Support fragments in UriComponentsBuilder.fromHttpUrl()

Prior to this commit, UriComponentsBuilder.fromHttpUrl() threw an
IllegalArgumentException if the provided URL contained a fragment.

This commit aligns the implementation of fromHttpUrl() with that of
fromUriString(), by parsing a fragment and storing it in the builder.

Closes spring-projectsgh-25300

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

@@ -59,6 +59,7 @@
  * @author Oliver Gierke
  * @author Brian Clozel
  * @author Sebastien Deleuze
+ * @author Sam Brannen
  * @since 3.1
  * @see #newInstance()
  * @see #fromPath(String)
@@ -95,7 +96,7 @@ public class UriComponentsBuilder implements UriBuilder, Cloneable {
 
 	private static final Pattern HTTP_URL_PATTERN = Pattern.compile(
 			"^" + HTTP_PATTERN + "(//(" + USERINFO_PATTERN + "@)?" + HOST_PATTERN + "(:" + PORT_PATTERN + ")?" + ")?" +
-					PATH_PATTERN + "(\\?" + LAST_PATTERN + ")?");
+					PATH_PATTERN + "(\\?" + QUERY_PATTERN + ")?" + "(#" + LAST_PATTERN + ")?");
 
 	private static final Pattern FORWARDED_HOST_PATTERN = Pattern.compile("host=\"?([^;,\"]+)\"?");
 
@@ -288,6 +289,10 @@ public static UriComponentsBuilder fromHttpUrl(String httpUrl) {
 			}
 			builder.path(matcher.group(8));
 			builder.query(matcher.group(10));
+			String fragment = matcher.group(12);
+			if (StringUtils.hasText(fragment)) {
+				builder.fragment(fragment);
+			}
 			return builder;
 		}
 		else {

spring-web/src/test/java/org/springframework/web/util/UriComponentsBuilderTests.java

@@ -248,6 +248,84 @@ void fromHttpUrlInvalidIPv6Host() {
 				UriComponentsBuilder.fromHttpUrl("http://[1abc:2abc:3abc::5ABC:6abc:8080/resource"));
 	}
 
+	@Test
+	void fromHttpUrlWithoutFragment() {
+		String httpUrl = "http://localhost:8080/test/print";
+		UriComponents uriComponents = UriComponentsBuilder.fromHttpUrl(httpUrl).build();
+		assertThat(uriComponents.getScheme()).isEqualTo("http");
+		assertThat(uriComponents.getUserInfo()).isNull();
+		assertThat(uriComponents.getHost()).isEqualTo("localhost");
+		assertThat(uriComponents.getPort()).isEqualTo(8080);
+		assertThat(uriComponents.getPath()).isEqualTo("/test/print");
+		assertThat(uriComponents.getPathSegments()).isEqualTo(Arrays.asList("test", "print"));
+		assertThat(uriComponents.getQuery()).isNull();
+		assertThat(uriComponents.getFragment()).isNull();
+		assertThat(uriComponents.toUri().toString()).isEqualTo(httpUrl);
+
+		httpUrl = "http://user:test@localhost:8080/test/print?foo=bar";
+		uriComponents = UriComponentsBuilder.fromHttpUrl(httpUrl).build();
+		assertThat(uriComponents.getScheme()).isEqualTo("http");
+		assertThat(uriComponents.getUserInfo()).isEqualTo("user:test");
+		assertThat(uriComponents.getHost()).isEqualTo("localhost");
+		assertThat(uriComponents.getPort()).isEqualTo(8080);
+		assertThat(uriComponents.getPath()).isEqualTo("/test/print");
+		assertThat(uriComponents.getPathSegments()).isEqualTo(Arrays.asList("test", "print"));
+		assertThat(uriComponents.getQuery()).isEqualTo("foo=bar");
+		assertThat(uriComponents.getFragment()).isNull();
+		assertThat(uriComponents.toUri().toString()).isEqualTo(httpUrl);
+
+		httpUrl = "http://localhost:8080/test/print?foo=bar";
+		uriComponents = UriComponentsBuilder.fromHttpUrl(httpUrl).build();
+		assertThat(uriComponents.getScheme()).isEqualTo("http");
+		assertThat(uriComponents.getUserInfo()).isNull();
+		assertThat(uriComponents.getHost()).isEqualTo("localhost");
+		assertThat(uriComponents.getPort()).isEqualTo(8080);
+		assertThat(uriComponents.getPath()).isEqualTo("/test/print");
+		assertThat(uriComponents.getPathSegments()).isEqualTo(Arrays.asList("test", "print"));
+		assertThat(uriComponents.getQuery()).isEqualTo("foo=bar");
+		assertThat(uriComponents.getFragment()).isNull();
+		assertThat(uriComponents.toUri().toString()).isEqualTo(httpUrl);
+	}
+
+	@Test  // gh-25300
+	void fromHttpUrlWithFragment() {
+		String httpUrl = "https://example.com#baz";
+		UriComponents uriComponents = UriComponentsBuilder.fromHttpUrl(httpUrl).build();
+		assertThat(uriComponents.getScheme()).isEqualTo("https");
+		assertThat(uriComponents.getUserInfo()).isNull();
+		assertThat(uriComponents.getHost()).isEqualTo("example.com");
+		assertThat(uriComponents.getPort()).isEqualTo(-1);
+		assertThat(uriComponents.getPath()).isNullOrEmpty();
+		assertThat(uriComponents.getPathSegments()).isEmpty();
+		assertThat(uriComponents.getQuery()).isNull();
+		assertThat(uriComponents.getFragment()).isEqualTo("baz");
+		assertThat(uriComponents.toUri().toString()).isEqualTo(httpUrl);
+
+		httpUrl = "http://localhost:8080/test/print#baz";
+		uriComponents = UriComponentsBuilder.fromHttpUrl(httpUrl).build();
+		assertThat(uriComponents.getScheme()).isEqualTo("http");
+		assertThat(uriComponents.getUserInfo()).isNull();
+		assertThat(uriComponents.getHost()).isEqualTo("localhost");
+		assertThat(uriComponents.getPort()).isEqualTo(8080);
+		assertThat(uriComponents.getPath()).isEqualTo("/test/print");
+		assertThat(uriComponents.getPathSegments()).isEqualTo(Arrays.asList("test", "print"));
+		assertThat(uriComponents.getQuery()).isNull();
+		assertThat(uriComponents.getFragment()).isEqualTo("baz");
+		assertThat(uriComponents.toUri().toString()).isEqualTo(httpUrl);
+
+		httpUrl = "http://localhost:8080/test/print?foo=bar#baz";
+		uriComponents = UriComponentsBuilder.fromHttpUrl(httpUrl).build();
+		assertThat(uriComponents.getScheme()).isEqualTo("http");
+		assertThat(uriComponents.getUserInfo()).isNull();
+		assertThat(uriComponents.getHost()).isEqualTo("localhost");
+		assertThat(uriComponents.getPort()).isEqualTo(8080);
+		assertThat(uriComponents.getPath()).isEqualTo("/test/print");
+		assertThat(uriComponents.getPathSegments()).isEqualTo(Arrays.asList("test", "print"));
+		assertThat(uriComponents.getQuery()).isEqualTo("foo=bar");
+		assertThat(uriComponents.getFragment()).isEqualTo("baz");
+		assertThat(uriComponents.toUri().toString()).isEqualTo(httpUrl);
+	}
+
 	@Test
 	void fromHttpRequest() {
 		MockHttpServletRequest request = new MockHttpServletRequest();