我有以下代码：

public class Router {
  private Iterable<Route> routes;

  public Router(Iterable<Route> routes) {
    this.routes = routes;
  }
  public void addRoute(Route route) {
    routes.add(route);\\problem is here
  }
}

我突出显示了无效的线路.在这里,我尝试向路线添加新对象.在主文件路由是：

public class RouterMain 
{
    public static void main(String[] arg) throws IllegalArgumentException 
    {
        List<Route> routes = new ArrayList<Route>();
        Router router = new Router(routes);
    }
}

任务是在Router类的iterable对象中添加一个对象.据我所知,Iterable可以迭代,而不是添加一些东西.那么我该怎么办,将Router类中的路由转换为List,添加一个元素并返回？

解决方法:

如果要添加它,您可以创建一个新列表并将所有当前元素添加到该列表中,然后只需添加您想要的对象,例如

public class Router {
  private Iterable<Route> routes;

  public Router(Iterable<Route> routes) {
    this.routes = routes;
  }
  public void addRoute(Route route) {

    //create new list
    ArrayList<Route> myList = new ArrayList<Route>();

    //iterate through current objects and add them to new list
    Iterator<Route> routeIterator = routes.iterator();
    while(routeIterator.hasNext()){
        myList.add(routeIterator.next());
    }


    //add object you would like to the list
    myList.add(route);

  }
}