Method to get all EditTexts in a View

EDIT

MByD pointed me to an error, thus making my answer almost identical to that of blackbelt. I have edited mine to the correct approach.

You could do a for-each loop and then check if each view is of the type EditText:

ArrayList<EditText> myEditTextList = new ArrayList<EditText>();

for( int i = 0; i < myLayout.getChildCount(); i++ )
  if( myLayout.getChildAt( i ) instanceof EditText )
    myEditTextList.add( (EditText) myLayout.getChildAt( i ) );

You could also, instead of having a list of EditTexts, have a list of ID's and then just add the id of the child to the list: myIdList.add( child.getId() );

To access your layout you need to get a reference for it. This means you need to provide an ID for your layout in your XML:

<LinearLayout android:id="@+id/myLinearLayout" >
   //Here is where your EditTexts would be declared
</LinearLayout>

Then when you inflate the layout in your activity you just make sure to save a reference to it:

LinearLayout myLinearLayout;

public void onCreate( Bundle savedInstanceState ) {
   super( savedInstanceState );
   setContentView( R.layout.myLayoutWithEditTexts );

   ...

   myLinearLayout = (LinearLayout) findViewById( R.id.myLinearLayout );
}

You then have a reference to your the holder of your EditTexts within the activity.

Here's a method I wrote to recursively check all EditText children of a ViewGroup, handy for a long sign-up form I had to do and probably more maintainable.

private EditText traverseEditTexts(ViewGroup v)
{
    EditText invalid = null;
    for (int i = 0; i < v.getChildCount(); i++)
    {
        Object child = v.getChildAt(i); 
        if (child instanceof EditText)
        {
            EditText e = (EditText)child;
            if(e.getText().length() == 0)    // Whatever logic here to determine if valid.
            {
                return e;   // Stops at first invalid one. But you could add this to a list.
            }
        }
        else if(child instanceof ViewGroup)
        {
            invalid = traverseEditTexts((ViewGroup)child);  // Recursive call.
            if(invalid != null)
            {
                break;
            }
        }
    }
    return invalid;
}

private boolean validateFields()
{   
    EditText emptyText = traverseEditTexts(mainLayout);
    if(emptyText != null)
    {
        Toast.makeText(this, "This field cannot be empty.", Toast.LENGTH_SHORT).show();
        emptyText.requestFocus();      // Scrolls view to this field.
    }
    return emptyText == null;
}

You can do it by calling View#getFocusables, which will return an arraylist of all focusable views in a View.

Then you can either check if they are EditTexts, with (instanceof) or act on all of them.

This Methods walks recursively through all ViewGroups and collects their TextViews. I use this to assign a new Color to all TextViews (even those embedded in predefined Widgets like Switch etc that make use of TextViews)

private HashSet<TextView> getTextViews(ViewGroup root){
    HashSet<TextView> views=new HashSet<>();
    for(int i=0;i<root.getChildCount();i++){
        View v=root.getChildAt(i);
        if(v instanceof TextView){
            views.add((TextView)v);
        }else if(v instanceof ViewGroup){
            views.addAll(getTextViews((ViewGroup)v));
        }
    }
    return views;
}