Today I found a useful free software called “SourceMonitor” which can help to calculate and monitor the java code ( and other programming language like C++, C# etc ) complexity.
For the definition and how to calculate cyclomatic complexity itself, please refer to detail in wikipedia.
In order to demonstrate the usage of this software, I use a very simple java class below for example:
package test; import java.util.ArrayList; public class monthTool { static ArrayList<String> monthCollection = new ArrayList<String>(); public static void main(String[] args) { monthTool tool = new monthTool(); tool.printV1(1); tool.printV2(2); tool.printV1(0); tool.printV2(-1); tool.printV3(3); tool.printV3(13); } public monthTool(){ monthCollection.add("Invalid"); monthCollection.add("January"); monthCollection.add("Febrary"); monthCollection.add("March"); monthCollection.add("April"); monthCollection.add("May"); monthCollection.add("June"); monthCollection.add("July"); monthCollection.add("August"); monthCollection.add("September"); monthCollection.add("October"); monthCollection.add("November"); monthCollection.add("December"); } public void printV1(int month){ System.out.println("Month is: " + getMonthNameV1(month)); } public void printV2(int month){ if( month >= 1 && month <= 12) System.out.println("Month is: " + getMonthNameV2(month)); else System.out.println("Please specify a valid month"); } public void printV3(int month) { System.out.println("Month is: " + getMonthNameV3(month)); } public String getMonthNameV2(int month){ if( month == 1) return "January"; else if( month == 2) return "Febrary"; else if( month == 3) return "March"; else if( month == 4) return "April"; else if( month == 5) return "May"; else if( month == 6) return "June"; else if( month == 7) return "July"; else if( month == 8) return "August"; else if( month == 9) return "September"; else if( month == 10) return "October"; else if( month == 11) return "November"; else if( month == 12) return "December"; else return "Invalid"; } public String getMonthNameV1(int month){ switch (month){ case 1: return "January"; case 2: return "Febrary"; case 3: return "March"; case 4: return "April"; case 5: return "May"; case 6: return "June"; case 7: return "July"; case 8: return "August"; case 9: return "September"; case 10: return "October"; case 11: return "November"; case 12: return "December"; default: return "Invalid"; } } public String getMonthNameV3(int month){ try { return monthCollection.get(month); } catch (java.lang.IndexOutOfBoundsException e){ return "Invalid"; } } }