001//////////////////////////////////////////////////////////////////////////////// 002// checkstyle: Checks Java source code for adherence to a set of rules. 003// Copyright (C) 2001-2015 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.regex.Pattern; 033 034import org.apache.commons.beanutils.ConversionException; 035import org.apache.commons.lang3.StringUtils; 036 037import com.google.common.collect.ImmutableList; 038import com.google.common.collect.Lists; 039import com.google.common.io.Closeables; 040import com.puppycrawl.tools.checkstyle.api.AbstractFileSetCheck; 041import com.puppycrawl.tools.checkstyle.api.CheckstyleException; 042import com.puppycrawl.tools.checkstyle.utils.CommonUtils; 043 044/** 045 * Abstract super class for header checks. 046 * Provides support for header and headerFile properties. 047 * @author o_sukhosolsky 048 */ 049public abstract class AbstractHeaderCheck extends AbstractFileSetCheck { 050 /** Pattern to detect occurrences of '\n' in text. */ 051 private static final Pattern ESCAPED_LINE_FEED_PATTERN = Pattern.compile("\\\\n"); 052 /** The file that contains the header to check against. */ 053 private String headerFile; 054 055 /** Name of a charset to use for loading the header from a file. */ 056 private String charset = System.getProperty("file.encoding", "UTF-8"); 057 058 /** The lines of the header file. */ 059 private final List<String> readerLines = Lists.newArrayList(); 060 061 /** 062 * Hook method for post processing header lines. 063 * This implementation does nothing. 064 */ 065 protected abstract void postProcessHeaderLines(); 066 067 /** 068 * Return the header lines to check against. 069 * @return the header lines to check against. 070 */ 071 protected ImmutableList<String> getHeaderLines() { 072 return ImmutableList.copyOf(readerLines); 073 } 074 075 /** 076 * Set the charset to use for loading the header from a file. 077 * @param charset the charset to use for loading the header from a file 078 * @throws UnsupportedEncodingException if charset is unsupported 079 */ 080 public void setCharset(String charset) throws UnsupportedEncodingException { 081 if (!Charset.isSupported(charset)) { 082 final String message = "unsupported charset: '" + charset + "'"; 083 throw new UnsupportedEncodingException(message); 084 } 085 this.charset = charset; 086 } 087 088 /** 089 * Set the header file to check against. 090 * @param fileName the file that contains the header to check against. 091 * @throws CheckstyleException if fileName is empty. 092 */ 093 public void setHeaderFile(String fileName) throws CheckstyleException { 094 if (StringUtils.isBlank(fileName)) { 095 throw new CheckstyleException( 096 "property 'headerFile' is missing or invalid in module " 097 + getConfiguration().getName()); 098 } 099 100 headerFile = fileName; 101 } 102 103 /** 104 * Load the header from a file. 105 * @throws CheckstyleException if the file cannot be loaded 106 */ 107 private void loadHeaderFile() throws CheckstyleException { 108 checkHeaderNotInitialized(); 109 Reader headerReader = null; 110 try { 111 final URI uri = CommonUtils.getUriByFilename(headerFile); 112 headerReader = new InputStreamReader(new BufferedInputStream( 113 uri.toURL().openStream()), charset); 114 loadHeader(headerReader); 115 } 116 catch (final IOException ex) { 117 throw new CheckstyleException( 118 "unable to load header file " + headerFile, ex); 119 } 120 finally { 121 Closeables.closeQuietly(headerReader); 122 } 123 } 124 125 /** 126 * Called before initializing the header. 127 * @throws ConversionException if header has already been set 128 */ 129 private void checkHeaderNotInitialized() { 130 if (!readerLines.isEmpty()) { 131 throw new ConversionException( 132 "header has already been set - " 133 + "set either header or headerFile, not both"); 134 } 135 } 136 137 /** 138 * Set the header to check against. Individual lines in the header 139 * must be separated by '\n' characters. 140 * @param header header content to check against. 141 * @throws ConversionException if the header cannot be interpreted 142 */ 143 public void setHeader(String header) { 144 if (StringUtils.isBlank(header)) { 145 return; 146 } 147 148 checkHeaderNotInitialized(); 149 150 final String headerExpandedNewLines = ESCAPED_LINE_FEED_PATTERN 151 .matcher(header).replaceAll("\n"); 152 153 final Reader headerReader = new StringReader(headerExpandedNewLines); 154 try { 155 loadHeader(headerReader); 156 } 157 catch (final IOException ex) { 158 throw new ConversionException("unable to load header", ex); 159 } 160 finally { 161 Closeables.closeQuietly(headerReader); 162 } 163 } 164 165 /** 166 * Load header to check against from a Reader into readerLines. 167 * @param headerReader delivers the header to check against 168 * @throws IOException if 169 */ 170 private void loadHeader(final Reader headerReader) throws IOException { 171 final LineNumberReader lnr = new LineNumberReader(headerReader); 172 readerLines.clear(); 173 while (true) { 174 final String line = lnr.readLine(); 175 if (line == null) { 176 break; 177 } 178 readerLines.add(line); 179 } 180 postProcessHeaderLines(); 181 } 182 183 @Override 184 protected final void finishLocalSetup() throws CheckstyleException { 185 if (headerFile != null) { 186 loadHeaderFile(); 187 } 188 if (readerLines.isEmpty()) { 189 setHeader(null); 190 } 191 } 192}