SEC-2955: Convert to "static" for inner classes

acl/src/main/java/org/springframework/security/acls/jdbc/BasicLookupStrategy.java

@@ -660,7 +660,7 @@ public class BasicLookupStrategy implements LookupStrategy {
 		}
 	}
 
-	private class StubAclParent implements Acl {
+	private static class StubAclParent implements Acl {
 		private final Long id;
 
 		public StubAclParent(Long id) {

config/src/main/java/org/springframework/security/config/annotation/web/messaging/MessageSecurityMetadataSourceRegistry.java

@@ -410,7 +410,7 @@ public class MessageSecurityMetadataSourceRegistry {
 		return "hasAnyAuthority('" + anyAuthorities + "')";
 	}
 
-	private class PreBuiltMatcherBuilder implements MatcherBuilder {
+	private static class PreBuiltMatcherBuilder implements MatcherBuilder {
 		private MessageMatcher<?> matcher;
 
 		private PreBuiltMatcherBuilder(MessageMatcher<?> matcher) {

config/src/main/java/org/springframework/security/config/annotation/web/socket/AbstractSecurityWebSocketMessageBrokerConfigurer.java

@@ -170,7 +170,7 @@ public abstract class AbstractSecurityWebSocketMessageBrokerConfigurer extends
 	protected void configureInbound(MessageSecurityMetadataSourceRegistry messages) {
 	}
 
-	private class WebSocketMessageSecurityMetadataSourceRegistry extends
+	private static class WebSocketMessageSecurityMetadataSourceRegistry extends
 			MessageSecurityMetadataSourceRegistry {
 		@Override
 		public MessageSecurityMetadataSource createMetadataSource() {

core/src/main/java/org/springframework/security/access/method/MapBasedMethodSecurityMetadataSource.java

@@ -279,7 +279,7 @@ public class MapBasedMethodSecurityMetadataSource extends
 	 * inherits but does not redeclare a method, the registered Class will be the Class
 	 * we're invoking against and the Method will provide details of the declared class.
 	 */
-	private class RegisteredMethod {
+	private static class RegisteredMethod {
 		private final Method method;
 		private final Class<?> registeredJavaType;
 

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

@@ -336,7 +336,7 @@ public class FilterChainProxy extends GenericFilterBean {
 		void validate(FilterChainProxy filterChainProxy);
 	}
 
-	private class NullFilterChainValidator implements FilterChainValidator {
+	private static class NullFilterChainValidator implements FilterChainValidator {
 		public void validate(FilterChainProxy filterChainProxy) {
 		}
 	}