Question

Set<String> tempSet = new HashSet<String>();
for (Map.Entry<String, String> entry : map.entrySet()) {
     String orginalKeys = entry.getKey();
     System.out.println(orginalKeys);
     String newKey = orginalKeys.replace('.','/');
     if (!newKey.equals(orginalKeys)) {
        map.put(newKey, entry.getValue());
        tempSet.add(orginalKeys);
        map.remove(orginalKeys);
     }
}
System.out.println(map);

This replaces only one key, but i want to replace all with the above occurrences. What is the wrong thing i am going with?

Answer 1

ideally this code should throw java.util.ConcurrentModificationException as you are iterating through the map.entrySet()) and at the same time updating the map.put(newKey, entry.getValue());

As indicated earlier, you could create a new temporary map and replace with original one

or
you could get the keys in a list and iterate the list

String[] keyArray = map.keySet().toArray(new String[map.size()]);
    Set<String> tempSet = new HashSet<String>();
    for (String orginalKeys : keyArray) {
        System.out.println(orginalKeys);
        String newKey = orginalKeys.replace('.', '/');
        if (!newKey.equals(orginalKeys)) {
            map.put(newKey, map.get(orginalKeys));
            tempSet.add(orginalKeys);
            map.remove(orginalKeys);
        }
    }
    System.out.println(map);