001////////////////////////////////////////////////////////////////////////////////
002// checkstyle: Checks Java source code for adherence to a set of rules.
003// Copyright (C) 2001-2020 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;
021
022import java.io.File;
023import java.io.IOException;
024import java.nio.charset.StandardCharsets;
025import java.util.List;
026import java.util.Locale;
027import java.util.regex.Matcher;
028import java.util.regex.Pattern;
029import java.util.stream.Collectors;
030
031import com.puppycrawl.tools.checkstyle.api.CheckstyleException;
032import com.puppycrawl.tools.checkstyle.api.DetailAST;
033import com.puppycrawl.tools.checkstyle.api.FileText;
034import com.puppycrawl.tools.checkstyle.xpath.XpathQueryGenerator;
035
036/**
037 * Class for constructing xpath queries to suppress nodes
038 * with specified line and column number.
039 */
040public final class SuppressionsStringPrinter {
041
042    /** Line and column number config value pattern. */
043    private static final Pattern VALID_SUPPRESSION_LINE_COLUMN_NUMBER_REGEX =
044            Pattern.compile("^([0-9]+):([0-9]+)$");
045
046    /** OS specific line separator. */
047    private static final String LINE_SEPARATOR = System.getProperty("line.separator");
048
049    /** Prevent instances. */
050    private SuppressionsStringPrinter() {
051        // no code
052    }
053
054    /**
055     * Prints generated suppressions.
056     *
057     * @param file the file to process.
058     * @param suppressionLineColumnNumber line and column number of the suppression
059     * @param tabWidth length of the tab character
060     * @return generated suppressions.
061     * @throws IOException if the file could not be read.
062     * @throws CheckstyleException if the file is not a Java source.
063     */
064    public static String printSuppressions(File file, String suppressionLineColumnNumber,
065                                           int tabWidth) throws IOException, CheckstyleException {
066        final Matcher matcher =
067                VALID_SUPPRESSION_LINE_COLUMN_NUMBER_REGEX.matcher(suppressionLineColumnNumber);
068        if (!matcher.matches()) {
069            final String exceptionMsg = String.format(Locale.ROOT,
070                    "%s does not match valid format 'line:column'.",
071                    suppressionLineColumnNumber);
072            throw new IllegalStateException(exceptionMsg);
073        }
074
075        final FileText fileText = new FileText(file.getAbsoluteFile(),
076                System.getProperty("file.encoding", StandardCharsets.UTF_8.name()));
077        final DetailAST detailAST =
078                JavaParser.parseFileText(fileText, JavaParser.Options.WITH_COMMENTS);
079        final int lineNumber = Integer.parseInt(matcher.group(1));
080        final int columnNumber = Integer.parseInt(matcher.group(2));
081        return generate(fileText, detailAST, lineNumber, columnNumber, tabWidth);
082    }
083
084    /**
085     * Creates {@code XpathQueryGenerator} instance and generates suppressions.
086     *
087     * @param fileText {@code FileText} object.
088     * @param detailAST {@code DetailAST} object.
089     * @param lineNumber line number.
090     * @param columnNumber column number.
091     * @param tabWidth length of the tab character.
092     * @return generated suppressions.
093     */
094    private static String generate(FileText fileText, DetailAST detailAST, int lineNumber,
095                                   int columnNumber, int tabWidth) {
096        final XpathQueryGenerator queryGenerator =
097                new XpathQueryGenerator(detailAST, lineNumber, columnNumber, fileText,
098                        tabWidth);
099        final List<String> suppressions = queryGenerator.generate();
100        return suppressions.stream().collect(Collectors.joining(LINE_SEPARATOR,
101                "", LINE_SEPARATOR));
102    }
103}