| Classes in this File | Line Coverage | Branch Coverage | Complexity | ||||
| AvoidStaticImportCheck |
|
| 3.25;3.25 |
| 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.imports; | |
| 20 | ||
| 21 | import com.puppycrawl.tools.checkstyle.api.Check; | |
| 22 | import com.puppycrawl.tools.checkstyle.api.DetailAST; | |
| 23 | import com.puppycrawl.tools.checkstyle.api.FullIdent; | |
| 24 | import com.puppycrawl.tools.checkstyle.api.TokenTypes; | |
| 25 | ||
| 26 | /** | |
| 27 | * <p> | |
| 28 | * Check that finds static imports. | |
| 29 | * </p> | |
| 30 | * <p> | |
| 31 | * Rationale: Importing static members can lead to naming conflicts | |
| 32 | * between class' members. It may lead to poor code readability since it | |
| 33 | * may no longer be clear what class a member resides (without looking | |
| 34 | * at the import statement). | |
| 35 | * </p> | |
| 36 | * <p> | |
| 37 | * An example of how to configure the check is: | |
| 38 | * </p> | |
| 39 | * <pre> | |
| 40 | * <module name="AvoidStaticImport"> | |
| 41 | * <property name="excludes" | |
| 42 | * value="java.lang.System.out,java.lang.Math.*"/> | |
| 43 | * </module> | |
| 44 | * </pre> | |
| 45 | * | |
| 46 | * The optional "excludes" property allows for certain classes via a star | |
| 47 | * notation to be excluded such as java.lang.Math.* or specific | |
| 48 | * static members to be excluded like java.lang.System.out for a variable | |
| 49 | * or java.lang.Math.random for a method. | |
| 50 | * | |
| 51 | * <p> | |
| 52 | * If you exclude a starred import on a class this automatically | |
| 53 | * excludes each member individually. | |
| 54 | * </p> | |
| 55 | * | |
| 56 | * <p> | |
| 57 | * For example: | |
| 58 | * Excluding java.lang.Math.* will allow the import of | |
| 59 | * each static member in the Math class individually like | |
| 60 | * java.lang.Math.PI | |
| 61 | * </p> | |
| 62 | * @author Travis Schneeberger | |
| 63 | * @version 1.0 | |
| 64 | */ | |
| 65 | 4 | public class AvoidStaticImportCheck |
| 66 | extends Check | |
| 67 | { | |
| 68 | /** the classes/static members to exempt from this check. */ | |
| 69 | 4 | private String[] mExcludes = new String[0]; |
| 70 | ||
| 71 | @Override | |
| 72 | public int[] getDefaultTokens() | |
| 73 | { | |
| 74 | 4 | return new int[] {TokenTypes.STATIC_IMPORT}; |
| 75 | } | |
| 76 | ||
| 77 | /** | |
| 78 | * Sets the list of classes or static members to be exempt from the check. | |
| 79 | * @param aExcludes a list of fully-qualified class names/specific | |
| 80 | * static members where static imports are ok | |
| 81 | */ | |
| 82 | public void setExcludes(String[] aExcludes) | |
| 83 | { | |
| 84 | 3 | mExcludes = aExcludes.clone(); |
| 85 | 3 | } |
| 86 | ||
| 87 | @Override | |
| 88 | public void visitToken(final DetailAST aAST) | |
| 89 | { | |
| 90 | 20 | final DetailAST startingDot = |
| 91 | aAST.getFirstChild().getNextSibling(); | |
| 92 | 20 | final FullIdent name = FullIdent.createFullIdent(startingDot); |
| 93 | ||
| 94 | 20 | if ((null != name) && !isExempt(name.getText())) { |
| 95 | 16 | log(startingDot.getLineNo(), "import.avoidStatic", name.getText()); |
| 96 | } | |
| 97 | 20 | } |
| 98 | ||
| 99 | /** | |
| 100 | * Checks if a class or static member is exempt from known excludes. | |
| 101 | * | |
| 102 | * @param aClassOrStaticMember | |
| 103 | * the class or static member | |
| 104 | * @return true if except false if not | |
| 105 | */ | |
| 106 | private boolean isExempt(String aClassOrStaticMember) | |
| 107 | { | |
| 108 | 54 | for (String exclude : mExcludes) { |
| 109 | 38 | if (aClassOrStaticMember.equals(exclude)) { |
| 110 | 2 | return true; |
| 111 | } | |
| 112 | 36 | else if (exclude.endsWith(".*")) { |
| 113 | //this section allows explicit imports | |
| 114 | //to be exempt when configured using | |
| 115 | //a starred import | |
| 116 | 7 | final String excludeMinusDotStar = |
| 117 | exclude.substring(0, exclude.length() - 2); | |
| 118 | 7 | if (aClassOrStaticMember.startsWith(excludeMinusDotStar)) { |
| 119 | 2 | final String member = |
| 120 | aClassOrStaticMember.substring( | |
| 121 | excludeMinusDotStar.length() + 1); | |
| 122 | //if it contains a dot then it is not a member but a package | |
| 123 | 2 | if (member.indexOf('.') == -1) { |
| 124 | 2 | return true; |
| 125 | } | |
| 126 | } | |
| 127 | } | |
| 128 | } | |
| 129 | 16 | return false; |
| 130 | } | |
| 131 | } |