DATAES-739 - Introduce nullable annotations for API validation.

Original PR: #387

src/main/java/org/springframework/data/elasticsearch/ElasticsearchException.java

@@ -17,15 +17,18 @@ package org.springframework.data.elasticsearch;
 
 import java.util.Map;
 
+import org.springframework.lang.Nullable;
+
 /**
  * ElasticsearchException
  *
  * @author Rizwan Idrees
  * @author Mohsin Husen
+ * @author Peter-Josef Meisch
  */
 public class ElasticsearchException extends RuntimeException {
 
-	private Map<String, String> failedDocuments;
+	@Nullable private Map<String, String> failedDocuments;
 
 	public ElasticsearchException(String message) {
 		super(message);
@@ -45,6 +48,7 @@ public class ElasticsearchException extends RuntimeException {
 		this.failedDocuments = failedDocuments;
 	}
 
+	@Nullable
 	public Map<String, String> getFailedDocuments() {
 		return failedDocuments;
 	}

src/main/java/org/springframework/data/elasticsearch/annotations/package-info.java

@@ -0,0 +1,3 @@
+@org.springframework.lang.NonNullApi
+@org.springframework.lang.NonNullFields
+package org.springframework.data.elasticsearch.annotations;

src/main/java/org/springframework/data/elasticsearch/client/ClientConfigurationBuilder.java

@@ -54,11 +54,11 @@ class ClientConfigurationBuilder
 	private @Nullable HostnameVerifier hostnameVerifier;
 	private Duration connectTimeout = Duration.ofSeconds(10);
 	private Duration soTimeout = Duration.ofSeconds(5);
-	private String username;
-	private String password;
-	private String pathPrefix;
-	private String proxy;
-	private Function<WebClient, WebClient> webClientConfigurer;
+	private @Nullable String username;
+	private @Nullable String password;
+	private @Nullable String pathPrefix;
+	private @Nullable String proxy;
+	private @Nullable Function<WebClient, WebClient> webClientConfigurer;
 
 	/*
 	 * (non-Javadoc)

src/main/java/org/springframework/data/elasticsearch/client/NodeClientFactoryBean.java

@@ -32,7 +32,9 @@ import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 import org.springframework.beans.factory.DisposableBean;
 import org.springframework.beans.factory.FactoryBean;
+import org.springframework.beans.factory.FactoryBeanNotInitializedException;
 import org.springframework.beans.factory.InitializingBean;
+import org.springframework.lang.Nullable;
 import org.springframework.util.StringUtils;
 
 /**
@@ -48,12 +50,12 @@ public class NodeClientFactoryBean implements FactoryBean<Client>, InitializingB
 	private static final Logger logger = LoggerFactory.getLogger(NodeClientFactoryBean.class);
 	private boolean local;
 	private boolean enableHttp;
-	private String clusterName;
-	private Node node;
-	private NodeClient nodeClient;
-	private String pathData;
-	private String pathHome;
-	private String pathConfiguration;
+	private @Nullable String clusterName;
+	private @Nullable Node node;
+	private @Nullable NodeClient nodeClient;
+	private @Nullable String pathData;
+	private @Nullable String pathHome;
+	private @Nullable String pathConfiguration;
 
 	public static class TestNode extends Node {
 
@@ -82,6 +84,11 @@ public class NodeClientFactoryBean implements FactoryBean<Client>, InitializingB
 
 	@Override
 	public NodeClient getObject() {
+
+		if (nodeClient == null) {
+			throw new FactoryBeanNotInitializedException();
+		}
+
 		return nodeClient;
 	}
 

src/main/java/org/springframework/data/elasticsearch/client/RestClientFactoryBean.java

@@ -25,18 +25,21 @@ import org.elasticsearch.client.RestClient;
 import org.elasticsearch.client.RestHighLevelClient;
 import org.springframework.beans.factory.DisposableBean;
 import org.springframework.beans.factory.FactoryBean;
+import org.springframework.beans.factory.FactoryBeanNotInitializedException;
 import org.springframework.beans.factory.InitializingBean;
+import org.springframework.lang.Nullable;
 import org.springframework.util.Assert;
 
 /**
  * RestClientFactoryBean
  *
  * @author Don Wellington
+ * @author Peter-Josef Meisch
  */
 @Slf4j
 public class RestClientFactoryBean implements FactoryBean<RestHighLevelClient>, InitializingBean, DisposableBean {
 
-	private RestHighLevelClient client;
+	private @Nullable RestHighLevelClient client;
 	private String hosts = "http://localhost:9200";
 	static final String COMMA = ",";
 
@@ -59,6 +62,11 @@ public class RestClientFactoryBean implements FactoryBean<RestHighLevelClient>,
 
 	@Override
 	public RestHighLevelClient getObject() {
+
+		if (client == null) {
+			throw new FactoryBeanNotInitializedException();
+		}
+
 		return client;
 	}
 
@@ -75,6 +83,7 @@ public class RestClientFactoryBean implements FactoryBean<RestHighLevelClient>,
 	protected void buildClient() throws Exception {
 
 		Assert.hasText(hosts, "[Assertion Failed] At least one host must be set.");
+
 		ArrayList<HttpHost> httpHosts = new ArrayList<>();
 		for (String host : hosts.split(COMMA)) {
 			URL hostUrl = new URL(host);

src/main/java/org/springframework/data/elasticsearch/client/TransportClientFactoryBean.java

@@ -24,7 +24,9 @@ import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 import org.springframework.beans.factory.DisposableBean;
 import org.springframework.beans.factory.FactoryBean;
+import org.springframework.beans.factory.FactoryBeanNotInitializedException;
 import org.springframework.beans.factory.InitializingBean;
+import org.springframework.lang.Nullable;
 
 /**
  * TransportClientFactoryBean
@@ -48,8 +50,8 @@ public class TransportClientFactoryBean implements FactoryBean<TransportClient>,
 	private Boolean clientIgnoreClusterName = Boolean.FALSE;
 	private String clientPingTimeout = "5s";
 	private String clientNodesSamplerInterval = "5s";
-	private TransportClient client;
-	private Properties properties;
+	private @Nullable TransportClient client;
+	private @Nullable Properties properties;
 
 	@Override
 	public void destroy() {
@@ -65,6 +67,10 @@ public class TransportClientFactoryBean implements FactoryBean<TransportClient>,
 
 	@Override
 	public TransportClient getObject() {
+
+		if (clientTransportSniff == null) {
+			throw new FactoryBeanNotInitializedException();
+		}
 		return client;
 	}
 

src/main/java/org/springframework/data/elasticsearch/client/package-info.java

@@ -0,0 +1,3 @@
+@org.springframework.lang.NonNullApi
+@org.springframework.lang.NonNullFields
+package org.springframework.data.elasticsearch.client;

src/main/java/org/springframework/data/elasticsearch/client/reactive/DefaultReactiveElasticsearchClient.java

@@ -865,8 +865,9 @@ public class DefaultReactiveElasticsearchClient implements ReactiveElasticsearch
 		private final Object lock = new Object();
 
 		private final List<String> pastIds = new ArrayList<>(1);
-		private String scrollId;
+		@Nullable private String scrollId;
 
+		@Nullable
 		String getScrollId() {
 			return scrollId;
 		}

src/main/java/org/springframework/data/elasticsearch/client/reactive/WebClientProvider.java

@@ -105,6 +105,7 @@ public interface WebClientProvider {
 	 * @return the pathPrefix if set.
 	 * @since 4.0
 	 */
+	@Nullable
 	String getPathPrefix();
 
 	/**
@@ -133,7 +134,9 @@ public interface WebClientProvider {
 	WebClientProvider withPathPrefix(String pathPrefix);
 
 	/**
-	 * Create a new instance of {@link WebClientProvider} calling the given {@link Function} to configure the {@link WebClient}.
+	 * Create a new instance of {@link WebClientProvider} calling the given {@link Function} to configure the
+	 * {@link WebClient}.
+	 * 
 	 * @param webClientConfigurer configuration function
 	 * @return new instance of {@link WebClientProvider}
 	 * @since 4.0

src/main/java/org/springframework/data/elasticsearch/client/reactive/package-info.java

@@ -1,6 +1,3 @@
-/**
- * Everything required for a Reactive Elasticsearch client.
- */
 @org.springframework.lang.NonNullApi
 @org.springframework.lang.NonNullFields
 package org.springframework.data.elasticsearch.client.reactive;

src/main/java/org/springframework/data/elasticsearch/client/util/package-info.java

@@ -0,0 +1,3 @@
+@org.springframework.lang.NonNullApi
+@org.springframework.lang.NonNullFields
+package org.springframework.data.elasticsearch.client.util;

src/main/java/org/springframework/data/elasticsearch/config/package-info.java

@@ -0,0 +1,3 @@
+@org.springframework.lang.NonNullApi
+@org.springframework.lang.NonNullFields
+package org.springframework.data.elasticsearch.config;

src/main/java/org/springframework/data/elasticsearch/core/AbstractElasticsearchTemplate.java

@@ -31,6 +31,7 @@ import org.springframework.data.elasticsearch.core.query.MoreLikeThisQuery;
 import org.springframework.data.elasticsearch.core.query.NativeSearchQueryBuilder;
 import org.springframework.data.elasticsearch.core.query.Query;
 import org.springframework.data.util.CloseableIterator;
+import org.springframework.lang.Nullable;
 import org.springframework.util.Assert;
 
 /**
@@ -41,9 +42,9 @@ import org.springframework.util.Assert;
  */
 public abstract class AbstractElasticsearchTemplate implements ElasticsearchOperations, ApplicationContextAware {
 
-	protected ElasticsearchConverter elasticsearchConverter;
-	protected RequestFactory requestFactory;
-	protected IndexOperations indexOperations;
+	protected @Nullable ElasticsearchConverter elasticsearchConverter;
+	protected @Nullable RequestFactory requestFactory;
+	protected @Nullable IndexOperations indexOperations;
 
 	// region Initialization
 	protected void initialize(ElasticsearchConverter elasticsearchConverter, IndexOperations indexOperations) {
@@ -74,6 +75,9 @@ public abstract class AbstractElasticsearchTemplate implements ElasticsearchOper
 	// region getter/setter
 	@Override
 	public IndexOperations getIndexOperations() {
+
+		Assert.notNull("indexOperations are not initialized");
+
 		return indexOperations;
 	}
 	// endregion
@@ -159,6 +163,9 @@ public abstract class AbstractElasticsearchTemplate implements ElasticsearchOper
 	// region Helper methods
 	@Override
 	public ElasticsearchConverter getElasticsearchConverter() {
+
+		Assert.notNull(elasticsearchConverter, "elasticsearchConverter is not initialized.");
+
 		return elasticsearchConverter;
 	}
 
@@ -166,6 +173,9 @@ public abstract class AbstractElasticsearchTemplate implements ElasticsearchOper
 	 * @since 4.0
 	 */
 	public RequestFactory getRequestFactory() {
+
+		Assert.notNull(requestFactory, "requestfactory not initialized");
+
 		return requestFactory;
 	}
 

src/main/java/org/springframework/data/elasticsearch/core/CriteriaFilterProcessor.java

@@ -34,6 +34,7 @@ import org.springframework.data.geo.Box;
 import org.springframework.data.geo.Distance;
 import org.springframework.data.geo.Metrics;
 import org.springframework.data.geo.Point;
+import org.springframework.lang.Nullable;
 import org.springframework.util.Assert;
 
 /**
@@ -100,7 +101,9 @@ class CriteriaFilterProcessor {
 		return filterList;
 	}
 
+	@Nullable
 	private QueryBuilder processCriteriaEntry(OperationKey key, Object value, String fieldName) {
+
 		if (value == null) {
 			return null;
 		}

src/main/java/org/springframework/data/elasticsearch/core/CriteriaQueryProcessor.java

@@ -30,6 +30,7 @@ import org.apache.lucene.queryparser.flexible.standard.QueryParserUtil;
 import org.elasticsearch.index.query.BoolQueryBuilder;
 import org.elasticsearch.index.query.QueryBuilder;
 import org.springframework.data.elasticsearch.core.query.Criteria;
+import org.springframework.lang.Nullable;
 import org.springframework.util.Assert;
 
 /**
@@ -46,8 +47,8 @@ import org.springframework.util.Assert;
 class CriteriaQueryProcessor {
 
 	QueryBuilder createQueryFromCriteria(Criteria criteria) {
-		if (criteria == null)
-			return null;
+
+		Assert.notNull(criteria, "criteria must not be null");
 
 		List<QueryBuilder> shouldQueryBuilderList = new LinkedList<>();
 		List<QueryBuilder> mustNotQueryBuilderList = new LinkedList<>();
@@ -109,6 +110,7 @@ class CriteriaQueryProcessor {
 		return query;
 	}
 
+	@Nullable
 	private QueryBuilder createQueryFragmentForCriteria(Criteria chainedCriteria) {
 		if (chainedCriteria.getQueryCriteriaEntries().isEmpty())
 			return null;
@@ -135,6 +137,7 @@ class CriteriaQueryProcessor {
 		return query;
 	}
 
+	@Nullable
 	private QueryBuilder processCriteriaEntry(Criteria.CriteriaEntry entry, String fieldName) {
 		OperationKey key = entry.getKey();
 		Object value = entry.getValue();

src/main/java/org/springframework/data/elasticsearch/core/ElasticsearchRestTemplate.java

@@ -93,10 +93,12 @@ public class ElasticsearchRestTemplate extends AbstractElasticsearchTemplate {
 
 	// region Initialization
 	public ElasticsearchRestTemplate(RestHighLevelClient client) {
+		this.client = client;
 		initialize(client, createElasticsearchConverter());
 	}
 
 	public ElasticsearchRestTemplate(RestHighLevelClient client, ElasticsearchConverter elasticsearchConverter) {
+		this.client = client;
 		initialize(client, elasticsearchConverter);
 	}
 
@@ -210,7 +212,7 @@ public class ElasticsearchRestTemplate extends AbstractElasticsearchTemplate {
 
 	// region SearchOperations
 	@Override
-	public long count(Query query, Class<?> clazz, IndexCoordinates index) {
+	public long count(Query query,@Nullable Class<?> clazz, IndexCoordinates index) {
 
 		Assert.notNull(query, "query must not be null");
 		Assert.notNull(index, "index must not be null");

src/main/java/org/springframework/data/elasticsearch/core/ElasticsearchTemplate.java

@@ -83,14 +83,16 @@ public class ElasticsearchTemplate extends AbstractElasticsearchTemplate {
 			.getLogger("org.springframework.data.elasticsearch.core.QUERY");
 
 	private Client client;
-	private String searchTimeout;
+	@Nullable private String searchTimeout;
 
 	// region Initialization
 	public ElasticsearchTemplate(Client client) {
+		this.client = client;
 		initialize(client, createElasticsearchConverter());
 	}
 
 	public ElasticsearchTemplate(Client client, ElasticsearchConverter elasticsearchConverter) {
+		this.client = client;
 		initialize(client, elasticsearchConverter);
 	}
 
@@ -102,6 +104,7 @@ public class ElasticsearchTemplate extends AbstractElasticsearchTemplate {
 	// endregion
 
 	// region getter/setter
+	@Nullable
 	public String getSearchTimeout() {
 		return searchTimeout;
 	}

src/main/java/org/springframework/data/elasticsearch/core/RequestFactory.java

@@ -867,6 +867,7 @@ class RequestFactory {
 		return clazz != null ? elasticsearchConverter.getMappingContext().getPersistentEntity(clazz) : null;
 	}
 
+	@Nullable
 	private String getPersistentEntityId(Object entity) {
 
 		Object identifier = elasticsearchConverter.getMappingContext() //

src/main/java/org/springframework/data/elasticsearch/core/ResourceUtil.java

@@ -21,6 +21,7 @@ import java.nio.charset.Charset;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 import org.springframework.core.io.ClassPathResource;
+import org.springframework.lang.Nullable;
 import org.springframework.util.StreamUtils;
 
 /**
@@ -40,6 +41,7 @@ public abstract class ResourceUtil {
 	 * @param url
 	 * @return
 	 */
+	@Nullable
 	public static String readFileFromClasspath(String url) {
 
 		ClassPathResource classPathResource = new ClassPathResource(url);

src/main/java/org/springframework/data/elasticsearch/core/ScrolledPage.java

@@ -2,12 +2,14 @@
 package org.springframework.data.elasticsearch.core;
 
 import org.springframework.data.domain.Page;
+import org.springframework.lang.Nullable;
 
 /**
  * @author Artur Konczak
+ * @author Peter-Josef Meisch
  */
 public interface ScrolledPage<T> extends Page<T> {
 
+    @Nullable
     String getScrollId();
-
 }

src/main/java/org/springframework/data/elasticsearch/core/aggregation/AggregatedPage.java

@@ -4,6 +4,7 @@ import org.elasticsearch.search.aggregations.Aggregation;
 import org.elasticsearch.search.aggregations.Aggregations;
 import org.springframework.data.elasticsearch.core.ScoredPage;
 import org.springframework.data.elasticsearch.core.ScrolledPage;
+import org.springframework.lang.Nullable;
 
 /**
  * @author Petar Tahchiev
@@ -16,7 +17,7 @@ public interface AggregatedPage<T> extends ScrolledPage<T>, ScoredPage<T> {
 
 	boolean hasAggregations();
 
-	Aggregations getAggregations();
+	@Nullable Aggregations getAggregations();
 
-	Aggregation getAggregation(String name);
+	@Nullable Aggregation getAggregation(String name);
 }

src/main/java/org/springframework/data/elasticsearch/core/aggregation/impl/AggregatedPageImpl.java

@@ -25,6 +25,7 @@ import org.springframework.data.domain.PageImpl;
 import org.springframework.data.domain.Pageable;
 import org.springframework.data.elasticsearch.core.aggregation.AggregatedPage;
 import org.springframework.data.elasticsearch.core.document.SearchDocumentResponse;
+import org.springframework.lang.Nullable;
 
 /**
  * @author Petar Tahchiev
@@ -35,8 +36,8 @@ import org.springframework.data.elasticsearch.core.document.SearchDocumentRespon
  */
 public class AggregatedPageImpl<T> extends PageImpl<T> implements AggregatedPage<T> {
 
-	private Aggregations aggregations;
-	private String scrollId;
+	@Nullable private Aggregations aggregations;
+	@Nullable private String scrollId;
 	private float maxScore;
 
 	private static Pageable pageableOrUnpaged(Pageable pageable) {
@@ -114,15 +115,18 @@ public class AggregatedPageImpl<T> extends PageImpl<T> implements AggregatedPage
 	}
 
 	@Override
+	@Nullable
 	public Aggregations getAggregations() {
 		return aggregations;
 	}
 
 	@Override
+	@Nullable
 	public Aggregation getAggregation(String name) {
 		return aggregations == null ? null : aggregations.get(name);
 	}
 
+	@Nullable
 	@Override
 	public String getScrollId() {
 		return scrollId;

src/main/java/org/springframework/data/elasticsearch/core/aggregation/impl/package-info.java

@@ -0,0 +1,3 @@
+@org.springframework.lang.NonNullApi
+@org.springframework.lang.NonNullFields
+package org.springframework.data.elasticsearch.core.aggregation.impl;

src/main/java/org/springframework/data/elasticsearch/core/aggregation/package-info.java

@@ -0,0 +1,3 @@
+@org.springframework.lang.NonNullApi
+@org.springframework.lang.NonNullFields
+package org.springframework.data.elasticsearch.core.aggregation;

src/main/java/org/springframework/data/elasticsearch/core/client/support/package-info.java

@@ -0,0 +1,3 @@
+@org.springframework.lang.NonNullApi
+@org.springframework.lang.NonNullFields
+package org.springframework.data.elasticsearch.core.client.support;

src/main/java/org/springframework/data/elasticsearch/core/completion/Completion.java

@@ -1,27 +1,23 @@
 package org.springframework.data.elasticsearch.core.completion;
 
-import com.fasterxml.jackson.annotation.JsonInclude;
-
 import java.util.List;
 import java.util.Map;
 
+import org.springframework.lang.Nullable;
+
 /**
  * Based on the reference doc -
  * https://www.elastic.co/guide/en/elasticsearch/reference/current/search-suggesters-completion.html
  *
  * @author Mewes Kochheim
  * @author Robert Gruendler
+ * @author Peter-Josef Meisch
  */
-@JsonInclude(value = JsonInclude.Include.NON_NULL)
 public class Completion {
 
 	private String[] input;
-	private Map<String, List<String>> contexts;
-	private Integer weight;
-
-	private Completion() {
-		// required by mapper to instantiate object
-	}
+	@Nullable private Map<String, List<String>> contexts;
+	@Nullable private Integer weight;
 
 	public Completion(String[] input) {
 		this.input = input;
@@ -35,6 +31,7 @@ public class Completion {
 		this.input = input;
 	}
 
+	@Nullable
 	public Integer getWeight() {
 		return weight;
 	}
@@ -43,6 +40,7 @@ public class Completion {
 		this.weight = weight;
 	}
 
+	@Nullable
 	public Map<String, List<String>> getContexts() {
 		return contexts;
 	}

src/main/java/org/springframework/data/elasticsearch/core/completion/package-info.java

@@ -0,0 +1,3 @@
+@org.springframework.lang.NonNullApi
+@org.springframework.lang.NonNullFields
+package org.springframework.data.elasticsearch.core.completion;

src/main/java/org/springframework/data/elasticsearch/core/convert/MappingElasticsearchConverter.java

@@ -147,7 +147,7 @@ public class MappingElasticsearchConverter
 
 	@Override
 	public <T> AggregatedPage<SearchHit<T>> mapResults(SearchDocumentResponse response, Class<T> type,
-			Pageable pageable) {
+			@Nullable Pageable pageable) {
 
 		List<SearchHit<T>> results = response.getSearchDocuments().stream() //
 				.map(searchDocument -> read(type, searchDocument)) //
@@ -653,6 +653,7 @@ public class MappingElasticsearchConverter
 			collectionSource.map(it -> {
 
 				if (it == null) {
+					//noinspection ReturnOfNull
 					return null;
 				}
 

src/main/java/org/springframework/data/elasticsearch/core/convert/package-info.java

@@ -1,2 +1,3 @@
 @org.springframework.lang.NonNullApi
+@org.springframework.lang.NonNullFields
 package org.springframework.data.elasticsearch.core.convert;

src/main/java/org/springframework/data/elasticsearch/core/document/DocumentAdapters.java

@@ -124,6 +124,7 @@ public class DocumentAdapters {
 
 		Assert.notNull(source, "MultiGetResponse must not be null");
 
+		//noinspection ReturnOfNull
 		return Arrays.stream(source.getResponses()) //
 				.map(itemResponse -> itemResponse.isFailed() ? null : DocumentAdapters.from(itemResponse.getResponse())) //
 				.filter(Objects::nonNull).collect(Collectors.toList());

src/main/java/org/springframework/data/elasticsearch/core/document/package-info.java

@@ -1,5 +1,3 @@
-/**
- * interfaces and classes related to the Document representation of Elasticsearch documents.
- */
 @org.springframework.lang.NonNullApi
+@org.springframework.lang.NonNullFields
 package org.springframework.data.elasticsearch.core.document;

src/main/java/org/springframework/data/elasticsearch/core/geo/package-info.java

@@ -0,0 +1,3 @@
+@org.springframework.lang.NonNullApi
+@org.springframework.lang.NonNullFields
+package org.springframework.data.elasticsearch.core.geo;

src/main/java/org/springframework/data/elasticsearch/core/index/package-info.java

@@ -1,5 +1,3 @@
-/**
- * infrastructure to define the Elasticsearch mapping for an index.
- */
 @org.springframework.lang.NonNullApi
+@org.springframework.lang.NonNullFields
 package org.springframework.data.elasticsearch.core.index;

src/main/java/org/springframework/data/elasticsearch/core/mapping/ElasticsearchPersistentEntity.java

@@ -41,20 +41,24 @@ public interface ElasticsearchPersistentEntity<T> extends PersistentEntity<T, El
 
 	boolean isUseServerConfiguration();
 
+	@Nullable
 	String getRefreshInterval();
 
+	@Nullable
 	String getIndexStoreType();
 
 	@Override
 	ElasticsearchPersistentProperty getVersionProperty();
 
+	@Nullable
 	String getParentType();
 
+	@Nullable
 	ElasticsearchPersistentProperty getParentIdProperty();
 
 	String settingPath();
 
-	VersionType getVersionType();
+	@Nullable VersionType getVersionType();
 
 	boolean isCreateIndexAndMapping();
 

src/main/java/org/springframework/data/elasticsearch/core/mapping/SimpleElasticsearchPersistentEntity.java

@@ -71,7 +71,7 @@ public class SimpleElasticsearchPersistentEntity<T> extends BasicPersistentEntit
 	private @Nullable ElasticsearchPersistentProperty parentIdProperty;
 	private @Nullable ElasticsearchPersistentProperty scoreProperty;
 	private @Nullable String settingPath;
-	private VersionType versionType;
+	private @Nullable VersionType versionType;
 	private boolean createIndexAndMapping;
 	private final Map<String, ElasticsearchPersistentProperty> fieldNamePropertyCache = new ConcurrentHashMap<>();
 
@@ -133,6 +133,7 @@ public class SimpleElasticsearchPersistentEntity<T> extends BasicPersistentEntit
 		return IndexCoordinates.of(getIndexName()).withTypes(getIndexType());
 	}
 
+	@Nullable
 	@Override
 	public String getIndexStoreType() {
 		return indexStoreType;
@@ -153,21 +154,25 @@ public class SimpleElasticsearchPersistentEntity<T> extends BasicPersistentEntit
 		return useServerConfiguration;
 	}
 
+	@Nullable
 	@Override
 	public String getRefreshInterval() {
 		return refreshInterval;
 	}
 
+	@Nullable
 	@Override
 	public String getParentType() {
 		return parentType;
 	}
 
+	@Nullable
 	@Override
 	public ElasticsearchPersistentProperty getParentIdProperty() {
 		return parentIdProperty;
 	}
 
+	@Nullable
 	@Override
 	public VersionType getVersionType() {
 		return versionType;

src/main/java/org/springframework/data/elasticsearch/core/mapping/SimpleElasticsearchPersistentProperty.java

@@ -53,7 +53,7 @@ public class SimpleElasticsearchPersistentProperty extends
 	private final boolean isParent;
 	private final boolean isId;
 	private final @Nullable String annotatedFieldName;
-	private ElasticsearchPersistentPropertyConverter propertyConverter;
+	@Nullable private ElasticsearchPersistentPropertyConverter propertyConverter;
 
 	public SimpleElasticsearchPersistentProperty(Property property,
 			PersistentEntity<?, ElasticsearchPersistentProperty> owner, SimpleTypeHolder simpleTypeHolder) {
@@ -86,6 +86,7 @@ public class SimpleElasticsearchPersistentProperty extends
 		return propertyConverter != null;
 	}
 
+	@Nullable
 	@Override
 	public ElasticsearchPersistentPropertyConverter getPropertyConverter() {
 		return propertyConverter;
@@ -167,7 +168,7 @@ public class SimpleElasticsearchPersistentProperty extends
 	 */
 	@Override
 	protected Association<ElasticsearchPersistentProperty> createAssociation() {
-		return null;
+		throw new UnsupportedOperationException();
 	}
 
 	/*

src/main/java/org/springframework/data/elasticsearch/core/mapping/package-info.java

@@ -1,5 +1,3 @@
-/**
- * Infrastructure for the Elasticsearch document-to-object mapping subsystem.
- */
 @org.springframework.lang.NonNullApi
+@org.springframework.lang.NonNullFields
 package org.springframework.data.elasticsearch.core.mapping;

src/main/java/org/springframework/data/elasticsearch/core/package-info.java

@@ -0,0 +1,3 @@
+@org.springframework.lang.NonNullApi
+@org.springframework.lang.NonNullFields
+package org.springframework.data.elasticsearch.core;

src/main/java/org/springframework/data/elasticsearch/core/query/AbstractQuery.java

@@ -26,6 +26,7 @@ import org.elasticsearch.action.search.SearchType;
 import org.elasticsearch.action.support.IndicesOptions;
 import org.springframework.data.domain.Pageable;
 import org.springframework.data.domain.Sort;
+import org.springframework.lang.Nullable;
 import org.springframework.util.Assert;
 
 /**
@@ -42,21 +43,22 @@ import org.springframework.util.Assert;
 abstract class AbstractQuery implements Query {
 
 	protected Pageable pageable = DEFAULT_PAGE;
-	protected Sort sort;
+	@Nullable protected Sort sort;
 	protected List<String> fields = new ArrayList<>();
-	protected SourceFilter sourceFilter;
+	@Nullable protected SourceFilter sourceFilter;
 	protected float minScore;
-	protected Collection<String> ids;
-	protected String route;
+	@Nullable protected Collection<String> ids;
+	@Nullable protected String route;
 	protected SearchType searchType = SearchType.DFS_QUERY_THEN_FETCH;
-	protected IndicesOptions indicesOptions;
+	@Nullable protected IndicesOptions indicesOptions;
 	protected boolean trackScores;
-	protected String preference;
-	protected Integer maxResults;
-	protected HighlightQuery highlightQuery;
+	@Nullable protected String preference;
+	@Nullable protected Integer maxResults;
+	@Nullable protected HighlightQuery highlightQuery;
 	private boolean trackTotalHits = false;
 
 	@Override
+	@Nullable
 	public Sort getSort() {
 		return this.sort;
 	}
@@ -90,6 +92,7 @@ abstract class AbstractQuery implements Query {
 		this.sourceFilter = sourceFilter;
 	}
 
+	@Nullable
 	@Override
 	public SourceFilter getSourceFilter() {
 		return sourceFilter;
@@ -120,6 +123,7 @@ abstract class AbstractQuery implements Query {
 		this.minScore = minScore;
 	}
 
+	@Nullable
 	@Override
 	public Collection<String> getIds() {
 		return ids;
@@ -129,6 +133,7 @@ abstract class AbstractQuery implements Query {
 		this.ids = ids;
 	}
 
+	@Nullable
 	@Override
 	public String getRoute() {
 		return route;
@@ -147,6 +152,7 @@ abstract class AbstractQuery implements Query {
 		return searchType;
 	}
 
+	@Nullable
 	@Override
 	public IndicesOptions getIndicesOptions() {
 		return indicesOptions;
@@ -175,6 +181,7 @@ abstract class AbstractQuery implements Query {
 		this.trackScores = trackScores;
 	}
 
+	@Nullable
 	@Override
 	public String getPreference() {
 		return preference;
@@ -190,6 +197,7 @@ abstract class AbstractQuery implements Query {
 		return maxResults != null;
 	}
 
+	@Nullable
 	@Override
 	public Integer getMaxResults() {
 		return maxResults;

src/main/java/org/springframework/data/elasticsearch/core/query/AliasBuilder.java

@@ -18,6 +18,8 @@ package org.springframework.data.elasticsearch.core.query;
 import java.util.Map;
 
 import org.elasticsearch.index.query.QueryBuilder;
+import org.springframework.lang.Nullable;
+import org.springframework.util.Assert;
 
 /**
  * @author Mohsin Husen
@@ -25,12 +27,12 @@ import org.elasticsearch.index.query.QueryBuilder;
  */
 public class AliasBuilder {
 
-	private String aliasName;
-	private QueryBuilder filterBuilder;
-	private Map<String, Object> filter;
-	private String searchRouting;
-	private String indexRouting;
-	private String routing;
+	@Nullable private String aliasName;
+	@Nullable private QueryBuilder filterBuilder;
+	@Nullable private Map<String, Object> filter;
+	@Nullable private String searchRouting;
+	@Nullable private String indexRouting;
+	@Nullable private String routing;
 
 	public AliasBuilder withAliasName(String aliasName) {
 		this.aliasName = aliasName;
@@ -63,8 +65,10 @@ public class AliasBuilder {
 	}
 
 	public AliasQuery build() {
-		AliasQuery aliasQuery = new AliasQuery();
-		aliasQuery.setAliasName(aliasName);
+
+		Assert.notNull(aliasName, "aliasName must not be null");
+
+		AliasQuery aliasQuery = new AliasQuery(aliasName);
 		aliasQuery.setFilterBuilder(filterBuilder);
 		aliasQuery.setFilter(filter);
 		aliasQuery.setSearchRouting(searchRouting);

src/main/java/org/springframework/data/elasticsearch/core/query/AliasQuery.java

@@ -18,6 +18,8 @@ package org.springframework.data.elasticsearch.core.query;
 import java.util.Map;
 
 import org.elasticsearch.index.query.QueryBuilder;
+import org.springframework.lang.Nullable;
+import org.springframework.util.Assert;
 
 /**
  * AliasQuery is useful for creating new alias or deleting existing ones
@@ -27,21 +29,25 @@ import org.elasticsearch.index.query.QueryBuilder;
  */
 public class AliasQuery {
 
+	public AliasQuery(String aliasName) {
+
+		Assert.notNull(aliasName, "aliasName must not be null");
+
+		this.aliasName = aliasName;
+	}
+
 	private String aliasName;
-	private QueryBuilder filterBuilder;
-	private Map<String, Object> filter;
-	private String searchRouting;
-	private String indexRouting;
-	private String routing;
+	@Nullable private QueryBuilder filterBuilder;
+	@Nullable private Map<String, Object> filter;
+	@Nullable private String searchRouting;
+	@Nullable private String indexRouting;
+	@Nullable private String routing;
 
 	public String getAliasName() {
 		return aliasName;
 	}
 
-	public void setAliasName(String aliasName) {
-		this.aliasName = aliasName;
-	}
-
+	@Nullable
 	public QueryBuilder getFilterBuilder() {
 		return filterBuilder;
 	}
@@ -50,6 +56,7 @@ public class AliasQuery {
 		this.filterBuilder = filterBuilder;
 	}
 
+	@Nullable
 	public Map<String, Object> getFilter() {
 		return filter;
 	}
@@ -58,6 +65,7 @@ public class AliasQuery {
 		this.filter = filter;
 	}
 
+	@Nullable
 	public String getSearchRouting() {
 		return searchRouting;
 	}
@@ -66,6 +74,7 @@ public class AliasQuery {
 		this.searchRouting = searchRouting;
 	}
 
+	@Nullable
 	public String getIndexRouting() {
 		return indexRouting;
 	}
@@ -74,6 +83,7 @@ public class AliasQuery {
 		this.indexRouting = indexRouting;
 	}
 
+	@Nullable
 	public String getRouting() {
 		return routing;
 	}

src/main/java/org/springframework/data/elasticsearch/core/query/Criteria.java

@@ -29,6 +29,7 @@ import org.springframework.data.elasticsearch.core.geo.GeoPoint;
 import org.springframework.data.geo.Box;
 import org.springframework.data.geo.Distance;
 import org.springframework.data.geo.Point;
+import org.springframework.lang.Nullable;
 import org.springframework.util.Assert;
 import org.springframework.util.ObjectUtils;
 import org.springframework.util.StringUtils;
@@ -57,7 +58,7 @@ public class Criteria {
 	private static final String OR_OPERATOR = " OR ";
 	private static final String AND_OPERATOR = " AND ";
 
-	private Field field;
+	private @Nullable Field field;
 	private float boost = Float.NaN;
 	private boolean negating = false;
 
@@ -84,8 +85,10 @@ public class Criteria {
 	 * @param field
 	 */
 	public Criteria(Field field) {
+
 		Assert.notNull(field, "Field for criteria must not be null");
 		Assert.hasText(field.getName(), "Field.name for criteria must not be null/empty");
+
 		this.criteriaChain.add(this);
 		this.field = field;
 	}
@@ -95,6 +98,7 @@ public class Criteria {
 	}
 
 	protected Criteria(List<Criteria> criteriaChain, Field field) {
+
 		Assert.notNull(criteriaChain, "CriteriaChain must not be null");
 		Assert.notNull(field, "Field for criteria must not be null");
 		Assert.hasText(field.getName(), "Field.name for criteria must not be null/empty");
@@ -525,6 +529,7 @@ public class Criteria {
 	 *
 	 * @return
 	 */
+	@Nullable
 	public Field getField() {
 		return this.field;
 	}

src/main/java/org/springframework/data/elasticsearch/core/query/CriteriaQuery.java

@@ -16,6 +16,7 @@
 package org.springframework.data.elasticsearch.core.query;
 
 import org.springframework.data.domain.Pageable;
+import org.springframework.lang.Nullable;
 import org.springframework.util.Assert;
 
 /**
@@ -28,7 +29,7 @@ import org.springframework.util.Assert;
  */
 public class CriteriaQuery extends AbstractQuery {
 
-	private Criteria criteria;
+	private @Nullable Criteria criteria;
 
 	private CriteriaQuery() {}
 
@@ -51,9 +52,9 @@ public class CriteriaQuery extends AbstractQuery {
 	}
 
 	public static <T extends CriteriaQuery> T fromQuery(CriteriaQuery source, T destination) {
-		if (source == null || destination == null) {
-			return null;
-		}
+
+		Assert.notNull(source, "source must not be null");
+		Assert.notNull(destination, "destination must not be null");
 
 		if (source.getCriteria() != null) {
 			destination.addCriteria(source.getCriteria());
@@ -77,6 +78,7 @@ public class CriteriaQuery extends AbstractQuery {
 		return (T) this;
 	}
 
+	@Nullable
 	public Criteria getCriteria() {
 		return this.criteria;
 	}

src/main/java/org/springframework/data/elasticsearch/core/query/DeleteQuery.java

@@ -16,6 +16,7 @@
 package org.springframework.data.elasticsearch.core.query;
 
 import org.elasticsearch.index.query.QueryBuilder;
+import org.springframework.lang.Nullable;
 
 /**
  * DeleteQuery
@@ -26,10 +27,11 @@ import org.elasticsearch.index.query.QueryBuilder;
  */
 public class DeleteQuery {
 
-	private QueryBuilder query;
-	private Integer pageSize;
-	private Long scrollTimeInMillis;
+	@Nullable private QueryBuilder query;
+	@Nullable private Integer pageSize;
+	@Nullable private Long scrollTimeInMillis;
 
+	@Nullable
 	public QueryBuilder getQuery() {
 		return query;
 	}
@@ -38,6 +40,7 @@ public class DeleteQuery {
 		this.query = query;
 	}
 
+	@Nullable
 	public Integer getPageSize() {
 		return pageSize;
 	}
@@ -46,6 +49,7 @@ public class DeleteQuery {
 		this.pageSize = pageSize;
 	}
 
+	@Nullable
 	public Long getScrollTimeInMillis() {
 		return scrollTimeInMillis;
 	}

src/main/java/org/springframework/data/elasticsearch/core/query/FetchSourceFilterBuilder.java

@@ -15,15 +15,18 @@
  */
 package org.springframework.data.elasticsearch.core.query;
 
+import org.springframework.lang.Nullable;
+
 /**
  * SourceFilter builder for providing includes and excludes.
  *
  * @Author Jon Tsiros
+ * @author Peter-Josef Meisch
  */
 public class FetchSourceFilterBuilder {
 
-	private String[] includes;
-	private String[] excludes;
+	@Nullable private String[] includes;
+	@Nullable private String[] excludes;
 
 	public FetchSourceFilterBuilder withIncludes(String... includes) {
 		this.includes = includes;
@@ -36,8 +39,10 @@ public class FetchSourceFilterBuilder {
 	}
 
 	public SourceFilter build() {
-		if (includes == null) includes = new String[0];
-		if (excludes == null) excludes = new String[0];
+		if (includes == null)
+			includes = new String[0];
+		if (excludes == null)
+			excludes = new String[0];
 
 		return new FetchSourceFilter(includes, excludes);
 	}

src/main/java/org/springframework/data/elasticsearch/core/query/GetQuery.java

@@ -20,23 +20,21 @@ package org.springframework.data.elasticsearch.core.query;
  *
  * @author Rizwan Idrees
  * @author Mohsin Husen
+ * @author Peter-Josef Meisch
  */
 public class GetQuery {
 
+	public GetQuery(String id) {
+		this.id = id;
+	}
+
 	private String id;
 
 	public String getId() {
 		return id;
 	}
 
-	public void setId(String id) {
-		this.id = id;
-	}
-
 	public static GetQuery getById(String id) {
-
-		GetQuery query = new GetQuery();
-		query.setId(id);
-		return query;
+		return new GetQuery(id);
 	}
 }

src/main/java/org/springframework/data/elasticsearch/core/query/IndexQuery.java

@@ -15,6 +15,8 @@
  */
 package org.springframework.data.elasticsearch.core.query;
 
+import org.springframework.lang.Nullable;
+
 /**
  * IndexQuery
  *
@@ -25,12 +27,13 @@ package org.springframework.data.elasticsearch.core.query;
 
 public class IndexQuery {
 
-	private String id;
-	private Object object;
-	private Long version;
-	private String source;
-	private String parentId;
+	@Nullable private String id;
+	@Nullable private Object object;
+	@Nullable private Long version;
+	@Nullable private String source;
+	@Nullable private String parentId;
 
+	@Nullable
 	public String getId() {
 		return id;
 	}
@@ -39,6 +42,7 @@ public class IndexQuery {
 		this.id = id;
 	}
 
+	@Nullable
 	public Object getObject() {
 		return object;
 	}
@@ -47,6 +51,7 @@ public class IndexQuery {
 		this.object = object;
 	}
 
+	@Nullable
 	public Long getVersion() {
 		return version;
 	}
@@ -55,6 +60,7 @@ public class IndexQuery {
 		this.version = version;
 	}
 
+	@Nullable
 	public String getSource() {
 		return source;
 	}
@@ -63,6 +69,7 @@ public class IndexQuery {
 		this.source = source;
 	}
 
+	@Nullable
 	public String getParentId() {
 		return parentId;
 	}

src/main/java/org/springframework/data/elasticsearch/core/query/IndexQueryBuilder.java

@@ -15,6 +15,8 @@
  */
 package org.springframework.data.elasticsearch.core.query;
 
+import org.springframework.lang.Nullable;
+
 /**
  * IndexQuery Builder
  *
@@ -24,11 +26,11 @@ package org.springframework.data.elasticsearch.core.query;
  */
 public class IndexQueryBuilder {
 
-	private String id;
-	private Object object;
-	private Long version;
-	private String source;
-	private String parentId;
+	@Nullable private String id;
+	@Nullable private Object object;
+	@Nullable private Long version;
+	@Nullable private String source;
+	@Nullable private String parentId;
 
 	public IndexQueryBuilder withId(String id) {
 		this.id = id;

src/main/java/org/springframework/data/elasticsearch/core/query/MoreLikeThisQuery.java

@@ -22,6 +22,7 @@ import java.util.ArrayList;
 import java.util.List;
 
 import org.springframework.data.domain.Pageable;
+import org.springframework.lang.Nullable;
 
 /**
  * MoreLikeThisQuery
@@ -32,22 +33,23 @@ import org.springframework.data.domain.Pageable;
  */
 public class MoreLikeThisQuery {
 
-	private String id;
+	@Nullable private String id;
 	private List<String> searchIndices = new ArrayList<>();
 	private List<String> searchTypes = new ArrayList<>();
 	private List<String> fields = new ArrayList<>();
-	private String routing;
-	private Float percentTermsToMatch;
-	private Integer minTermFreq;
-	private Integer maxQueryTerms;
+	@Nullable private String routing;
+	@Nullable private Float percentTermsToMatch;
+	@Nullable private Integer minTermFreq;
+	@Nullable private Integer maxQueryTerms;
 	private List<String> stopWords = new ArrayList<>();
-	private Integer minDocFreq;
-	private Integer maxDocFreq;
-	private Integer minWordLen;
-	private Integer maxWordLen;
-	private Float boostTerms;
+	@Nullable private Integer minDocFreq;
+	@Nullable private Integer maxDocFreq;
+	@Nullable private Integer minWordLen;
+	@Nullable private Integer maxWordLen;
+	@Nullable private Float boostTerms;
 	private Pageable pageable = DEFAULT_PAGE;
 
+	@Nullable
 	public String getId() {
 		return id;
 	}
@@ -80,6 +82,7 @@ public class MoreLikeThisQuery {
 		addAll(this.fields, fields);
 	}
 
+	@Nullable
 	public String getRouting() {
 		return routing;
 	}
@@ -88,6 +91,7 @@ public class MoreLikeThisQuery {
 		this.routing = routing;
 	}
 
+	@Nullable
 	public Float getPercentTermsToMatch() {
 		return percentTermsToMatch;
 	}
@@ -96,6 +100,7 @@ public class MoreLikeThisQuery {
 		this.percentTermsToMatch = percentTermsToMatch;
 	}
 
+	@Nullable
 	public Integer getMinTermFreq() {
 		return minTermFreq;
 	}
@@ -104,6 +109,7 @@ public class MoreLikeThisQuery {
 		this.minTermFreq = minTermFreq;
 	}
 
+	@Nullable
 	public Integer getMaxQueryTerms() {
 		return maxQueryTerms;
 	}
@@ -120,6 +126,7 @@ public class MoreLikeThisQuery {
 		addAll(this.stopWords, stopWords);
 	}
 
+	@Nullable
 	public Integer getMinDocFreq() {
 		return minDocFreq;
 	}
@@ -128,6 +135,7 @@ public class MoreLikeThisQuery {
 		this.minDocFreq = minDocFreq;
 	}
 
+	@Nullable
 	public Integer getMaxDocFreq() {
 		return maxDocFreq;
 	}
@@ -136,6 +144,7 @@ public class MoreLikeThisQuery {
 		this.maxDocFreq = maxDocFreq;
 	}
 
+	@Nullable
 	public Integer getMinWordLen() {
 		return minWordLen;
 	}
@@ -144,6 +153,7 @@ public class MoreLikeThisQuery {
 		this.minWordLen = minWordLen;
 	}
 
+	@Nullable
 	public Integer getMaxWordLen() {
 		return maxWordLen;
 	}
@@ -152,6 +162,7 @@ public class MoreLikeThisQuery {
 		this.maxWordLen = maxWordLen;
 	}
 
+	@Nullable
 	public Float getBoostTerms() {
 		return boostTerms;
 	}

src/main/java/org/springframework/data/elasticsearch/core/query/NativeSearchQuery.java

@@ -24,6 +24,7 @@ import org.elasticsearch.search.aggregations.AbstractAggregationBuilder;
 import org.elasticsearch.search.collapse.CollapseBuilder;
 import org.elasticsearch.search.fetch.subphase.highlight.HighlightBuilder;
 import org.elasticsearch.search.sort.SortBuilder;
+import org.springframework.lang.Nullable;
 
 /**
  * NativeSearchQuery
@@ -38,14 +39,14 @@ import org.elasticsearch.search.sort.SortBuilder;
 public class NativeSearchQuery extends AbstractQuery {
 
 	private QueryBuilder query;
-	private QueryBuilder filter;
-	private List<SortBuilder> sorts;
+	@Nullable private QueryBuilder filter;
+	@Nullable private List<SortBuilder> sorts;
 	private final List<ScriptField> scriptFields = new ArrayList<>();
-	private CollapseBuilder collapseBuilder;
-	private List<AbstractAggregationBuilder> aggregations;
-	private HighlightBuilder highlightBuilder;
-	private HighlightBuilder.Field[] highlightFields;
-	private List<IndexBoost> indicesBoost;
+	@Nullable private CollapseBuilder collapseBuilder;
+	@Nullable private List<AbstractAggregationBuilder> aggregations;
+	@Nullable private HighlightBuilder highlightBuilder;
+	@Nullable private HighlightBuilder.Field[] highlightFields;
+	@Nullable private List<IndexBoost> indicesBoost;
 
 	public NativeSearchQuery(QueryBuilder query) {
 
@@ -88,6 +89,7 @@ public class NativeSearchQuery extends AbstractQuery {
 		return query;
 	}
 
+	@Nullable
 	public QueryBuilder getFilter() {
 		return filter;
 	}
@@ -96,6 +98,7 @@ public class NativeSearchQuery extends AbstractQuery {
 		return sorts;
 	}
 
+	@Nullable
 	public HighlightBuilder getHighlightBuilder() {
 		return highlightBuilder;
 	}
@@ -116,6 +119,7 @@ public class NativeSearchQuery extends AbstractQuery {
 		scriptFields.addAll(Arrays.asList(scriptField));
 	}
 
+	@Nullable
 	public CollapseBuilder getCollapseBuilder() {
 		return collapseBuilder;
 	}
@@ -124,6 +128,7 @@ public class NativeSearchQuery extends AbstractQuery {
 		this.collapseBuilder = collapseBuilder;
 	}
 
+	@Nullable
 	public List<AbstractAggregationBuilder> getAggregations() {
 		return aggregations;
 	}
@@ -141,6 +146,7 @@ public class NativeSearchQuery extends AbstractQuery {
 		this.aggregations = aggregations;
 	}
 
+	@Nullable
 	public List<IndexBoost> getIndicesBoost() {
 		return indicesBoost;
 	}

src/main/java/org/springframework/data/elasticsearch/core/query/NativeSearchQueryBuilder.java

@@ -29,6 +29,7 @@ import org.elasticsearch.search.collapse.CollapseBuilder;
 import org.elasticsearch.search.fetch.subphase.highlight.HighlightBuilder;
 import org.elasticsearch.search.sort.SortBuilder;
 import org.springframework.data.domain.Pageable;
+import org.springframework.lang.Nullable;
 
 /**
  * NativeSearchQuery
@@ -46,25 +47,25 @@ import org.springframework.data.domain.Pageable;
  */
 public class NativeSearchQueryBuilder {
 
-	private QueryBuilder queryBuilder;
-	private QueryBuilder filterBuilder;
+	@Nullable private QueryBuilder queryBuilder;
+	@Nullable private QueryBuilder filterBuilder;
 	private List<ScriptField> scriptFields = new ArrayList<>();
 	private List<SortBuilder> sortBuilders = new ArrayList<>();
 	private List<AbstractAggregationBuilder> aggregationBuilders = new ArrayList<>();
-	private HighlightBuilder highlightBuilder;
-	private HighlightBuilder.Field[] highlightFields;
+	@Nullable private HighlightBuilder highlightBuilder;
+	@Nullable private HighlightBuilder.Field[] highlightFields;
 	private Pageable pageable = Pageable.unpaged();
-	private String[] fields;
-	private SourceFilter sourceFilter;
-	private CollapseBuilder collapseBuilder;
-	private List<IndexBoost> indicesBoost;
+	@Nullable private String[] fields;
+	@Nullable private SourceFilter sourceFilter;
+	@Nullable private CollapseBuilder collapseBuilder;
+	@Nullable private List<IndexBoost> indicesBoost;
 	private float minScore;
 	private boolean trackScores;
-	private Collection<String> ids;
-	private String route;
-	private SearchType searchType;
-	private IndicesOptions indicesOptions;
-	private String preference;
+	@Nullable private Collection<String> ids;
+	@Nullable private String route;
+	@Nullable private SearchType searchType;
+	@Nullable private IndicesOptions indicesOptions;
+	@Nullable private String preference;
 
 	public NativeSearchQueryBuilder withQuery(QueryBuilder queryBuilder) {
 		this.queryBuilder = queryBuilder;

src/main/java/org/springframework/data/elasticsearch/core/query/Query.java

@@ -81,6 +81,7 @@ public interface Query {
 	/**
 	 * @return null if not set
 	 */
+	@Nullable
 	Sort getSort();
 
 	/**
@@ -109,6 +110,7 @@ public interface Query {
 	 *
 	 * @return SourceFilter
 	 */
+	@Nullable
 	SourceFilter getSourceFilter();
 
 	/**
@@ -131,6 +133,7 @@ public interface Query {
 	 *
 	 * @return
 	 */
+	@Nullable
 	Collection<String> getIds();
 
 	/**
@@ -138,6 +141,7 @@ public interface Query {
 	 *
 	 * @return
 	 */
+	@Nullable
 	String getRoute();
 
 	/**
@@ -152,6 +156,7 @@ public interface Query {
 	 *
 	 * @return null if not set
 	 */
+	@Nullable
 	IndicesOptions getIndicesOptions();
 
 	/**
@@ -160,6 +165,7 @@ public interface Query {
 	 * @return
 	 * @since 3.2
 	 */
+	@Nullable
 	String getPreference();
 
 	/**
@@ -183,17 +189,18 @@ public interface Query {
 	 *
 	 * @since 4.0
 	 */
+	@Nullable
 	default Integer getMaxResults() {
 		return null;
 	}
 
 	/**
-	 * Sets the {@link HighlightQuery}.*
+	 * Sets the {@link HighlightQuery}.
 	 * 
 	 * @param highlightQuery the query to set
 	 * @since 4.0
 	 */
-	void setHighlightQuery(@Nullable HighlightQuery highlightQuery);
+	void setHighlightQuery(HighlightQuery highlightQuery);
 
 	/**
 	 * @return the optional set {@link HighlightQuery}.

src/main/java/org/springframework/data/elasticsearch/core/query/SimpleField.java

@@ -29,12 +29,15 @@ public class SimpleField implements Field {
 	private String name;
 
 	public SimpleField(String name) {
-		setName(name);
+		Assert.notNull(name, "name must not be null");
+
+		this.name = name;
 	}
 
 	@Override
 	public void setName(String name) {
 		Assert.notNull(name, "name must not be null");
+
 		this.name = name;
 	}
 

src/main/java/org/springframework/data/elasticsearch/core/query/UpdateQuery.java

@@ -16,6 +16,7 @@
 package org.springframework.data.elasticsearch.core.query;
 
 import org.elasticsearch.action.update.UpdateRequest;
+import org.springframework.lang.Nullable;
 
 /**
  * @author Rizwan Idrees
@@ -24,10 +25,11 @@ import org.elasticsearch.action.update.UpdateRequest;
  */
 public class UpdateQuery {
 
-	private String id;
-	private UpdateRequest updateRequest;
+	@Nullable private String id;
+	@Nullable private UpdateRequest updateRequest;
 	private boolean doUpsert;
 
+	@Nullable
 	public String getId() {
 		return id;
 	}
@@ -36,6 +38,7 @@ public class UpdateQuery {
 		this.id = id;
 	}
 
+	@Nullable
 	public UpdateRequest getUpdateRequest() {
 		return updateRequest;
 	}

src/main/java/org/springframework/data/elasticsearch/core/query/UpdateQueryBuilder.java

@@ -17,6 +17,7 @@ package org.springframework.data.elasticsearch.core.query;
 
 import org.elasticsearch.action.index.IndexRequest;
 import org.elasticsearch.action.update.UpdateRequest;
+import org.springframework.lang.Nullable;
 
 /**
  * @author Rizwan Idrees
@@ -25,9 +26,9 @@ import org.elasticsearch.action.update.UpdateRequest;
  */
 public class UpdateQueryBuilder {
 
-	private String id;
-	private UpdateRequest updateRequest;
-	private IndexRequest indexRequest;
+	@Nullable private String id;
+	@Nullable private UpdateRequest updateRequest;
+	@Nullable private IndexRequest indexRequest;
 	private boolean doUpsert;
 
 	public UpdateQueryBuilder withId(String id) {

src/main/java/org/springframework/data/elasticsearch/core/query/package-info.java

@@ -0,0 +1,3 @@
+@org.springframework.lang.NonNullApi
+@org.springframework.lang.NonNullFields
+package org.springframework.data.elasticsearch.core.query;

src/main/java/org/springframework/data/elasticsearch/package-info.java

@@ -0,0 +1,3 @@
+@org.springframework.lang.NonNullApi
+@org.springframework.lang.NonNullFields
+package org.springframework.data.elasticsearch;

src/main/java/org/springframework/data/elasticsearch/repository/cdi/package-info.java

@@ -0,0 +1,3 @@
+@org.springframework.lang.NonNullApi
+@org.springframework.lang.NonNullFields
+package org.springframework.data.elasticsearch.repository.cdi;

src/main/java/org/springframework/data/elasticsearch/repository/config/package-info.java

@@ -0,0 +1,3 @@
+@org.springframework.lang.NonNullApi
+@org.springframework.lang.NonNullFields
+package org.springframework.data.elasticsearch.repository.config;

src/main/java/org/springframework/data/elasticsearch/repository/query/package-info.java

@@ -0,0 +1,3 @@
+@org.springframework.lang.NonNullApi
+@org.springframework.lang.NonNullFields
+package org.springframework.data.elasticsearch.repository.query;

src/main/java/org/springframework/data/elasticsearch/repository/query/parser/package-info.java

@@ -1,5 +1,3 @@
-/**
- * Infrastructure for the Elasticsearch document-to-object mapping subsystem.
- */
 @org.springframework.lang.NonNullApi
+@org.springframework.lang.NonNullFields
 package org.springframework.data.elasticsearch.repository.query.parser;

src/main/java/org/springframework/data/elasticsearch/repository/support/AbstractElasticsearchRepository.java

@@ -79,10 +79,8 @@ public abstract class AbstractElasticsearchRepository<T, ID> implements Elastics
 	protected ElasticsearchOperations operations;
 	protected IndexOperations indexOperations;
 
-	protected Class<T> entityClass;
-	protected ElasticsearchEntityInformation<T, ID> entityInformation;
-
-	public AbstractElasticsearchRepository() {}
+	protected @Nullable Class<T> entityClass;
+	protected @Nullable ElasticsearchEntityInformation<T, ID> entityInformation;
 
 	public AbstractElasticsearchRepository(ElasticsearchOperations operations) {
 		Assert.notNull(operations, "ElasticsearchOperations must not be null.");
@@ -125,8 +123,7 @@ public abstract class AbstractElasticsearchRepository<T, ID> implements Elastics
 
 	@Override
 	public Optional<T> findById(ID id) {
-		GetQuery query = new GetQuery();
-		query.setId(stringIdRepresentation(id));
+		GetQuery query = new GetQuery(stringIdRepresentation(id));
 		return Optional.ofNullable(operations.get(query, getEntityClass(), getIndexCoordinates()));
 	}
 
@@ -250,9 +247,11 @@ public abstract class AbstractElasticsearchRepository<T, ID> implements Elastics
 
 	@SuppressWarnings("unchecked")
 	@Override
-	public Page<T> searchSimilar(T entity, String[] fields, Pageable pageable) {
+	public Page<T> searchSimilar(T entity, @Nullable String[] fields, Pageable pageable) {
+
 		Assert.notNull(entity, "Cannot search similar records for 'null'.");
 		Assert.notNull(pageable, "'pageable' cannot be 'null'");
+
 		MoreLikeThisQuery query = new MoreLikeThisQuery();
 		query.setId(stringIdRepresentation(extractIdFromBean(entity)));
 		query.setPageable(pageable);
@@ -395,7 +394,7 @@ public abstract class AbstractElasticsearchRepository<T, ID> implements Elastics
 		return stringIds;
 	}
 
-	protected abstract String stringIdRepresentation(@Nullable ID id);
+	protected abstract @Nullable String stringIdRepresentation(@Nullable ID id);
 
 	private Long extractVersionFromBean(T entity) {
 		return entityInformation.getVersion(entity);

src/main/java/org/springframework/data/elasticsearch/repository/support/ElasticsearchRepositoryFactory.java

@@ -35,6 +35,7 @@ import org.springframework.data.repository.query.QueryLookupStrategy;
 import org.springframework.data.repository.query.QueryLookupStrategy.Key;
 import org.springframework.data.repository.query.QueryMethodEvaluationContextProvider;
 import org.springframework.data.repository.query.RepositoryQuery;
+import org.springframework.lang.Nullable;
 import org.springframework.util.Assert;
 
 /**
@@ -47,6 +48,7 @@ import org.springframework.util.Assert;
  * @author Mark Paluch
  * @author Christoph Strobl
  * @author Sascha Woo
+ * @author Peter-Josef Meisch
  */
 public class ElasticsearchRepositoryFactory extends RepositoryFactorySupport {
 
@@ -87,7 +89,7 @@ public class ElasticsearchRepositoryFactory extends RepositoryFactorySupport {
 	}
 
 	@Override
-	protected Optional<QueryLookupStrategy> getQueryLookupStrategy(Key key,
+	protected Optional<QueryLookupStrategy> getQueryLookupStrategy(@Nullable Key key,
 			QueryMethodEvaluationContextProvider evaluationContextProvider) {
 		return Optional.of(new ElasticsearchQueryLookupStrategy());
 	}

src/main/java/org/springframework/data/elasticsearch/repository/support/ElasticsearchRepositoryFactoryBean.java

@@ -21,6 +21,7 @@ import org.springframework.data.elasticsearch.core.ElasticsearchOperations;
 import org.springframework.data.repository.Repository;
 import org.springframework.data.repository.core.support.RepositoryFactoryBeanSupport;
 import org.springframework.data.repository.core.support.RepositoryFactorySupport;
+import org.springframework.lang.Nullable;
 import org.springframework.util.Assert;
 
 /**
@@ -30,11 +31,12 @@ import org.springframework.util.Assert;
  * @author Rizwan Idrees
  * @author Mohsin Husen
  * @author Mark Paluch
+ * @author Peter-Josef Meisch
  */
-public class ElasticsearchRepositoryFactoryBean<T extends Repository<S, ID>, S, ID extends Serializable> extends
-		RepositoryFactoryBeanSupport<T, S, ID> {
+public class ElasticsearchRepositoryFactoryBean<T extends Repository<S, ID>, S, ID extends Serializable>
+		extends RepositoryFactoryBeanSupport<T, S, ID> {
 
-	private ElasticsearchOperations operations;
+	@Nullable private ElasticsearchOperations operations;
 
 	/**
 	 * Creates a new {@link ElasticsearchRepositoryFactoryBean} for the given repository interface.
@@ -70,6 +72,9 @@ public class ElasticsearchRepositoryFactoryBean<T extends Repository<S, ID>, S,
 
 	@Override
 	protected RepositoryFactorySupport createRepositoryFactory() {
+
+		Assert.notNull(operations, "operations are not initialized");
+
 		return new ElasticsearchRepositoryFactory(operations);
 	}
 }

src/main/java/org/springframework/data/elasticsearch/repository/support/SimpleElasticsearchRepository.java

@@ -18,6 +18,7 @@ package org.springframework.data.elasticsearch.repository.support;
 import java.util.Objects;
 
 import org.springframework.data.elasticsearch.core.ElasticsearchOperations;
+import org.springframework.lang.Nullable;
 
 /**
  * Elasticsearch specific repository implementation. Likely to be used as target within
@@ -27,13 +28,10 @@ import org.springframework.data.elasticsearch.core.ElasticsearchOperations;
  * @author Mohsin Husen
  * @author Ryan Henszey
  * @author Sascha Woo
+ * @author Peter-Josef Meisch
  */
 public class SimpleElasticsearchRepository<T, ID> extends AbstractElasticsearchRepository<T, ID> {
 
-	public SimpleElasticsearchRepository() {
-		super();
-	}
-
 	public SimpleElasticsearchRepository(ElasticsearchEntityInformation<T, ID> metadata,
 			ElasticsearchOperations elasticsearchOperations) {
 		super(metadata, elasticsearchOperations);
@@ -44,7 +42,7 @@ public class SimpleElasticsearchRepository<T, ID> extends AbstractElasticsearchR
 	}
 
 	@Override
-	protected String stringIdRepresentation(ID id) {
+	protected @Nullable String stringIdRepresentation(@Nullable ID id) {
 		return Objects.toString(id, null);
 	}
 }

src/main/java/org/springframework/data/elasticsearch/repository/support/package-info.java

@@ -1,5 +1,3 @@
-/**
- * infrastructure to define the Elasticsearch mapping for an index.
- */
 @org.springframework.lang.NonNullApi
+@org.springframework.lang.NonNullFields
 package org.springframework.data.elasticsearch.repository.support;

src/main/java/org/springframework/data/elasticsearch/support/package-info.java

@@ -0,0 +1,3 @@
+@org.springframework.lang.NonNullApi
+@org.springframework.lang.NonNullFields
+package org.springframework.data.elasticsearch.support;

src/test/java/org/springframework/data/elasticsearch/NestedObjectTests.java

@@ -149,8 +149,7 @@ public class NestedObjectTests {
 		indexOperations.refresh(PersonMultipleLevelNested.class);
 
 		// then
-		GetQuery getQuery = new GetQuery();
-		getQuery.setId("1");
+		GetQuery getQuery = new GetQuery("1");
 		PersonMultipleLevelNested personIndexed = operations.get(getQuery, PersonMultipleLevelNested.class,
 				IndexCoordinates.of("test-index-person-multiple-level-nested").withTypes("user"));
 		assertThat(personIndexed).isNotNull();

src/test/java/org/springframework/data/elasticsearch/client/reactive/package-info.java

@@ -0,0 +1,3 @@
+@org.springframework.lang.NonNullApi
+@org.springframework.lang.NonNullFields
+package org.springframework.data.elasticsearch.client.reactive;

src/test/java/org/springframework/data/elasticsearch/client/util/package-info.java

@@ -0,0 +1,3 @@
+@org.springframework.lang.NonNullApi
+@org.springframework.lang.NonNullFields
+package org.springframework.data.elasticsearch.client.util;

src/test/java/org/springframework/data/elasticsearch/config/abstractelasticsearchconfiguration/ElasticsearchConfigurationTests.java

@@ -28,6 +28,7 @@ import org.springframework.data.elasticsearch.annotations.Document;
 import org.springframework.data.elasticsearch.config.AbstractElasticsearchConfiguration;
 import org.springframework.data.elasticsearch.repository.ElasticsearchRepository;
 import org.springframework.data.elasticsearch.repository.config.EnableElasticsearchRepositories;
+import org.springframework.lang.Nullable;
 import org.springframework.test.context.ContextConfiguration;
 import org.springframework.test.context.junit.jupiter.SpringExtension;
 
@@ -68,7 +69,7 @@ public class ElasticsearchConfigurationTests {
 	@Document(indexName = "test-index-config-abstractelasticsearchconfiguraiton", createIndex = false)
 	static class CreateIndexFalseEntity {
 
-		@Id private String id;
+		@Nullable @Id private String id;
 	}
 
 	interface CreateIndexFalseRepository extends ElasticsearchRepository<CreateIndexFalseEntity, String> {}

src/test/java/org/springframework/data/elasticsearch/config/abstractelasticsearchconfiguration/package-info.java

@@ -0,0 +1,3 @@
+@org.springframework.lang.NonNullApi
+@org.springframework.lang.NonNullFields
+package org.springframework.data.elasticsearch.config.abstractelasticsearchconfiguration;

src/test/java/org/springframework/data/elasticsearch/config/notnested/EnableElasticsearchRepositoriesTests.java

@@ -47,6 +47,7 @@ import org.springframework.data.elasticsearch.repository.ElasticsearchRepository
 import org.springframework.data.elasticsearch.repository.config.EnableElasticsearchRepositories;
 import org.springframework.data.elasticsearch.utils.IndexInitializer;
 import org.springframework.data.repository.Repository;
+import org.springframework.lang.Nullable;
 import org.springframework.test.context.ContextConfiguration;
 
 /**
@@ -60,7 +61,7 @@ import org.springframework.test.context.ContextConfiguration;
 @ContextConfiguration(classes = { EnableElasticsearchRepositoriesTests.Config.class })
 public class EnableElasticsearchRepositoriesTests implements ApplicationContextAware {
 
-	ApplicationContext context;
+	@Nullable ApplicationContext context;
 
 	@Override
 	public void setApplicationContext(ApplicationContext applicationContext) throws BeansException {

src/test/java/org/springframework/data/elasticsearch/config/notnested/package-info.java

@@ -0,0 +1,3 @@
+@org.springframework.lang.NonNullApi
+@org.springframework.lang.NonNullFields
+package org.springframework.data.elasticsearch.config.notnested;

src/test/java/org/springframework/data/elasticsearch/core/CriteriaQueryMappingTests.java

@@ -32,6 +32,7 @@ import org.springframework.data.elasticsearch.core.convert.MappingElasticsearchC
 import org.springframework.data.elasticsearch.core.mapping.SimpleElasticsearchMappingContext;
 import org.springframework.data.elasticsearch.core.query.Criteria;
 import org.springframework.data.elasticsearch.core.query.CriteriaQuery;
+import org.springframework.lang.Nullable;
 
 /**
  * Tests for the mapping of {@link CriteriaQuery} by a
@@ -95,10 +96,10 @@ public class CriteriaQueryMappingTests {
 	}
 
 	static class Person {
-		@Id String id;
-		@Field(name = "first-name") String firstName;
-		@Field(name = "last-name") String lastName;
-		@Field(name = "birth-date", type = FieldType.Date, format = DateFormat.custom,
+		@Nullable @Id String id;
+		@Nullable @Field(name = "first-name") String firstName;
+		@Nullable @Field(name = "last-name") String lastName;
+		@Nullable @Field(name = "birth-date", type = FieldType.Date, format = DateFormat.custom,
 				pattern = "dd.MM.uuuu") LocalDate birthDate;
 	}
 }

src/test/java/org/springframework/data/elasticsearch/core/ElasticsearchPartQueryTests.java

@@ -44,6 +44,7 @@ import org.springframework.data.elasticsearch.repository.query.ElasticsearchQuer
 import org.springframework.data.projection.SpelAwareProxyProjectionFactory;
 import org.springframework.data.repository.core.support.DefaultRepositoryMetadata;
 import org.springframework.data.repository.query.ParametersParameterAccessor;
+import org.springframework.lang.Nullable;
 
 /**
  * Tests for {@link ElasticsearchPartQuery}. Resides in the core package, as we need an instance of the
@@ -549,11 +550,12 @@ class ElasticsearchPartQueryTests {
 	}
 
 	static class Book {
-		@Id private String id;
-		private String name;
-		private Integer price;
+		@Nullable @Id private String id;
+		@Nullable private String name;
+		@Nullable private Integer price;
 		@Field(type = FieldType.Boolean) private boolean available;
 
+		@Nullable
 		public String getId() {
 			return id;
 		}
@@ -562,6 +564,7 @@ class ElasticsearchPartQueryTests {
 			this.id = id;
 		}
 
+		@Nullable
 		public String getName() {
 			return name;
 		}
@@ -570,6 +573,7 @@ class ElasticsearchPartQueryTests {
 			this.name = name;
 		}
 
+		@Nullable
 		public Integer getPrice() {
 			return price;
 		}

src/test/java/org/springframework/data/elasticsearch/core/ElasticsearchTemplateTests.java

@@ -76,6 +76,7 @@ import org.springframework.data.elasticsearch.core.geo.GeoPoint;
 import org.springframework.data.elasticsearch.core.mapping.IndexCoordinates;
 import org.springframework.data.elasticsearch.core.query.*;
 import org.springframework.data.util.CloseableIterator;
+import org.springframework.lang.Nullable;
 
 /**
  * Base for testing rest/transport templates. Contains the test common to both implementing classes.
@@ -199,8 +200,7 @@ public abstract class ElasticsearchTemplateTests {
 		operations.index(indexQuery, index);
 
 		// when
-		GetQuery getQuery = new GetQuery();
-		getQuery.setId(documentId);
+		GetQuery getQuery = new GetQuery(documentId);
 		SampleEntity sampleEntity1 = operations.get(getQuery, SampleEntity.class, index);
 
 		// then
@@ -415,8 +415,7 @@ public abstract class ElasticsearchTemplateTests {
 		operations.bulkUpdate(queries, index);
 
 		// then
-		GetQuery getQuery = new GetQuery();
-		getQuery.setId(documentId);
+		GetQuery getQuery = new GetQuery(documentId);
 		SampleEntity indexedEntity = operations.get(getQuery, SampleEntity.class, index);
 		assertThat(indexedEntity.getMessage()).isEqualTo(messageAfterUpdate);
 	}
@@ -1431,8 +1430,7 @@ public abstract class ElasticsearchTemplateTests {
 		operations.update(updateQuery, index);
 
 		// then
-		GetQuery getQuery = new GetQuery();
-		getQuery.setId(documentId);
+		GetQuery getQuery = new GetQuery(documentId);
 		SampleEntity indexedEntity = operations.get(getQuery, SampleEntity.class, index);
 		assertThat(indexedEntity.getMessage()).isEqualTo(messageAfterUpdate);
 	}
@@ -1497,8 +1495,7 @@ public abstract class ElasticsearchTemplateTests {
 		operations.update(updateQuery, index);
 
 		// then
-		GetQuery getQuery = new GetQuery();
-		getQuery.setId(documentId);
+		GetQuery getQuery = new GetQuery(documentId);
 		SampleEntity indexedEntity = operations.get(getQuery, SampleEntity.class, index);
 		assertThat(indexedEntity.getMessage()).isEqualTo(message);
 	}
@@ -1741,8 +1738,7 @@ public abstract class ElasticsearchTemplateTests {
 		// then
 		assertThat(sampleEntity.getId()).isEqualTo(documentId);
 
-		GetQuery getQuery = new GetQuery();
-		getQuery.setId(documentId);
+		GetQuery getQuery = new GetQuery(documentId);
 		SampleEntity result = operations.get(getQuery, SampleEntity.class, index);
 		assertThat(result.getId()).isEqualTo(documentId);
 	}
@@ -3043,8 +3039,10 @@ public abstract class ElasticsearchTemplateTests {
 
 		static class NestedEntity {
 
+			@Nullable
 			@Field(type = Text) private String someField;
 
+			@Nullable
 			public String getSomeField() {
 				return someField;
 			}

src/test/java/org/springframework/data/elasticsearch/core/RequestFactoryTest.java

@@ -35,14 +35,15 @@ import org.springframework.data.elasticsearch.core.mapping.SimpleElasticsearchMa
 import org.springframework.data.elasticsearch.core.query.Criteria;
 import org.springframework.data.elasticsearch.core.query.CriteriaQuery;
 import org.springframework.data.elasticsearch.core.query.GeoDistanceOrder;
+import org.springframework.lang.Nullable;
 
 /**
  * @author Peter-Josef Meisch
  */
 class RequestFactoryTest {
 
-	private static RequestFactory requestFactory;
-	private static MappingElasticsearchConverter converter;
+	@Nullable private static RequestFactory requestFactory;
+	@Nullable private static MappingElasticsearchConverter converter;
 
 	@BeforeAll
 
@@ -118,8 +119,8 @@ class RequestFactoryTest {
 	}
 
 	static class Person {
-		@Id String id;
-		@Field(name = "last-name") String lastName;
-		@Field(name = "current-location") GeoPoint location;
+		@Nullable @Id String id;
+		@Nullable @Field(name = "last-name") String lastName;
+		@Nullable @Field(name = "current-location") GeoPoint location;
 	}
 }

src/test/java/org/springframework/data/elasticsearch/core/completion/ElasticsearchTemplateCompletionTests.java

@@ -43,6 +43,7 @@ import org.springframework.data.elasticsearch.core.query.IndexQuery;
 import org.springframework.data.elasticsearch.junit.jupiter.ElasticsearchRestTemplateConfiguration;
 import org.springframework.data.elasticsearch.junit.jupiter.SpringIntegrationTest;
 import org.springframework.data.elasticsearch.utils.IndexInitializer;
+import org.springframework.lang.Nullable;
 import org.springframework.test.context.ContextConfiguration;
 
 /**
@@ -217,10 +218,11 @@ public class ElasticsearchTemplateCompletionTests {
 	 */
 	static class NonDocumentEntity {
 
-		@Id private String someId;
-		private String someField1;
-		private String someField2;
+		@Nullable @Id private String someId;
+		@Nullable private String someField1;
+		@Nullable private String someField2;
 
+		@Nullable
 		public String getSomeField1() {
 			return someField1;
 		}
@@ -229,6 +231,7 @@ public class ElasticsearchTemplateCompletionTests {
 			this.someField1 = someField1;
 		}
 
+		@Nullable
 		public String getSomeField2() {
 			return someField2;
 		}
@@ -244,11 +247,11 @@ public class ElasticsearchTemplateCompletionTests {
 	@Document(indexName = "test-index-core-completion", replicas = 0, refreshInterval = "-1")
 	static class CompletionEntity {
 
-		@Id private String id;
+		@Nullable @Id private String id;
 
-		private String name;
+		@Nullable private String name;
 
-		@CompletionField(maxInputLength = 100) private Completion suggest;
+		@Nullable @CompletionField(maxInputLength = 100) private Completion suggest;
 
 		private CompletionEntity() {}
 
@@ -256,6 +259,7 @@ public class ElasticsearchTemplateCompletionTests {
 			this.id = id;
 		}
 
+		@Nullable
 		public String getId() {
 			return id;
 		}
@@ -264,6 +268,7 @@ public class ElasticsearchTemplateCompletionTests {
 			this.id = id;
 		}
 
+		@Nullable
 		public String getName() {
 			return name;
 		}
@@ -272,6 +277,7 @@ public class ElasticsearchTemplateCompletionTests {
 			this.name = name;
 		}
 
+		@Nullable
 		public Completion getSuggest() {
 			return suggest;
 		}
@@ -327,10 +333,9 @@ public class ElasticsearchTemplateCompletionTests {
 	@Document(indexName = "test-index-annotated-completion", replicas = 0, refreshInterval = "-1")
 	static class AnnotatedCompletionEntity {
 
-		@Id private String id;
-		private String name;
-
-		@CompletionField(maxInputLength = 100) private Completion suggest;
+		@Nullable @Id private String id;
+		@Nullable private String name;
+		@Nullable @CompletionField(maxInputLength = 100) private Completion suggest;
 
 		private AnnotatedCompletionEntity() {}
 
@@ -338,6 +343,7 @@ public class ElasticsearchTemplateCompletionTests {
 			this.id = id;
 		}
 
+		@Nullable
 		public String getId() {
 			return id;
 		}
@@ -346,6 +352,7 @@ public class ElasticsearchTemplateCompletionTests {
 			this.id = id;
 		}
 
+		@Nullable
 		public String getName() {
 			return name;
 		}
@@ -354,6 +361,7 @@ public class ElasticsearchTemplateCompletionTests {
 			this.name = name;
 		}
 
+		@Nullable
 		public Completion getSuggest() {
 			return suggest;
 		}

src/test/java/org/springframework/data/elasticsearch/core/completion/ElasticsearchTemplateCompletionWithContextsTests.java

@@ -51,6 +51,7 @@ import org.springframework.data.elasticsearch.core.query.IndexQuery;
 import org.springframework.data.elasticsearch.junit.jupiter.ElasticsearchRestTemplateConfiguration;
 import org.springframework.data.elasticsearch.junit.jupiter.SpringIntegrationTest;
 import org.springframework.data.elasticsearch.utils.IndexInitializer;
+import org.springframework.lang.Nullable;
 import org.springframework.test.context.ContextConfiguration;
 
 /**
@@ -216,10 +217,11 @@ public class ElasticsearchTemplateCompletionWithContextsTests {
 	 */
 	static class NonDocumentEntity {
 
-		@Id private String someId;
-		private String someField1;
-		private String someField2;
+		@Nullable @Id private String someId;
+		@Nullable private String someField1;
+		@Nullable private String someField2;
 
+		@Nullable
 		public String getSomeField1() {
 			return someField1;
 		}
@@ -228,6 +230,7 @@ public class ElasticsearchTemplateCompletionWithContextsTests {
 			this.someField1 = someField1;
 		}
 
+		@Nullable
 		public String getSomeField2() {
 			return someField2;
 		}
@@ -245,10 +248,10 @@ public class ElasticsearchTemplateCompletionWithContextsTests {
 	static class ContextCompletionEntity {
 
 		public static final String LANGUAGE_CATEGORY = "language";
-		@Id private String id;
-		private String name;
+		@Nullable @Id private String id;
+		@Nullable private String name;
 
-		@CompletionField(maxInputLength = 100, contexts = {
+		@Nullable @CompletionField(maxInputLength = 100, contexts = {
 				@CompletionContext(name = LANGUAGE_CATEGORY, type = ContextMapping.Type.CATEGORY) }) private Completion suggest;
 
 		private ContextCompletionEntity() {}
@@ -257,6 +260,7 @@ public class ElasticsearchTemplateCompletionWithContextsTests {
 			this.id = id;
 		}
 
+		@Nullable
 		public String getId() {
 			return id;
 		}
@@ -265,6 +269,7 @@ public class ElasticsearchTemplateCompletionWithContextsTests {
 			this.id = id;
 		}
 
+		@Nullable
 		public String getName() {
 			return name;
 		}
@@ -273,6 +278,7 @@ public class ElasticsearchTemplateCompletionWithContextsTests {
 			this.name = name;
 		}
 
+		@Nullable
 		public Completion getSuggest() {
 			return suggest;
 		}

src/test/java/org/springframework/data/elasticsearch/core/convert/MappingElasticsearchConverterUnitTests.java

@@ -26,7 +26,6 @@ import lombok.Getter;
 import lombok.NoArgsConstructor;
 import lombok.RequiredArgsConstructor;
 
-import java.io.IOException;
 import java.time.LocalDate;
 import java.util.ArrayList;
 import java.util.Arrays;
@@ -61,6 +60,7 @@ import org.springframework.data.geo.Circle;
 import org.springframework.data.geo.Point;
 import org.springframework.data.geo.Polygon;
 import org.springframework.data.mapping.context.MappingContext;
+import org.springframework.lang.Nullable;
 
 /**
  * Unit tests for {@link MappingElasticsearchConverter}.
@@ -629,10 +629,10 @@ public class MappingElasticsearchConverterUnitTests {
 
 	public static class Sample {
 
-		public @ReadOnlyProperty String readOnly;
-		public @Transient String annotatedTransientProperty;
-		public transient String javaTransientProperty;
-		public String property;
+		@Nullable public @ReadOnlyProperty String readOnly;
+		@Nullable public @Transient String annotatedTransientProperty;
+		@Nullable public transient String javaTransientProperty;
+		@Nullable public String property;
 	}
 
 	@Data

src/test/java/org/springframework/data/elasticsearch/core/index/MappingBuilderTests.java

@@ -65,6 +65,7 @@ import org.springframework.data.geo.Box;
 import org.springframework.data.geo.Circle;
 import org.springframework.data.geo.Point;
 import org.springframework.data.geo.Polygon;
+import org.springframework.lang.Nullable;
 import org.springframework.test.context.ContextConfiguration;
 
 /**
@@ -562,59 +563,59 @@ public class MappingBuilderTests extends MappingContextBaseTests {
 
 		@Document(indexName = "fieldname-index")
 		static class IdEntity {
-			@Id @Field("id-property") private String id;
+			@Nullable @Id @Field("id-property") private String id;
 		}
 
 		@Document(indexName = "fieldname-index")
 		static class TextEntity {
 
-			@Id @Field("id-property") private String id;
+			@Nullable @Id @Field("id-property") private String id;
 
 			@Field(name = "text-property", type = FieldType.Text) //
-			private String textProperty;
+			@Nullable private String textProperty;
 		}
 
 		@Document(indexName = "fieldname-index")
 		static class MappingEntity {
 
-			@Id @Field("id-property") private String id;
+			@Nullable @Id @Field("id-property") private String id;
 
 			@Field("mapping-property") @Mapping(mappingPath = "/mappings/test-field-analyzed-mappings.json") //
-			private byte[] mappingProperty;
+			@Nullable private byte[] mappingProperty;
 		}
 
 		@Document(indexName = "fieldname-index")
 		static class GeoPointEntity {
 
-			@Id @Field("id-property") private String id;
+			@Nullable @Id @Field("id-property") private String id;
 
-			@Field("geopoint-property") private GeoPoint geoPoint;
+			@Nullable @Field("geopoint-property") private GeoPoint geoPoint;
 		}
 
 		@Document(indexName = "fieldname-index")
 		static class CircularEntity {
 
-			@Id @Field("id-property") private String id;
+			@Nullable @Id @Field("id-property") private String id;
 
-			@Field(name = "circular-property", type = FieldType.Object, ignoreFields = { "circular-property" }) //
+			@Nullable @Field(name = "circular-property", type = FieldType.Object, ignoreFields = { "circular-property" }) //
 			private CircularEntity circularProperty;
 		}
 
 		@Document(indexName = "fieldname-index")
 		static class CompletionEntity {
 
-			@Id @Field("id-property") private String id;
+			@Nullable @Id @Field("id-property") private String id;
 
-			@Field("completion-property") @CompletionField(maxInputLength = 100) //
+			@Nullable @Field("completion-property") @CompletionField(maxInputLength = 100) //
 			private Completion suggest;
 		}
 
 		@Document(indexName = "fieldname-index")
 		static class MultiFieldEntity {
 
-			@Id @Field("id-property") private String id;
+			@Nullable @Id @Field("id-property") private String id;
 
-			@Field("multifield-property") //
+			@Nullable @Field("multifield-property") //
 			@MultiField(mainField = @Field(type = FieldType.Text, analyzer = "whitespace"), otherFields = {
 					@InnerField(suffix = "prefix", type = FieldType.Text, analyzer = "stop", searchAnalyzer = "standard") }) //
 			private String description;
@@ -629,9 +630,9 @@ public class MappingBuilderTests extends MappingContextBaseTests {
 	@Document(indexName = "test-index-minimal")
 	static class MinimalChildEntity {
 
-		@Id private String id;
+		@Nullable @Id private String id;
 
-		@Parent(type = "parentType") private String parentId;
+		@Nullable @Parent(type = "parentType") private String parentId;
 	}
 
 	/**
@@ -663,8 +664,9 @@ public class MappingBuilderTests extends MappingContextBaseTests {
 	@Document(indexName = "test-index-simple-recursive-mapping-builder", replicas = 0, refreshInterval = "-1")
 	static class SimpleRecursiveEntity {
 
-		@Id private String id;
-		@Field(type = FieldType.Object, ignoreFields = { "circularObject" }) private SimpleRecursiveEntity circularObject;
+		@Nullable @Id private String id;
+		@Nullable @Field(type = FieldType.Object,
+				ignoreFields = { "circularObject" }) private SimpleRecursiveEntity circularObject;
 	}
 
 	/**
@@ -713,9 +715,10 @@ public class MappingBuilderTests extends MappingContextBaseTests {
 	 */
 	static class Author {
 
-		private String id;
-		private String name;
+		@Nullable private String id;
+		@Nullable private String name;
 
+		@Nullable
 		public String getId() {
 			return id;
 		}
@@ -724,6 +727,7 @@ public class MappingBuilderTests extends MappingContextBaseTests {
 			this.id = id;
 		}
 
+		@Nullable
 		public String getName() {
 			return name;
 		}
@@ -739,8 +743,9 @@ public class MappingBuilderTests extends MappingContextBaseTests {
 	@Document(indexName = "test-index-sample-inherited-mapping-builder", replicas = 0, refreshInterval = "-1")
 	static class SampleInheritedEntity extends AbstractInheritedEntity {
 
-		@Field(type = Text, index = false, store = true, analyzer = "standard") private String message;
+		@Nullable @Field(type = Text, index = false, store = true, analyzer = "standard") private String message;
 
+		@Nullable
 		public String getMessage() {
 			return message;
 		}
@@ -808,10 +813,11 @@ public class MappingBuilderTests extends MappingContextBaseTests {
 	 */
 	static class AbstractInheritedEntity {
 
-		@Id private String id;
+		@Nullable @Id private String id;
 
-		@Field(type = FieldType.Date, index = false) private Date createdDate;
+		@Nullable @Field(type = FieldType.Date, index = false) private Date createdDate;
 
+		@Nullable
 		public String getId() {
 			return id;
 		}
@@ -820,6 +826,7 @@ public class MappingBuilderTests extends MappingContextBaseTests {
 			this.id = id;
 		}
 
+		@Nullable
 		public Date getCreatedDate() {
 			return createdDate;
 		}
@@ -835,12 +842,13 @@ public class MappingBuilderTests extends MappingContextBaseTests {
 	@Document(indexName = "test-index-recursive-mapping-mapping-builder", replicas = 0, refreshInterval = "-1")
 	static class SampleTransientEntity {
 
-		@Id private String id;
+		@Nullable @Id private String id;
 
-		@Field(type = Text, index = false, store = true, analyzer = "standard") private String message;
+		@Nullable @Field(type = Text, index = false, store = true, analyzer = "standard") private String message;
 
-		@Transient private SampleTransientEntity.NestedEntity nested;
+		@Nullable @Transient private SampleTransientEntity.NestedEntity nested;
 
+		@Nullable
 		public String getId() {
 			return id;
 		}
@@ -849,6 +857,7 @@ public class MappingBuilderTests extends MappingContextBaseTests {
 			this.id = id;
 		}
 
+		@Nullable
 		public String getMessage() {
 			return message;
 		}
@@ -860,7 +869,7 @@ public class MappingBuilderTests extends MappingContextBaseTests {
 		static class NestedEntity {
 
 			@Field private static SampleTransientEntity.NestedEntity someField = new SampleTransientEntity.NestedEntity();
-			@Field private Boolean something;
+			@Nullable @Field private Boolean something;
 
 			public SampleTransientEntity.NestedEntity getSomeField() {
 				return someField;
@@ -870,6 +879,7 @@ public class MappingBuilderTests extends MappingContextBaseTests {
 				NestedEntity.someField = someField;
 			}
 
+			@Nullable
 			public Boolean getSomething() {
 				return something;
 			}
@@ -913,7 +923,7 @@ public class MappingBuilderTests extends MappingContextBaseTests {
 	 */
 	@Document(indexName = "test-index-user-mapping-builder")
 	static class User {
-		@Id private String id;
+		@Nullable @Id private String id;
 
 		@Field(type = FieldType.Nested, ignoreFields = { "users" }) private Set<Group> groups = new HashSet<>();
 	}
@@ -924,54 +934,55 @@ public class MappingBuilderTests extends MappingContextBaseTests {
 	@Document(indexName = "test-index-group-mapping-builder")
 	static class Group {
 
-		@Id String id;
+		@Nullable @Id String id;
 
 		@Field(type = FieldType.Nested, ignoreFields = { "groups" }) private Set<User> users = new HashSet<>();
 	}
 
 	@Document(indexName = "test-index-field-mapping-parameters")
 	static class FieldMappingParameters {
-		@Field private String indexTrue;
-		@Field(index = false) private String indexFalse;
-		@Field(store = true) private String storeTrue;
-		@Field private String storeFalse;
-		@Field private String coerceTrue;
-		@Field(coerce = false) private String coerceFalse;
-		@Field(fielddata = true) private String fielddataTrue;
-		@Field private String fielddataFalse;
-		@Field(copyTo = { "foo", "bar" }) private String copyTo;
-		@Field(ignoreAbove = 42) private String ignoreAbove;
-		@Field(type = FieldType.Integer) private String type;
-		@Field(type = FieldType.Date, format = DateFormat.custom, pattern = "YYYYMMDD") private LocalDate date;
-		@Field(analyzer = "ana", searchAnalyzer = "sana", normalizer = "norma") private String analyzers;
-		@Field(type = Keyword) private String docValuesTrue;
-		@Field(type = Keyword, docValues = false) private String docValuesFalse;
-		@Field(ignoreMalformed = true) private String ignoreMalformedTrue;
-		@Field() private String ignoreMalformedFalse;
-		@Field(indexOptions = IndexOptions.none) private String indexOptionsNone;
-		@Field(indexOptions = IndexOptions.positions) private String indexOptionsPositions;
-		@Field(indexPhrases = true) private String indexPhrasesTrue;
-		@Field() private String indexPhrasesFalse;
-		@Field(indexPrefixes = @IndexPrefixes) private String defaultIndexPrefixes;
-		@Field(indexPrefixes = @IndexPrefixes(minChars = 1, maxChars = 10)) private String customIndexPrefixes;
-		@Field private String normsTrue;
-		@Field(norms = false) private String normsFalse;
-		@Field private String nullValueNotSet;
-		@Field(nullValue = "NULLNULL") private String nullValueSet;
-		@Field(positionIncrementGap = 42) private String positionIncrementGap;
-		@Field private String similarityDefault;
-		@Field(similarity = Similarity.Boolean) private String similarityBoolean;
-		@Field private String termVectorDefault;
-		@Field(termVector = TermVector.with_offsets) private String termVectorWithOffsets;
-		@Field(type = FieldType.Scaled_Float, scalingFactor = 100.0) Double scaledFloat;
+		@Nullable @Field private String indexTrue;
+		@Nullable @Field(index = false) private String indexFalse;
+		@Nullable @Field(store = true) private String storeTrue;
+		@Nullable @Field private String storeFalse;
+		@Nullable @Field private String coerceTrue;
+		@Nullable @Field(coerce = false) private String coerceFalse;
+		@Nullable @Field(fielddata = true) private String fielddataTrue;
+		@Nullable @Field private String fielddataFalse;
+		@Nullable @Field(copyTo = { "foo", "bar" }) private String copyTo;
+		@Nullable @Field(ignoreAbove = 42) private String ignoreAbove;
+		@Nullable @Field(type = FieldType.Integer) private String type;
+		@Nullable @Field(type = FieldType.Date, format = DateFormat.custom, pattern = "YYYYMMDD") private LocalDate date;
+		@Nullable @Field(analyzer = "ana", searchAnalyzer = "sana", normalizer = "norma") private String analyzers;
+		@Nullable @Field(type = Keyword) private String docValuesTrue;
+		@Nullable @Field(type = Keyword, docValues = false) private String docValuesFalse;
+		@Nullable @Field(ignoreMalformed = true) private String ignoreMalformedTrue;
+		@Nullable @Field() private String ignoreMalformedFalse;
+		@Nullable @Field(indexOptions = IndexOptions.none) private String indexOptionsNone;
+		@Nullable @Field(indexOptions = IndexOptions.positions) private String indexOptionsPositions;
+		@Nullable @Field(indexPhrases = true) private String indexPhrasesTrue;
+		@Nullable @Field() private String indexPhrasesFalse;
+		@Nullable @Field(indexPrefixes = @IndexPrefixes) private String defaultIndexPrefixes;
+		@Nullable @Field(indexPrefixes = @IndexPrefixes(minChars = 1, maxChars = 10)) private String customIndexPrefixes;
+		@Nullable @Field private String normsTrue;
+		@Nullable @Field(norms = false) private String normsFalse;
+		@Nullable @Field private String nullValueNotSet;
+		@Nullable @Field(nullValue = "NULLNULL") private String nullValueSet;
+		@Nullable @Field(positionIncrementGap = 42) private String positionIncrementGap;
+		@Nullable @Field private String similarityDefault;
+		@Nullable @Field(similarity = Similarity.Boolean) private String similarityBoolean;
+		@Nullable @Field private String termVectorDefault;
+		@Nullable @Field(termVector = TermVector.with_offsets) private String termVectorWithOffsets;
+		@Nullable @Field(type = FieldType.Scaled_Float, scalingFactor = 100.0) Double scaledFloat;
 	}
 
 	@Document(indexName = "test-index-configure-dynamic-mapping")
 	@DynamicMapping(DynamicMappingValue.False)
 	static class ConfigureDynamicMappingEntity {
 
-		@DynamicMapping(DynamicMappingValue.Strict) @Field(type = FieldType.Object) private Author author;
+		@Nullable @DynamicMapping(DynamicMappingValue.Strict) @Field(type = FieldType.Object) private Author author;
 
+		@Nullable
 		public Author getAuthor() {
 			return author;
 		}

src/test/java/org/springframework/data/elasticsearch/core/index/MappingParametersTest.java

@@ -10,6 +10,7 @@ import org.springframework.data.elasticsearch.annotations.FieldType;
 import org.springframework.data.elasticsearch.annotations.InnerField;
 import org.springframework.data.elasticsearch.annotations.Score;
 import org.springframework.data.elasticsearch.core.mapping.ElasticsearchPersistentEntity;
+import org.springframework.lang.Nullable;
 
 /**
  * @author Peter-Josef Meisch
@@ -59,10 +60,10 @@ public class MappingParametersTest extends MappingContextBaseTests {
 	}
 
 	static class AnnotatedClass {
-		@Field private String field;
-		@InnerField(suffix = "test", type = FieldType.Text) private String innerField;
+		@Nullable @Field private String field;
+		@Nullable @InnerField(suffix = "test", type = FieldType.Text) private String innerField;
 		@Score private float score;
-		@Field(type = FieldType.Text, docValues = false) private String docValuesText;
-		@Field(type = FieldType.Nested, docValues = false) private String docValuesNested;
+		@Nullable @Field(type = FieldType.Text, docValues = false) private String docValuesText;
+		@Nullable @Field(type = FieldType.Nested, docValues = false) private String docValuesNested;
 	}
 }

src/test/java/org/springframework/data/elasticsearch/core/index/SimpleDynamicTemplatesMappingTests.java

@@ -17,7 +17,6 @@ package org.springframework.data.elasticsearch.core.index;
 
 import static org.assertj.core.api.Assertions.*;
 
-import java.io.IOException;
 import java.util.HashMap;
 import java.util.Map;
 
@@ -29,6 +28,7 @@ import org.springframework.data.elasticsearch.annotations.Field;
 import org.springframework.data.elasticsearch.annotations.FieldType;
 import org.springframework.data.elasticsearch.junit.jupiter.ElasticsearchTemplateConfiguration;
 import org.springframework.data.elasticsearch.junit.jupiter.SpringIntegrationTest;
+import org.springframework.lang.Nullable;
 import org.springframework.test.context.ContextConfiguration;
 
 /**
@@ -46,8 +46,7 @@ public class SimpleDynamicTemplatesMappingTests extends MappingContextBaseTests
 
 		String mapping = getMappingBuilder().buildPropertyMapping(SampleDynamicTemplatesEntity.class);
 
-		String EXPECTED_MAPPING_ONE = "{\"dynamic_templates\":"
-				+ "[{\"with_custom_analyzer\":{"
+		String EXPECTED_MAPPING_ONE = "{\"dynamic_templates\":" + "[{\"with_custom_analyzer\":{"
 				+ "\"mapping\":{\"type\":\"string\",\"analyzer\":\"standard_lowercase_asciifolding\"},"
 				+ "\"path_match\":\"names.*\"}}]," + "\"properties\":{\"names\":{\"type\":\"object\"}}}";
 
@@ -58,8 +57,7 @@ public class SimpleDynamicTemplatesMappingTests extends MappingContextBaseTests
 	public void testCorrectDynamicTemplatesMappingsTwo() {
 
 		String mapping = getMappingBuilder().buildPropertyMapping(SampleDynamicTemplatesEntityTwo.class);
-		String EXPECTED_MAPPING_TWO = "{\"dynamic_templates\":"
-				+ "[{\"with_custom_analyzer\":{"
+		String EXPECTED_MAPPING_TWO = "{\"dynamic_templates\":" + "[{\"with_custom_analyzer\":{"
 				+ "\"mapping\":{\"type\":\"string\",\"analyzer\":\"standard_lowercase_asciifolding\"},"
 				+ "\"path_match\":\"names.*\"}}," + "{\"participantA1_with_custom_analyzer\":{"
 				+ "\"mapping\":{\"type\":\"string\",\"analyzer\":\"standard_lowercase_asciifolding\"},"
@@ -71,27 +69,25 @@ public class SimpleDynamicTemplatesMappingTests extends MappingContextBaseTests
 	/**
 	 * @author Petr Kukral
 	 */
-	@Document(indexName = "test-dynamictemplates", indexStoreType = "memory",
-			replicas = 0, refreshInterval = "-1")
+	@Document(indexName = "test-dynamictemplates", indexStoreType = "memory", replicas = 0, refreshInterval = "-1")
 	@DynamicTemplates(mappingPath = "/mappings/test-dynamic_templates_mappings.json")
 	static class SampleDynamicTemplatesEntity {
 
-		@Id private String id;
+		@Nullable @Id private String id;
 
-		@Field(type = FieldType.Object) private Map<String, String> names = new HashMap<>();
+		@Nullable @Field(type = FieldType.Object) private Map<String, String> names = new HashMap<>();
 	}
 
 	/**
 	 * @author Petr Kukral
 	 */
-	@Document(indexName = "test-dynamictemplates", indexStoreType = "memory",
-			replicas = 0, refreshInterval = "-1")
+	@Document(indexName = "test-dynamictemplates", indexStoreType = "memory", replicas = 0, refreshInterval = "-1")
 	@DynamicTemplates(mappingPath = "/mappings/test-dynamic_templates_mappings_two.json")
 	static class SampleDynamicTemplatesEntityTwo {
 
-		@Id private String id;
+		@Nullable @Id private String id;
 
-		@Field(type = FieldType.Object) private Map<String, String> names = new HashMap<>();
+		@Nullable @Field(type = FieldType.Object) private Map<String, String> names = new HashMap<>();
 	}
 
 }

src/test/java/org/springframework/data/elasticsearch/core/mapping/SimpleElasticsearchPersistentEntityTests.java

@@ -27,6 +27,7 @@ import org.springframework.data.mapping.model.Property;
 import org.springframework.data.mapping.model.SimpleTypeHolder;
 import org.springframework.data.util.ClassTypeInformation;
 import org.springframework.data.util.TypeInformation;
+import org.springframework.lang.Nullable;
 import org.springframework.util.ReflectionUtils;
 
 /**
@@ -105,8 +106,9 @@ public class SimpleElasticsearchPersistentEntityTests {
 
 	private class EntityWithWrongVersionType {
 
-		@Version private String version;
+		@Nullable @Version private String version;
 
+		@Nullable
 		public String getVersion() {
 			return version;
 		}
@@ -118,9 +120,10 @@ public class SimpleElasticsearchPersistentEntityTests {
 
 	private class EntityWithMultipleVersionField {
 
-		@Version private Long version1;
-		@Version private Long version2;
+		@Nullable @Version private Long version1;
+		@Nullable @Version private Long version2;
 
+		@Nullable
 		public Long getVersion1() {
 			return version1;
 		}
@@ -129,6 +132,7 @@ public class SimpleElasticsearchPersistentEntityTests {
 			this.version1 = version1;
 		}
 
+		@Nullable
 		public Long getVersion2() {
 			return version2;
 		}
@@ -147,7 +151,7 @@ public class SimpleElasticsearchPersistentEntityTests {
 	}
 
 	private static class FieldNameEntity {
-		@Id private String id;
-		@Field(name = "renamed-field") private String renamedField;
+		@Nullable @Id private String id;
+		@Nullable @Field(name = "renamed-field") private String renamedField;
 	}
 }

src/test/java/org/springframework/data/elasticsearch/core/mapping/SimpleElasticsearchPersistentPropertyUnitTests.java

@@ -27,6 +27,7 @@ import org.springframework.data.elasticsearch.annotations.Field;
 import org.springframework.data.elasticsearch.annotations.FieldType;
 import org.springframework.data.elasticsearch.annotations.Score;
 import org.springframework.data.mapping.MappingException;
+import org.springframework.lang.Nullable;
 
 /**
  * Unit tests for {@link SimpleElasticsearchPersistentProperty}.
@@ -110,20 +111,20 @@ public class SimpleElasticsearchPersistentPropertyUnitTests {
 	}
 
 	static class InvalidScoreProperty {
-		@Score String scoreProperty;
+		@Nullable @Score String scoreProperty;
 	}
 
 	static class FieldNameProperty {
-		@Field(name = "by-name") String fieldProperty;
+		@Nullable @Field(name = "by-name") String fieldProperty;
 	}
 
 	static class FieldValueProperty {
-		@Field(value = "by-value") String fieldProperty;
+		@Nullable @Field(value = "by-value") String fieldProperty;
 	}
 
 	static class DatesProperty {
-		@Field(type = FieldType.Date, format = DateFormat.basic_date) Date date;
-		@Field(type = FieldType.Date, format = DateFormat.custom, pattern = "dd.MM.uuuu") LocalDate localDate;
-		@Field(type = FieldType.Date, format = DateFormat.basic_date_time) LocalDateTime localDateTime;
+		@Nullable @Field(type = FieldType.Date, format = DateFormat.basic_date) Date date;
+		@Nullable @Field(type = FieldType.Date, format = DateFormat.custom, pattern = "dd.MM.uuuu") LocalDate localDate;
+		@Nullable @Field(type = FieldType.Date, format = DateFormat.basic_date_time) LocalDateTime localDateTime;
 	}
 }

src/test/java/org/springframework/data/elasticsearch/core/query/HighlightQueryBuilderTests.java

@@ -30,6 +30,7 @@ import org.springframework.data.elasticsearch.annotations.HighlightField;
 import org.springframework.data.elasticsearch.annotations.HighlightParameters;
 import org.springframework.data.elasticsearch.core.ResourceUtil;
 import org.springframework.data.elasticsearch.core.mapping.SimpleElasticsearchMappingContext;
+import org.springframework.lang.Nullable;
 import org.springframework.util.Assert;
 
 /**
@@ -117,10 +118,11 @@ class HighlightQueryBuilderTests {
 
 	@Document(indexName = "dont-care")
 	private static class HighlightEntity {
-		@Id private String id;
-		@Field(name = "some-field") private String someField;
-		@Field(name = "other-field") private String otherField;
+		@Nullable @Id private String id;
+		@Nullable @Field(name = "some-field") private String someField;
+		@Nullable @Field(name = "other-field") private String otherField;
 
+		@Nullable
 		public String getId() {
 			return id;
 		}
@@ -129,6 +131,7 @@ class HighlightQueryBuilderTests {
 			this.id = id;
 		}
 
+		@Nullable
 		public String getSomeField() {
 			return someField;
 		}

src/test/java/org/springframework/data/elasticsearch/repositories/cdi/CdiRepositoryClient.java

@@ -17,17 +17,21 @@ package org.springframework.data.elasticsearch.repositories.cdi;
 
 import javax.inject.Inject;
 
+import org.springframework.lang.Nullable;
+
 /**
  * @author Mohsin Husen
  * @author Oliver Gierke
  * @author Mark Paluch
+ * @author Peter-Josef Meisch
  */
 class CdiRepositoryClient {
 
-	private CdiProductRepository repository;
-	private SamplePersonRepository samplePersonRepository;
-	private QualifiedProductRepository qualifiedProductRepository;
+	@Nullable private CdiProductRepository repository;
+	@Nullable private SamplePersonRepository samplePersonRepository;
+	@Nullable private QualifiedProductRepository qualifiedProductRepository;
 
+	@Nullable
 	public CdiProductRepository getRepository() {
 		return repository;
 	}
@@ -37,6 +41,7 @@ class CdiRepositoryClient {
 		this.repository = repository;
 	}
 
+	@Nullable
 	public SamplePersonRepository getSamplePersonRepository() {
 		return samplePersonRepository;
 	}
@@ -46,6 +51,7 @@ class CdiRepositoryClient {
 		this.samplePersonRepository = samplePersonRepository;
 	}
 
+	@Nullable
 	public QualifiedProductRepository getQualifiedProductRepository() {
 		return qualifiedProductRepository;
 	}

src/test/java/org/springframework/data/elasticsearch/repositories/cdi/CdiRepositoryTests.java

@@ -41,6 +41,7 @@ import org.springframework.data.elasticsearch.annotations.Field;
 import org.springframework.data.elasticsearch.annotations.FieldType;
 import org.springframework.data.elasticsearch.annotations.InnerField;
 import org.springframework.data.elasticsearch.annotations.MultiField;
+import org.springframework.lang.Nullable;
 
 /**
  * @author Mohsin Husen
@@ -50,7 +51,7 @@ import org.springframework.data.elasticsearch.annotations.MultiField;
  */
 public class CdiRepositoryTests {
 
-	private static CdiTestContainer cdiContainer;
+	@Nullable private static CdiTestContainer cdiContainer;
 	private CdiProductRepository repository;
 	private SamplePersonRepository personRepository;
 	private QualifiedProductRepository qualifiedProductRepository;
@@ -158,8 +159,7 @@ public class CdiRepositoryTests {
 	@NoArgsConstructor
 	@AllArgsConstructor
 	@Builder
-	@Document(indexName = "test-index-product-cdi-repository", replicas = 0,
-			refreshInterval = "-1")
+	@Document(indexName = "test-index-product-cdi-repository", replicas = 0, refreshInterval = "-1")
 	static class Product {
 
 		@Id private String id;
@@ -188,8 +188,7 @@ public class CdiRepositoryTests {
 	}
 
 	@Data
-	@Document(indexName = "test-index-person-cdi-repository", replicas = 0,
-			refreshInterval = "-1")
+	@Document(indexName = "test-index-person-cdi-repository", replicas = 0, refreshInterval = "-1")
 	static class Person {
 
 		@Id private String id;
@@ -206,8 +205,7 @@ public class CdiRepositoryTests {
 	@NoArgsConstructor
 	@AllArgsConstructor
 	@Builder
-	@Document(indexName = "test-index-book-cdi-repository", replicas = 0,
-			refreshInterval = "-1")
+	@Document(indexName = "test-index-book-cdi-repository", replicas = 0, refreshInterval = "-1")
 	static class Book {
 
 		@Id private String id;

src/test/java/org/springframework/data/elasticsearch/repositories/cdi/package-info.java

@@ -0,0 +1,3 @@
+@org.springframework.lang.NonNullApi
+@org.springframework.lang.NonNullFields
+package org.springframework.data.elasticsearch.repositories.cdi;

src/test/java/org/springframework/data/elasticsearch/repository/query/ElasticsearchStringQueryUnitTests.java

@@ -50,6 +50,7 @@ import org.springframework.data.elasticsearch.core.query.StringQuery;
 import org.springframework.data.projection.SpelAwareProxyProjectionFactory;
 import org.springframework.data.repository.Repository;
 import org.springframework.data.repository.core.support.DefaultRepositoryMetadata;
+import org.springframework.lang.Nullable;
 
 /**
  * @author Christoph Strobl
@@ -123,18 +124,15 @@ public class ElasticsearchStringQueryUnitTests {
 	 * @author Artur Konczak
 	 */
 
-	@Document(indexName = "test-index-person-query-unittest", replicas = 0,
-			refreshInterval = "-1")
+	@Document(indexName = "test-index-person-query-unittest", replicas = 0, refreshInterval = "-1")
 	static class Person {
 
-		@Id private String id;
-
-		private String name;
-
-		@Field(type = FieldType.Nested) private List<Car> car;
-
-		@Field(type = FieldType.Nested, includeInParent = true) private List<Book> books;
+		@Nullable @Id private String id;
+		@Nullable private String name;
+		@Nullable @Field(type = FieldType.Nested) private List<Car> car;
+		@Nullable @Field(type = FieldType.Nested, includeInParent = true) private List<Book> books;
 
+		@Nullable
 		public String getId() {
 			return id;
 		}
@@ -143,6 +141,7 @@ public class ElasticsearchStringQueryUnitTests {
 			this.id = id;
 		}
 
+		@Nullable
 		public String getName() {
 			return name;
 		}
@@ -151,6 +150,7 @@ public class ElasticsearchStringQueryUnitTests {
 			this.name = name;
 		}
 
+		@Nullable
 		public List<Car> getCar() {
 			return car;
 		}
@@ -159,6 +159,7 @@ public class ElasticsearchStringQueryUnitTests {
 			this.car = car;
 		}
 
+		@Nullable
 		public List<Book> getBooks() {
 			return books;
 		}
@@ -178,8 +179,7 @@ public class ElasticsearchStringQueryUnitTests {
 	@NoArgsConstructor
 	@AllArgsConstructor
 	@Builder
-	@Document(indexName = "test-index-book-query-unittest", replicas = 0,
-			refreshInterval = "-1")
+	@Document(indexName = "test-index-book-query-unittest", replicas = 0, refreshInterval = "-1")
 	static class Book {
 
 		@Id private String id;
@@ -229,9 +229,10 @@ public class ElasticsearchStringQueryUnitTests {
 	 */
 	static class Author {
 
-		private String id;
-		private String name;
+		@Nullable private String id;
+		@Nullable private String name;
 
+		@Nullable
 		public String getId() {
 			return id;
 		}
@@ -240,6 +241,7 @@ public class ElasticsearchStringQueryUnitTests {
 			this.id = id;
 		}
 
+		@Nullable
 		public String getName() {
 			return name;
 		}

src/test/java/org/springframework/data/elasticsearch/repository/query/ReactiveElasticsearchQueryMethodUnitTests.java

@@ -48,6 +48,7 @@ import org.springframework.data.projection.ProjectionFactory;
 import org.springframework.data.projection.SpelAwareProxyProjectionFactory;
 import org.springframework.data.repository.Repository;
 import org.springframework.data.repository.core.support.DefaultRepositoryMetadata;
+import org.springframework.lang.Nullable;
 
 /**
  * @author Christoph Strobl
@@ -152,14 +153,15 @@ public class ReactiveElasticsearchQueryMethodUnitTests {
 	@Document(indexName = INDEX_NAME, replicas = 0, refreshInterval = "-1")
 	static class Person {
 
-		@Id private String id;
+		@Nullable @Id private String id;
 
-		private String name;
+		@Nullable private String name;
 
-		@Field(type = FieldType.Nested) private List<Car> car;
+		@Nullable @Field(type = FieldType.Nested) private List<Car> car;
 
-		@Field(type = FieldType.Nested, includeInParent = true) private List<Book> books;
+		@Nullable @Field(type = FieldType.Nested, includeInParent = true) private List<Book> books;
 
+		@Nullable
 		public String getId() {
 			return id;
 		}
@@ -168,6 +170,7 @@ public class ReactiveElasticsearchQueryMethodUnitTests {
 			this.id = id;
 		}
 
+		@Nullable
 		public String getName() {
 			return name;
 		}
@@ -176,6 +179,7 @@ public class ReactiveElasticsearchQueryMethodUnitTests {
 			this.name = name;
 		}
 
+		@Nullable
 		public List<Car> getCar() {
 			return car;
 		}
@@ -184,6 +188,7 @@ public class ReactiveElasticsearchQueryMethodUnitTests {
 			this.car = car;
 		}
 
+		@Nullable
 		public List<Book> getBooks() {
 			return books;
 		}
@@ -203,8 +208,7 @@ public class ReactiveElasticsearchQueryMethodUnitTests {
 	@NoArgsConstructor
 	@AllArgsConstructor
 	@Builder
-	@Document(indexName = "test-index-book-reactive-repository-query", replicas = 0,
-			refreshInterval = "-1")
+	@Document(indexName = "test-index-book-reactive-repository-query", replicas = 0, refreshInterval = "-1")
 	static class Book {
 
 		@Id private String id;
@@ -254,9 +258,10 @@ public class ReactiveElasticsearchQueryMethodUnitTests {
 	 */
 	static class Author {
 
-		private String id;
-		private String name;
+		@Nullable private String id;
+		@Nullable private String name;
 
+		@Nullable
 		public String getId() {
 			return id;
 		}
@@ -265,6 +270,7 @@ public class ReactiveElasticsearchQueryMethodUnitTests {
 			this.id = id;
 		}
 
+		@Nullable
 		public String getName() {
 			return name;
 		}

src/test/java/org/springframework/data/elasticsearch/repository/query/ReactiveElasticsearchStringQueryUnitTests.java

@@ -55,6 +55,7 @@ import org.springframework.data.repository.Repository;
 import org.springframework.data.repository.core.support.DefaultRepositoryMetadata;
 import org.springframework.data.repository.query.QueryMethodEvaluationContextProvider;
 import org.springframework.expression.spel.standard.SpelExpressionParser;
+import org.springframework.lang.Nullable;
 
 /**
  * @author Christoph Strobl
@@ -175,18 +176,18 @@ public class ReactiveElasticsearchStringQueryUnitTests {
 	 * @author Artur Konczak
 	 */
 
-	@Document(indexName = "test-index-person-reactive-repository-string-query", replicas = 0,
-			refreshInterval = "-1")
+	@Document(indexName = "test-index-person-reactive-repository-string-query", replicas = 0, refreshInterval = "-1")
 	public class Person {
 
-		@Id private String id;
+		@Nullable @Id private String id;
 
-		private String name;
+		@Nullable private String name;
 
-		@Field(type = FieldType.Nested) private List<Car> car;
+		@Nullable @Field(type = FieldType.Nested) private List<Car> car;
 
-		@Field(type = FieldType.Nested, includeInParent = true) private List<Book> books;
+		@Nullable @Field(type = FieldType.Nested, includeInParent = true) private List<Book> books;
 
+		@Nullable
 		public String getId() {
 			return id;
 		}
@@ -195,6 +196,7 @@ public class ReactiveElasticsearchStringQueryUnitTests {
 			this.id = id;
 		}
 
+		@Nullable
 		public String getName() {
 			return name;
 		}
@@ -203,6 +205,7 @@ public class ReactiveElasticsearchStringQueryUnitTests {
 			this.name = name;
 		}
 
+		@Nullable
 		public List<Car> getCar() {
 			return car;
 		}
@@ -211,6 +214,7 @@ public class ReactiveElasticsearchStringQueryUnitTests {
 			this.car = car;
 		}
 
+		@Nullable
 		public List<Book> getBooks() {
 			return books;
 		}
@@ -230,8 +234,7 @@ public class ReactiveElasticsearchStringQueryUnitTests {
 	@NoArgsConstructor
 	@AllArgsConstructor
 	@Builder
-	@Document(indexName = "test-index-book-reactive-repository-string-query", replicas = 0,
-			refreshInterval = "-1")
+	@Document(indexName = "test-index-book-reactive-repository-string-query", replicas = 0, refreshInterval = "-1")
 	static class Book {
 
 		@Id private String id;
@@ -281,9 +284,10 @@ public class ReactiveElasticsearchStringQueryUnitTests {
 	 */
 	static class Author {
 
-		private String id;
-		private String name;
+		@Nullable private String id;
+		@Nullable private String name;
 
+		@Nullable
 		public String getId() {
 			return id;
 		}
@@ -292,6 +296,7 @@ public class ReactiveElasticsearchStringQueryUnitTests {
 			this.id = id;
 		}
 
+		@Nullable
 		public String getName() {
 			return name;
 		}

src/test/java/org/springframework/data/elasticsearch/repository/query/StubParameterAccessor.java

@@ -43,7 +43,7 @@ class StubParameterAccessor implements ElasticsearchParameterAccessor {
 	 */
 	@Override
 	public Pageable getPageable() {
-		return null;
+		return Pageable.unpaged();
 	}
 
 	/*