1 /////////////////////////////////////////////////////////////////////////////////////////////// 2 // checkstyle: Checks Java source code and other text files for adherence to a set of rules. 3 // Copyright (C) 2001-2024 the original author or authors. 4 // 5 // This library is free software; you can redistribute it and/or 6 // modify it under the terms of the GNU Lesser General Public 7 // License as published by the Free Software Foundation; either 8 // version 2.1 of the License, or (at your option) any later version. 9 // 10 // This library is distributed in the hope that it will be useful, 11 // but WITHOUT ANY WARRANTY; without even the implied warranty of 12 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 13 // Lesser General Public License for more details. 14 // 15 // You should have received a copy of the GNU Lesser General Public 16 // License along with this library; if not, write to the Free Software 17 // Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA 18 /////////////////////////////////////////////////////////////////////////////////////////////// 19 20 package com.puppycrawl.tools.checkstyle.checks.coding; 21 22 import java.util.Arrays; 23 import java.util.Collections; 24 import java.util.HashSet; 25 import java.util.Set; 26 import java.util.stream.Collectors; 27 28 import com.puppycrawl.tools.checkstyle.StatelessCheck; 29 import com.puppycrawl.tools.checkstyle.api.AbstractCheck; 30 import com.puppycrawl.tools.checkstyle.api.DetailAST; 31 import com.puppycrawl.tools.checkstyle.api.FullIdent; 32 import com.puppycrawl.tools.checkstyle.api.TokenTypes; 33 import com.puppycrawl.tools.checkstyle.utils.AnnotationUtil; 34 import com.puppycrawl.tools.checkstyle.utils.CheckUtil; 35 36 /** 37 * <div> 38 * Checks that specified types are not declared to be thrown. 39 * Declaring that a method throws {@code java.lang.Error} or 40 * {@code java.lang.RuntimeException} is almost never acceptable. 41 * </div> 42 * <ul> 43 * <li> 44 * Property {@code ignoreOverriddenMethods} - Allow to ignore checking overridden methods 45 * (marked with {@code Override} or {@code java.lang.Override} annotation). 46 * Type is {@code boolean}. 47 * Default value is {@code true}. 48 * </li> 49 * <li> 50 * Property {@code ignoredMethodNames} - Specify names of methods to ignore. 51 * Type is {@code java.lang.String[]}. 52 * Default value is {@code finalize}. 53 * </li> 54 * <li> 55 * Property {@code illegalClassNames} - Specify throw class names to reject. 56 * Type is {@code java.lang.String[]}. 57 * Default value is {@code Error, RuntimeException, Throwable, java.lang.Error, 58 * java.lang.RuntimeException, java.lang.Throwable}. 59 * </li> 60 * </ul> 61 * 62 * <p> 63 * Parent is {@code com.puppycrawl.tools.checkstyle.TreeWalker} 64 * </p> 65 * 66 * <p> 67 * Violation Message Keys: 68 * </p> 69 * <ul> 70 * <li> 71 * {@code illegal.throw} 72 * </li> 73 * </ul> 74 * 75 * @since 4.0 76 */ 77 @StatelessCheck 78 public final class IllegalThrowsCheck extends AbstractCheck { 79 80 /** 81 * A key is pointing to the warning message text in "messages.properties" 82 * file. 83 */ 84 public static final String MSG_KEY = "illegal.throw"; 85 86 /** Specify names of methods to ignore. */ 87 private final Set<String> ignoredMethodNames = 88 Arrays.stream(new String[] {"finalize", }).collect(Collectors.toCollection(HashSet::new)); 89 90 /** Specify throw class names to reject. */ 91 private final Set<String> illegalClassNames = Arrays.stream( 92 new String[] {"Error", "RuntimeException", "Throwable", "java.lang.Error", 93 "java.lang.RuntimeException", "java.lang.Throwable", }) 94 .collect(Collectors.toCollection(HashSet::new)); 95 96 /** 97 * Allow to ignore checking overridden methods (marked with {@code Override} 98 * or {@code java.lang.Override} annotation). 99 */ 100 private boolean ignoreOverriddenMethods = true; 101 102 /** 103 * Setter to specify throw class names to reject. 104 * 105 * @param classNames 106 * array of illegal exception classes 107 * @since 4.0 108 */ 109 public void setIllegalClassNames(final String... classNames) { 110 illegalClassNames.clear(); 111 illegalClassNames.addAll( 112 CheckUtil.parseClassNames(classNames)); 113 } 114 115 @Override 116 public int[] getDefaultTokens() { 117 return getRequiredTokens(); 118 } 119 120 @Override 121 public int[] getRequiredTokens() { 122 return new int[] {TokenTypes.LITERAL_THROWS}; 123 } 124 125 @Override 126 public int[] getAcceptableTokens() { 127 return getRequiredTokens(); 128 } 129 130 @Override 131 public void visitToken(DetailAST detailAST) { 132 final DetailAST methodDef = detailAST.getParent(); 133 // Check if the method with the given name should be ignored. 134 if (!isIgnorableMethod(methodDef)) { 135 DetailAST token = detailAST.getFirstChild(); 136 while (token != null) { 137 final FullIdent ident = FullIdent.createFullIdent(token); 138 final String identText = ident.getText(); 139 if (illegalClassNames.contains(identText)) { 140 log(token, MSG_KEY, identText); 141 } 142 token = token.getNextSibling(); 143 } 144 } 145 } 146 147 /** 148 * Checks if current method is ignorable due to Check's properties. 149 * 150 * @param methodDef {@link TokenTypes#METHOD_DEF METHOD_DEF} 151 * @return true if method is ignorable. 152 */ 153 private boolean isIgnorableMethod(DetailAST methodDef) { 154 return shouldIgnoreMethod(methodDef.findFirstToken(TokenTypes.IDENT).getText()) 155 || ignoreOverriddenMethods 156 && AnnotationUtil.hasOverrideAnnotation(methodDef); 157 } 158 159 /** 160 * Check if the method is specified in the ignore method list. 161 * 162 * @param name the name to check 163 * @return whether the method with the passed name should be ignored 164 */ 165 private boolean shouldIgnoreMethod(String name) { 166 return ignoredMethodNames.contains(name); 167 } 168 169 /** 170 * Setter to specify names of methods to ignore. 171 * 172 * @param methodNames array of ignored method names 173 * @since 5.4 174 */ 175 public void setIgnoredMethodNames(String... methodNames) { 176 ignoredMethodNames.clear(); 177 Collections.addAll(ignoredMethodNames, methodNames); 178 } 179 180 /** 181 * Setter to allow to ignore checking overridden methods 182 * (marked with {@code Override} or {@code java.lang.Override} annotation). 183 * 184 * @param ignoreOverriddenMethods Check's property. 185 * @since 6.4 186 */ 187 public void setIgnoreOverriddenMethods(boolean ignoreOverriddenMethods) { 188 this.ignoreOverriddenMethods = ignoreOverriddenMethods; 189 } 190 191 }