Check for "(non-Javadoc)" comments

Closes gh-186

Author: philwebb

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

@@ -18,13 +18,16 @@
 
 import java.util.ArrayList;
 import java.util.Collections;
+import java.util.HashMap;
 import java.util.HashSet;
 import java.util.List;
+import java.util.Map;
 import java.util.Set;
 import java.util.regex.Matcher;
 import java.util.regex.Pattern;
 
 import com.puppycrawl.tools.checkstyle.api.DetailAST;
+import com.puppycrawl.tools.checkstyle.api.FileContents;
 import com.puppycrawl.tools.checkstyle.api.TextBlock;
 import com.puppycrawl.tools.checkstyle.api.TokenTypes;
 
@@ -55,6 +58,8 @@ public class SpringJavadocCheck extends AbstractSpringCheck {
 
 	private static final Pattern AT_TAG_PATTERN = Pattern.compile("@\\w+\\s+.*");
 
+	private static final Pattern NON_JAVADOC_COMMENT = Pattern.compile("\\(non-Javadoc\\)", Pattern.CASE_INSENSITIVE);
+
 	private static final Set<Integer> TOP_LEVEL_TYPES;
 	static {
 		Set<Integer> topLevelTypes = new HashSet<Integer>();
@@ -69,6 +74,10 @@ public class SpringJavadocCheck extends AbstractSpringCheck {
 
 	private boolean publicOnlySinceTags;
 
+	private boolean allowNonJavadocComments;
+
+	private Map<Integer, TextBlock> blockComments;
+
 	@Override
 	public int[] getDefaultTokens() {
 		return new int[] { TokenTypes.INTERFACE_DEF, TokenTypes.CLASS_DEF, TokenTypes.ENUM_DEF,
@@ -82,13 +91,38 @@ public int[] getAcceptableTokens() {
 				TokenTypes.ANNOTATION_FIELD_DEF };
 	}
 
+	@Override
+	public void beginTree(DetailAST rootAST) {
+		super.beginTree(rootAST);
+		this.blockComments = new HashMap<>();
+		FileContents contents = getFileContents();
+		for (List<TextBlock> blockComments : contents.getBlockComments().values()) {
+			for (TextBlock blockComment : blockComments) {
+				this.blockComments.put(blockComment.getEndLineNo(), blockComment);
+			}
+		}
+	}
+
 	@Override
 	public void visitToken(DetailAST ast) {
 		int lineNumber = ast.getLineNo();
 		TextBlock javadoc = getFileContents().getJavadocBefore(lineNumber);
 		if (javadoc != null) {
 			checkJavadoc(ast, javadoc);
 		}
+		if (!this.allowNonJavadocComments) {
+			checkForNonJavadocComments(javadoc);
+			checkForNonJavadocComments(getBlockCommentBefore(lineNumber));
+		}
+	}
+
+	public TextBlock getBlockCommentBefore(int lineNoBefore) {
+		FileContents contents = getFileContents();
+		int lineNo = lineNoBefore - 1;
+		while (lineNo > 0 && (contents.lineIsBlank(lineNo) || contents.lineIsComment(lineNo))) {
+			lineNo--;
+		}
+		return this.blockComments.get(lineNo);
 	}
 
 	private void checkJavadoc(DetailAST ast, TextBlock javadoc) {
@@ -167,6 +201,18 @@ private boolean startsWithUppercase(String description) {
 		return description.length() > 0 && Character.isUpperCase(description.charAt(0));
 	}
 
+	private void checkForNonJavadocComments(TextBlock block) {
+		if (block == null) {
+			return;
+		}
+		String[] text = block.getText();
+		for (int i = 0; i < text.length; i++) {
+			if (NON_JAVADOC_COMMENT.matcher(text[i]).find()) {
+				log(block.getStartLineNo() + i - 1, 0, "javadoc.nonJavadocComment");
+			}
+		}
+	}
+
 	public void setRequireSinceTag(boolean requireSinceTag) {
 		this.requireSinceTag = requireSinceTag;
 	}
@@ -175,6 +221,10 @@ public void setPublicOnlySinceTags(boolean publicOnlySinceTags) {
 		this.publicOnlySinceTags = publicOnlySinceTags;
 	}
 
+	public void setAllowNonJavadocComments(boolean allowNonJavadocComments) {
+		this.allowNonJavadocComments = allowNonJavadocComments;
+	}
+
 	private DetailAST getInterfaceDef(DetailAST ast) {
 		return findParent(ast, TokenTypes.INTERFACE_DEF);
 	}

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

@@ -11,6 +11,7 @@ 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.emptyLineBeforeTag=Method Javadoc should not have empty line before tag.
+javadoc.nonJavadocComment=Comments should not include \"(non-Javadoc)\".
 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/JavadocNonJavadocComment.txt

@@ -0,0 +1,3 @@
++23:1: Comments should not include "(non-Javadoc)"
++30:1: Comments should not include "(non-Javadoc)"
++2 errors

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

@@ -0,0 +1,36 @@
+/*
+ * Copyright 2017-2020 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.
+ */
+
+/**
+ * Example with non javadoc comments.
+ *
+ * @author Phillip Webb
+ */
+public class JavadocNonJavadocComment {
+
+	/* (non-Javadoc)
+	 * Example.
+	 */
+	public void one() {
+	}
+
+	/**
+	 * (non-Javadoc).
+	 */
+	public void two() {
+	}
+
+}