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

 // 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.design;

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

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

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

 /**

  * <p>

  * Restricts throws statements to a specified count (default = 1).

  * </p>

  * <p>

  * Rationale:

  * Exceptions form part of a methods interface. Declaring

  * a method to throw too many differently rooted

  * exceptions makes exception handling onerous and leads

  * to poor programming practices such as catch

  * (Exception). This check forces developers to put

  * exceptions into a hierarchy such that in the simplest

  * case, only one type of exception need be checked for by

  * a caller but allows any sub-classes to be caught

  * specifically if necessary.

  * </p>

  * @author <a href="mailto:simon@redhillconsulting.com.au">Simon Harris</a>

  */

 public final class ThrowsCountCheck extends Check

 {

     /** default value of max property */

     private static final int DEFAULT_MAX = 1;

     /** maximum allowed throws statements */

     private int mMax;

     /** Creates new instance of the check. */

     public ThrowsCountCheck()

     {

         setMax(DEFAULT_MAX);

     }

     @Override

     public int[] getDefaultTokens()

     {

         return new int[] {

             TokenTypes.LITERAL_THROWS,

         };

     }

     @Override

     public int[] getRequiredTokens()

     {

         return getDefaultTokens();

     }

     /**

      * Getter for max property.

      * @return maximum allowed throws statements.

      */

     public int getMax()

     {

         return mMax;

     }

     /**

      * Setter for max property.

      * @param aMax maximum allowed throws statements.

      */

     public void setMax(int aMax)

     {

         mMax = aMax;

     }

     @Override

     public void visitToken(DetailAST aAST)

     {

         switch (aAST.getType()) {

         case TokenTypes.LITERAL_THROWS:

             visitLiteralThrows(aAST);

             break;

         default:

             throw new IllegalStateException(aAST.toString());

         }

     }

     /**

      * Checks number of throws statements.

      * @param aAST throws for check.

      */

     private void visitLiteralThrows(DetailAST aAST)

     {

         // Account for all the commas!

         final int count = (aAST.getChildCount() + 1) / 2;

         if (count > getMax()) {

             log(aAST.getLineNo(),  aAST.getColumnNo(), "throws.count",

                 count, getMax());

         }

     }

 }