首先这是一项任务，所以我更多的是寻求帮助，然后是编码答案（不想作弊！）。我的任务是创建一个程序来处理车站的火车/铁路网络。我坚持的部分添加了站点、它们的连接，并将这些连接作为字符串数组列表返回。我已经在下面包含了到目前为止的代码，以及作业的摘录（与我现在正在讨论的部分相关）。我整个周末都在努力解决这个问题，所以任何帮助都将不胜感激。
这只是我需要编辑的接口的实现，“MyNetwork”类。我只是觉得我一直在兜圈子，甚至可能没有右脚下车？
从任务中；
创建一个实现 Network 接口的 MyNetwork 类。
此类的 getConnections 方法应返回一个数组，该数组仅包含那些直接连接到 fromStation 参数的站。提示 1：您可以使用 HashMap 来执行此操作，键是字符串（表示站点），值是字符串的 ArrayLists（表示有直接连接的站点）。
提示 2：虽然 getConnections 方法返回一个字符串数组，但 HashMap 中的值最好是字符串的 ArrayLists
接口；
public interface Network {
/**
* Add a station to the network.
* @param station The station to be added.
*/
public void addStation(String station);
/**
* Add a direct connection from one station to another.
* @pre both fromStation and toStation have already been added by the method
* addStation.
* @param fromStation The station from which the connection begins.
* @param toStation The station at which the connection ends.
*/
public void addConnection(String fromStation, String toStation);
/**
* Get a list of all stations directly connected to a given station.
* @pre fromStation has been added to the network by the method addStation.
* @param fromStation
* @return A list of all the stations to which there is a direct connection
* from fromStation.
*/
public String[] getConnections(String fromStation);
/**
* Search for a station in the network.
* @param station Station to be searched for,
* @return true if the Station exists in the network, false otherwise.
*/
public boolean hasStation(String station);
/**
* Get all stations in the network.
* @return An array containing all the stations in the network, with no
* duplicates.
*/
public String[] getStations();
实施：
public class MyNetwork implements Network {
@Override
public void addStation(String station) {
ArrayList<String> Stations = new ArrayList<>();
Stations.add(station);
}
@Override
public void addConnection(String fromStation, String toStation) {
Map<String,String> Connections = new HashMap<>();
Connections.put(fromStation, toStation);
}
@Override
public String[] getConnections(String fromStation) {
return null; // dummy value!
}
@Override
public boolean hasStation(String station) {
return false; // dummy value!
}
@Override
public String[] getStations() {
return null; // dummy value!
}
}