Allow separator configuration in PathPatternParser

This commit allows to configure a custom path separator when parsing and
matching path patterns with `PathPatternParser`, but also when parsing
incoming paths as `PathContainer` instances.

Closes gh-23092

Author: bclozel

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

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2018 the original author or authors.
+ * Copyright 2002-2019 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -89,11 +89,13 @@ public String toString() {
 	}
 
 
-	static PathContainer createFromUrlPath(String path) {
+	static PathContainer createFromUrlPath(String path, String separator) {
 		if (path.equals("")) {
 			return EMPTY_PATH;
 		}
-		String separator = "/";
+		if (separator.length() == 0) {
+			throw new IllegalArgumentException("separator should not be empty");
+		}
 		Separator separatorElement = separator.equals(SEPARATOR.value()) ? SEPARATOR : () -> separator;
 		List<Element> elements = new ArrayList<>();
 		int begin;

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

@@ -65,14 +65,26 @@ default PathContainer subPath(int startIndex, int endIndex) {
 	}
 
 
+	/**
+	 * Parse the path value into a sequence of {@code "/"} {@link Separator Separator}
+	 * and {@link PathSegment PathSegment} elements.
+	 * @param path the encoded, raw path value to parse
+	 * @return the parsed path
+	 */
+	static PathContainer parsePath(String path) {
+		return DefaultPathContainer.createFromUrlPath(path, "/");
+	}
+
 	/**
 	 * Parse the path value into a sequence of {@link Separator Separator} and
 	 * {@link PathSegment PathSegment} elements.
-	 * @param path the encoded, raw URL path value to parse
+	 * @param path the encoded, raw path value to parse
+	 * @param separator the decoded separator for parsing patterns
 	 * @return the parsed path
+	 * @since 5.2
 	 */
-	static PathContainer parsePath(String path) {
-		return DefaultPathContainer.createFromUrlPath(path);
+	static PathContainer parsePath(String path, String separator) {
+		return DefaultPathContainer.createFromUrlPath(path, separator);
 	}
 
 

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

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2017 the original author or authors.
+ * Copyright 2002-2019 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -36,6 +36,8 @@ public class PathPatternParser {
 
 	private boolean caseSensitive = true;
 
+	private char separator = '/';
+
 
 	/**
 	 * Whether a {@link PathPattern} produced by this parser should should
@@ -75,14 +77,20 @@ public boolean isCaseSensitive() {
 	}
 
 	/**
-	 * Accessor used for the separator to use.
-	 * <p>Currently not exposed for configuration with URI path patterns and
-	 * mainly for use in InternalPathPatternParser and PathPattern. If required
-	 * in the future, a similar option would also need to be exposed in
-	 * {@link org.springframework.http.server.PathContainer PathContainer}.
+	 * Char that represents the separator to use in the patterns.
+	 * <p>The default is {@code '/'}.
+	 * @since 5.2
+	 */
+	public void setSeparator(char separator) {
+		this.separator = separator;
+	}
+
+	/**
+	 * Char that represents the separator to use in the patterns.
+	 * @since 5.2
 	 */
-	char getSeparator() {
-		return '/';
+	public char getSeparator() {
+		return this.separator;
 	}
 
 

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

@@ -27,6 +27,7 @@
 import org.springframework.util.MultiValueMap;
 
 import static org.assertj.core.api.Assertions.assertThat;
+import static org.assertj.core.api.Assertions.assertThatIllegalArgumentException;
 
 /**
  * Unit tests for {@link DefaultPathContainer}.
@@ -111,15 +112,18 @@ public void path() throws Exception {
 		testPath("//%20/%20", "//%20/%20", Arrays.asList("/", "/", "%20", "/", "%20"));
 	}
 
-	private void testPath(String input, String value, List<String> expectedElements) {
-
-		PathContainer path = PathContainer.parsePath(input);
+	private void testPath(String input, String separator, String value, List<String> expectedElements) {
+		PathContainer path = PathContainer.parsePath(input, separator);
 
 		assertThat(path.value()).as("value: '" + input + "'").isEqualTo(value);
 		assertThat(path.elements().stream()
 				.map(PathContainer.Element::value).collect(Collectors.toList())).as("elements: " + input).isEqualTo(expectedElements);
 	}
 
+	private void testPath(String input, String value, List<String> expectedElements) {
+		testPath(input, "/", value, expectedElements);
+	}
+
 	@Test
 	public void subPath() throws Exception {
 		// basic
@@ -137,4 +141,14 @@ public void subPath() throws Exception {
 		assertThat(path.subPath(2).value()).isEqualTo("/b/");
 	}
 
+	@Test
+	public void pathWithCustomSeparator() throws Exception {
+		testPath("a.b.c", ".", "a.b.c", Arrays.asList("a", ".", "b", ".", "c"));
+	}
+
+	@Test
+	public void emptySeparator() {
+		assertThatIllegalArgumentException().isThrownBy(() -> PathContainer.parsePath("path", ""));
+	}
+
 }

spring-web/src/test/java/org/springframework/web/util/pattern/PathPatternParserTests.java

@@ -408,6 +408,15 @@ public void compareTests() {
 		assertThat(patterns.get(1)).isEqualTo(p2);
 	}
 
+	@Test
+	public void separatorTests() {
+		PathPatternParser parser = new PathPatternParser();
+		parser.setSeparator('.');
+		String rawPattern = "first.second.{last}";
+		PathPattern pattern = parser.parse(rawPattern);
+		assertThat(pattern.computePatternString()).isEqualTo(rawPattern);
+	}
+
 	private PathPattern parse(String pattern) {
 		PathPatternParser patternParser = new PathPatternParser();
 		return patternParser.parse(pattern);