实例化片段的最佳方法？

Question

Method 1

public static MyFragment newInstance(int index) {

    MyFragment f = new MyFragment();

    Bundle args = new Bundle(1);

    args.putInt("index", index);

    f.setArguments(args);

    return f;

  }

Usge

Myfragment.newInstance(1);

Method 2

 public MyFragment newInstance(int index) {

    Bundle args = new Bundle(1);

    args.putInt("index", index);

    setArguments(args);

    return this;
  }

Usge

new Myfragment().newInstance(1);

In the above snippets which one is more appropriate and preferable way and please point out why ?

And now am doing this..

 List<Fragment> fragments = new ArrayList<>();
            fragments.add(new MyFragment().newInstance(defaultId));
            int i = 1;
            for (Categories categories : mCategories) {
                String id = categories.getCategory_id();
                String name = categories.getCategory_name();
//                String slno = categories.getSlno();
                fragments.add(new MyFragment().newInstance(defaultId));
                Titles[i] = name;
                i++;
            }

Anything wrong with this ?

Answer 1

Method 1 would be preferred over Method 2.

That's because in Method 1 you really create a MyFragment object. In Method 2 you first create a MyFragment object and then you initialize it with newInstance(...) . If you want to use method 2 i'd suggest to do it in 2 lines:

MyFragment frag = new MyFragment();
frag.initialize(1);

with the initialize method:

public void initialize(int index) {
    Bundle args = new Bundle(1);
    args.putInt("index", index);
    setArguments(args);
}

Answer 2

Go ahead with Method 1 . Always try to use Static Factory Methods over Constructors . Why you need to use this could be found out in the famous book Effective Java By Joshua Bloch: Item1 - Static Factory Method.

Also you could refer: Effective Java By Joshua Bloch: Item1 - Static Factory Method