Refine UriComponentsBuilder parsing

This commit refines the expressions for the scheme, user info, host and
port parts of the URL in UriComponentsBuilder to better conform to
RFC 3986.

Fixes gh-32616

spring-web/src/main/java/org/springframework/web/util/UriComponentsBuilder.java

@@ -72,19 +72,19 @@ public class UriComponentsBuilder implements UriBuilder, Cloneable {
 
 	private static final Pattern QUERY_PARAM_PATTERN = Pattern.compile("([^&=]+)(=?)([^&]+)?");
 
-	private static final String SCHEME_PATTERN = "([^:/?#]+):";
+	private static final String SCHEME_PATTERN = "([^:/?#\\\\]+):";
 
 	private static final String HTTP_PATTERN = "(?i)(http|https):";
 
-	private static final String USERINFO_PATTERN = "([^/?#]*)";
+	private static final String USERINFO_PATTERN = "([^/?#\\\\]*)";
 
-	private static final String HOST_IPV4_PATTERN = "[^/?#:]*";
+	private static final String HOST_IPV4_PATTERN = "[^/?#:\\\\]*";
 
 	private static final String HOST_IPV6_PATTERN = "\\[[\\p{XDigit}:.]*[%\\p{Alnum}]*]";
 
 	private static final String HOST_PATTERN = "(" + HOST_IPV6_PATTERN + "|" + HOST_IPV4_PATTERN + ")";
 
-	private static final String PORT_PATTERN = "(\\{[^}]+\\}?|[^/?#]*)";
+	private static final String PORT_PATTERN = "(\\{[^}]+\\}?|[^/?#\\\\]*)";
 
 	private static final String PATH_PATTERN = "([^?#]*)";