Java tutorial
//////////////////////////////////////////////////////////////////////////////// // checkstyle: Checks Java source code for adherence to a set of rules. // Copyright (C) 2001-2016 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.regexp; import java.io.File; import java.io.IOException; import java.util.List; import java.util.regex.Pattern; import com.google.common.io.Files; import com.puppycrawl.tools.checkstyle.api.AbstractFileSetCheck; import com.puppycrawl.tools.checkstyle.api.CheckstyleException; import com.puppycrawl.tools.checkstyle.utils.CommonUtils; /** * <p> * Implementation of a check that looks for a file name and/or path match (or * mis-match) against specified patterns. It can also be used to verify files * match specific naming patterns not covered by other checks (Ex: properties, * xml, etc.). * </p> * * <p> * When customizing the check, the properties are applied in a specific order. * The fileExtensions property first picks only files that match any of the * specific extensions supplied. Once files are matched against the * fileExtensions, the match property is then used in conjuction with the * patterns to determine if the check is looking for a match or mis-match on * those files. If the fileNamePattern is supplied, the matching is only applied * to the fileNamePattern and not the folderPattern. If no fileNamePattern is * supplied, then matching is applied to the folderPattern only and will result * in all files in a folder to be reported on violations. If no folderPattern is * supplied, then all folders that checkstyle finds are examined for violations. * The ignoreFileNameExtensions property drops the file extension and applies * the fileNamePattern only to the rest of file name. For example, if the file * is named 'test.java' and this property is turned on, the pattern is only * applied to 'test'. * </p> * * <p> * If this check is configured with no properties, then the default behavior of * this check is to report file names with spaces in them. When at least one * pattern property is supplied, the entire check is under the user's control to * allow them to fully customize the behavior. * </p> * * <p> * It is recommended that if you create your own pattern, to also specify a * custom error message. This allows the error message printed to be clear what * the violation is, especially if multiple RegexpOnFilename checks are used. * Argument 0 for the message populates the check's folderPattern. Argument 1 * for the message populates the check's fileNamePattern. The file name is not * passed as an argument since it is part of CheckStyle's default error * messages. * </p> * * <p> * Check have following options: * </p> * <ul> * <li> * folderPattern - Regular expression to match the folder path against. Default * value is null.</li> * * <li> * fileNamePattern - Regular expression to match the file name against. Default * value is null.</li> * * <li> * match - Whether to look for a match or mis-match on the file name, if the * fileNamePattern is supplied, otherwise it is applied on the folderPattern. * Default value is true.</li> * * <li> * ignoreFileNameExtensions - Whether to ignore the file extension for the file * name match. Default value is false.</li> * * <li> * fileExtensions - File type extension of files to process. If this is * specified, then only files that match these types are examined with the other * patterns. Default value is {}.</li> * </ul> * <br> * * <p> * To configure the check to report file names that contain a space: * </p> * * <pre> * <module name="RegexpOnFilename"/> * </pre> * <p> * To configure the check to force picture files to not be 'gif': * </p> * * <pre> * <module name="RegexpOnFilename"> * <property name="fileNamePattern" value="\\.gif$"/> * </module> * </pre> * <p> * OR: * </p> * * <pre> * <module name="RegexpOnFilename"> * <property name="fileNamePattern" value="."/> * <property name="fileExtensions" value="gif"/> * </module> * </pre> * * <p> * To configure the check to only allow property and xml files to be located in * the resource folder: * </p> * * <pre> * <module name="RegexpOnFilename"> * <property name="folderPattern" * value="[\\/]src[\\/]\\w+[\\/]resources[\\/]"/> * <property name="match" value="false"/> * <property name="fileExtensions" value="properties, xml"/> * </module> * </pre> * * <p> * To configure the check to only allow Java and XML files in your folders use * the below. * </p> * * <pre> * <module name="RegexpOnFilename"> * <property name="fileNamePattern" value="\\.(java|xml)$"/> * <property name="match" value="false"/> * </module> * </pre> * <p> * To configure the check to only allow Java and XML files only in your source * folder and ignore any other folders: * </p> * * <p> * <b>Note:</b> 'folderPattern' must be specified if checkstyle is analyzing * more than the normal source folder, like the 'bin' folder where class files * can be located. * </p> * * <pre> * <module name="RegexpOnFilename"> * <property name="folderPattern" value="[\\/]src[\\/]"/> * <property name="fileNamePattern" value="\\.(java|xml)$"/> * <property name="match" value="false"/> * </module> * </pre> * <p> * To configure the check to only allow file names to be camel case: * </p> * * <pre> * <module name="RegexpOnFilename"> * <property name="fileNamePattern" * value="^([A-Z][a-z0-9]+\.?)+$"/> * <property name="match" value="false"/> * <property name="ignoreFileNameExtensions" value="true"/> * </module> * </pre> * * @author Richard Veach */ public class RegexpOnFilenameCheck extends AbstractFileSetCheck { /** * A key is pointing to the warning message text in "messages.properties" * file. */ public static final String MSG_MATCH = "regexp.filename.match"; /** * A key is pointing to the warning message text in "messages.properties" * file. */ public static final String MSG_MISMATCH = "regexp.filename.mismatch"; /** Compiled regexp to match a folder. */ private Pattern folderPattern; /** Compiled regexp to match a file. */ private Pattern fileNamePattern; /** Whether to look for a file name match or mismatch. */ private boolean match = true; /** Whether to ignore the file's extension when looking for matches. */ private boolean ignoreFileNameExtensions; /** * Setter for folder format. * * @param folderPattern format of folder. * @throws org.apache.commons.beanutils.ConversionException if unable to * create Pattern object. */ public void setFolderPattern(String folderPattern) { this.folderPattern = CommonUtils.createPattern(folderPattern); } /** * Setter for file name format. * * @param fileNamePattern format of file. * @throws org.apache.commons.beanutils.ConversionException if unable to * create Pattern object. */ public void setFileNamePattern(String fileNamePattern) { this.fileNamePattern = CommonUtils.createPattern(fileNamePattern); } /** * Sets whether the check should look for a file name match or mismatch. * * @param match check's option for matching file names. */ public void setMatch(boolean match) { this.match = match; } /** * Sets whether file name matching should drop the file extension or not. * * @param ignoreFileNameExtensions check's option for ignoring file extension. */ public void setIgnoreFileNameExtensions(boolean ignoreFileNameExtensions) { this.ignoreFileNameExtensions = ignoreFileNameExtensions; } @Override public void init() { if (fileNamePattern == null && folderPattern == null) { fileNamePattern = CommonUtils.createPattern("\\s"); } } @Override protected void processFiltered(File file, List<String> lines) throws CheckstyleException { final String fileName = getFileName(file); final String folderPath = getFolderPath(file); if (isMatchFolder(folderPath) && isMatchFile(fileName)) { log(); } } /** * Retrieves the file name from the given {@code file}. * * @param file Input file to examine. * @return The file name. */ private String getFileName(File file) { String fileName = file.getName(); if (ignoreFileNameExtensions) { fileName = Files.getNameWithoutExtension(fileName); } return fileName; } /** * Retrieves the folder path from the given {@code file}. * * @param file Input file to examine. * @return The folder path. * @throws CheckstyleException if there is an error getting the canonical * path of the {@code file}. */ private static String getFolderPath(File file) throws CheckstyleException { try { return file.getParentFile().getCanonicalPath(); } catch (IOException ex) { throw new CheckstyleException("unable to create canonical path names for " + file.getAbsolutePath(), ex); } } /** * Checks if the given {@code folderPath} matches the specified * {@link #folderPattern}. * * @param folderPath Input folder path to examine. * @return true if they do match. */ private boolean isMatchFolder(String folderPath) { final boolean result; // null pattern always matches, regardless of value of 'match' if (folderPattern == null) { result = true; } else { final boolean useMatch; // null pattern means 'match' applies to the folderPattern matching if (fileNamePattern == null) { useMatch = match; } else { useMatch = true; } result = folderPattern.matcher(folderPath).find() == useMatch; } return result; } /** * Checks if the given {@code fileName} matches the specified * {@link #fileNamePattern}. * * @param fileName Input file name to examine. * @return true if they do match. */ private boolean isMatchFile(String fileName) { final boolean result; // null pattern always matches, regardless of value of 'match' if (fileNamePattern == null) { result = true; } else { result = fileNamePattern.matcher(fileName).find() == match; } return result; } /** Logs the errors for the check. */ private void log() { final String folder = getStringOrDefault(folderPattern, ""); final String fileName = getStringOrDefault(fileNamePattern, ""); if (match) { log(0, MSG_MATCH, folder, fileName); } else { log(0, MSG_MISMATCH, folder, fileName); } } /** * Retrieves the String form of the {@code pattern} or {@code defaultString} * if null. * * @param pattern The pattern to convert. * @param defaultString The result to use if {@code pattern} is null. * @return The String form of the {@code pattern}. */ private static String getStringOrDefault(Pattern pattern, String defaultString) { final String result; if (pattern == null) { result = defaultString; } else { result = pattern.toString(); } return result; } }