Question

任何人都可以让我知道下面的代码有什么问题。为什么不执行while循环块？我在清单文件中拥有必要的权限。

public class MainActivity extends Activity {

static TextView t;

protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    t=(TextView)findViewById(R.id.txt);
    NetConnect th=new NetConnect();
    th.start();
}
public class NetConnect extends Thread {
    public void run(){
        try{
            runOnUiThread(new Runnable(){public void run(){t.append("Thread start...");}});
            Socket client = new Socket("time-b.nist.gov", 13);
            BufferedReader in =new BufferedReader(new InputStreamReader(client.getInputStream()));
            String str;
            while((str=in.readLine())!=null)
                t.append(str);
        }catch(Exception e){
            Log.e("Internet:",e.toString());
        }
    }
}

Answer 1

“time-b.nist.gov”似乎有问题。我在java项目中尝试了以下简单套接字示例（以简化创建Android项目）：

import java.io.IOException;
import java.io.InputStream;
import java.net.Socket;
import java.net.UnknownHostException;

public class TestSocketClass {

    public static void main(String[] args) {
        String hostname = "time-b.nist.gov";

        try {
            Socket theSocket = new Socket(hostname, 13);
            InputStream timeStream = theSocket.getInputStream();
            StringBuffer time = new StringBuffer();
            int c;
            while ((c = timeStream.read()) != -1)
                time.append((char) c);
            String timeString = time.toString().trim();
            System.out.println("It is " + timeString + " at " + hostname);
        } // end try
        catch (UnknownHostException ex) {
            System.err.println(ex);
        } catch (IOException ex) {
            System.err.println(ex);
        }
    }
}

如果String hostname = "time-b.nist.gov";：

，则不会返回任何内容

时间是-b.nist.gov

但如果我将其更改为String hostname = "time.nist.gov";，我会：

是56438 13-05-26 11:49:57 50 0 0 809.9 UTC（NIST）* at time.nist.gov

Android中的简单套接字示例问题

1 个答案: