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.coding; 021 022import java.util.LinkedList; 023import java.util.List; 024import java.util.Set; 025 026import com.google.common.collect.Sets; 027import com.puppycrawl.tools.checkstyle.api.Check; 028import com.puppycrawl.tools.checkstyle.api.DetailAST; 029import com.puppycrawl.tools.checkstyle.api.FullIdent; 030import com.puppycrawl.tools.checkstyle.api.TokenTypes; 031 032/** 033 * Catching java.lang.Exception, java.lang.Error or java.lang.RuntimeException 034 * is almost never acceptable. 035 * @author <a href="mailto:simon@redhillconsulting.com.au">Simon Harris</a> 036 * @author <a href="mailto:IliaDubinin91@gmail.com">Ilja Dubinin</a> 037 */ 038public final class IllegalCatchCheck extends Check { 039 040 /** 041 * A key is pointing to the warning message text in "messages.properties" 042 * file. 043 */ 044 public static final String MSG_KEY = "illegal.catch"; 045 046 /** Illegal class names. */ 047 private final Set<String> illegalClassNames = Sets.newHashSet("Exception", "Error", 048 "RuntimeException", "Throwable", "java.lang.Error", "java.lang.Exception", 049 "java.lang.RuntimeException", "java.lang.Throwable"); 050 051 /** 052 * Set the list of illegal classes. 053 * 054 * @param classNames 055 * array of illegal exception classes 056 */ 057 public void setIllegalClassNames(final String... classNames) { 058 illegalClassNames.clear(); 059 for (final String name : classNames) { 060 illegalClassNames.add(name); 061 final int lastDot = name.lastIndexOf('.'); 062 if (lastDot > 0 && lastDot < name.length() - 1) { 063 final String shortName = name 064 .substring(name.lastIndexOf('.') + 1); 065 illegalClassNames.add(shortName); 066 } 067 } 068 } 069 070 @Override 071 public int[] getDefaultTokens() { 072 return new int[] {TokenTypes.LITERAL_CATCH}; 073 } 074 075 @Override 076 public int[] getRequiredTokens() { 077 return getDefaultTokens(); 078 } 079 080 @Override 081 public int[] getAcceptableTokens() { 082 return new int[] {TokenTypes.LITERAL_CATCH}; 083 } 084 085 @Override 086 public void visitToken(DetailAST detailAST) { 087 final DetailAST parameterDef = 088 detailAST.findFirstToken(TokenTypes.PARAMETER_DEF); 089 final DetailAST excTypeParent = 090 parameterDef.findFirstToken(TokenTypes.TYPE); 091 final List<DetailAST> excTypes = getAllExceptionTypes(excTypeParent); 092 093 for (DetailAST excType : excTypes) { 094 final FullIdent ident = FullIdent.createFullIdent(excType); 095 096 if (illegalClassNames.contains(ident.getText())) { 097 log(detailAST, MSG_KEY, ident.getText()); 098 } 099 } 100 } 101 102 /** 103 * Finds all exception types in current catch. 104 * We need it till we can have few different exception types into one catch. 105 * @param parentToken - parent node for types (TYPE or BOR) 106 * @return list, that contains all exception types in current catch 107 */ 108 private static List<DetailAST> getAllExceptionTypes(DetailAST parentToken) { 109 DetailAST currentNode = parentToken.getFirstChild(); 110 final List<DetailAST> exceptionTypes = new LinkedList<>(); 111 if (currentNode.getType() == TokenTypes.BOR) { 112 exceptionTypes.addAll(getAllExceptionTypes(currentNode)); 113 currentNode = currentNode.getNextSibling(); 114 if (currentNode != null) { 115 exceptionTypes.add(currentNode); 116 } 117 } 118 else { 119 exceptionTypes.add(currentNode); 120 currentNode = currentNode.getNextSibling(); 121 while (currentNode != null) { 122 exceptionTypes.add(currentNode); 123 currentNode = currentNode.getNextSibling(); 124 } 125 } 126 return exceptionTypes; 127 } 128}