001////////////////////////////////////////////////////////////////////////////////
002// checkstyle: Checks Java source code for adherence to a set of rules.
003// Copyright (C) 2001-2016 the original author or authors.
004//
005// This library is free software; you can redistribute it and/or
006// modify it under the terms of the GNU Lesser General Public
007// License as published by the Free Software Foundation; either
008// version 2.1 of the License, or (at your option) any later version.
009//
010// This library is distributed in the hope that it will be useful,
011// but WITHOUT ANY WARRANTY; without even the implied warranty of
012// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
013// Lesser General Public License for more details.
014//
015// You should have received a copy of the GNU Lesser General Public
016// License along with this library; if not, write to the Free Software
017// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
018////////////////////////////////////////////////////////////////////////////////
019
020package com.puppycrawl.tools.checkstyle.checks;
021
022import com.puppycrawl.tools.checkstyle.api.AbstractCheck;
023import com.puppycrawl.tools.checkstyle.api.DetailAST;
024import com.puppycrawl.tools.checkstyle.api.FileContents;
025import com.puppycrawl.tools.checkstyle.utils.CommonUtils;
026
027/**
028 * Holds the current file contents for global access when configured
029 * as a TreeWalker sub-module. For example,
030 * a filter can access the current file contents through this module.
031 * @author Mike McMahon
032 * @author Rick Giles
033 */
034public class FileContentsHolder
035    extends AbstractCheck {
036    /** The current file contents. */
037    private static final ThreadLocal<FileContents> FILE_CONTENTS = new ThreadLocal<>();
038
039    /**
040     * @return the current file contents.
041     */
042    public static FileContents getContents() {
043        return FILE_CONTENTS.get();
044    }
045
046    @Override
047    public int[] getDefaultTokens() {
048        return getAcceptableTokens();
049    }
050
051    @Override
052    public int[] getAcceptableTokens() {
053        return CommonUtils.EMPTY_INT_ARRAY;
054    }
055
056    @Override
057    public int[] getRequiredTokens() {
058        return getAcceptableTokens();
059    }
060
061    @Override
062    public void beginTree(DetailAST rootAST) {
063        FILE_CONTENTS.set(getFileContents());
064    }
065
066    @Override
067    public void destroy() {
068        // This needs to be called in destroy, rather than finishTree()
069        // as finishTree() is called before the messages are passed to the
070        // filters. Without calling remove, there is a memory leak.
071        FILE_CONTENTS.remove();
072    }
073}