Encapsulate choice of URI encoding within RequestPath

Currently the URI path is always treated as UTF-8 so we can eliminate
the encoding parameter from RequestPath#parse.

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

@@ -61,7 +61,7 @@ public abstract class AbstractServerHttpRequest implements ServerHttpRequest {
 	 */
 	public AbstractServerHttpRequest(URI uri, String contextPath, HttpHeaders headers) {
 		this.uri = uri;
-		this.path = new DefaultRequestPath(uri, contextPath, StandardCharsets.UTF_8);
+		this.path = RequestPath.parse(uri, contextPath);
 		this.headers = HttpHeaders.readOnlyHttpHeaders(headers);
 	}
 

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

@@ -17,7 +17,6 @@
 package org.springframework.http.server.reactive;
 
 import java.net.URI;
-import java.nio.charset.Charset;
 import java.nio.charset.StandardCharsets;
 import java.util.List;
 
@@ -40,8 +39,8 @@ class DefaultRequestPath implements RequestPath {
 	private final PathContainer pathWithinApplication;
 
 
-	DefaultRequestPath(URI uri, @Nullable String contextPath, Charset charset) {
-		this.fullPath = PathContainer.parse(uri.getRawPath(), charset);
+	DefaultRequestPath(URI uri, @Nullable String contextPath) {
+		this.fullPath = PathContainer.parse(uri.getRawPath(), StandardCharsets.UTF_8);
 		this.contextPath = initContextPath(this.fullPath, contextPath);
 		this.pathWithinApplication = extractPathWithinApplication(this.fullPath, this.contextPath);
 	}
@@ -86,7 +85,6 @@ class DefaultRequestPath implements RequestPath {
 
 	// PathContainer methods..
 
-
 	@Override
 	public String value() {
 		return this.fullPath.value();

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

@@ -18,7 +18,6 @@ package org.springframework.http.server.reactive;
 
 import java.net.URI;
 import java.net.URISyntaxException;
-import java.nio.charset.StandardCharsets;
 
 import org.springframework.http.HttpHeaders;
 import org.springframework.http.HttpMethod;
@@ -107,14 +106,14 @@ class DefaultServerHttpRequestBuilder implements ServerHttpRequest.Builder {
 
 	@Nullable
 	private RequestPath getRequestPathToUse(@Nullable URI uriToUse) {
-		if (uriToUse == null) {
-			if (this.contextPath == null) {
-				return null;
-			}
+		if (uriToUse == null && this.contextPath == null) {
+			return null;
+		}
+		else if (uriToUse == null) {
 			return new DefaultRequestPath(this.delegate.getPath(), this.contextPath);
 		}
 		else {
-			return new DefaultRequestPath(uriToUse, this.contextPath, StandardCharsets.UTF_8);
+			return RequestPath.parse(uriToUse, this.contextPath);
 		}
 	}
 

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

@@ -16,7 +16,8 @@
 package org.springframework.http.server.reactive;
 
 import java.net.URI;
-import java.nio.charset.Charset;
+
+import org.springframework.lang.Nullable;
 
 /**
  * Represents the complete path for a request.
@@ -41,11 +42,12 @@ public interface RequestPath extends PathContainer {
 	 */
 	PathContainer pathWithinApplication();
 
+
 	/**
 	 * Create a new {@code RequestPath} with the given parameters.
 	 */
-	static RequestPath create(URI uri, String contextPath, Charset charset) {
-		return new DefaultRequestPath(uri, contextPath, charset);
+	static RequestPath parse(URI uri, @Nullable String contextPath) {
+		return new DefaultRequestPath(uri, contextPath);
 	}
 
 }

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

@@ -261,12 +261,11 @@ public class PathPattern implements Comparable<PathPattern> {
 	 * @return the subset of the path that is matched by pattern or "" if none of it is matched by pattern elements
 	 */
 	public PathContainer extractPathWithinPattern(PathContainer path) {
+		// TODO: implement extractPathWithinPattern for PathContainer
 		String result = extractPathWithinPattern(path.value());
 		return PathContainer.parse(result, StandardCharsets.UTF_8);
 	}
 
-	// TODO: implement extractPathWithinPattern natively for PathContainer
-
 	private String extractPathWithinPattern(String path) {
 		// assert this.matches(path)
 		PathElement elem = head;