How to use binary search on unsorted array with key and value in java?

import java.util.HashMap;
import java.util.Map;

public class BinarySearchUnsorted {

	int binary(Map<Integer, Integer> map, int start, int end, int x) {
		if (end >= start) {
			int test=start+(end-start);
			int mid = test / 2;
			System.out.println(mid);
			System.out.println(map.get(mid));
			if (map.get(mid) == x) {
				return map.get(mid);
			}
			if (map.get(mid) > x) {
				return binary(map, start, mid - 1, x);
			}
			return binary(map, mid + 1, end, x);
		}

		return -1;
	}

	public static void main(String[] args) {
		int x = 3;
		int[] arr = { 2, 4, 3, 8 };
		int length = arr.length;
		
		HashMap<Integer, Integer> map = new HashMap<Integer, Integer>();

		for (int i = 0; i < length; i++) {
			map.put(arr[i],i );

		}
		BinarySearchUnsorted ob = new BinarySearchUnsorted();
		int result = ob.binary(map, 0, length - 1, x);
		if (result == -1) {
			System.out.println("Element not present");
		}
		else {
			System.out.println("Element found at index " + result);
		}
	}
}

I have given array of integers added unsorted and integer that I want to find on which position it is. I want to use binary search which use only sorted arrays so I sort the numbers from the array and save their first position. Every help will be good.

Thanks in advance!

Here is the answer

public static class MyEntry {
		int key;
		int value;

		public MyEntry(Integer k, Integer v) {
			key = k;
			value = v;
		}

		public String toString() {
			return ("(" + key + "," + value + ") ");
		}
	}

	public static int BinSearch(MyEntry[] arr,int low, int high, int k) {
		int  mid;

		
		mid = (high + low) / 2;
	
		if (high >= low) {
		
			if (arr[mid].key == k) {
				return (mid);
			}
			if (arr[mid].key > k) {
				return BinSearch(arr, low, mid - 1, k);
			}
			return BinSearch(arr, mid + 1, high, k);
		}

		return -1;
	}
	

	public static void main(String[] args) {
		int[] arr = { 2, 4, 3, 8 };
		int len = arr.length;
		System.out.println(len + "dulj");
		MyEntry[] entry = new MyEntry[len];

		for (int i = 0; i < len; i++) {
			entry[i] = new MyEntry(arr[i], i);
		}

		for (int i = 0; i < entry.length; i++)
			System.out.print(i + ":" + entry[i]);
		System.out.println();

		int result = BinSearch(entry,0, len-1, 8);
		System.out.println(result);
	}