Source code

001////////////////////////////////////////////////////////////////////////////////
002// checkstyle: Checks Java source code for adherence to a set of rules.
003// Copyright (C) 2001-2014  Oliver Burn
004//
005// This library is free software; you can redistribute it and/or
006// modify it under the terms of the GNU Lesser General Public
007// License as published by the Free Software Foundation; either
008// version 2.1 of the License, or (at your option) any later version.
009//
010// This library is distributed in the hope that it will be useful,
011// but WITHOUT ANY WARRANTY; without even the implied warranty of
012// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
013// Lesser General Public License for more details.
014//
015// You should have received a copy of the GNU Lesser General Public
016// License along with this library; if not, write to the Free Software
017// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
018////////////////////////////////////////////////////////////////////////////////
019package com.puppycrawl.tools.checkstyle.checks.metrics;
020
021import java.math.BigInteger;
022
023import com.puppycrawl.tools.checkstyle.api.DetailAST;
024import com.puppycrawl.tools.checkstyle.api.TokenTypes;
025
026/**
027 * Checks cyclomatic complexity against a specified limit. The complexity is
028 * measured by the number of "if", "while", "do", "for", "?:", "catch",
029 * "switch", "case", "&amp;&amp;" and "||" statements (plus one) in the body of
030 * the member. It is a measure of the minimum number of possible paths through
031 * the source and therefore the number of required tests. Generally 1-4 is
032 * considered good, 5-7 ok, 8-10 consider re-factoring, and 11+ re-factor now!
033 *
034 * @author <a href="mailto:simon@redhillconsulting.com.au">Simon Harris</a>
035 * @author Oliver Burn
036 */
037public class CyclomaticComplexityCheck
038    extends AbstractComplexityCheck
039{
040    /** default allowed complexity */
041    private static final int DEFAULT_VALUE = 10;
042
043    /** Create an instance. */
044    public CyclomaticComplexityCheck()
045    {
046        super(DEFAULT_VALUE);
047    }
048
049    @Override
050    public int[] getDefaultTokens()
051    {
052        return new int[] {
053            TokenTypes.CTOR_DEF,
054            TokenTypes.METHOD_DEF,
055            TokenTypes.INSTANCE_INIT,
056            TokenTypes.STATIC_INIT,
057            TokenTypes.LITERAL_WHILE,
058            TokenTypes.LITERAL_DO,
059            TokenTypes.LITERAL_FOR,
060            TokenTypes.LITERAL_IF,
061            TokenTypes.LITERAL_CASE,
062            TokenTypes.LITERAL_CATCH,
063            TokenTypes.QUESTION,
064            TokenTypes.LAND,
065            TokenTypes.LOR,
066        };
067    }
068
069    @Override
070    protected final void visitTokenHook(DetailAST ast)
071    {
072        incrementCurrentValue(BigInteger.ONE);
073    }
074
075    @Override
076    protected final String getMessageID()
077    {
078        return "cyclomaticComplexity";
079    }
080}