//////////////////////////////////////////////////////////////////////////////// // checkstyle: Checks Java source code for adherence to a set of rules. // Copyright (C) 2001-2017 the original author or authors. // // This library is free software; you can redistribute it and/or // modify it under the terms of the GNU Lesser General Public // License as published by the Free Software Foundation; either // version 2.1 of the License, or (at your option) any later version. // // This library is distributed in the hope that it will be useful, // but WITHOUT ANY WARRANTY; without even the implied warranty of // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU // Lesser General Public License for more details. // // You should have received a copy of the GNU Lesser General Public // License along with this library; if not, write to the Free Software // Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA //////////////////////////////////////////////////////////////////////////////// package com.puppycrawl.tools.checkstyle.checks; import java.io.File; import java.io.IOException; import java.io.RandomAccessFile; import java.util.List; import java.util.Locale; import com.google.common.io.Closeables; import com.puppycrawl.tools.checkstyle.api.AbstractFileSetCheck; /** * <p> * Checks that there is a newline at the end of each file. * </p> * <p> * An example of how to configure the check is: * </p> * <pre> * <module name="NewlineAtEndOfFile"/></pre> * <p> * This will check against the platform-specific default line separator. * </p> * <p> * It is also possible to enforce the use of a specific line-separator across * platforms, with the 'lineSeparator' property: * </p> * <pre> * <module name="NewlineAtEndOfFile"> * <property name="lineSeparator" value="lf"/> * </module></pre> * <p> * Valid values for the 'lineSeparator' property are 'system' (system default), * 'crlf' (windows), 'cr' (mac), 'lf' (unix) and 'lf_cr_crlf' (lf, cr or crlf). * </p> * * @author Christopher Lenz * @author lkuehne */ public class NewlineAtEndOfFileCheck extends AbstractFileSetCheck { /** * A key is pointing to the warning message text in "messages.properties" * file. */ public static final String MSG_KEY_UNABLE_OPEN = "unable.open"; /** * A key is pointing to the warning message text in "messages.properties" * file. */ public static final String MSG_KEY_NO_NEWLINE_EOF = "noNewlineAtEOF"; /** The line separator to check against. */ private LineSeparatorOption lineSeparator = LineSeparatorOption.SYSTEM; @Override protected void processFiltered(File file, List<String> lines) { // Cannot use lines as the line separators have been removed! try { final RandomAccessFile randomAccessFile = new RandomAccessFile(file, "r"); boolean threw = true; try { if (!endsWithNewline(randomAccessFile)) { log(0, MSG_KEY_NO_NEWLINE_EOF, file.getPath()); } threw = false; } finally { Closeables.close(randomAccessFile, threw); } } catch (final IOException ignored) { log(0, MSG_KEY_UNABLE_OPEN, file.getPath()); } } /** * Sets the line separator to one of 'crlf', 'lf','cr', 'lf_cr_crlf' or 'system'. * * @param lineSeparatorParam The line separator to set * @throws IllegalArgumentException If the specified line separator is not * one of 'crlf', 'lf', 'cr', 'lf_cr_crlf' or 'system' */ public void setLineSeparator(String lineSeparatorParam) { try { lineSeparator = Enum.valueOf(LineSeparatorOption.class, lineSeparatorParam.trim() .toUpperCase(Locale.ENGLISH)); } catch (IllegalArgumentException iae) { throw new IllegalArgumentException("unable to parse " + lineSeparatorParam, iae); } } /** * Checks whether the content provided by the Reader ends with the platform * specific line separator. * @param randomAccessFile The reader for the content to check * @return boolean Whether the content ends with a line separator * @throws IOException When an IO error occurred while reading from the * provided reader */ private boolean endsWithNewline(RandomAccessFile randomAccessFile) throws IOException { final boolean result; final int len = lineSeparator.length(); if (randomAccessFile.length() < len) { result = false; } else { randomAccessFile.seek(randomAccessFile.length() - len); final byte[] lastBytes = new byte[len]; final int readBytes = randomAccessFile.read(lastBytes); if (readBytes != len) { throw new IOException("Unable to read " + len + " bytes, got " + readBytes); } result = lineSeparator.matches(lastBytes); } return result; } }