeComparator implements Comparator<Result> {
@@ -69,7 +70,7 @@ public class ResultTypeComparator implements Comparator<Result> {
 			.map(
 				cf -> cf
 					.stream()
-					.map(c -> c.getKey())
+					.map(KeyValue::getKey)
 					.collect(Collectors.toCollection(HashSet::new)))
 			.orElse(new HashSet<>());
 	}

src/main/java/eu/dnetlib/dhp/schema/orcid/Contributor.java

@@ -3,12 +3,9 @@ package eu.dnetlib.dhp.schema.orcid;
 
 import java.io.Serializable;
 
-import eu.dnetlib.dhp.schema.orcid.AuthorData;
-
 /**
  * This class models the data related to a contributor, that are retrieved from an orcid publication
  */
-
 public class Contributor extends AuthorData implements Serializable {
 	private String sequence;
 	private String role;

src/main/java/eu/dnetlib/dhp/schema/orcid/WorkDetail.java

@@ -4,11 +4,6 @@ package eu.dnetlib.dhp.schema.orcid;
 import java.io.Serializable;
 import java.util.List;
 
-import eu.dnetlib.dhp.schema.orcid.Contributor;
-import eu.dnetlib.dhp.schema.orcid.ExternalId;
-import eu.dnetlib.dhp.schema.orcid.OrcidData;
-import eu.dnetlib.dhp.schema.orcid.PublicationDate;
-
 /**
  * This class models the data that are retrieved from orcid publication
  */

src/test/java/eu/dnetlib/dhp/schema/action/AtomicActionTest.java

@@ -14,10 +14,11 @@ import eu.dnetlib.dhp.schema.common.ModelConstants;
 import eu.dnetlib.dhp.schema.oaf.Relation;
 
 /** @author claudio.atzori */
-public class AtomicActionTest {
+class AtomicActionTest {
 
 	@Test
-	public void serializationTest() throws IOException {
+	@SuppressWarnings("unchecked")
+	void serializationTest() throws IOException {
 
 		Relation rel = new Relation();
 		rel.setSource("1");

src/test/java/eu/dnetlib/dhp/schema/common/ModelSupportTest.java

@@ -17,7 +17,7 @@ public class ModelSupportTest {
 	class IsSubClass {
 
 		@Test
-		public void shouldReturnFalseWhenSubClassDoesNotExtendSuperClass() {
+		void shouldReturnFalseWhenSubClassDoesNotExtendSuperClass() {
 			// when
 			Boolean result = ModelSupport.isSubClass(Relation.class, OafEntity.class);
 
@@ -26,7 +26,7 @@ public class ModelSupportTest {
 		}
 
 		@Test
-		public void shouldReturnTrueWhenSubClassExtendsSuperClass() {
+		void shouldReturnTrueWhenSubClassExtendsSuperClass() {
 			// when
 			Boolean result = ModelSupport.isSubClass(Result.class, OafEntity.class);
 

src/test/java/eu/dnetlib/dhp/schema/oaf/MeasureTest.java

@@ -12,13 +12,13 @@ import com.fasterxml.jackson.core.type.TypeReference;
 import com.fasterxml.jackson.databind.ObjectMapper;
 import com.google.common.collect.Lists;
 
-public class MeasureTest {
+class MeasureTest {
 
 	public static final ObjectMapper OBJECT_MAPPER = new ObjectMapper()
 		.setSerializationInclusion(JsonInclude.Include.NON_NULL);
 
 	@Test
-	public void testMeasureSerialization() throws IOException {
+	void testMeasureSerialization() throws IOException {
 
 		Measure popularity = new Measure();
 		popularity.setId("popularity");

src/test/java/eu/dnetlib/dhp/schema/oaf/MergeTest.java

@@ -10,7 +10,7 @@ import java.util.List;
 import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.Test;
 
-public class MergeTest {
+class MergeTest {
 
 	OafEntity oaf;
 
@@ -20,7 +20,8 @@ public class MergeTest {
 	}
 
 	@Test
-	public void mergeListsTest() {
+	@SuppressWarnings("unchecked")
+	void mergeListsTest() {
 
 		// string list merge test
 		List<String> a = Arrays.asList("a", "b", "c", "e");
@@ -35,7 +36,7 @@ public class MergeTest {
 	}
 
 	@Test
-	public void mergePublicationCollectedFromTest() {
+	void mergePublicationCollectedFromTest() {
 
 		Publication a = publication();
 		Publication b = publication();
@@ -50,7 +51,7 @@ public class MergeTest {
 	}
 
 	@Test
-	public void mergePublicationDateOfAcceptanceTest_bothPresent() {
+	void mergePublicationDateOfAcceptanceTest_bothPresent() {
 
 		Publication a = publication();
 		Publication b = publication();
@@ -65,7 +66,7 @@ public class MergeTest {
 	}
 
 	@Test
-	public void mergePublicationDateOfAcceptanceTest_bothPresent_1() {
+	void mergePublicationDateOfAcceptanceTest_bothPresent_1() {
 
 		Publication a = publication("0.8");
 		Publication b = publication("0.9");
@@ -80,7 +81,7 @@ public class MergeTest {
 	}
 
 	@Test
-	public void mergePublicationDateOfAcceptanceTest_bothPresent_2() {
+	void mergePublicationDateOfAcceptanceTest_bothPresent_2() {
 
 		Publication a = publication("0.9");
 		Publication b = publication("0.8");
@@ -95,7 +96,7 @@ public class MergeTest {
 	}
 
 	@Test
-	public void mergePublicationDateOfAcceptanceTest_leftMissing() {
+	void mergePublicationDateOfAcceptanceTest_leftMissing() {
 
 		Publication a = publication();
 		Publication b = publication();
@@ -109,7 +110,7 @@ public class MergeTest {
 	}
 
 	@Test
-	public void mergePublicationDateOfAcceptanceTest_leftMissing_1() {
+	void mergePublicationDateOfAcceptanceTest_leftMissing_1() {
 
 		Publication a = publication("0.9");
 		Publication b = publication("0.8");
@@ -123,7 +124,7 @@ public class MergeTest {
 	}
 
 	@Test
-	public void mergePublicationDateOfAcceptanceTest_leftMissing_2() {
+	void mergePublicationDateOfAcceptanceTest_leftMissing_2() {
 
 		Publication a = publication("0.8");
 		Publication b = publication("0.9");
@@ -137,7 +138,7 @@ public class MergeTest {
 	}
 
 	@Test
-	public void mergePublicationDateOfAcceptanceTest_rightMissing() {
+	void mergePublicationDateOfAcceptanceTest_rightMissing() {
 
 		Publication a = publication();
 		Publication b = publication();
@@ -151,7 +152,7 @@ public class MergeTest {
 	}
 
 	@Test
-	public void mergePublicationDateOfAcceptanceTest_rightMissing_1() {
+	void mergePublicationDateOfAcceptanceTest_rightMissing_1() {
 
 		Publication a = publication("0.8");
 		Publication b = publication("0.9");
@@ -165,7 +166,7 @@ public class MergeTest {
 	}
 
 	@Test
-	public void mergePublicationDateOfAcceptanceTest_rightMissing_2() {
+	void mergePublicationDateOfAcceptanceTest_rightMissing_2() {
 
 		Publication a = publication("0.9");
 		Publication b = publication("0.8");
@@ -179,7 +180,7 @@ public class MergeTest {
 	}
 
 	@Test
-	public void mergePublicationSubjectTest() {
+	void mergePublicationSubjectTest() {
 
 		Publication a = publication();
 		Publication b = publication();
@@ -194,7 +195,7 @@ public class MergeTest {
 	}
 
 	@Test
-	public void mergeRelationTest() {
+	void mergeRelationTest() {
 
 		Relation a = createRel(null, null);
 		Relation b = createRel(null, null);
@@ -235,7 +236,7 @@ public class MergeTest {
 	}
 
 	@Test
-	public void mergeRelationTestParseException() {
+	void mergeRelationTestParseException() {
 		assertThrows(DateTimeParseException.class, () -> {
 			Relation a = createRel(true, "Once upon a time ...");
 			Relation b = createRel(true, "... in a far away land");
@@ -279,7 +280,7 @@ public class MergeTest {
 	}
 
 	private <T> Field<T> field(T value) {
-		Field<T> f = new Field<T>();
+		Field<T> f = new Field();
 		f.setValue(value);
 		return f;
 	}

src/test/java/eu/dnetlib/dhp/schema/oaf/utils/BlackListProviderTest.java

@@ -6,10 +6,10 @@ import java.util.Set;
 import org.junit.jupiter.api.Assertions;
 import org.junit.jupiter.api.Test;
 
-public class BlackListProviderTest {
+class BlackListProviderTest {
 
 	@Test
-	public void blackListTest() {
+	void blackListTest() {
 
 		Assertions.assertNotNull(PidBlacklistProvider.getBlacklist());
 		Assertions.assertNotNull(PidBlacklistProvider.getBlacklist().get("doi"));

src/test/java/eu/dnetlib/dhp/schema/oaf/utils/IdentifierFactoryTest.java

@@ -14,13 +14,13 @@ import com.fasterxml.jackson.databind.ObjectMapper;
 
 import eu.dnetlib.dhp.schema.oaf.Publication;
 
-public class IdentifierFactoryTest {
+class IdentifierFactoryTest {
 
 	private static final ObjectMapper OBJECT_MAPPER = new ObjectMapper()
 		.configure(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES, false);
 
 	@Test
-	public void testCreateIdentifierForPublication() throws IOException {
+	void testCreateIdentifierForPublication() throws IOException {
 
 		verifyIdentifier(
 			"publication_doi1.json", "50|doi_________::79dbc7a2a56dc1532659f9038843256e", true);
@@ -51,7 +51,7 @@ public class IdentifierFactoryTest {
 	}
 
 	@Test
-	public void testCreateIdentifierForPublicationNoHash() throws IOException {
+	void testCreateIdentifierForPublicationNoHash() throws IOException {
 
 		verifyIdentifier("publication_doi1.json", "50|doi_________::10.1016/j.cmet.2010.03.013", false);
 		verifyIdentifier("publication_doi2.json", "50|doi_________::10.1016/j.cmet.2010.03.013", false);