001////////////////////////////////////////////////////////////////////////////////
002// checkstyle: Checks Java source code for adherence to a set of rules.
003// Copyright (C) 2001-2017 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.coding;
021
022import java.io.File;
023
024import com.puppycrawl.tools.checkstyle.FileStatefulCheck;
025import com.puppycrawl.tools.checkstyle.api.AbstractCheck;
026import com.puppycrawl.tools.checkstyle.api.DetailAST;
027import com.puppycrawl.tools.checkstyle.api.FullIdent;
028import com.puppycrawl.tools.checkstyle.api.TokenTypes;
029
030/**
031 * Ensures there is a package declaration.
032 * Optionally checks if directory structure matches package name.
033 * Rationale: Classes that live in the null package cannot be
034 * imported. Many novice developers are not aware of this.
035 * Packages provide logical namespace to classes and should be stored in
036 * the form of directory levels to provide physical grouping to your classes.
037 * These directories are added to the classpath so that your classes
038 * are visible to JVM when it runs the code.
039 *
040 * @author <a href="mailto:simon@redhillconsulting.com.au">Simon Harris</a>
041 * @author Oliver Burn
042 * @author Vikramaditya Kukreja
043 */
044@FileStatefulCheck
045public final class PackageDeclarationCheck extends AbstractCheck {
046
047    /**
048     * A key is pointing to the warning message text in "messages.properties"
049     * file.
050     */
051    public static final String MSG_KEY_MISSING = "missing.package.declaration";
052
053    /**
054     * A key is pointing to the warning message text in "messages.properties"
055     * file.
056     */
057    public static final String MSG_KEY_MISMATCH = "mismatch.package.directory";
058
059    /** Line number used to log violation when no AST nodes are present in file. */
060    private static final int DEFAULT_LINE_NUMBER = 1;
061
062    /** Is package defined. */
063    private boolean defined;
064
065    /** Whether to check for directory and package name match. */
066    private boolean matchDirectoryStructure = true;
067
068    /**
069     * Set whether to check for directory and package name match.
070     * @param matchDirectoryStructure the new value.
071     */
072    public void setMatchDirectoryStructure(boolean matchDirectoryStructure) {
073        this.matchDirectoryStructure = matchDirectoryStructure;
074    }
075
076    @Override
077    public int[] getDefaultTokens() {
078        return getRequiredTokens();
079    }
080
081    @Override
082    public int[] getRequiredTokens() {
083        return new int[] {TokenTypes.PACKAGE_DEF};
084    }
085
086    @Override
087    public int[] getAcceptableTokens() {
088        return getRequiredTokens();
089    }
090
091    @Override
092    public void beginTree(DetailAST ast) {
093        defined = false;
094    }
095
096    @Override
097    public void finishTree(DetailAST ast) {
098        if (!defined) {
099            int lineNumber = DEFAULT_LINE_NUMBER;
100            if (ast != null) {
101                lineNumber = ast.getLineNo();
102            }
103            log(lineNumber, MSG_KEY_MISSING);
104        }
105    }
106
107    @Override
108    public void visitToken(DetailAST ast) {
109        defined = true;
110
111        if (matchDirectoryStructure) {
112
113            final DetailAST packageNameAst = ast.getLastChild().getPreviousSibling();
114            final FullIdent fullIdent = FullIdent.createFullIdent(packageNameAst);
115            final String packageName = fullIdent.getText().replace('.', File.separatorChar);
116
117            final String directoryName = getDirectoryName();
118
119            if (!directoryName.endsWith(packageName)) {
120                log(fullIdent.getLineNo(), MSG_KEY_MISMATCH, packageName);
121            }
122        }
123    }
124
125    /**
126     * Returns the directory name this file is in.
127     * @return Directory name.
128     */
129    private String getDirectoryName() {
130        final String fileName = getFileContents().getFileName();
131        final int lastSeparatorPos = fileName.lastIndexOf(File.separatorChar);
132        return fileName.substring(0, lastSeparatorPos);
133    }
134}