Make classes final where possible

Update classes that have private constructors so that they are also
declared final. In a few cases, inner-classes used private constructors
but were subclassed. These have now been changed to have package-private
constructors.

Issue gh-8945

web/src/main/java/org/springframework/security/web/FilterChainProxy.java

@@ -294,7 +294,7 @@ public class FilterChainProxy extends GenericFilterBean {
 	 * Internal {@code FilterChain} implementation that is used to pass a request through
 	 * the additional internal list of filters which match the request.
 	 */
-	private static class VirtualFilterChain implements FilterChain {
+	private static final class VirtualFilterChain implements FilterChain {
 
 		private final FilterChain originalChain;
 

web/src/main/java/org/springframework/security/web/server/authorization/DelegatingReactiveAuthorizationManager.java

@@ -35,7 +35,7 @@ import org.springframework.web.server.ServerWebExchange;
  * @author Mathieu Ouellet
  * @since 5.0
  */
-public class DelegatingReactiveAuthorizationManager implements ReactiveAuthorizationManager<ServerWebExchange> {
+public final class DelegatingReactiveAuthorizationManager implements ReactiveAuthorizationManager<ServerWebExchange> {
 
 	private static final Log logger = LogFactory.getLog(DelegatingReactiveAuthorizationManager.class);
 
@@ -63,7 +63,7 @@ public class DelegatingReactiveAuthorizationManager implements ReactiveAuthoriza
 		return new DelegatingReactiveAuthorizationManager.Builder();
 	}
 
-	public static class Builder {
+	public static final class Builder {
 
 		private final List<ServerWebExchangeMatcherEntry<ReactiveAuthorizationManager<AuthorizationContext>>> mappings = new ArrayList<>();
 

web/src/main/java/org/springframework/security/web/server/context/NoOpServerSecurityContextRepository.java

@@ -28,13 +28,15 @@ import org.springframework.web.server.ServerWebExchange;
  * @author Rob Winch
  * @since 5.0
  */
-public class NoOpServerSecurityContextRepository implements ServerSecurityContextRepository {
+public final class NoOpServerSecurityContextRepository implements ServerSecurityContextRepository {
 
 	private static final NoOpServerSecurityContextRepository INSTANCE = new NoOpServerSecurityContextRepository();
 
+	private NoOpServerSecurityContextRepository() {
+	}
+
 	public Mono<Void> save(ServerWebExchange exchange, SecurityContext context) {
 		return Mono.empty();
-
 	}
 
 	public Mono<SecurityContext> load(ServerWebExchange exchange) {
@@ -45,7 +47,4 @@ public class NoOpServerSecurityContextRepository implements ServerSecurityContex
 		return INSTANCE;
 	}
 
-	private NoOpServerSecurityContextRepository() {
-	}
-
 }

web/src/main/java/org/springframework/security/web/server/savedrequest/NoOpServerRequestCache.java

@@ -30,7 +30,10 @@ import org.springframework.web.server.ServerWebExchange;
  * @author Rob Winch
  * @since 5.0
  */
-public class NoOpServerRequestCache implements ServerRequestCache {
+public final class NoOpServerRequestCache implements ServerRequestCache {
+
+	private NoOpServerRequestCache() {
+	}
 
 	@Override
 	public Mono<Void> saveRequest(ServerWebExchange exchange) {
@@ -51,7 +54,4 @@ public class NoOpServerRequestCache implements ServerRequestCache {
 		return new NoOpServerRequestCache();
 	}
 
-	private NoOpServerRequestCache() {
-	}
-
 }

web/src/main/java/org/springframework/security/web/util/matcher/AntPathRequestMatcher.java

@@ -263,7 +263,7 @@ public final class AntPathRequestMatcher implements RequestMatcher, RequestVaria
 
 	}
 
-	private static class SpringAntMatcher implements Matcher {
+	private static final class SpringAntMatcher implements Matcher {
 
 		private final AntPathMatcher antMatcher;
 
@@ -296,7 +296,7 @@ public final class AntPathRequestMatcher implements RequestMatcher, RequestVaria
 	/**
 	 * Optimized matcher for trailing wildcards
 	 */
-	private static class SubpathMatcher implements Matcher {
+	private static final class SubpathMatcher implements Matcher {
 
 		private final String subpath;