Allow @since on members of an annotation with default visibility

Closes gh-344

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

@@ -165,8 +165,8 @@ private void checkSinceTag(DetailAST ast, TextBlock javadoc) {
 			return;
 		}
 		String[] text = javadoc.getText();
-		DetailAST interfaceDef = getInterfaceDef(ast);
-		boolean privateType = !isPublicOrProtected(ast) && (interfaceDef == null || !isPublicOrProtected(interfaceDef));
+		DetailAST interfaceOrAnnotationDef = getInterfaceOrAnnotationDef(ast);
+		boolean privateType = !isPublicOrProtected(ast) && (interfaceOrAnnotationDef == null || !isPublicOrProtected(interfaceOrAnnotationDef));
 		boolean innerType = ast.getParent() != null && ast.getParent().getType() != TokenTypes.COMPILATION_UNIT;
 		boolean found = false;
 		for (int i = 0; i < text.length; i++) {
@@ -225,14 +225,16 @@ public void setAllowNonJavadocComments(boolean allowNonJavadocComments) {
 		this.allowNonJavadocComments = allowNonJavadocComments;
 	}
 
-	private DetailAST getInterfaceDef(DetailAST ast) {
-		return findParent(ast, TokenTypes.INTERFACE_DEF);
+	private DetailAST getInterfaceOrAnnotationDef(DetailAST ast) {
+		return findParent(ast, TokenTypes.INTERFACE_DEF, TokenTypes.ANNOTATION_DEF);
 	}
-
-	private DetailAST findParent(DetailAST ast, int classDef) {
+	
+	private DetailAST findParent(DetailAST ast, int... classDefs) {
 		while (ast != null) {
-			if (ast.getType() == classDef) {
-				return ast;
+			for (int classDef: classDefs) {
+				if (ast.getType() == classDef) {
+					return ast;
+				}
 			}
 			ast = ast.getParent();
 		}

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

@@ -0,0 +1 @@
++0 errors

spring-javaformat/spring-javaformat-checkstyle/src/test/resources/config/JavadocNonPublicSinceInsideAnnotation.xml

@@ -0,0 +1,11 @@
+<?xml version="1.0"?>
+<!DOCTYPE module PUBLIC
+		"-//Checkstyle//DTD Checkstyle Configuration 1.3//EN"
+		"https://checkstyle.org/dtds/configuration_1_3.dtd">
+<module name="com.puppycrawl.tools.checkstyle.Checker">
+	<module name="com.puppycrawl.tools.checkstyle.TreeWalker">
+		<module name="io.spring.javaformat.checkstyle.check.SpringJavadocCheck">
+			<property name="publicOnlySinceTags" value="true"/>
+		</module>
+	</module>
+</module>

spring-javaformat/spring-javaformat-checkstyle/src/test/resources/source/JavadocNonPublicSinceInsideAnnotation.java

@@ -0,0 +1,36 @@
+/*
+ * Copyright 2017-2022 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.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+/**
+ * Javadoc with a good since tag.
+ *
+ * @author Phillip Webb
+ * @since 1.2.3
+ */
+public @interface JavadocNonPublicSinceInsideAnnotation {
+
+	/**
+	 * Inner enum.
+	 *
+	 * @since 1.2.3
+	 */
+	enum Inner {
+
+		FOO
+
+	}
+
+}