Coverage Report - com.puppycrawl.tools.checkstyle.checks.imports.AvoidStarImportCheck
 
Classes in this File Line Coverage Branch Coverage Complexity
AvoidStarImportCheck
100%
28/28
100%
16/16
2
 
 1  
 ////////////////////////////////////////////////////////////////////////////////
 2  
 // checkstyle: Checks Java source code for adherence to a set of rules.
 3  
 // Copyright (C) 2001-2017 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.imports;
 21  
 
 22  
 import java.util.ArrayList;
 23  
 import java.util.List;
 24  
 
 25  
 import com.puppycrawl.tools.checkstyle.StatelessCheck;
 26  
 import com.puppycrawl.tools.checkstyle.api.AbstractCheck;
 27  
 import com.puppycrawl.tools.checkstyle.api.DetailAST;
 28  
 import com.puppycrawl.tools.checkstyle.api.FullIdent;
 29  
 import com.puppycrawl.tools.checkstyle.api.TokenTypes;
 30  
 
 31  
 /**
 32  
  * <p>
 33  
  * Check that finds import statements that use the * notation.
 34  
  * </p>
 35  
  * <p>
 36  
  * Rationale: Importing all classes from a package or static
 37  
  * members from a class leads to tight coupling between packages
 38  
  * or classes and might lead to problems when a new version of a
 39  
  * library introduces name clashes.
 40  
  * </p>
 41  
  * <p>
 42  
  * An example of how to configure the check is:
 43  
  * </p>
 44  
  * <pre>
 45  
  * &lt;module name="AvoidStarImport"&gt;
 46  
  *   &lt;property name="excludes" value="java.io,java.net,java.lang.Math"/&gt;
 47  
  *   &lt;property name="allowClassImports" value="false"/&gt;
 48  
  *   &lt;property name="allowStaticMemberImports" value="false"/&gt;
 49  
  * &lt;/module&gt;
 50  
  * </pre>
 51  
  * The optional "excludes" property allows for certain packages like
 52  
  * java.io or java.net to be exempted from the rule. It also is used to
 53  
  * allow certain classes like java.lang.Math or java.io.File to be
 54  
  * excluded in order to support static member imports.
 55  
  *
 56  
  * <p>The optional "allowClassImports" when set to true, will allow starred
 57  
  * class imports but will not affect static member imports.
 58  
  *
 59  
  * <p>The optional "allowStaticMemberImports" when set to true will allow
 60  
  * starred static member imports but will not affect class imports.
 61  
  *
 62  
  * @author Oliver Burn
 63  
  * @author <a href="bschneider@vecna.com">Bill Schneider</a>
 64  
  * @author Travis Schneeberger
 65  
  */
 66  
 @StatelessCheck
 67  18
 public class AvoidStarImportCheck
 68  
     extends AbstractCheck {
 69  
 
 70  
     /**
 71  
      * A key is pointing to the warning message text in "messages.properties"
 72  
      * file.
 73  
      */
 74  
     public static final String MSG_KEY = "import.avoidStar";
 75  
 
 76  
     /** Suffix for the star import. */
 77  
     private static final String STAR_IMPORT_SUFFIX = ".*";
 78  
 
 79  
     /** The packages/classes to exempt from this check. */
 80  18
     private final List<String> excludes = new ArrayList<>();
 81  
 
 82  
     /** Whether to allow all class imports. */
 83  
     private boolean allowClassImports;
 84  
 
 85  
     /** Whether to allow all static member imports. */
 86  
     private boolean allowStaticMemberImports;
 87  
 
 88  
     @Override
 89  
     public int[] getDefaultTokens() {
 90  25
         return getRequiredTokens();
 91  
     }
 92  
 
 93  
     @Override
 94  
     public int[] getAcceptableTokens() {
 95  6
         return getRequiredTokens();
 96  
     }
 97  
 
 98  
     @Override
 99  
     public int[] getRequiredTokens() {
 100  
         // original implementation checks both IMPORT and STATIC_IMPORT tokens to avoid ".*" imports
 101  
         // however user can allow using "import" or "import static"
 102  
         // by configuring allowClassImports and allowStaticMemberImports
 103  
         // To avoid potential confusion when user specifies conflicting options on configuration
 104  
         // (see example below) we are adding both tokens to Required list
 105  
         //   <module name="AvoidStarImport">
 106  
         //      <property name="tokens" value="IMPORT"/>
 107  
         //      <property name="allowStaticMemberImports" value="false"/>
 108  
         //   </module>
 109  57
         return new int[] {TokenTypes.IMPORT, TokenTypes.STATIC_IMPORT};
 110  
     }
 111  
 
 112  
     /**
 113  
      * Sets the list of packages or classes to be exempt from the check.
 114  
      * The excludes can contain a .* or not.
 115  
      * @param excludesParam a list of package names/fully-qualifies class names
 116  
      *     where star imports are ok.
 117  
      */
 118  
     public void setExcludes(String... excludesParam) {
 119  9
         for (final String exclude : excludesParam) {
 120  7
             if (exclude.endsWith(STAR_IMPORT_SUFFIX)) {
 121  1
                 excludes.add(exclude);
 122  
             }
 123  
             else {
 124  6
                 excludes.add(exclude + STAR_IMPORT_SUFFIX);
 125  
             }
 126  
         }
 127  2
     }
 128  
 
 129  
     /**
 130  
      * Sets whether or not to allow all non-static class imports.
 131  
      * @param allow true to allow false to disallow
 132  
      */
 133  
     public void setAllowClassImports(boolean allow) {
 134  2
         allowClassImports = allow;
 135  2
     }
 136  
 
 137  
     /**
 138  
      * Sets whether or not to allow all static member imports.
 139  
      * @param allow true to allow false to disallow
 140  
      */
 141  
     public void setAllowStaticMemberImports(boolean allow) {
 142  2
         allowStaticMemberImports = allow;
 143  2
     }
 144  
 
 145  
     @Override
 146  
     public void visitToken(final DetailAST ast) {
 147  132
         if (!allowClassImports && ast.getType() == TokenTypes.IMPORT) {
 148  84
             final DetailAST startingDot = ast.getFirstChild();
 149  84
             logsStarredImportViolation(startingDot);
 150  84
         }
 151  48
         else if (!allowStaticMemberImports
 152  43
             && ast.getType() == TokenTypes.STATIC_IMPORT) {
 153  
             // must navigate past the static keyword
 154  15
             final DetailAST startingDot = ast.getFirstChild().getNextSibling();
 155  15
             logsStarredImportViolation(startingDot);
 156  
         }
 157  132
     }
 158  
 
 159  
     /**
 160  
      * Gets the full import identifier.  If the import is a starred import and
 161  
      * it's not excluded then a violation is logged.
 162  
      * @param startingDot the starting dot for the import statement
 163  
      */
 164  
     private void logsStarredImportViolation(DetailAST startingDot) {
 165  99
         final FullIdent name = FullIdent.createFullIdent(startingDot);
 166  99
         final String importText = name.getText();
 167  99
         if (importText.endsWith(STAR_IMPORT_SUFFIX) && !excludes.contains(importText)) {
 168  14
             log(startingDot.getLineNo(), MSG_KEY, importText);
 169  
         }
 170  99
     }
 171  
 
 172  
 }