Updating a java map entry

Use

table.put(key, val);

to add a new key/value pair or overwrite an existing key's value.

From the Javadocs:

V put(K key, V value): Associates the specified value with the specified key in this map (optional operation). If the map previously contained a mapping for the key, the old value is replaced by the specified value. (A map m is said to contain a mapping for a key k if and only if m.containsKey(k) would return true.)

If key is present table.put(key, val) will just overwrite the value else it'll create a new entry. Poof! and you are done. :)

you can get the value from a map by using key is table.get(key); That's about it