我正在尝试进入物联网，并希望使应用程序将字符串从Android手机发送到Linux PC。该应用程序通过实现asynctask来做到这一点:
//From the java docs, slightly modified
private Void sendThroughSocket(String s, String host, int port) {
Log.d("E", "In send through socket");
final String hostName = host;//Host is the address of the receiver, can be IP or domain
int portNumber = port;
//Check if device is connected to internet
try {
Socket clientsocket = new Socket(hostName, portNumber); //one of 2-way point communication
Log.d("E", "Created Socket: ");
DataOutputStream DOS = new DataOutputStream(clientsocket.getOutputStream());
if (clientsocket.isConnected())
Log.d("E", "Socket connected");
DOS.writeUTF(s);
clientsocket.close();
} catch (UnknownHostException e) {
System.err.println("Don't know about host " + hostName);
new Runnable() {
public void run() {
Toast.makeText(context, "Don't know about host " + hostName, Toast.LENGTH_SHORT).show();
}
};
} catch (IOException e) {
System.err.println("Couldn't get I/O for the connection to " + hostName);
//Toast can not be run using asynctask since it acesses UI
new Runnable() {
public void run() {
Toast.makeText(context, "Couldn't get I/O for the connection to " + hostName + " , check the port", Toast.LENGTH_SHORT).show();
}
};
} catch (Exception e) {
Log.d("E", "#fares" + e.getClass().getName().toString());
}
return null;
}
我有3次尝试发送所有从搜索栏触发的字符串(我将搜索栏进度值作为字符串发送):
公共(public)无效onProgressChanged(SeekBar seekBar，int i，boolean b)
公共(public)无效onStartTrackingTouch(SeekBar seekBar)
公共(public)无效onStopTrackingTouch(SeekBar seekBar)
所有这三个的实现是相同的:
公共(public)无效onProgressChanged(SeekBar seekBar，int i，boolean b){
progressvalue = i;
textView.setText("Brightness = " + progressvalue + " %");
if (((RecieverPort.equals("Please enter port Number")) || (RecieverIP.equals("Please enter receiver IP")))) {
//Make sure toast isn't persistent
if (IPPortToastcount++ == 0)
Toast.makeText(MainActivity.this, "Please set both IP and Port ", Toast.LENGTH_SHORT).show();
} else {
//Check if connected to internet
if (!isConnectedtoInternet(MainActivity.this)) {
if (ConnectivityToastCount++ < 1)
Toast.makeText(MainActivity.this, "You are not connected to the Internet", Toast.LENGTH_SHORT).show();
} else {
//Send text over wifi
SendText ST = new SendText(getApplicationContext());
ST.execute(String.valueOf(progressvalue), RecieverIP, RecieverPort);
ST.cancel(false);
}
}
}
主要是
//Send text over wifi
SendText ST = new SendText(getApplicationContext());
ST.execute(String.valueOf(progressvalue), RecieverIP, RecieverPort);
ST.cancel(false);
服务器端(我的电脑)非常简单:
int portNumber = 44339; // Choose unused port on router
//Open a socket
try {
//System.out.println("in try statement");
try (ServerSocket serverSocket1 = new ServerSocket(portNumber)) {
portNumber = serverSocket1.getLocalPort();
System.out.println("Created socket at port " + portNumber);
Socket clientSocket = serverSocket1.accept();
System.out.println("Accepted");
DataInputStream DIS = new DataInputStream(clientSocket.getInputStream()); //get input from socket
//System.out.println("Created reader");
String inputLine;
// System.out.println("About to read");
while (DIS.available() > 0) {
inputLine = DIS.readUTF();
System.out.println(inputLine);
}
}
} catch (Exception e) {
System.out.println("Exception caught when trying to listen on port "
+ portNumber + " or listening for a connection");
System.out.println(e.getClass().getSimpleName());
}
这种工作方式是不同的，除了在接受服务器套接字之前需要花费很长时间(几秒钟)。它也只能在onprogresschanged下工作，这使我相信多次尝试
//Send text over wifi
SendText ST = new SendText(getApplicationContext());
ST.execute(String.valueOf(progressvalue), RecieverIP, RecieverPort);
ST.cancel(false);
在成功创建套接字并连接到PC之前，需要使用它们。如何确保一键点击或一次调用该函数足以发送字符串？
抱歉，很长的帖子，但这是我第一次问:)
编辑:我的新服务器代码:
try {
//System.out.println("in try statement");
try ( ServerSocket serverSocket1 = new ServerSocket(portNumber))
{
portNumber = serverSocket1.getLocalPort();
System.out.println("Created socket at port " + portNumber);
while(true){
Socket clientSocket = serverSocket1.accept();
// System.out.println("Accepted");
DataInputStream DIS = new DataInputStream(clientSocket.getInputStream()); //get input from socket
//System.out.println("Created reader");
//String inputLine;
//System.out.println("About to read");
System.out.println(DIS.readUTF());
}
}
} catch (Exception e) {
System.out.println("Exception caught when trying to listen on port "
+ portNumber + " or listening for a connection");
System.out.println(e.getClass().getSimpleName());
}
值得注意的是，即使在while true循环中，服务器也将始终显示4个数字然后停止。
编辑:这是一个示例日志:
10-06 20:08:09.145 26372-26372/com.example.fares.ledslider D/E:＃测试方法值中的票价= 50
10-06 20:08:26.475 26372-26372/com.example.fares.ledslider D/E:＃开始跟踪票价
10-06 20:08:26.722 26372-27004/com.example.fares.ledslider D/E:#fares已连接套接字
10-06 20:08:26.810 26372-26764/com.example.fares.ledslider D/E:#fares已连接套接字
10-06 20:08:27.241 26372-27003/com.example.fares.ledslider D/E:#fares已连接套接字
10-06 20:08:27.304 26372-26372/com.example.fares.ledslider D/E:＃停止跟踪中的票价
最佳答案
可以删除ST.cancel()。也没有等待可用性看起来并不好。