Are the strings like "custom" pre-defined? If the number of such strings are limited, then you would also profit by making them into methods such as Manager.hasCustom() if not, you can go for Manager.has(Manager.CUSTOM) where CUSTOM could be an attribute in the Manager class.
Consider memoizing the lookup.
class Manager {
public final String CUSTOM = "custom";
public boolean has(String key) {
if (!map.containsKey(key)) map.put(StringUtils.contains(name, key))
return map.get(key);
}
public boolean hasCustom() { return has(CUSTOM); }
}
Finally, if your class takes decisions based on a flag in another class, you might want to rewrite it to reduce coupling. And perhaps use a pattern like Strategy.