BroadcastEventBridge.java 文件源码

private List<OnSharedPreferenceChangeListener> putIfAbsentListeners(String prefName, Map<String,
        List<OnSharedPreferenceChangeListener>> allListeners) {
    if (allListeners.containsKey(prefName)) {
        return allListeners.get(prefName);
    }
    List<OnSharedPreferenceChangeListener> listeners = new ArrayList<>();
    allListeners.put(prefName, listeners);
    return listeners;
}