001///////////////////////////////////////////////////////////////////////////////////////////////
002// checkstyle: Checks Java source code and other text files for adherence to a set of rules.
003// Copyright (C) 2001-2026 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.header;
021
022import java.io.File;
023import java.util.BitSet;
024
025import com.puppycrawl.tools.checkstyle.StatelessCheck;
026import com.puppycrawl.tools.checkstyle.api.FileText;
027import com.puppycrawl.tools.checkstyle.utils.TokenUtil;
028
029/**
030 * <div>
031 * Checks that a source file begins with a specified header.
032 * Property {@code headerFile} specifies a file that contains the required header.
033 * Alternatively, the header specification can be set directly in the
034 * {@code header} property without the need for an external file.
035 * </div>
036 *
037 * <p>
038 * Notes:
039 * In default configuration, if header is not specified, the default value
040 * of header is set to {@code null} and the check does not rise any violations.
041 * </p>
042 *
043 * @since 3.2
044 */
045@StatelessCheck
046public class HeaderCheck extends AbstractHeaderCheck {
047
048    /**
049     * A key is pointing to the warning message text in "messages.properties"
050     * file.
051     */
052    public static final String MSG_MISSING = "header.missing";
053
054    /**
055     * A key is pointing to the warning message text in "messages.properties"
056     * file.
057     */
058    public static final String MSG_MISMATCH = "header.mismatch";
059
060    /** Specifies the line numbers to ignore when matching lines in a content of headerFile. */
061    private BitSet ignoreLines = new BitSet();
062
063    /**
064     * Creates a new {@code HeaderCheck} instance.
065     */
066    public HeaderCheck() {
067        // no code by default
068    }
069
070    /**
071     * Returns true if lineNo is header lines or false.
072     *
073     * @param lineNo a line number
074     * @return if {@code lineNo} is one of the ignored header lines.
075     */
076    private boolean isIgnoreLine(int lineNo) {
077        return ignoreLines.get(lineNo);
078    }
079
080    /**
081     * Checks if a code line matches the required header line.
082     *
083     * @param lineNumber the line number to check against the header
084     * @param line the line contents
085     * @return true if and only if the line matches the required header line
086     */
087    private boolean isMatch(int lineNumber, String line) {
088        // skip lines we are meant to ignore
089        return isIgnoreLine(lineNumber + 1)
090            || getHeaderLines().get(lineNumber).equals(line);
091    }
092
093    /**
094     * Setter to specifies the line numbers
095     * to ignore when matching lines in a content of headerFile.
096     *
097     * @param lines line numbers to ignore in header.
098     * @since 3.2
099     */
100    public void setIgnoreLines(int... lines) {
101        ignoreLines = TokenUtil.asBitSet(lines);
102    }
103
104    @Override
105    protected void processFiltered(File file, FileText fileText) {
106        if (getHeaderLines().size() > fileText.size()) {
107            log(1, MSG_MISSING);
108        }
109        else {
110            for (int i = 0; i < getHeaderLines().size(); i++) {
111                if (!isMatch(i, fileText.get(i))) {
112                    log(i + 1, MSG_MISMATCH, getHeaderLines().get(i));
113                    break;
114                }
115            }
116        }
117    }
118
119    @Override
120    protected void postProcessHeaderLines() {
121        // no code
122    }
123
124}