android - InetAddress.getByName 导致 NetworkOnMainThreadException

Question

意识到我不得不担心基于网络的线程会对我的 UI 线程造成严重破坏，我经历了为我的 TCP/IP 网络乒乓命令和应用程序之间的响应创建自定义处理程序和自定义线程的整个过程远程服务器。效果很好。 (您会在下面的代码中看到它被引用为 mainCommunicationThread(controlCommands);)

不过，在触发该线程/处理程序之前，我从 SQL 中提取 IP 或主机名(将其称为 currIPstr)，然后将其与一堆其他变量一起发送到线程/处理程序。不过，我需要做的一件事是确保它是 A) 有效的 IP 地址，或 B) 主机名已解析 - 否则，甚至没有必要开始尝试。

好的，没问题，我只是调用这个:

currIP = InetAddress.getByName(currIPstr).toString().split("/")[1];

不过，我刚刚遇到的是，在运行 Gingerbread 或 StrictMode 时，上面的行会触发可怕的 NetworkOnMainThreadException。

是的，对 InetAddress.getByName 的简单调用就足够了。好吧，我一直在努力解决问题，所以我将整个函数移到了可运行的内部:

private String currStatIP = null;
private String currentStatIPstr = null;
private Integer currentStatIDstr = -1;
private String currentPort = null;
private String currentLocation = null;
private String currUserName = null;
private String currPassword = null;
private Integer currStatID = -1;
public void StatControl(Cursor c, final String[] commandtosend){


    /*the object will always start off with the first 4 fields being the current login information.
     * [0] = IP Address
     * [1] = port number
     * [2] = username
     * [3] = password
     * [4] = COMMAND -- this will be used in a switchcase inside the pingpong to decide what to do.
     *               -- if the Socket is not open, the first 4 fields will be used to re-initiate the connection
     *               -- otherwise, the command is drawn from this field and sent directly.
     * */


    currentStatIDstr = c.getInt(0);
    currentStatIPstr = c.getString(1);
    currentPort = c.getString(2);
    currentLocation = c.getString(3);
    currUserName = c.getString(4);
    currPassword = c.getString(5);
    currStatID = currentStatIDstr;


    Handler networkLookupHandler = new Handler();
    Runnable networkLookupRunnable = new Runnable() {
         public void run() {
             try {
                    currStatIP = InetAddress.getByName(currentStatIPstr).toString().split("/")[1];
                } catch (UnknownHostException e) {
                    e.printStackTrace();
                }
             int portNumber = 0;
                try {
                    portNumber = Integer.parseInt(currentPort);
                } catch(NumberFormatException nfe) {
                   nfe.printStackTrace();
                }
                String userName = currUserName;
                String passWord = currPassword;
                String[] command = commandtosend;

                Object[] controlCommands = new Object[]{
                        currStatID,
                        currStatIP, //InetAddress of String representing the IP address
                        portNumber,     //int representation of the port number, taken from String
                        currentLocation,
                        userName,
                        passWord,
                        command
                        };
                /*for(int i=0;i<controlCommands.length;i++){
                    Log.d("object work","controlCommands[" + i + "] is " + controlCommands[i]);
                }*/

                mainCommunicationThread(controlCommands);
         }   
    };
    networkLookupHandler.post(networkLookupRunnable);
}

而且，耶!有效!我不再收到 NetworkOnMainThreadException。哦……等等……是的，我是。

以上不会触发 API 10、12、14 的异常，甚至 16 在模拟器中也能正常工作，但是，如果我将它加载到运行 Jellybean 4.1.1 的三星 Google Galaxy Nexus 上，我会遇到 NetworkOnMainThreadException 崩溃。即使上面包裹在 runnable 中。

我完全不知道如何解决这个问题。

Answer 1

我的解决方案:

public static InetAddress getInetAddressByName(String name)
{
    AsyncTask<String, Void, InetAddress> task = new AsyncTask<String, Void, InetAddress>()
            {

                @Override
                protected InetAddress doInBackground(String... params)
                {
                    try
                    {
                        return InetAddress.getByName(params[0]);
                    }
                    catch (UnknownHostException e)
                    {           
                        return null;
                    }                       
                }           
            };
    try
    {
        return task.execute(name).get();
    }
    catch (InterruptedException e)
    {
        return null;
    }
    catch (ExecutionException e)
    {
        return null;
    }

}