From static to instance-based PathContainer#subPath

spring-web/src/main/java/org/springframework/http/server/reactive/DefaultRequestPath.java

@@ -69,7 +69,7 @@ class DefaultRequestPath implements RequestPath {
 				counter += ((Segment) element).semicolonContent().length();
 			}
 			if (length == counter) {
-				return DefaultPathContainer.subPath(path, 0, i + 1);
+				return path.subPath(0, i + 1);
 			}
 		}
 
@@ -79,7 +79,7 @@ class DefaultRequestPath implements RequestPath {
 	}
 
 	private static PathContainer extractPathWithinApplication(PathContainer fullPath, PathContainer contextPath) {
-		return PathContainer.subPath(fullPath, contextPath.elements().size());
+		return fullPath.subPath(contextPath.elements().size());
 	}
 
 

spring-web/src/main/java/org/springframework/http/server/reactive/PathContainer.java

@@ -22,16 +22,21 @@ import java.util.List;
 import org.springframework.util.MultiValueMap;
 
 /**
- * Structured path representation.
+ * Structured representation of a path whose {@link Element Elements} are
+ * accessible as a sequence of either {@link Separator Separator} and/or
+ * {@link Segment Segment} (element) types.
  *
- * <p>Typically consumed via {@link ServerHttpRequest#getPath()} but can also
- * be created by parsing a path value via {@link #parse(String, Charset)}.
+ * <p>Each {@code Segment} exposes its own structure decoded safely without the
+ * risk of encoded reserved characters altering the path or segment structure.
+ *
+ * <p>An instance of this class can also be created via
+ * {@link #parse(String, Charset)}. The path for an HTTP request is parsed once
+ * and subsequently accessible via {@link ServerHttpRequest#getPath()}.
  *
  * @author Rossen Stoyanchev
  */
 public interface PathContainer {
 
-
 	/**
 	 * The original, raw (encoded) path value including path parameters.
 	 */
@@ -42,6 +47,26 @@ public interface PathContainer {
 	 */
 	List<Element> elements();
 
+	/**
+	 * Extract a sub-path from the given offset into the elements list.
+	 * @param index the start element index (inclusive)
+	 * @return the sub-path
+	 */
+	default PathContainer subPath(int index) {
+		return subPath(index, elements().size());
+	}
+
+	/**
+	 * Extract a sub-path from the given start offset (inclusive) into the
+	 * element list and to the end offset (exclusive).
+	 * @param startIndex the start element index (inclusive)
+	 * @param endIndex the end element index (exclusive)
+	 * @return the sub-path
+	 */
+	default PathContainer subPath(int startIndex, int endIndex) {
+		return DefaultPathContainer.subPath(this, startIndex, endIndex);
+	}
+
 
 	/**
 	 * Parse the given path value into a {@link PathContainer}.
@@ -53,29 +78,10 @@ public interface PathContainer {
 		return DefaultPathContainer.parsePath(path, encoding);
 	}
 
-	/**
-	 * Extract a sub-path from the given offset into the path elements list.
-	 * @param path the path to extract from
-	 * @param index the start element index (inclusive)
-	 * @return the sub-path
-	 */
-	static PathContainer subPath(PathContainer path, int index) {
-		return subPath(path, index, path.elements().size());
-	}
 
 	/**
-	 * Extract a sub-path from the given start offset (inclusive) into the path
-	 * element list and to the end offset (exclusive).
-	 * @param path the path to extract from
-	 * @param startIndex the start element index (inclusive)
-	 * @param endIndex the end element index (exclusive)
-	 * @return the sub-path
+	 * Common representation of a path element, e.g. separator or segment.
 	 */
-	static PathContainer subPath(PathContainer path, int startIndex, int endIndex) {
-		return DefaultPathContainer.subPath(path, startIndex, endIndex);
-	}
-
-
 	interface Element {
 
 		/**
@@ -86,14 +92,14 @@ public interface PathContainer {
 
 
 	/**
-	 * A path separator element.
+	 * Path separator element.
 	 */
 	interface Separator extends Element {
 	}
 
 
 	/**
-	 * A path segment element.
+	 * Path segment element.
 	 */
 	interface Segment extends Element {
 

spring-web/src/main/java/org/springframework/web/util/pattern/PathPattern.java

@@ -205,7 +205,7 @@ public class PathPattern implements Comparable<PathPattern> {
 				info = new PathRemainingMatchInfo(EMPTY_PATH, matchingContext.getPathMatchResult());
 			}
 			else {
-				info = new PathRemainingMatchInfo(PathContainer.subPath(pathContainer, matchingContext.remainingPathIndex),
+				info = new PathRemainingMatchInfo(pathContainer.subPath(matchingContext.remainingPathIndex),
 						 matchingContext.getPathMatchResult());
 			}
 			return info;

spring-web/src/test/java/org/springframework/http/server/reactive/DefaultPathContainerTests.java

@@ -127,17 +127,17 @@ public class DefaultPathContainerTests {
 	public void subPath() throws Exception {
 		// basic
 		PathContainer path = PathContainer.parse("/a/b/c", UTF_8);
-		assertSame(path, PathContainer.subPath(path, 0));
-		assertEquals("/b/c", PathContainer.subPath(path, 2).value());
-		assertEquals("/c", PathContainer.subPath(path, 4).value());
+		assertSame(path, path.subPath(0));
+		assertEquals("/b/c", path.subPath(2).value());
+		assertEquals("/c", path.subPath(4).value());
 
 		// root path
 		path = PathContainer.parse("/", UTF_8);
-		assertEquals("/", PathContainer.subPath(path, 0).value());
+		assertEquals("/", path.subPath(0).value());
 
 		// trailing slash
 		path = PathContainer.parse("/a/b/", UTF_8);
-		assertEquals("/b/", PathContainer.subPath(path, 2).value());
+		assertEquals("/b/", path.subPath(2).value());
 	}
 
 }

spring-webflux/src/main/java/org/springframework/web/reactive/resource/ResourceUrlProvider.java

@@ -215,7 +215,7 @@ public class ResourceUrlProvider implements ApplicationListener<ContextRefreshed
 				.map(entry -> {
 					PathContainer path = entry.getKey().extractPathWithinPattern(lookupPath);
 					int endIndex = lookupPath.elements().size() - path.elements().size();
-					PathContainer mapping = PathContainer.subPath(lookupPath, 0, endIndex);
+					PathContainer mapping = lookupPath.subPath(0, endIndex);
 					if (logger.isTraceEnabled()) {
 						logger.trace("Invoking ResourceResolverChain for URL pattern " +
 								"\"" + entry.getKey() + "\"");