Java competitive programming template

Following is one useful java template that I use for competitive programming

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.math.BigInteger;
import java.util.*;

public class Test implements Runnable {

        //write logic in this method
 private void solve() throws IOException {
           //writer.println(your_answer);
 }

        //main method
 public static void main(String[] args) {
  new Test().run();
 }

 BufferedReader reader;
 StringTokenizer tokenizer;
 PrintWriter writer;

 public void run() {
  try {
   reader = new BufferedReader(new InputStreamReader(System.in));
   tokenizer = null;
   writer = new PrintWriter(System.out);
   solve();
   reader.close();
   writer.close();
  } catch (Exception e) {
   e.printStackTrace();
   System.exit(1);
  }
 }

 int nextInt() throws IOException {
  return Integer.parseInt(nextToken());
 }

 long nextLong() throws IOException {
  return Long.parseLong(nextToken());
 }

 double nextDouble() throws IOException {
  return Double.parseDouble(nextToken());
 }

 String nextToken() throws IOException {
  while (tokenizer == null || !tokenizer.hasMoreTokens()) {
   tokenizer = new StringTokenizer(reader.readLine());
  }
  return tokenizer.nextToken();
 }
}