diff --git a/config/src/main/java/org/springframework/security/config/annotation/web/builders/FilterOrderRegistration.java b/config/src/main/java/org/springframework/security/config/annotation/web/builders/FilterOrderRegistration.java
index cddb6ce5e4b..09d9766f111 100644
--- a/config/src/main/java/org/springframework/security/config/annotation/web/builders/FilterOrderRegistration.java
+++ b/config/src/main/java/org/springframework/security/config/annotation/web/builders/FilterOrderRegistration.java
@@ -127,11 +127,7 @@ final class FilterOrderRegistration {
 	 * @param position the position to associate with the {@link Filter}
 	 */
 	void put(Class<? extends Filter> filter, int position) {
-		String className = filter.getName();
-		if (this.filterToOrder.containsKey(className)) {
-			return;
-		}
-		this.filterToOrder.put(className, position);
+		this.filterToOrder.putIfAbsent(filter.getName(), position);
 	}
 
 	/**
diff --git a/core/src/main/java/org/springframework/security/authentication/AbstractAuthenticationToken.java b/core/src/main/java/org/springframework/security/authentication/AbstractAuthenticationToken.java
index 78cec888126..cfd066a912a 100644
--- a/core/src/main/java/org/springframework/security/authentication/AbstractAuthenticationToken.java
+++ b/core/src/main/java/org/springframework/security/authentication/AbstractAuthenticationToken.java
@@ -68,14 +68,14 @@ public Collection<GrantedAuthority> getAuthorities() {
 
 	@Override
 	public String getName() {
-		if (this.getPrincipal() instanceof UserDetails) {
-			return ((UserDetails) this.getPrincipal()).getUsername();
+		if (this.getPrincipal() instanceof UserDetails userDetails) {
+			return userDetails.getUsername();
 		}
-		if (this.getPrincipal() instanceof AuthenticatedPrincipal) {
-			return ((AuthenticatedPrincipal) this.getPrincipal()).getName();
+		if (this.getPrincipal() instanceof AuthenticatedPrincipal authenticatedPrincipal) {
+			return authenticatedPrincipal.getName();
 		}
-		if (this.getPrincipal() instanceof Principal) {
-			return ((Principal) this.getPrincipal()).getName();
+		if (this.getPrincipal() instanceof Principal principal) {
+			return principal.getName();
 		}
 		return (this.getPrincipal() == null) ? "" : this.getPrincipal().toString();
 	}
@@ -119,10 +119,9 @@ private void eraseSecret(Object secret) {
 
 	@Override
 	public boolean equals(Object obj) {
-		if (!(obj instanceof AbstractAuthenticationToken)) {
+		if (!(obj instanceof AbstractAuthenticationToken test)) {
 			return false;
 		}
-		AbstractAuthenticationToken test = (AbstractAuthenticationToken) obj;
 		if (!this.authorities.equals(test.authorities)) {
 			return false;
 		}
diff --git a/core/src/main/java/org/springframework/security/authentication/AnonymousAuthenticationToken.java b/core/src/main/java/org/springframework/security/authentication/AnonymousAuthenticationToken.java
index 2e92d105f74..2e2a47b7e44 100644
--- a/core/src/main/java/org/springframework/security/authentication/AnonymousAuthenticationToken.java
+++ b/core/src/main/java/org/springframework/security/authentication/AnonymousAuthenticationToken.java
@@ -74,8 +74,7 @@ public boolean equals(Object obj) {
 		if (!super.equals(obj)) {
 			return false;
 		}
-		if (obj instanceof AnonymousAuthenticationToken) {
-			AnonymousAuthenticationToken test = (AnonymousAuthenticationToken) obj;
+		if (obj instanceof AnonymousAuthenticationToken test) {
 			return (this.getKeyHash() == test.getKeyHash());
 		}
 		return false;
diff --git a/core/src/main/java/org/springframework/security/authentication/jaas/JaasGrantedAuthority.java b/core/src/main/java/org/springframework/security/authentication/jaas/JaasGrantedAuthority.java
index d0d76b89d1f..8096947840e 100644
--- a/core/src/main/java/org/springframework/security/authentication/jaas/JaasGrantedAuthority.java
+++ b/core/src/main/java/org/springframework/security/authentication/jaas/JaasGrantedAuthority.java
@@ -58,9 +58,8 @@ public boolean equals(Object obj) {
 		if (this == obj) {
 			return true;
 		}
-		if (obj instanceof JaasGrantedAuthority) {
-			JaasGrantedAuthority jga = (JaasGrantedAuthority) obj;
-			return this.role.equals(jga.role) && this.principal.equals(jga.principal);
+		if (obj instanceof JaasGrantedAuthority jga) {
+			return this.role.equals(jga.getAuthority()) && this.principal.equals(jga.getPrincipal());
 		}
 		return false;
 	}
diff --git a/core/src/main/java/org/springframework/security/core/authority/SimpleGrantedAuthority.java b/core/src/main/java/org/springframework/security/core/authority/SimpleGrantedAuthority.java
index 71719d48010..54b889e6177 100644
--- a/core/src/main/java/org/springframework/security/core/authority/SimpleGrantedAuthority.java
+++ b/core/src/main/java/org/springframework/security/core/authority/SimpleGrantedAuthority.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2016 the original author or authors.
+ * Copyright 2002-2023 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -50,8 +50,8 @@ public boolean equals(Object obj) {
 		if (this == obj) {
 			return true;
 		}
-		if (obj instanceof SimpleGrantedAuthority) {
-			return this.role.equals(((SimpleGrantedAuthority) obj).role);
+		if (obj instanceof SimpleGrantedAuthority sga) {
+			return this.role.equals(sga.getAuthority());
 		}
 		return false;
 	}
diff --git a/core/src/main/java/org/springframework/security/core/userdetails/User.java b/core/src/main/java/org/springframework/security/core/userdetails/User.java
index 141f65dde81..2c518fd7d8e 100644
--- a/core/src/main/java/org/springframework/security/core/userdetails/User.java
+++ b/core/src/main/java/org/springframework/security/core/userdetails/User.java
@@ -179,8 +179,8 @@ private static SortedSet<GrantedAuthority> sortAuthorities(Collection<? extends
 	 */
 	@Override
 	public boolean equals(Object obj) {
-		if (obj instanceof User) {
-			return this.username.equals(((User) obj).username);
+		if (obj instanceof User user) {
+			return this.username.equals(user.getUsername());
 		}
 		return false;
 	}
@@ -208,7 +208,7 @@ public String toString() {
 	}
 
 	/**
-	 * Creates a UserBuilder with a specified user name
+	 * Creates a UserBuilder with a specified username
 	 * @param username the username to use
 	 * @return the UserBuilder
 	 */
diff --git a/ldap/src/main/java/org/springframework/security/ldap/userdetails/LdapAuthority.java b/ldap/src/main/java/org/springframework/security/ldap/userdetails/LdapAuthority.java
index 9e89a5d6313..e08678b2a45 100644
--- a/ldap/src/main/java/org/springframework/security/ldap/userdetails/LdapAuthority.java
+++ b/ldap/src/main/java/org/springframework/security/ldap/userdetails/LdapAuthority.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2014 the original author or authors.
+ * Copyright 2002-2023 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -113,14 +113,13 @@ public boolean equals(Object obj) {
 		if (this == obj) {
 			return true;
 		}
-		if (!(obj instanceof LdapAuthority)) {
+		if (!(obj instanceof LdapAuthority other)) {
 			return false;
 		}
-		LdapAuthority other = (LdapAuthority) obj;
-		if (!this.dn.equals(other.dn)) {
+		if (!this.dn.equals(other.getDn())) {
 			return false;
 		}
-		return this.role.equals(other.role);
+		return this.role.equals(other.getAuthority());
 	}
 
 	@Override
diff --git a/web/src/main/java/org/springframework/security/web/authentication/switchuser/SwitchUserGrantedAuthority.java b/web/src/main/java/org/springframework/security/web/authentication/switchuser/SwitchUserGrantedAuthority.java
index a05155e9e07..4be683e554f 100644
--- a/web/src/main/java/org/springframework/security/web/authentication/switchuser/SwitchUserGrantedAuthority.java
+++ b/web/src/main/java/org/springframework/security/web/authentication/switchuser/SwitchUserGrantedAuthority.java
@@ -64,9 +64,8 @@ public boolean equals(Object obj) {
 		if (this == obj) {
 			return true;
 		}
-		if (obj instanceof SwitchUserGrantedAuthority) {
-			SwitchUserGrantedAuthority swa = (SwitchUserGrantedAuthority) obj;
-			return this.role.equals(swa.role) && this.source.equals(swa.source);
+		if (obj instanceof SwitchUserGrantedAuthority swa) {
+			return this.role.equals(swa.getAuthority()) && this.source.equals(swa.getSource());
 		}
 		return false;
 	}
diff --git a/web/src/main/java/org/springframework/security/web/jaasapi/JaasApiIntegrationFilter.java b/web/src/main/java/org/springframework/security/web/jaasapi/JaasApiIntegrationFilter.java
index be8b52ebda2..a01ce81e950 100644
--- a/web/src/main/java/org/springframework/security/web/jaasapi/JaasApiIntegrationFilter.java
+++ b/web/src/main/java/org/springframework/security/web/jaasapi/JaasApiIntegrationFilter.java
@@ -127,10 +127,9 @@ protected Subject obtainSubject(ServletRequest request) {
 		if (!authentication.isAuthenticated()) {
 			return null;
 		}
-		if (!(authentication instanceof JaasAuthenticationToken)) {
+		if (!(authentication instanceof JaasAuthenticationToken token)) {
 			return null;
 		}
-		JaasAuthenticationToken token = (JaasAuthenticationToken) authentication;
 		LoginContext loginContext = token.getLoginContext();
 		if (loginContext == null) {
 			return null;