NoCodeInFileCheck.java
////////////////////////////////////////////////////////////////////////////////
// checkstyle: Checks Java source code for adherence to a set of rules.
// Copyright (C) 2001-2021 the original author or authors.
//
// This library is free software; you can redistribute it and/or
// modify it under the terms of the GNU Lesser General Public
// License as published by the Free Software Foundation; either
// version 2.1 of the License, or (at your option) any later version.
//
// This library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
// Lesser General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public
// License along with this library; if not, write to the Free Software
// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
////////////////////////////////////////////////////////////////////////////////
package com.puppycrawl.tools.checkstyle.checks;
import com.puppycrawl.tools.checkstyle.StatelessCheck;
import com.puppycrawl.tools.checkstyle.api.AbstractCheck;
import com.puppycrawl.tools.checkstyle.api.DetailAST;
import com.puppycrawl.tools.checkstyle.utils.CommonUtil;
/**
* <p>
* Checks whether file contains code. Files which are considered to have no code:
* </p>
* <ul>
* <li>
* File with no text
* </li>
* <li>
* File with single line comment(s)
* </li>
* <li>
* File with a multi line comment(s).
* </li>
* </ul>
* <p>
* To configure the check:
* </p>
* <pre>
* <module name="NoCodeInFile"/>
* </pre>
* <p>
* Example:
* </p>
* <p>
* Content of the files:
* </p>
* <pre>
* // single line comment // violation
* </pre>
* <pre>
* /* // violation
* block comment
* */
* </pre>
* <p>
* Parent is {@code com.puppycrawl.tools.checkstyle.TreeWalker}
* </p>
* <p>
* Violation Message Keys:
* </p>
* <ul>
* <li>
* {@code nocode.in.file}
* </li>
* </ul>
*
* @since 8.33
*/
@StatelessCheck
public class NoCodeInFileCheck extends AbstractCheck {
/**
* A key is pointing to the warning message text in "messages.properties"
* file.
*/
public static final String MSG_KEY_NO_CODE = "nocode.in.file";
/** Line number used to log violation when no AST nodes are present in file. */
private static final int DEFAULT_LINE_NUMBER = 1;
@Override
public int[] getDefaultTokens() {
return getRequiredTokens();
}
@Override
public int[] getAcceptableTokens() {
return getRequiredTokens();
}
@Override
public int[] getRequiredTokens() {
return CommonUtil.EMPTY_INT_ARRAY;
}
@Override
public void finishTree(DetailAST ast) {
if (ast == null) {
log(DEFAULT_LINE_NUMBER, MSG_KEY_NO_CODE);
}
}
}