001////////////////////////////////////////////////////////////////////////////////
002// checkstyle: Checks Java source code for adherence to a set of rules.
003// Copyright (C) 2001-2015 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.naming;
021
022import com.puppycrawl.tools.checkstyle.api.DetailAST;
023import com.puppycrawl.tools.checkstyle.api.FullIdent;
024import com.puppycrawl.tools.checkstyle.api.TokenTypes;
025import com.puppycrawl.tools.checkstyle.checks.AbstractFormatCheck;
026
027/**
028 * <p>
029 * Checks that package names conform to a format specified
030 * by the format property. The format is a
031 * {@link java.util.regex.Pattern regular expression}
032 * and defaults to
033 * <strong>^[a-z]+(\.[a-zA-Z_][a-zA-Z_0-9]*)*$</strong>.
034 * </p>
035 * <p>
036 * The default format has been chosen to match the requirements in the
037 * <a
038 * href="http://docs.oracle.com/javase/specs/jls/se8/html/jls-7.html">
039 * Java Language specification</a> and the Sun coding conventions.
040 * However both underscores and uppercase letters are rather uncommon,
041 * so most projects should probably use
042 * <strong>^[a-z]+(\.[a-z][a-z0-9]*)*$</strong>.
043 * </p>
044 * <p>
045 * An example of how to configure the check is:
046 * </p>
047 * <pre>
048 * &lt;module name="PackageName"/&gt;
049 * </pre>
050 * <p>
051 * An example of how to configure the check for package names that begin with
052 * {@code com.puppycrawl.tools.checkstyle} is:
053 * </p>
054 * <pre>
055 * &lt;module name="PackageName"&gt;
056 *    &lt;property name="format"
057 *              value="^com\.puppycrawl\.tools\.checkstyle(\\.[a-zA-Z_][a-zA-Z_0-9]*)*$"/&gt;
058 * &lt;/module&gt;
059 * </pre>
060 *
061 * @author Oliver Burn
062 */
063public class PackageNameCheck
064    extends AbstractFormatCheck {
065    /**
066     * Creates a new {@code PackageNameCheck} instance.
067     */
068    public PackageNameCheck() {
069        // Uppercase letters seem rather uncommon, but they're allowed in
070        // http://docs.oracle.com/javase/specs/
071        //   second_edition/html/packages.doc.html#40169
072        super("^[a-z]+(\\.[a-zA-Z_][a-zA-Z0-9_]*)*$");
073    }
074
075    @Override
076    public int[] getDefaultTokens() {
077        return getAcceptableTokens();
078    }
079
080    @Override
081    public int[] getAcceptableTokens() {
082        return new int[] {TokenTypes.PACKAGE_DEF};
083    }
084
085    @Override
086    public int[] getRequiredTokens() {
087        return getAcceptableTokens();
088    }
089
090    @Override
091    public void visitToken(DetailAST ast) {
092        final DetailAST nameAST = ast.getLastChild().getPreviousSibling();
093        final FullIdent full = FullIdent.createFullIdent(nameAST);
094        if (!getRegexp().matcher(full.getText()).find()) {
095            log(full.getLineNo(),
096                full.getColumnNo(),
097                "name.invalidPattern",
098                full.getText(),
099                getFormat());
100        }
101    }
102}