001//////////////////////////////////////////////////////////////////////////////// 002// checkstyle: Checks Java source code for adherence to a set of rules. 003// Copyright (C) 2001-2016 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; 021 022import java.io.File; 023import java.io.IOException; 024import java.io.RandomAccessFile; 025import java.util.List; 026import java.util.Locale; 027 028import org.apache.commons.beanutils.ConversionException; 029 030import com.google.common.io.Closeables; 031import com.puppycrawl.tools.checkstyle.api.AbstractFileSetCheck; 032 033/** 034 * <p> 035 * Checks that there is a newline at the end of each file. 036 * </p> 037 * <p> 038 * An example of how to configure the check is: 039 * </p> 040 * <pre> 041 * <module name="NewlineAtEndOfFile"/></pre> 042 * <p> 043 * This will check against the platform-specific default line separator. 044 * </p> 045 * <p> 046 * It is also possible to enforce the use of a specific line-separator across 047 * platforms, with the 'lineSeparator' property: 048 * </p> 049 * <pre> 050 * <module name="NewlineAtEndOfFile"> 051 * <property name="lineSeparator" value="lf"/> 052 * </module></pre> 053 * <p> 054 * Valid values for the 'lineSeparator' property are 'system' (system default), 055 * 'crlf' (windows), 'cr' (mac), 'lf' (unix) and 'lf_cr_crlf' (lf, cr or crlf). 056 * </p> 057 * 058 * @author Christopher Lenz 059 * @author lkuehne 060 */ 061public class NewlineAtEndOfFileCheck 062 extends AbstractFileSetCheck { 063 064 /** 065 * A key is pointing to the warning message text in "messages.properties" 066 * file. 067 */ 068 public static final String MSG_KEY_UNABLE_OPEN = "unable.open"; 069 070 /** 071 * A key is pointing to the warning message text in "messages.properties" 072 * file. 073 */ 074 public static final String MSG_KEY_NO_NEWLINE_EOF = "noNewlineAtEOF"; 075 076 /** The line separator to check against. */ 077 private LineSeparatorOption lineSeparator = LineSeparatorOption.SYSTEM; 078 079 @Override 080 protected void processFiltered(File file, List<String> lines) { 081 // Cannot use lines as the line separators have been removed! 082 try { 083 final RandomAccessFile randomAccessFile = new RandomAccessFile(file, "r"); 084 boolean threw = true; 085 try { 086 if (!endsWithNewline(randomAccessFile)) { 087 log(0, MSG_KEY_NO_NEWLINE_EOF, file.getPath()); 088 } 089 threw = false; 090 } 091 finally { 092 Closeables.close(randomAccessFile, threw); 093 } 094 } 095 catch (final IOException ignored) { 096 log(0, MSG_KEY_UNABLE_OPEN, file.getPath()); 097 } 098 } 099 100 /** 101 * Sets the line separator to one of 'crlf', 'lf','cr', 'lf_cr_crlf' or 'system'. 102 * 103 * @param lineSeparatorParam The line separator to set 104 * @throws IllegalArgumentException If the specified line separator is not 105 * one of 'crlf', 'lf', 'cr', 'lf_cr_crlf' or 'system' 106 */ 107 public void setLineSeparator(String lineSeparatorParam) { 108 try { 109 lineSeparator = 110 Enum.valueOf(LineSeparatorOption.class, lineSeparatorParam.trim() 111 .toUpperCase(Locale.ENGLISH)); 112 } 113 catch (IllegalArgumentException iae) { 114 throw new ConversionException("unable to parse " + lineSeparatorParam, 115 iae); 116 } 117 } 118 119 /** 120 * Checks whether the content provided by the Reader ends with the platform 121 * specific line separator. 122 * @param randomAccessFile The reader for the content to check 123 * @return boolean Whether the content ends with a line separator 124 * @throws IOException When an IO error occurred while reading from the 125 * provided reader 126 */ 127 private boolean endsWithNewline(RandomAccessFile randomAccessFile) 128 throws IOException { 129 final int len = lineSeparator.length(); 130 if (randomAccessFile.length() < len) { 131 return false; 132 } 133 randomAccessFile.seek(randomAccessFile.length() - len); 134 final byte[] lastBytes = new byte[len]; 135 final int readBytes = randomAccessFile.read(lastBytes); 136 if (readBytes != len) { 137 throw new IOException("Unable to read " + len + " bytes, got " 138 + readBytes); 139 } 140 return lineSeparator.matches(lastBytes); 141 } 142}