Save value in memory and get it

Question

I am working on swing application, the steps below explains my problem.

1. I have a dialog box where I need to select the College.

2. Once I select the department, that window will be closed with the "dispose();" method.

3. Then one more window will pop-up, where I have to select the department based on the selected college.

Now the issue is the object of the Collage class has been destroyed, as that pop-up has been closed, so how can I can store the selected collage value in memory in Java.

Code Example :

public class Test
{
    public static void main(String args[])
    {
        Sample first = new Sample();
        first.setData(1);

        Sample second = new Sample();
        System.out.println(first.getData());  // 1
        System.out.println(second.getData()); // 0
    }

}


public class Sample
{
    private int number;

    public int getNumber()
    {
        return number;
    }

    public void setNumber(int number)
    {
        this.number = number;
    }

    public void setData(int a)
    {
        setNumber(a);
    }

    public int getData()
    {
        return getNumber();
    }
}

I want value 1 using the second object, it should be like "second.getData()" should bring the value 1. is it possible if yes then how ? Thanks.

Answer 1

You can try somewhat likewise,

I have been represent idea , now you can lead ahead by your own requirement-wise,

public class InputSelect {

    public static final String[] colleges = { "College-1", "College-2", "College-3", "College-4" };

    public static final String[][] dept = {{"college-1 Department-1","college-1 Department-2"},{"college-2 Department-1","college-2 Department-2"},{"college-3 Department-1","college-3 Department-2"},{"college-4 Department-1","college-4 Department-2"}};

      public static void main(String[] args)
      {

        JFrame frame = new JFrame("Input Dialog Example 3");
        String favoritecollege = (String) JOptionPane.showInputDialog(frame, 
            "Select Your Choice Colleges : ",
            "Choose College",
            JOptionPane.QUESTION_MESSAGE, 
            null, 
            colleges, 
            colleges[0]);

        int index = 0;

        for(String clg : colleges){
            if(favoritecollege.equals(clg)){
                break;
            }else{
                index++;
            }
        }

        String favouriteDept = (String) JOptionPane.showInputDialog(frame, 
                "Select Your Choice Department : ",
                "Choose Dept of "+ favoritecollege +" college : ",
                JOptionPane.QUESTION_MESSAGE, 
                null, 
                dept[index], 
                dept[index][0]);

        System.out.printf("Favorite College is %s.\n", favoritecollege);
        System.out.printf("Favorite Dept is %s.\n", favouriteDept);


      }

}

EDITED

public static void main(String args[])
    {
        Sample first = new Sample();
        first.setData(1);
        //Either
        //Sample second = new Sample();
        //second.setData(1);
        //or 
        Sample second = first;

        System.out.println(first.getData());  // 1
        System.out.println(second.getData()); // here, you will get 1 after above changes made.
    }

You can do Either way,

Make sure if you choose this way,

Sample second = first;

then wherever you made changes Either on first or second. that should be reflect on both instance i.e. first and second. because it's not 2-different instance. it's just one instance.

but if you choose this way,

Sample second = new Sample();
second.setData(1);

then it's different then first, means if you made any change on second then it should not reflect on first.

So, you can do whatever way, you are convenient . Best of luck.