I wanted to do something like authorization. What am I doing wrong?

Question

Java

package main;

import java.io.File;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.util.Formatter;
import java.util.Scanner;

public class FileTest {
  static Scanner v;
  static Formatter f;
  public static void main(String[] args) {
    String db = new File("text.txt").getAbsolutePath();
    System.out.println(db);
    File db2 = new File(db);
    try {
      f = new Formatter(db2);
    } catch (FileNotFoundException e) {
      // TODO Auto-generated catch block
      System.err.println("error! file not found");
      System.err.println("creating file...");
      try {
        boolean isCreated = db2.createNewFile();
        if(isCreated)
          System.out.println("File Created!");
      } catch (IOException e1) {
        // TODO Auto-generated catch block
        System.err.println("error creating file!");
        e1.printStackTrace();
      }
    }
     static void startnow() {
      try {
        String db3 = new File("text.txt").getAbsolutePath();
        File db23 = new File(db);
        v = new Scanner(db2);
      } catch (FileNotFoundException e12) {
        // TODO Auto-generated catch block
        System.err.println("error! file still not found");
      }
      String[] inp;
      try {
        String db1 = new File("text.txt").getAbsolutePath();
        File db21 = new File(db);
        v = new Scanner(db2);
      } catch (FileNotFoundException e13) {
        // TODO Auto-generated catch block
        e13.printStackTrace();
      }
      String p = v.nextLine();
      inp = p.split(":");
      System.out.println(inp.length);
      if(inp[0] == null) { System.out.println("not registered");
      System.out.println("Please Register. Enter your login ");
      Scanner inp2 = new Scanner(System.in);
      String login = inp2.nextLine();
      System.out.println("Enter Password");
      String pass = inp2.nextLine();
      f.format("%s:%s", login, pass); }
      else { System.out.println("You are registered");
      System.out.println("Please enter your login");
      Scanner inp2 = new Scanner(System.in);
      String llogin = inp2.nextLine();
      System.out.println("Enter pass");
      String lpass = inp2.nextLine();
      if(inp[0].equals(llogin) && inp[1].equals(lpass)) System.out.println("You Logged In!");
      else if (inp[0].equals(llogin) || inp[1].equals(lpass)) System.out.println("Wrong login or pass!");
      }
    }
} }

What did I do wrong?