Remove all objects in an arraylist that exist in another arraylist Java

ArrayList<String> firstArr = new ArrayList<>();
firstArr.add("1");
firstArr.add("2");
firstArr.add("3");

// array/list to be removed from firstArr
ArrayList<String> filterArr = new ArrayList<>();
filterArr.add("1");
filterArr.add("3");

// filter now
filterArr.removeAll(blockedArr);

// Dump
System.out.println(filterArr.toString); // output 1 and 3