Android4.0 之后不允许在主线程进行网络连接

Android4.0 以后不允许在主线程进行网络连接
Android4.0 以后不允许在主线程进行网络连接，否则会出现 android.os.NetworkOnMainThreadException。因此，必须另起一个线程进行网络连接方面的操作。

import java.io.IOException; 
import java.net.Socket; 
import java.net.UnknownHostException; 
import java.util.Scanner; 
  
public class ResourceDao { 
  
    String returnLine = "hi"; 
  
    public String getAllContentByName() { 
        Runnable r = new NetWorkHandler(); 
        Thread thread = new Thread(r); 
        thread.start(); 
  
        try { 
            Thread.sleep(15000); 
        } catch (InterruptedException e) { 
            e.printStackTrace(); 
        } 
        return returnLine; 
    } 
  
    private class NetWorkHandler implements Runnable { 
  
        String line = "line"; 
        Socket socket = null; 
        Scanner scanner = null; 
        @Override
        public void run() { 
            try { 
                socket = new Socket("time-A.timefreq.bldrdoc.gov", 13); 
                scanner = new Scanner(socket.getInputStream()); 
                while (scanner.hasNextLine()) { 
                    line = scanner.nextLine(); 
                    returnLine += line; 
                } 
  
            } catch (UnknownHostException e) { 
                e.printStackTrace(); 
            } catch (IOException e) { 
                e.printStackTrace(); 
            } finally { 
                scanner.close(); 
                try { 
                    socket.close(); 
                } catch (IOException e) { 
                    e.printStackTrace(); 
                } 
            } 
        } 
    } 
}

由于网络连接需要一定时间，为了在主界面上进行网络信息的展现，暂时用sleep()方法简单实现，使主线程等待网络信息读取完成。
Thread.sleep(5000);

来自为知笔记(Wiz)

posted on 2014-04-28 13:58 转折点人生阅读(205) 评论(0) 收藏举报