how find most occur byte in file

If still hard to understand here is ready solution for analyzing

ArrayList<Integer> maxRepeatBytes = new ArrayList<Integer>();
      int maxRepeatCount = 0;

      // Looping through the array
      for(int i = 0; i<list.size()-1; i++){ //checking the last element against itself is wrong
          int tempElement = list.get(i);
          int tempCount = 0;

          for (int j = i+1; j<list.size(); j++){ // <-should be either j<list.size() or j<=list.size()-1
              if (list.get(j)==tempElement){
                  tempCount++;
                  if (tempCount>maxRepeatCount) {
                      maxRepeatCount = tempCount;
                      maxRepeatBytes.removeAll(maxRepeatBytes);
                      maxRepeatBytes.add(tempElement);
                  }else if (tempCount==maxRepeatCount) {
                      maxRepeatBytes.add(tempElement);
                  }
              } //C:\Users\Vladimir\OneDrive\Desktop\Javarush.txt
          }
      }
      //maxRepeatBytes.forEach((k) -> System.out.print(k + " ")); <-one extra space in the end, wrong
      System.out.print(maxRepeatBytes.get(0));
      for(int k = 1; k<maxRepeatBytes.size(); k++){
          System.out.print(" " + maxRepeatBytes.get(k));

For those who experience problems with this task here's how it can be done. After reading out the file bytes into the arraylist: Method 1 (using arraylist and an int). Create an empty arraylist to store max repeated bytes and maxRepeatNumber counter. Traverse the list, taking each element and comparing it with the rest of elements, counting repetitions. If this is the maximum number so far, store it, empty the repeatedBytes list containing elements repeated less times, and add the element to the cleared repeatedBytes list. If the number is the same as found so far, just add the element to the list without clearing. Hint: you need two nested loops, carefully look at which last element you use, and you don't need both loops to start from zero. Then do some magic with printing. Method 2 (using HashMap). Create an empty HashMap.. Traverse the list, comparing each element to the remaining ones, count repetitions. If the element exists in the HashMap, do nothing, if it doesn't, store it with the number of repetitions. Then, find a max among the HashMap values, collect all the keys in the HashMap with this value and do the magic with the printing.

#1 you need to use HashSet to find the most repeated bytes from file following is the logic that you need to implement #1.1 create 2 hash set to store the all bytes from file in first set and repeated bytes in second set

Set<Integer> set = new HashSet<Integer>();
Set<Integer> diffSet = new HashSet<Integer>();

#2 when you loop through all the byted then store every byte in the first set if it is not already exist and if it exists then store byte in second set and if in second set byte already exist then just print it you can follow below code snippet

if(!set.contains(data)){
                set.add(data);
            }else{
                if(!(diffSet.contains(data))) diffSet.add(data);
                else System.out.print(data+"\t");
            }