sorting java task by user-entered dates -

i'm creating tasks list in java , want able sort data user-entered due dates. below have far. case 3 of switch statement want sort variable duedate in case 2: how access this? use collection.sort date?

import java.io.*; import java.util.scanner;  public class main {      public static string filename = "/users/desktop/tasklistjava/src/javatask.txt";      public static void main(string[] args) throws ioexception {          int menuitem = -1;         while(menuitem != 0){             menuitem = menu();             switch (menuitem){                 case 1:                     showtasklist();                     break;                 case 2:                     addtask();                     break;                 case 3:                     sortlist();                     break;                 case 0:                     break;                 default:                     system.out.println("invalid input");              }         }     }     static int menu(){         int choice;         scanner sc = new scanner(system.in);         system.out.println("\n task list menu \n");         system.out.println("0: exit menu");         system.out.println("1: show tasks in list");         system.out.println("2: add task list");         system.out.println("3: sort tasks due date");         system.out.println();         system.out.println("enter choice: ");             choice = sc.nextint();             return choice;     }      static void showtasklist(){         system.out.println("\ntask list\n");         try {             scanner infile = new scanner(new filereader(filename));             string line;             int number = 1;             while(infile.hasnextline()){                 line = infile.nextline();                 system.out.println(number + ". " + line);                 ++number;             }             system.out.println();             infile.close();         } catch (filenotfoundexception ioe) {             system.out.println(ioe);         }     }      static void addtask(){         system.out.println("\nadd task\n");         try {             scanner input = new scanner(system.in);             printwriter outfile = new printwriter(new filewriter(filename, true));             system.out.println("enter task: ");             string addedtask = input.nextline();             system.out.println("set due date task(yyyy-mm-dd): ");             string duedate = input.nextline();             outfile.println(addedtask + " " + duedate);             outfile.close();         } catch (ioexception ioe) {             system.out.println(ioe);         }     }     static void sortlist(){         system.out.println("\nsorted list\n");    }  } 

yes, can use collections.sort().

however, you'll need implement comparable or comparator add in own logic sort it.

try searching comparable , comparator , should see how it.