Polishing

spring-core/src/main/java/org/springframework/util/xml/XmlValidationModeDetector.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2020 the original author or authors.
+ * Copyright 2002-2022 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.
@@ -58,7 +58,7 @@ public class XmlValidationModeDetector {
 
 
 	/**
-	 * The token in a XML document that declares the DTD to use for validation
+	 * The token in an XML document that declares the DTD to use for validation
 	 * and thus that DTD validation is being used.
 	 */
 	private static final String DOCTYPE = "DOCTYPE";
@@ -82,13 +82,15 @@ public class XmlValidationModeDetector {
 
 	/**
 	 * Detect the validation mode for the XML document in the supplied {@link InputStream}.
-	 * Note that the supplied {@link InputStream} is closed by this method before returning.
+	 * <p>Note that the supplied {@link InputStream} is closed by this method before returning.
 	 * @param inputStream the InputStream to parse
 	 * @throws IOException in case of I/O failure
 	 * @see #VALIDATION_DTD
 	 * @see #VALIDATION_XSD
 	 */
 	public int detectValidationMode(InputStream inputStream) throws IOException {
+		this.inComment = false;
+
 		// Peek into the file to look for DOCTYPE.
 		try (BufferedReader reader = new BufferedReader(new InputStreamReader(inputStream))) {
 			boolean isDtdValidated = false;
@@ -125,9 +127,11 @@ public class XmlValidationModeDetector {
 	}
 
 	/**
-	 * Does the supplied content contain an XML opening tag. If the parse state is currently
-	 * in an XML comment then this method always returns false. It is expected that all comment
-	 * tokens will have consumed for the supplied content before passing the remainder to this method.
+	 * Determine if the supplied content contains an XML opening tag.
+	 * <p>It is expected that all comment tokens will have been consumed for the
+	 * supplied content before passing the remainder to this method. However, as
+	 * a sanity check, if the parse state is currently in an XML comment this
+	 * method always returns {@code false}.
 	 */
 	private boolean hasOpeningTag(String content) {
 		if (this.inComment) {
@@ -166,7 +170,7 @@ public class XmlValidationModeDetector {
 	}
 
 	/**
-	 * Consume the next comment token, update the "inComment" flag
+	 * Consume the next comment token, update the "inComment" flag,
 	 * and return the remaining content.
 	 */
 	@Nullable
@@ -183,14 +187,19 @@ public class XmlValidationModeDetector {
 		return commentToken(line, START_COMMENT, true);
 	}
 
+	/**
+	 * Try to consume the {@link #END_COMMENT} token.
+	 * @see #commentToken(String, String, boolean)
+	 */
 	private int endComment(String line) {
 		return commentToken(line, END_COMMENT, false);
 	}
 
 	/**
 	 * Try to consume the supplied token against the supplied content and update the
-	 * in comment parse state to the supplied value. Returns the index into the content
-	 * which is after the token or -1 if the token is not found.
+	 * "in comment" parse state to the supplied value.
+	 * <p>Returns the index into the content which is after the token or -1 if the
+	 * token is not found.
 	 */
 	private int commentToken(String line, String token, boolean inCommentIfPresent) {
 		int index = line.indexOf(token);

spring-core/src/test/java/org/springframework/util/xml/XmlValidationModeDetectorTests.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2019 the original author or authors.
+ * Copyright 2002-2022 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.
@@ -16,6 +16,7 @@
 
 package org.springframework.util.xml;
 
+import java.io.IOException;
 import java.io.InputStream;
 
 import org.junit.jupiter.params.ParameterizedTest;
@@ -39,8 +40,16 @@ class XmlValidationModeDetectorTests {
 	@ValueSource(strings = { "dtdWithTrailingComment.xml", "dtdWithLeadingComment.xml", "dtdWithCommentOnNextLine.xml",
 		"dtdWithMultipleComments.xml" })
 	void dtdDetection(String fileName) throws Exception {
-		InputStream inputStream = getClass().getResourceAsStream(fileName);
-		assertThat(xmlValidationModeDetector.detectValidationMode(inputStream)).isEqualTo(VALIDATION_DTD);
+		assertValidationMode(fileName, VALIDATION_DTD);
+	}
+
+
+	private void assertValidationMode(String fileName, int expectedValidationMode) throws IOException {
+		try (InputStream inputStream = getClass().getResourceAsStream(fileName)) {
+			assertThat(xmlValidationModeDetector.detectValidationMode(inputStream))
+				.as("Validation Mode")
+				.isEqualTo(expectedValidationMode);
+		}
 	}
 
 }