001//////////////////////////////////////////////////////////////////////////////// 002// checkstyle: Checks Java source code for adherence to a set of rules. 003// Copyright (C) 2001-2018 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.utils; 021 022import java.io.IOException; 023import java.io.InputStream; 024import java.net.URI; 025import java.net.URL; 026 027import com.puppycrawl.tools.checkstyle.api.CheckstyleException; 028 029/** 030 * Utility methods for suppression filters. 031 * 032 * @author Timur Tibeyev. 033 */ 034public final class FilterUtils { 035 036 /** Stop instances being created. **/ 037 private FilterUtils() { 038 } 039 040 /** 041 * Checks if suppression source with given fileName exists. 042 * @param fileName name of the suppressions file. 043 * @return true if suppression file exists, otherwise false 044 */ 045 public static boolean isFileExists(String fileName) { 046 boolean suppressionSourceExists = true; 047 InputStream sourceInput = null; 048 try { 049 final URI uriByFilename = CommonUtils.getUriByFilename(fileName); 050 final URL url = uriByFilename.toURL(); 051 sourceInput = url.openStream(); 052 } 053 catch (CheckstyleException | IOException ignored) { 054 suppressionSourceExists = false; 055 } 056 finally { 057 suppressionSourceExists = closeQuietlyWithResult(sourceInput, suppressionSourceExists); 058 } 059 return suppressionSourceExists; 060 } 061 062 /** 063 * Close input. 064 * This method is required till https://github.com/cobertura/cobertura/issues/170 065 * @param sourceInput stream to close 066 * @param suppressionSourceExists previous state of flag 067 * @return result of close operation 068 */ 069 private static boolean closeQuietlyWithResult(InputStream sourceInput, 070 boolean suppressionSourceExists) { 071 boolean closed = suppressionSourceExists; 072 if (sourceInput != null) { 073 try { 074 sourceInput.close(); 075 } 076 catch (IOException ignored) { 077 closed = false; 078 } 079 } 080 return closed; 081 } 082 083}