首先建立服务端：利用socket通信持续监听客户端发来的消息再做相应的操作

public class Pc_service {

	static ServerSocket serversocket = null;// 服务socket
	static DataInputStream data_input = null;// 输入流
	static DataOutputStream data_output = null;// 输出流

	public static void main(String[] args) {
		try {
			//开启WiFi
			startNet();
			// 监听30000端口
			serversocket = new ServerSocket(30000);
			System.out.println("listening 30000 port");

			while (true) {
				// 获取客户端套接字
				Socket client_socket = serversocket.accept();
				String send_msg = "";
				try {

					// 获取输入流,读取客户端传来的数据
					data_input = new DataInputStream(client_socket
							.getInputStream());
					String msg = data_input.readUTF();
					System.out.println(msg);
					// 判断输入，进行相应的操作
					data_output = new DataOutputStream(client_socket
							.getOutputStream());
					if ("shutdown".equals(msg)) {
						 Shutdown();
						// 发送消息回Android端
						send_msg = "60秒后关机 ";
					} else if ("restart".equals(msg)) {
						 Restart();
						send_msg = "60秒后重启";
					} else if ("cancel".equals(msg)) {
						cancel();
						send_msg = "关机已取消";
					}
				} catch (Exception e) {
					// TODO: handle exception
				} finally {
					try {
						if (data_output != null) {
							data_output.writeUTF(send_msg);
							data_output.close();
						}
						data_input.close();
						// 关闭连接
						client_socket.close();
					} catch (IOException e) {
						// TODO Auto-generated catch block
						e.printStackTrace();
					}
				}
			}
		} catch (Exception e) {
			// TODO: handle exception
			e.printStackTrace();
		}
	}
	
	//打开承载网络
	private static void startNet()throws IOException{
		Process p = Runtime.getRuntime().exec("netsh wlan start hostednetwork");
	}

	// 关机
	private static void Shutdown() throws IOException {
		Process p = Runtime.getRuntime().exec("shutdown -s -t 60");
		System.out.println("shutdown ,60 seconds later ");
	}

	// 重启
	private static void Restart() throws IOException {
		Process p = Runtime.getRuntime().exec("shutdown -r -t 60");
		System.out.println("restart ,60 seconds later ");
	}

	// 取消登陆
	private static void cancel() throws IOException {
		Process p = Runtime.getRuntime().exec("shutdown -a");
		System.out.println("cancel ");
	}
}

Socket socket = new Socket();
InetSocketAddress s = new InetSocketAddress(resultIP+i, 30000);
socket.connect(s,50);

for(int i=1;i<255;i++){
		try {
			Socket socket = new Socket();
			InetSocketAddress s = new InetSocketAddress(resultIP+i, 30000);
			socket.connect(s,50);
			Message message = new Message();
			message.what=1000;
			message.obj=resultIP+i;
			handler.sendMessage(message);
			flag =true;
			socket.close();
			break;
		} catch (IOException e) {
			handler.sendEmptyMessage(i);
		}
	}

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