package com.package

import java.util.Scanner;
import java.util.concurrent.Executors;
import java.util.concurrent.ThreadPoolExecutor;

class Main {

  static int[] mass = { 1, 2, 3, 4, 5, 6, 7 };
  static int find;
  public static BoolPointer gotIt = new BoolPointer(false);

  public static void main(String[] args) {
    Scanner in = new Scanner(System.in);
    System.out.print("Введите искомое число: ");
    find = in.nextInt();
    in.close();

    ThreadPoolExecutor executor = (ThreadPoolExecutor) Executors
        .newFixedThreadPool(Runtime.getRuntime().availableProcessors() + 1);

    for (int i = 0; i < mass.length; i++) {
      Task task = new Task(mass[i], find, i, gotIt);
      executor.execute(task);
    }
    executor.shutdown();
    if (!gotIt.value)
    {
      System.out.print("Массив не содержит такого числа\n");
    }

  }
}

package com.package

public class BoolPointer
{
  boolean value;
  public BoolPointer(boolean val)
  {
    this.value = val;
  }
}

package com.package

public class Task implements Runnable{
    int el;
    int find;
    int i;
    BoolPointer flag;

    public Task(int el, int find, int i,  BoolPointer flag) {
        this.el = el;
        this.find = find;
        this.i = i;
        this.flag = flag;
    }

    @Override
    public void run() {
        if(el == find)
        {
            flag.value = true;
            System.out.println(el + " находится на " + (i+1) + " позиции");
        }
    }
}