how to get the max value of an array java

 // Initializing array of integers 
        Integer[] num = { 2, 4, 7, 5, 9 }; 
// using Collections.min() to find minimum element 
        // using only 1 line. 
        int min = Collections.min(Arrays.asList(num)); 
  
        // using Collections.max() to find maximum element 
        // using only 1 line. 
        int max = Collections.max(Arrays.asList(num)); 

public static double arrayMax(double[] arr) {
    double max = Double.NEGATIVE_INFINITY;

    for(double cur: arr)
        max = Math.max(max, cur);

    return max;
}

import java.util.Random;

public class Main {

public static void main(String[] args) {
   int a[] = new int [100];
   Random rnd = new Random ();

    for (int i = 0; i< a.length; i++) {
        a[i] = rnd.nextInt(99-0)+0;
        System.out.println(a[i]);
    }

    int max = 0;          

    for (int i = 0; i < a.length; i++) {
        a[i] = max;


        for (int j = i+1; j<a.length; j++) {
            if (a[j] > max) {
               max = a[j];
            }

        }
    }

    System.out.println("Max element: " + max);
}
}