Complete nullability annotations in remaining equals methods

In this commit, we'll finally add nullability annotations to the equals
method for consistency with other projects. We've already done this, but
we recently added jspecify support to new modules.

Signed-off-by: Andrey Litvitski <andrey1010102008@gmail.com>

Author: therepanic

oauth2/oauth2-authorization-server/src/main/java/org/springframework/security/oauth2/server/authorization/OAuth2Authorization.java

@@ -196,7 +196,7 @@ public Map<String, Object> getAttributes() {
 	}
 
 	@Override
-	public boolean equals(Object obj) {
+	public boolean equals(@Nullable Object obj) {
 		if (this == obj) {
 			return true;
 		}
@@ -363,7 +363,7 @@ protected static Map<String, Object> defaultMetadata() {
 		}
 
 		@Override
-		public boolean equals(Object obj) {
+		public boolean equals(@Nullable Object obj) {
 			if (this == obj) {
 				return true;
 			}

oauth2/oauth2-authorization-server/src/main/java/org/springframework/security/oauth2/server/authorization/OAuth2AuthorizationConsent.java

@@ -24,6 +24,8 @@
 import java.util.Set;
 import java.util.function.Consumer;
 
+import org.jspecify.annotations.Nullable;
+
 import org.springframework.security.core.GrantedAuthority;
 import org.springframework.security.core.authority.SimpleGrantedAuthority;
 import org.springframework.security.oauth2.server.authorization.client.RegisteredClient;
@@ -107,7 +109,7 @@ public Set<String> getScopes() {
 	}
 
 	@Override
-	public boolean equals(Object obj) {
+	public boolean equals(@Nullable Object obj) {
 		if (this == obj) {
 			return true;
 		}

oauth2/oauth2-authorization-server/src/main/java/org/springframework/security/oauth2/server/authorization/OAuth2TokenType.java

@@ -19,6 +19,8 @@
 import java.io.Serial;
 import java.io.Serializable;
 
+import org.jspecify.annotations.Nullable;
+
 import org.springframework.util.Assert;
 
 /**
@@ -64,7 +66,7 @@ public String getValue() {
 	}
 
 	@Override
-	public boolean equals(Object obj) {
+	public boolean equals(@Nullable Object obj) {
 		if (this == obj) {
 			return true;
 		}

oauth2/oauth2-authorization-server/src/main/java/org/springframework/security/oauth2/server/authorization/authentication/OAuth2TokenExchangeActor.java

@@ -22,6 +22,8 @@
 import java.util.Map;
 import java.util.Objects;
 
+import org.jspecify.annotations.Nullable;
+
 import org.springframework.security.oauth2.core.ClaimAccessor;
 import org.springframework.security.oauth2.server.authorization.token.OAuth2TokenClaimNames;
 import org.springframework.util.Assert;
@@ -65,7 +67,7 @@ public String getSubject() {
 	}
 
 	@Override
-	public boolean equals(Object obj) {
+	public boolean equals(@Nullable Object obj) {
 		if (!(obj instanceof OAuth2TokenExchangeActor other)) {
 			return false;
 		}

oauth2/oauth2-authorization-server/src/main/java/org/springframework/security/oauth2/server/authorization/client/RegisteredClient.java

@@ -203,7 +203,7 @@ public TokenSettings getTokenSettings() {
 	}
 
 	@Override
-	public boolean equals(Object obj) {
+	public boolean equals(@Nullable Object obj) {
 		if (this == obj) {
 			return true;
 		}

oauth2/oauth2-authorization-server/src/main/java/org/springframework/security/oauth2/server/authorization/settings/AbstractSettings.java

@@ -67,7 +67,7 @@ public Map<String, Object> getSettings() {
 	}
 
 	@Override
-	public boolean equals(Object obj) {
+	public boolean equals(@Nullable Object obj) {
 		if (this == obj) {
 			return true;
 		}

oauth2/oauth2-authorization-server/src/main/java/org/springframework/security/oauth2/server/authorization/settings/OAuth2TokenFormat.java

@@ -19,6 +19,8 @@
 import java.io.Serial;
 import java.io.Serializable;
 
+import org.jspecify.annotations.Nullable;
+
 import org.springframework.util.Assert;
 
 /**
@@ -65,7 +67,7 @@ public String getValue() {
 	}
 
 	@Override
-	public boolean equals(Object obj) {
+	public boolean equals(@Nullable Object obj) {
 		if (this == obj) {
 			return true;
 		}

webauthn/src/main/java/org/springframework/security/web/webauthn/api/ImmutablePublicKeyCredentialUserEntity.java

@@ -137,7 +137,7 @@ public static PublicKeyCredentialUserEntityBuilder builder() {
 	}
 
 	@Override
-	public boolean equals(Object obj) {
+	public boolean equals(@Nullable Object obj) {
 		if (this == obj) {
 			return true;
 		}