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.header; 021 022import java.io.BufferedInputStream; 023import java.io.IOException; 024import java.io.InputStreamReader; 025import java.io.LineNumberReader; 026import java.io.Reader; 027import java.io.StringReader; 028import java.io.UnsupportedEncodingException; 029import java.net.URI; 030import java.nio.charset.Charset; 031import java.util.List; 032import java.util.Set; 033import java.util.regex.Pattern; 034 035import org.apache.commons.beanutils.ConversionException; 036 037import com.google.common.collect.ImmutableList; 038import com.google.common.collect.ImmutableSet; 039import com.google.common.collect.Lists; 040import com.google.common.io.Closeables; 041import com.puppycrawl.tools.checkstyle.api.AbstractFileSetCheck; 042import com.puppycrawl.tools.checkstyle.api.CheckstyleException; 043import com.puppycrawl.tools.checkstyle.api.ExternalResourceHolder; 044import com.puppycrawl.tools.checkstyle.utils.CommonUtils; 045 046/** 047 * Abstract super class for header checks. 048 * Provides support for header and headerFile properties. 049 * @author o_sukhosolsky 050 */ 051public abstract class AbstractHeaderCheck extends AbstractFileSetCheck 052 implements ExternalResourceHolder { 053 /** Pattern to detect occurrences of '\n' in text. */ 054 private static final Pattern ESCAPED_LINE_FEED_PATTERN = Pattern.compile("\\\\n"); 055 056 /** The lines of the header file. */ 057 private final List<String> readerLines = Lists.newArrayList(); 058 059 /** The file that contains the header to check against. */ 060 private String headerFile; 061 062 /** Name of a charset to use for loading the header from a file. */ 063 private String charset = System.getProperty("file.encoding", "UTF-8"); 064 065 /** 066 * Hook method for post processing header lines. 067 * This implementation does nothing. 068 */ 069 protected abstract void postProcessHeaderLines(); 070 071 /** 072 * Return the header lines to check against. 073 * @return the header lines to check against. 074 */ 075 protected ImmutableList<String> getHeaderLines() { 076 return ImmutableList.copyOf(readerLines); 077 } 078 079 /** 080 * Set the charset to use for loading the header from a file. 081 * @param charset the charset to use for loading the header from a file 082 * @throws UnsupportedEncodingException if charset is unsupported 083 */ 084 public void setCharset(String charset) throws UnsupportedEncodingException { 085 if (!Charset.isSupported(charset)) { 086 final String message = "unsupported charset: '" + charset + "'"; 087 throw new UnsupportedEncodingException(message); 088 } 089 this.charset = charset; 090 } 091 092 /** 093 * Set the header file to check against. 094 * @param fileName the file that contains the header to check against. 095 * @throws CheckstyleException if fileName is empty. 096 */ 097 public void setHeaderFile(String fileName) throws CheckstyleException { 098 if (CommonUtils.isBlank(fileName)) { 099 throw new CheckstyleException( 100 "property 'headerFile' is missing or invalid in module " 101 + getConfiguration().getName()); 102 } 103 104 headerFile = fileName; 105 } 106 107 /** 108 * Load the header from a file. 109 * @throws CheckstyleException if the file cannot be loaded 110 */ 111 private void loadHeaderFile() throws CheckstyleException { 112 checkHeaderNotInitialized(); 113 Reader headerReader = null; 114 try { 115 final URI uri = CommonUtils.getUriByFilename(headerFile); 116 headerReader = new InputStreamReader(new BufferedInputStream( 117 uri.toURL().openStream()), charset); 118 loadHeader(headerReader); 119 } 120 catch (final IOException ex) { 121 throw new CheckstyleException( 122 "unable to load header file " + headerFile, ex); 123 } 124 finally { 125 Closeables.closeQuietly(headerReader); 126 } 127 } 128 129 /** 130 * Called before initializing the header. 131 * @throws ConversionException if header has already been set 132 */ 133 private void checkHeaderNotInitialized() { 134 if (!readerLines.isEmpty()) { 135 throw new ConversionException( 136 "header has already been set - " 137 + "set either header or headerFile, not both"); 138 } 139 } 140 141 /** 142 * Set the header to check against. Individual lines in the header 143 * must be separated by '\n' characters. 144 * @param header header content to check against. 145 * @throws ConversionException if the header cannot be interpreted 146 */ 147 public void setHeader(String header) { 148 if (!CommonUtils.isBlank(header)) { 149 checkHeaderNotInitialized(); 150 151 final String headerExpandedNewLines = ESCAPED_LINE_FEED_PATTERN 152 .matcher(header).replaceAll("\n"); 153 154 final Reader headerReader = new StringReader(headerExpandedNewLines); 155 try { 156 loadHeader(headerReader); 157 } 158 catch (final IOException ex) { 159 throw new ConversionException("unable to load header", ex); 160 } 161 finally { 162 Closeables.closeQuietly(headerReader); 163 } 164 } 165 } 166 167 /** 168 * Load header to check against from a Reader into readerLines. 169 * @param headerReader delivers the header to check against 170 * @throws IOException if 171 */ 172 private void loadHeader(final Reader headerReader) throws IOException { 173 readerLines.clear(); 174 final LineNumberReader lnr = new LineNumberReader(headerReader); 175 while (true) { 176 final String line = lnr.readLine(); 177 if (line == null) { 178 break; 179 } 180 readerLines.add(line); 181 } 182 postProcessHeaderLines(); 183 } 184 185 @Override 186 protected final void finishLocalSetup() throws CheckstyleException { 187 if (headerFile != null) { 188 loadHeaderFile(); 189 } 190 if (readerLines.isEmpty()) { 191 setHeader(null); 192 } 193 } 194 195 @Override 196 public Set<String> getExternalResourceLocations() { 197 return ImmutableSet.of(headerFile); 198 } 199}