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.sizes; 020 021import com.puppycrawl.tools.checkstyle.api.Check; 022import com.puppycrawl.tools.checkstyle.api.DetailAST; 023import com.puppycrawl.tools.checkstyle.api.FileContents; 024import com.puppycrawl.tools.checkstyle.api.TokenTypes; 025 026/** 027 * <p> 028 * Checks for long methods. 029 * </p> 030 * <p> 031 * Rationale: If a method becomes very long it is hard to understand. 032 * Therefore long methods should usually be refactored into several 033 * individual methods that focus on a specific task. 034 * </p> 035 *<p> 036 * The default maximum method length is 150 lines. To change the maximum 037 * number of lines, set property max. 038 * </p> 039 * <p> 040 * An example of how to configure the check is: 041 * </p> 042 * <pre> 043 * <module name="MethodLength"/> 044 * </pre> 045 * <p> 046 * An example of how to configure the check so that it accepts methods with at 047 * most 60 lines is: 048 * </p> 049 * <pre> 050 * <module name="MethodLength"> 051 * <property name="max" value="60"/> 052 * </module> 053 * </pre> 054 * @author Lars Kühne 055 */ 056public class MethodLengthCheck extends Check 057{ 058 /** whether to ignore empty lines and single line comments */ 059 private boolean countEmpty = true; 060 061 /** default maximum number of lines */ 062 private static final int DEFAULT_MAX_LINES = 150; 063 064 /** the maximum number of lines */ 065 private int max = DEFAULT_MAX_LINES; 066 067 @Override 068 public int[] getDefaultTokens() 069 { 070 return new int[] {TokenTypes.METHOD_DEF, TokenTypes.CTOR_DEF}; 071 } 072 073 @Override 074 public void visitToken(DetailAST ast) 075 { 076 final DetailAST openingBrace = ast.findFirstToken(TokenTypes.SLIST); 077 if (openingBrace != null) { 078 final DetailAST closingBrace = 079 openingBrace.findFirstToken(TokenTypes.RCURLY); 080 int length = 081 closingBrace.getLineNo() - openingBrace.getLineNo() + 1; 082 083 if (!countEmpty) { 084 final FileContents contents = getFileContents(); 085 final int lastLine = closingBrace.getLineNo(); 086 for (int i = openingBrace.getLineNo() - 1; i < lastLine; i++) { 087 if (contents.lineIsBlank(i) || contents.lineIsComment(i)) { 088 length--; 089 } 090 } 091 } 092 if (length > max) { 093 log(ast.getLineNo(), ast.getColumnNo(), "maxLen.method", 094 length, max); 095 } 096 } 097 } 098 099 /** 100 * @param length the maximum length of a method. 101 */ 102 public void setMax(int length) 103 { 104 max = length; 105 } 106 107 /** 108 * @param countEmpty whether to count empty and single line comments 109 * of the form //. 110 */ 111 public void setCountEmpty(boolean countEmpty) 112 { 113 this.countEmpty = countEmpty; 114 } 115}