001////////////////////////////////////////////////////////////////////////////////
002// checkstyle: Checks Java source code for adherence to a set of rules.
003// Copyright (C) 2001-2019 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 */
041@FileStatefulCheck
042public final class PackageDeclarationCheck extends AbstractCheck {
043
044    /**
045     * A key is pointing to the warning message text in "messages.properties"
046     * file.
047     */
048    public static final String MSG_KEY_MISSING = "missing.package.declaration";
049
050    /**
051     * A key is pointing to the warning message text in "messages.properties"
052     * file.
053     */
054    public static final String MSG_KEY_MISMATCH = "mismatch.package.directory";
055
056    /** Line number used to log violation when no AST nodes are present in file. */
057    private static final int DEFAULT_LINE_NUMBER = 1;
058
059    /** Is package defined. */
060    private boolean defined;
061
062    /** Whether to check for directory and package name match. */
063    private boolean matchDirectoryStructure = true;
064
065    /**
066     * Set whether to check for directory and package name match.
067     * @param matchDirectoryStructure the new value.
068     */
069    public void setMatchDirectoryStructure(boolean matchDirectoryStructure) {
070        this.matchDirectoryStructure = matchDirectoryStructure;
071    }
072
073    @Override
074    public int[] getDefaultTokens() {
075        return getRequiredTokens();
076    }
077
078    @Override
079    public int[] getRequiredTokens() {
080        return new int[] {TokenTypes.PACKAGE_DEF};
081    }
082
083    @Override
084    public int[] getAcceptableTokens() {
085        return getRequiredTokens();
086    }
087
088    @Override
089    public void beginTree(DetailAST ast) {
090        defined = false;
091    }
092
093    @Override
094    public void finishTree(DetailAST ast) {
095        if (!defined) {
096            int lineNumber = DEFAULT_LINE_NUMBER;
097            if (ast != null) {
098                lineNumber = ast.getLineNo();
099            }
100            log(lineNumber, MSG_KEY_MISSING);
101        }
102    }
103
104    @Override
105    public void visitToken(DetailAST ast) {
106        defined = true;
107
108        if (matchDirectoryStructure) {
109            final DetailAST packageNameAst = ast.getLastChild().getPreviousSibling();
110            final FullIdent fullIdent = FullIdent.createFullIdent(packageNameAst);
111            final String packageName = fullIdent.getText().replace('.', File.separatorChar);
112
113            final String directoryName = getDirectoryName();
114
115            if (!directoryName.endsWith(packageName)) {
116                log(fullIdent.getLineNo(), MSG_KEY_MISMATCH, packageName);
117            }
118        }
119    }
120
121    /**
122     * Returns the directory name this file is in.
123     * @return Directory name.
124     */
125    private String getDirectoryName() {
126        final String fileName = getFileContents().getFileName();
127        final int lastSeparatorPos = fileName.lastIndexOf(File.separatorChar);
128        return fileName.substring(0, lastSeparatorPos);
129    }
130
131}