001////////////////////////////////////////////////////////////////////////////////
002// checkstyle: Checks Java source code for adherence to a set of rules.
003// Copyright (C) 2001-2014  Oliver Burn
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////////////////////////////////////////////////////////////////////////////////
019package com.puppycrawl.tools.checkstyle.checks.coding;
020
021import com.puppycrawl.tools.checkstyle.api.Check;
022import com.puppycrawl.tools.checkstyle.api.DetailAST;
023import com.puppycrawl.tools.checkstyle.api.TokenTypes;
024
025/**
026 * Ensures there is a package declaration.
027 * Rationale: Classes that live in the null package cannot be
028 * imported. Many novice developers are not aware of this.
029 *
030 * @author <a href="mailto:simon@redhillconsulting.com.au">Simon Harris</a>
031 * @author Oliver Burn
032 */
033public final class PackageDeclarationCheck extends Check
034{
035    /** is package defined. */
036    private boolean defined;
037
038    @Override
039    public int[] getDefaultTokens()
040    {
041        return new int[] {TokenTypes.PACKAGE_DEF};
042    }
043
044    @Override
045    public int[] getRequiredTokens()
046    {
047        return getDefaultTokens();
048    }
049
050    @Override
051    public void beginTree(DetailAST ast)
052    {
053        defined = false;
054    }
055
056    @Override
057    public void finishTree(DetailAST ast)
058    {
059        if (!defined) {
060            log(ast.getLineNo(), "missing.package.declaration");
061        }
062    }
063
064    @Override
065    public void visitToken(DetailAST ast)
066    {
067        defined = true;
068    }
069}