Polish 'Add checkstyle rule for method javadoc empty lines'

See gh-199

Author: philwebb

spring-javaformat/spring-javaformat-checkstyle/src/main/java/io/spring/javaformat/checkstyle/check/SpringJavadocCheck.java

@@ -53,7 +53,7 @@ public class SpringJavadocCheck extends AbstractSpringCheck {
 
 	private static final Pattern SINCE_TAG_PATTERN = Pattern.compile("@since\\s+(.*)");
 
-	private static final Pattern PARAM_TAG_PATTERN = Pattern.compile("@param\\s+(.*)");
+	private static final Pattern AT_TAG_PATTERN = Pattern.compile("@\\w+\\s+.*");
 
 	private static final Set<Integer> TOP_LEVEL_TYPES;
 	static {
@@ -98,21 +98,6 @@ private void checkJavadoc(DetailAST ast, TextBlock javadoc) {
 		checkMethodJavaDoc(ast, javadoc);
 	}
 
-	private void checkMethodJavaDoc(DetailAST ast, TextBlock javadoc) {
-		if (TokenTypes.METHOD_DEF != ast.getType()) {
-			return;
-		}
-		else {
-			String[] text = javadoc.getText();
-			for (int i = 0; i < text.length; i++) {
-				Matcher matcher = SINCE_TAG_PATTERN.matcher(text[i]);
-				if (matcher.find() && text[i - 1].trim().equals("*")) {
-					log(javadoc.getStartLineNo() + i - 1, 0, "javadoc.whiteSpace");
-				}
-			}
-		}
-	}
-
 	private void checkBannedTags(DetailAST ast, TextBlock javadoc) {
 		String[] text = javadoc.getText();
 		for (int i = 0; i < text.length; i++) {
@@ -165,6 +150,19 @@ private void checkSinceTag(DetailAST ast, TextBlock javadoc) {
 		}
 	}
 
+	private void checkMethodJavaDoc(DetailAST ast, TextBlock javadoc) {
+		if (TokenTypes.METHOD_DEF != ast.getType()) {
+			return;
+		}
+		String[] text = javadoc.getText();
+		for (int i = 0; i < text.length; i++) {
+			Matcher matcher = AT_TAG_PATTERN.matcher(text[i]);
+			if (matcher.find() && i > 0 && text[i - 1].trim().equals("*")) {
+				log(javadoc.getStartLineNo() + i - 1, 0, "javadoc.emptyLineBeforeTag");
+			}
+		}
+	}
+
 	private boolean startsWithUppercase(String description) {
 		return description.length() > 0 && Character.isUpperCase(description.charAt(0));
 	}

spring-javaformat/spring-javaformat-checkstyle/src/main/resources/io/spring/javaformat/checkstyle/check/messages.properties

@@ -9,7 +9,7 @@ javadoc.badCase=Javadoc element descriptions should not start with an uppercase
 javadoc.bannedTag=Javadoc tag ''{0}'' should not be used.
 javadoc.missingSince=Missing Javadoc @since tag.
 javadoc.publicSince=Javadoc @since tag should not be used on private classes.
-javadoc.whiteSpace=Line matches the illegal pattern 'Trailing whitespace'.
+javadoc.emptyLineBeforeTag=Method Javadoc should not have empty line before tag.
 junit5.bannedImport=Import ''{0}'' should not be used in a JUnit 5 test.
 junit5.bannedTestAnnotation=JUnit 4 @Test annotation should not be used in a JUnit 5 test.
 junit5.lifecyclePrivateMethod=Lifecycle method ''{0}'' should not be private.

spring-javaformat/spring-javaformat-checkstyle/src/test/resources/check/JavadocMethodEmptyLineBeforeTag.txt

@@ -0,0 +1,2 @@
++Method Javadoc should not have empty line before tag.
++1 error

spring-javaformat/spring-javaformat-checkstyle/src/test/resources/check/JavadocWhiteSpace.txt

@@ -19,10 +19,11 @@
  * @param <T> this is a valid param
  * @author Sushant Kumar Singh
  */
-public class JavaDocWhiteSpace<T> {
+public class JavadocMethodEmptyLineBeforeTag<T> {
+
 	/**
 	 * Do something.
-	 * 
+	 *
 	 * @param something a lovely thing
 	 */
 	public void test(String something) {