Add Nullable annotation to parameter of overridden equals method.

Closes: #2196
Original pull request: #2197

spring-data-rest-core/src/main/java/org/springframework/data/rest/core/Path.java

@@ -17,6 +17,7 @@
 
 import java.util.regex.Pattern;
 
+import org.springframework.lang.Nullable;
 import org.springframework.util.StringUtils;
 
 /**
@@ -103,7 +104,7 @@ public String toString() {
 	}
 
 	@Override
-	public boolean equals(Object obj) {
+	public boolean equals(@Nullable Object obj) {
 
 		if (this == obj) {
 			return true;

spring-data-rest-core/src/main/java/org/springframework/data/rest/core/config/EntityLookupConfiguration.java

@@ -29,6 +29,7 @@
 import org.springframework.data.rest.core.support.EntityLookup;
 import org.springframework.data.util.MethodInvocationRecorder;
 import org.springframework.data.util.StreamUtils;
+import org.springframework.lang.Nullable;
 import org.springframework.util.Assert;
 
 /**
@@ -238,7 +239,7 @@ public Lookup<R, ID> getLookup() {
 		}
 
 		@Override
-		public boolean equals(final java.lang.Object o) {
+		public boolean equals(@Nullable final java.lang.Object o) {
 
 			if (o == this) {
 				return true;

spring-data-rest-core/src/main/java/org/springframework/data/rest/core/config/ProjectionDefinitionConfiguration.java

@@ -24,6 +24,7 @@
 import org.springframework.core.annotation.AnnotationUtils;
 import org.springframework.data.rest.core.projection.ProjectionDefinitions;
 import org.springframework.data.util.ProxyUtils;
+import org.springframework.lang.Nullable;
 import org.springframework.util.Assert;
 import org.springframework.util.StringUtils;
 
@@ -225,7 +226,7 @@ public String getName() {
 		}
 
 		@Override
-		public boolean equals(Object o) {
+		public boolean equals(@Nullable Object o) {
 
 			if (o == this) {
 				return true;

spring-data-rest-core/src/main/java/org/springframework/data/rest/core/event/AnnotatedEventHandlerInvoker.java

@@ -33,6 +33,7 @@
 import org.springframework.core.annotation.AnnotationUtils;
 import org.springframework.data.rest.core.annotation.*;
 import org.springframework.data.util.ProxyUtils;
+import org.springframework.lang.Nullable;
 import org.springframework.util.Assert;
 import org.springframework.util.ClassUtils;
 import org.springframework.util.LinkedMultiValueMap;
@@ -191,7 +192,7 @@ public int compareTo(EventHandlerMethod o) {
 		}
 
 		@Override
-		public boolean equals(final java.lang.Object o) {
+		public boolean equals(@Nullable final java.lang.Object o) {
 
 			if (o == this) {
 				return true;

spring-data-rest-core/src/main/java/org/springframework/data/rest/core/mapping/ParameterMetadata.java

@@ -18,6 +18,7 @@
 import org.springframework.core.MethodParameter;
 import org.springframework.data.rest.core.annotation.Description;
 import org.springframework.hateoas.LinkRelation;
+import org.springframework.lang.Nullable;
 import org.springframework.util.Assert;
 
 /**
@@ -71,7 +72,7 @@ public ResourceDescription getDescription() {
 	}
 
 	@Override
-	public boolean equals(Object obj) {
+	public boolean equals(@Nullable Object obj) {
 
 		if (this == obj) {
 			return true;

spring-data-rest-webmvc/src/main/java/org/springframework/data/rest/webmvc/config/DelegatingHandlerMapping.java

@@ -173,7 +173,7 @@ public HandlerSelectionResult(HttpServletRequest request, HandlerMapping mapping
 		}
 
 		@Override
-		public boolean equals(final java.lang.Object o) {
+		public boolean equals(@Nullable final java.lang.Object o) {
 
 			if (o == this) {
 				return true;

spring-data-rest-webmvc/src/main/java/org/springframework/data/rest/webmvc/json/patch/SpelPath.java

@@ -93,7 +93,7 @@ public String toString() {
 	}
 
 	@Override
-	public boolean equals(Object obj) {
+	public boolean equals(@Nullable Object obj) {
 
 		if (this == obj) {
 			return true;
@@ -173,7 +173,7 @@ public static CacheKey of(Class<?> type, UntypedSpelPath path, BindContext conte
 			}
 
 			@Override
-			public boolean equals(Object o) {
+			public boolean equals(@Nullable Object o) {
 
 				if (o == this) {
 					return true;
@@ -529,7 +529,7 @@ public SkippedPropertyPath nested(String segment) {
 			}
 
 			@Override
-			public boolean equals(Object o) {
+			public boolean equals(@Nullable Object o) {
 
 				if (o == this) {
 					return true;
@@ -691,7 +691,7 @@ public SpelExpressionBuilder next(String segment) {
 			}
 
 			@Override
-			public boolean equals(Object o) {
+			public boolean equals(@Nullable Object o) {
 
 				if (o == this) {
 					return true;
@@ -721,7 +721,7 @@ public java.lang.String toString() {
 		}
 
 		@Override
-		public boolean equals(final java.lang.Object o) {
+		public boolean equals(@Nullable final java.lang.Object o) {
 
 			if (o == this) {
 				return true;

spring-data-rest-webmvc/src/main/java/org/springframework/data/rest/webmvc/support/DefaultedPageable.java

@@ -18,6 +18,7 @@
 import java.util.Objects;
 
 import org.springframework.data.domain.Pageable;
+import org.springframework.lang.Nullable;
 import org.springframework.util.Assert;
 
 /**
@@ -67,7 +68,7 @@ public Pageable unpagedIfDefault() {
 	}
 
 	@Override
-	public boolean equals(Object o) {
+	public boolean equals(@Nullable Object o) {
 
 		if (o == this) {
 			return true;

spring-data-rest-webmvc/src/main/java/org/springframework/data/rest/webmvc/support/ETag.java

@@ -25,6 +25,7 @@
 import org.springframework.data.mapping.PersistentPropertyAccessor;
 import org.springframework.data.rest.webmvc.PersistentEntityResource;
 import org.springframework.http.HttpHeaders;
+import org.springframework.lang.Nullable;
 import org.springframework.util.Assert;
 
 /**
@@ -170,7 +171,7 @@ private static Optional<String> getVersionInformation(PersistentEntity<?, ? exte
 	}
 
 	@Override
-	public boolean equals(Object o) {
+	public boolean equals(@Nullable Object o) {
 
 		if (o == this) {
 			return true;

spring-data-rest-webmvc/src/main/java/org/springframework/data/rest/webmvc/support/RepositoryConstraintViolationExceptionMessage.java

@@ -100,7 +100,7 @@ public String getMessage() {
 		}
 
 		@Override
-		public boolean equals(Object o) {
+		public boolean equals(@Nullable Object o) {
 
 			if (o == this) {
 				return true;