////////////////////////////////////////////////////////////////////////////////

 // checkstyle: Checks Java source code for adherence to a set of rules.

 // Copyright (C) 2001-2014  Oliver Burn

 //

 // This library is free software; you can redistribute it and/or

 // modify it under the terms of the GNU Lesser General Public

 // License as published by the Free Software Foundation; either

 // version 2.1 of the License, or (at your option) any later version.

 //

 // This library is distributed in the hope that it will be useful,

 // but WITHOUT ANY WARRANTY; without even the implied warranty of

 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU

 // Lesser General Public License for more details.

 //

 // You should have received a copy of the GNU Lesser General Public

 // License along with this library; if not, write to the Free Software

 // Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA

 ////////////////////////////////////////////////////////////////////////////////

 package com.puppycrawl.tools.checkstyle.checks.imports;

 import java.util.List;

 import com.google.common.collect.Lists;

 import com.puppycrawl.tools.checkstyle.api.Check;

 import com.puppycrawl.tools.checkstyle.api.DetailAST;

 import com.puppycrawl.tools.checkstyle.api.FullIdent;

 import com.puppycrawl.tools.checkstyle.api.TokenTypes;

 /**

  * <p>

  * Check that finds import statements that use the * notation.

  * </p>

  * <p>

  * Rationale: Importing all classes from a package or static

  * members from a class leads to tight coupling between packages

  * or classes and might lead to problems when a new version of a

  * library introduces name clashes.

  * </p>

  * <p>

  * An example of how to configure the check is:

  * </p>

  * <pre>

  * <module name="AvoidStarImport">

  *   <property name="excludes" value="java.io,java.net,java.lang.Math"/>

  *   <property name="allowClassImports" value="false"/>

  *   <property name="allowStaticMemberImports" value="false"/>

  * </module>

  * </pre>

  *

  * The optional "excludes" property allows for certain packages like

  * java.io or java.net to be exempted from the rule. It also is used to

  * allow certain classes like java.lang.Math or java.io.File to be

  * excluded in order to support static member imports.

  *

  * The optional "allowClassImports" when set to true, will allow starred

  * class imports but will not affect static member imports.

  *

  * The optional "allowStaticMemberImports" when set to true will allow

  * starred static member imports but will not affect class imports.

  *

  * @author Oliver Burn

  * @author <a href="bschneider@vecna.com">Bill Schneider</a>

  * @author Travis Schneeberger

  * @version 2.0

  */

 public class AvoidStarImportCheck

     extends Check

 {

     /** the packages/classes to exempt from this check. */

     private final List<String> mExcludes = Lists.newArrayList();

     /** whether to allow all class imports */

     private boolean mAllowClassImports;

     /** whether to allow all static member imports */

     private boolean mAllowStaticMemberImports;

     @Override

     public int[] getDefaultTokens()

     {

         return new int[] {TokenTypes.IMPORT, TokenTypes.STATIC_IMPORT};

     }

     /**

      * Sets the list of packages or classes to be exempt from the check.

      * The excludes can contain a .* or not.

      * @param aExcludes a list of package names/fully-qualifies class names

      * where star imports are ok

      */

     public void setExcludes(String[] aExcludes)

     {

         mExcludes.clear();

         for (final String exclude : aExcludes) {

             mExcludes.add(exclude.endsWith(".*") ? exclude : exclude + ".*");

         }

     }

     /**

      * Sets whether or not to allow all non-static class imports.

      * @param aAllow true to allow false to disallow

      */

     public void setAllowClassImports(boolean aAllow)

     {

         mAllowClassImports = aAllow;

     }

     /**

      * Sets whether or not to allow all static member imports.

      * @param aAllow true to allow false to disallow

      */

     public void setAllowStaticMemberImports(boolean aAllow)

     {

         mAllowStaticMemberImports = aAllow;

     }

     @Override

     public void visitToken(final DetailAST aAST)

     {

         if (!mAllowClassImports && (TokenTypes.IMPORT == aAST.getType())) {

             final DetailAST startingDot = aAST.getFirstChild();

             logsStarredImportViolation(startingDot);

         }

         else if (!mAllowStaticMemberImports

             && (TokenTypes.STATIC_IMPORT == aAST.getType()))

         {

             // must navigate past the static keyword

             final DetailAST startingDot = aAST.getFirstChild().getNextSibling();

             logsStarredImportViolation(startingDot);

         }

     }

     /**

      * Gets the full import identifier.  If the import is a starred import and

      * it's not excluded then a violation is logged.

      * @param aStartingDot the starting dot for the import statement

      */

     private void logsStarredImportViolation(DetailAST aStartingDot)

     {

         final FullIdent name = FullIdent.createFullIdent(aStartingDot);

         if (isStaredImport(name) && !mExcludes.contains(name.getText())) {

             log(aStartingDot.getLineNo(), "import.avoidStar", name.getText());

         }

     }

     /**

      * Checks is an import is a stared import.

      * @param aImportIdent the full import identifier

      * @return true if a start import false if not

      */

     private boolean isStaredImport(FullIdent aImportIdent)

     {

         return (null != aImportIdent) && aImportIdent.getText().endsWith(".*");

     }

 }