private String doRegister(String key) {
if (server.getKeys().contains(key)) {
return "fail to register key, key [" + key + "] has already been registered before";
}
server.getKeys().add(key);
return "key [" + key + "] has registered";
}
boolean isKeyRegistered(String key) {
return server.getKeys().contains(key);
}
private String doUnregister(String key) {
server.getKeys().remove(key);
return "key [" + key + "] has unregistered";
}
