| Classes in this File | Line Coverage | Branch Coverage | Complexity | ||||
| MutableExceptionCheck |
|
| 1.8888888888888888;1.889 |
| 1 | //////////////////////////////////////////////////////////////////////////////// | |
| 2 | // checkstyle: Checks Java source code for adherence to a set of rules. | |
| 3 | // Copyright (C) 2001-2014 Oliver Burn | |
| 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 | package com.puppycrawl.tools.checkstyle.checks.design; | |
| 20 | ||
| 21 | import com.puppycrawl.tools.checkstyle.api.DetailAST; | |
| 22 | import com.puppycrawl.tools.checkstyle.api.FastStack; | |
| 23 | import com.puppycrawl.tools.checkstyle.api.TokenTypes; | |
| 24 | import com.puppycrawl.tools.checkstyle.checks.AbstractFormatCheck; | |
| 25 | ||
| 26 | /** | |
| 27 | * <p> Ensures that exceptions (defined as any class name conforming | |
| 28 | * to some regular expression) are immutable. That is, have only final | |
| 29 | * fields.</p> | |
| 30 | * <p> Rationale: Exception instances should represent an error | |
| 31 | * condition. Having non final fields not only allows the state to be | |
| 32 | * modified by accident and therefore mask the original condition but | |
| 33 | * also allows developers to accidentally forget to initialise state | |
| 34 | * thereby leading to code catching the exception to draw incorrect | |
| 35 | * conclusions based on the state.</p> | |
| 36 | * | |
| 37 | * @author <a href="mailto:simon@redhillconsulting.com.au">Simon Harris</a> | |
| 38 | */ | |
| 39 | public final class MutableExceptionCheck extends AbstractFormatCheck | |
| 40 | { | |
| 41 | /** Default value for format property. */ | |
| 42 | private static final String DEFAULT_FORMAT = "^.*Exception$|^.*Error$"; | |
| 43 | /** Stack of checking information for classes. */ | |
| 44 | 1 | private final FastStack<Boolean> mCheckingStack = FastStack.newInstance(); |
| 45 | /** Should we check current class or not. */ | |
| 46 | private boolean mChecking; | |
| 47 | ||
| 48 | /** Creates new instance of the check. */ | |
| 49 | public MutableExceptionCheck() | |
| 50 | { | |
| 51 | 1 | super(DEFAULT_FORMAT); |
| 52 | 1 | } |
| 53 | ||
| 54 | @Override | |
| 55 | public int[] getDefaultTokens() | |
| 56 | { | |
| 57 | 1 | return new int[] {TokenTypes.CLASS_DEF, TokenTypes.VARIABLE_DEF}; |
| 58 | } | |
| 59 | ||
| 60 | @Override | |
| 61 | public int[] getRequiredTokens() | |
| 62 | { | |
| 63 | 0 | return getDefaultTokens(); |
| 64 | } | |
| 65 | ||
| 66 | @Override | |
| 67 | public void visitToken(DetailAST aAST) | |
| 68 | { | |
| 69 | 9 | switch (aAST.getType()) { |
| 70 | case TokenTypes.CLASS_DEF: | |
| 71 | 4 | visitClassDef(aAST); |
| 72 | 4 | break; |
| 73 | case TokenTypes.VARIABLE_DEF: | |
| 74 | 5 | visitVariableDef(aAST); |
| 75 | 5 | break; |
| 76 | default: | |
| 77 | 0 | throw new IllegalStateException(aAST.toString()); |
| 78 | } | |
| 79 | 9 | } |
| 80 | ||
| 81 | @Override | |
| 82 | public void leaveToken(DetailAST aAST) | |
| 83 | { | |
| 84 | 9 | switch (aAST.getType()) { |
| 85 | case TokenTypes.CLASS_DEF: | |
| 86 | 4 | leaveClassDef(); |
| 87 | 4 | break; |
| 88 | default: | |
| 89 | // Do nothing | |
| 90 | } | |
| 91 | 9 | } |
| 92 | ||
| 93 | /** | |
| 94 | * Called when we start processing class definition. | |
| 95 | * @param aAST class definition node | |
| 96 | */ | |
| 97 | private void visitClassDef(DetailAST aAST) | |
| 98 | { | |
| 99 | 4 | mCheckingStack.push(mChecking ? Boolean.TRUE : Boolean.FALSE); |
| 100 | 4 | mChecking = |
| 101 | isExceptionClass(aAST.findFirstToken(TokenTypes.IDENT).getText()); | |
| 102 | 4 | } |
| 103 | ||
| 104 | /** Called when we leave class definition. */ | |
| 105 | private void leaveClassDef() | |
| 106 | { | |
| 107 | 4 | mChecking = (mCheckingStack.pop()).booleanValue(); |
| 108 | 4 | } |
| 109 | ||
| 110 | /** | |
| 111 | * Checks variable definition. | |
| 112 | * @param aAST variable def node for check. | |
| 113 | */ | |
| 114 | private void visitVariableDef(DetailAST aAST) | |
| 115 | { | |
| 116 | 5 | if (mChecking && (aAST.getParent().getType() == TokenTypes.OBJBLOCK)) { |
| 117 | 3 | final DetailAST modifiersAST = |
| 118 | aAST.findFirstToken(TokenTypes.MODIFIERS); | |
| 119 | ||
| 120 | 3 | if (!(modifiersAST.findFirstToken(TokenTypes.FINAL) != null)) { |
| 121 | 2 | log(aAST.getLineNo(), aAST.getColumnNo(), "mutable.exception", |
| 122 | aAST.findFirstToken(TokenTypes.IDENT).getText()); | |
| 123 | } | |
| 124 | } | |
| 125 | 5 | } |
| 126 | ||
| 127 | /** | |
| 128 | * @param aClassName class name to check | |
| 129 | * @return true if a given class name confirms specified format | |
| 130 | */ | |
| 131 | private boolean isExceptionClass(String aClassName) | |
| 132 | { | |
| 133 | 4 | return getRegexp().matcher(aClassName).find(); |
| 134 | } | |
| 135 | } |