How many methods in Java to get input from user ?

Answer 1

Buffered Reader:
BufferedReader reader = new BufferedReader(new InputStreamReader(System.in));
String name = reader.readLine();

Scanner:
Scanner sc = new Scanner(System.in)
String name = sc.nextLine();

// There's also one console class method but Scanner is perfect!

Answer 2

1 - Importing
2 - Declaring
3 - Using

Answer 3

Nice Davye

Answer 4

also a fairly easy one:
String input = JOptionPane.showInputDialog ("Enter a number");