public class AdderBusinessLogic
{
- private final Map<String, Long> state;
+ private final Map<String, AdderResult> state;
public AdderBusinessLogic()
this(new HashMap<>());
}
- public AdderBusinessLogic(Map<String, Long> state)
+ public AdderBusinessLogic(Map<String, AdderResult> state)
{
this.state = state;
}
- public synchronized void startSum(String user)
- {
- if (state.containsKey(user))
- throw new IllegalStateException("Sumation for " + user + " already in progress, state: " + state.get(user));
-
- state.put(user, 0l);
- }
-
public synchronized Optional<Long> getSum(String user)
{
- return Optional.ofNullable(state.get(user));
+ return Optional.ofNullable(state.get(user)).map(result -> result.sum);
}
public synchronized void addToSum(String user, Integer value)
{
- if (!state.containsKey(user))
- throw new IllegalStateException("No sumation for " + user + " in progress");
if (value == null || value < 1)
throw new IllegalArgumentException("Not a positive number: " + value);
- long result = state.get(user) + value;
- state.put(user, result);
+ long sum =
+ Optional
+ .ofNullable(state.get(user))
+ .map(result -> result.sum)
+ .orElse(0l);
+ state.put(user, new AdderResult(value, sum + value));
}
- public synchronized Long endSum(String user)
+ public synchronized AdderResult calculate(String user)
{
if (!state.containsKey(user))
throw new IllegalStateException("No sumation for " + user + " in progress");
return state.remove(user);
}
- protected Map<String, Long> getState()
+ protected Map<String, AdderResult> getState()
{
return state;
}