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。

 

package com.lujinhong.irmcdc.dao;



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();

				}

			}

		}

	}

}

 

 

1、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);