Is it Possible to Return Two ArrayList values in One method in java?

Question

Is there any way to return two values from one method....

Example:

public Class Sample
{
  public List<Date> returnTwoArrayList()
   {
      List<Date> startDate=new ArrayList<Date>();
      
      List<Date> endDate=new ArrayList<Date>();

     //So I want to Return Two values startDate and endDate ...It is Possible????
   }
}

i'm calling this method into My Service class and in that Storing StartDate and endDate into Database here these are Two different Columns

**StartDate      endDate**
2012-12-01     2012-12-05
2012-12-01     2012-12-15
2012-12-02     2012-12-10
2012-12-20     2012-12-25
2012-12-25     2012-12-31
 

Answer 1

You cannot return separate structures via one method call, but you can return a composite of them. For example, returning a list of your lists would be a possible solution:

   public List<List<Date>> returnTwoArrayList()
   {
      List<Date> startDates = new ArrayList<Date>();
      List<Date> endDates = new ArrayList<Date>();

      List<List<Date>> result = new ArrayList<List<Date>>();
      result.add(startDates);
      result.add(endDates);

      return result;
   }

You can use get() method to retrieve these lists later on. Suppose you have made a call like List<List<Date>> twoLists = returnTwoArrayList(); then you can get startDate by calling twoLists.get(0) and similarly endDate with twoLists.get(1)

Answer 2

No you can not return two value from a method.

Best way would be create a custom class with two field and return that object.

class ObjectHolder{
    private List<Date> startDate=new ArrayList<Date>();
    private List<Date> endDate=new ArrayList<Date>();

    <getter & setter method>
}

and -

public ObjectHolder returnTwoArrayList(){
    ObjectHolder oh = new ObjectHolder();
    List<Date> startDate=new ArrayList<Date>();
    oh.setStartDate(startDate);
    List<Date> endDate=new ArrayList<Date>();
    oh.setEndDate(endDate);
    return oh;
}