Java tutorial
//////////////////////////////////////////////////////////////////////////////// // checkstyle: Checks Java source code for adherence to a set of rules. // Copyright (C) 2001-2015 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.header; import java.io.BufferedInputStream; import java.io.IOException; import java.io.InputStreamReader; import java.io.LineNumberReader; import java.io.Reader; import java.io.StringReader; import java.io.UnsupportedEncodingException; import java.net.URI; import java.nio.charset.Charset; import java.util.List; import java.util.regex.Pattern; import org.apache.commons.beanutils.ConversionException; import org.apache.commons.lang3.StringUtils; import com.google.common.collect.ImmutableList; import com.google.common.collect.Lists; import com.google.common.io.Closeables; import com.puppycrawl.tools.checkstyle.api.AbstractFileSetCheck; import com.puppycrawl.tools.checkstyle.api.CheckstyleException; import com.puppycrawl.tools.checkstyle.utils.CommonUtils; /** * Abstract super class for header checks. * Provides support for header and headerFile properties. * @author o_sukhosolsky */ public abstract class AbstractHeaderCheck extends AbstractFileSetCheck { /** Pattern to detect occurrences of '\n' in text. */ private static final Pattern ESCAPED_LINE_FEED_PATTERN = Pattern.compile("\\\\n"); /** The file that contains the header to check against. */ private String filename; /** Name of a charset to use for loading the header from a file. */ private String charset = System.getProperty("file.encoding", "UTF-8"); /** The lines of the header file. */ private final List<String> readerLines = Lists.newArrayList(); /** * Hook method for post processing header lines. * This implementation does nothing. */ protected abstract void postProcessHeaderLines(); /** * Return the header lines to check against. * @return the header lines to check against. */ protected ImmutableList<String> getHeaderLines() { return ImmutableList.copyOf(readerLines); } /** * Set the charset to use for loading the header from a file. * @param charset the charset to use for loading the header from a file * @throws UnsupportedEncodingException if charset is unsupported */ public void setCharset(String charset) throws UnsupportedEncodingException { if (!Charset.isSupported(charset)) { final String message = "unsupported charset: '" + charset + "'"; throw new UnsupportedEncodingException(message); } this.charset = charset; } /** * Set the header file to check against. * @param fileName the file that contains the header to check against. * @throws CheckstyleException if fileName is empty. */ public void setHeaderFile(String fileName) throws CheckstyleException { if (StringUtils.isBlank(fileName)) { throw new CheckstyleException( "property 'headerFile' is missing or invalid in module " + getConfiguration().getName()); } filename = fileName; } /** * Load the header from a file. * @throws CheckstyleException if the file cannot be loaded */ private void loadHeaderFile() throws CheckstyleException { checkHeaderNotInitialized(); Reader headerReader = null; try { final URI uri = CommonUtils.getUriByFilename(filename); headerReader = new InputStreamReader(new BufferedInputStream(uri.toURL().openStream()), charset); loadHeader(headerReader); } catch (final IOException ex) { throw new CheckstyleException("unable to load header file " + filename, ex); } finally { Closeables.closeQuietly(headerReader); } } /** * Called before initializing the header. * @throws ConversionException if header has already been set */ private void checkHeaderNotInitialized() { if (!readerLines.isEmpty()) { throw new ConversionException( "header has already been set - " + "set either header or headerFile, not both"); } } /** * Set the header to check against. Individual lines in the header * must be separated by '\n' characters. * @param header header content to check against. * @throws ConversionException if the header cannot be interpreted */ public void setHeader(String header) { if (StringUtils.isBlank(header)) { return; } checkHeaderNotInitialized(); final String headerExpandedNewLines = ESCAPED_LINE_FEED_PATTERN.matcher(header).replaceAll("\n"); final Reader headerReader = new StringReader(headerExpandedNewLines); try { loadHeader(headerReader); } catch (final IOException ex) { throw new ConversionException("unable to load header", ex); } finally { Closeables.closeQuietly(headerReader); } } /** * Load header to check against from a Reader into readerLines. * @param headerReader delivers the header to check against * @throws IOException if */ private void loadHeader(final Reader headerReader) throws IOException { final LineNumberReader lnr = new LineNumberReader(headerReader); readerLines.clear(); while (true) { final String line = lnr.readLine(); if (line == null) { break; } readerLines.add(line); } postProcessHeaderLines(); } @Override protected final void finishLocalSetup() throws CheckstyleException { if (filename != null) { loadHeaderFile(); } if (readerLines.isEmpty()) { setHeader(null); } } }