Play 内存过度使用!框架方法调用

Question

在我的一个 Controller 中，我有多个 URL，它们最终将以相同的方式呈现。例如，此方法扫描服务器所在的网络，缓存每个连接设备和每个监听特定端口的设备的 String 表示，然后将该信息发送到另一个方法进行渲染:

public static void networkScan(String networkTarget, String port)
{
    //These two lists will never have more than 256 total entries
    List<InetSocketAddress> listeningDevices;
    Map<String, String> allDevices;

    ...Logic for discovering network devices...

    //Store the results in a cache, for history preservation in the browser
    Cache.set(session.getId() + "listeningDevices", listeningDevices);
    Cache.set(session.getId() + "allDevices", allDevices);
    showScan(listeningDevices, allDevices);
}

public static void showScan(List<InetSocketAddress> listeningDevices, Map<String, String> allDevices)
{
    render(listeningDevices, allDevices);
}

public static void getCachedScan()
{
    List<InetSocketAddress> listeningDevices = (List<InetSocketAddress>)Cache.get(session.getId() + "listeningDevices");
    Map<String, String> allDevices = (Map<String, String>)Cache.get(session.getId() + "allDevices");
    if(listeningDevices == null)
        listeningDevices = new ArrayList<InetSocketAddress>();
    if(allDevices == null)
        allDevices = new TreeMap<String, String>();

    renderScan(listeningDevices, allDevices);
}

这样做会导致 Play 进行一些奇怪的数组复制，最终会占用无限内存。如果我改变我的电话 showScan()简单地 render()并创建一个名为 networkScan.html 的 View ，一切正常，没有内存错误。

根据不同的缓存设置，我还有其他几种方法也使用 showScan。我不想要很多本质上都是彼此副本的 View ，所以我试图通过一种方法来处理一个相应的 View 。

Answer 1

这行不通:

   showScan(listeningDevices, allDevices);
}

public static void showScan(List<InetSocketAddress> listeningDevices, Map<String, String> allDevices)
{

因为 play 会将 listenDevices + allDevices 序列化为 Strings 并尝试从中构建一个 url。

要么直接在 networkScan() 中呈现结果，要么将内容存储在特定键下的缓存中
就像你已经做的那样，然后做类似的事情

public static void networkScan(String networkTarget, String port)
{
    //These two lists will never have more than 256 total entries
    List<InetSocketAddress> listeningDevices;
    Map<String, String> allDevices;



       ...Logic for discovering network devices...

        //Store the results in a cache, for history preservation in the browser
        Cache.set(session.getId() + "listeningDevices", listeningDevices);
        Cache.set(session.getId() + "allDevices", allDevices);
        showScan(session.getId());
    }

    public static void showScan(String sessionId)
    {
    List<InetSocketAddress> listeningDevices = Cache.get(sessionId + "listeningDevices");
    Map<String, String> allDevices = Cache.get(sessionId + "allDevices");
        render(listeningDevices, allDevices);
    }