与Android(客户端)和Node.js(服务器)的异步通信

Question

我想与Android和Node.js进行通信。

我实现了程序，当它们在同一个网络上时，它运行良好(我的意思是相同的WIFI(。但是当我断开我的安卓手机与wifi的连接并连接到移动数据时，通信就无法了。搜索后，发现存在跨域问题。 但是我找不到适合我情况的解决方案。 请问你能帮我解决这个问题吗？

这是我的服务器端代码(服务器.js(。

var https = require('https');
var express = require('express');
var fs = require('fs');
var app = express();
var port = 9000;
var cors = require('cors');
var welcome = "new msg from server!";
app.get('/get', function(req, res) {
console.log('>> send new msg to client...');
res.json(welcome);
})
app.post('/post', function(req, res) {
console.log('<< receive new msg from client...');
var info_from_client;
req.on('data', function(data) {
info_from_client = JSON.parse(data);
})
req.on('end', function(data) {
var log_temp = "contents : nname = " + info_from_client.user_name +          "nfinger_print = " + info_from_client.finger_print;
console.log(log_temp);
res.write(log_temp);
res.end();
})
})
app.listen(port, function() {
console.log('now server is starting...');
})

这是我的客户端代码。

public class SendToServer extends AsyncTask<String, String, String> {
private TextView tv;
private int action;
private int get = 1;
private int post = 2;

public SendToServer (TextView tv, int action) {
this.tv = tv;
this.action = action;
}
public String get_action(HttpURLConnection connection) {
InputStream stream;
BufferedReader reader = null;
StringBuffer buffer;
try {
connection.connect();
stream = connection.getInputStream();
reader = new BufferedReader(new InputStreamReader(stream));
buffer = new StringBuffer();
String line = "";
while ((line = reader.readLine()) != null) {
buffer.append(line);
}
return buffer.toString();
}
catch (MalformedURLException e) {
e.printStackTrace();
}
catch (IOException e) {
e.printStackTrace();
}
finally {
if (connection != null) {
connection.disconnect();
}
try {
if (reader != null) {
reader.close();
}
}
catch (Exception e) {
e.printStackTrace();
}
}//end of finally
return null;
}
public String post_action(HttpURLConnection connection) {
JSONObject jsonObject = new JSONObject();
try {
jsonObject.accumulate("user_name", "Na Jun Yeop");
jsonObject.accumulate("finger_print", "12388452218");
} catch (JSONException e) {
e.printStackTrace();
}

OutputStream outputStream;
InputStream inputStream;
BufferedWriter writer = null;
BufferedReader reader = null;
StringBuffer buffer;
try {
connection.setRequestMethod("POST");
connection.setRequestProperty("Cache-Control", "no-cache");
connection.setRequestProperty("Content-Type", "application/json");
connection.setRequestProperty("Accept", "text/html");
connection.setDoOutput(true);
connection.setDoInput(true);
connection.connect();
outputStream = connection.getOutputStream();
writer = new BufferedWriter(new OutputStreamWriter(outputStream));
writer.write(jsonObject.toString());
writer.flush();
writer.close();
inputStream = connection.getInputStream();
reader = new BufferedReader(new InputStreamReader(inputStream));
buffer = new StringBuffer();
String line = "";
while ((line = reader.readLine()) != null) {
buffer.append(line);
}
return buffer.toString();
}
catch (MalformedURLException e) {
e.printStackTrace();
}
catch (IOException e) {
e.printStackTrace();
}
finally {
if (connection != null) {
connection.disconnect();
}
try {
if (reader != null) {
reader.close();
}
}
catch (Exception e) {
e.printStackTrace();
}
}//end of finally
return null;
}
@Override
protected String doInBackground(String... strings) {
HttpURLConnection connection = null;
BufferedReader reader = null;
try {
URL url = new URL(strings[0]);
connection = (HttpURLConnection)url.openConnection();
if (action == get) {
return get_action(connection);
}
else if (action == post) {
return post_action(connection);
}
connection.connect();
InputStream stream = connection.getInputStream();
reader = new BufferedReader(new InputStreamReader(stream));
StringBuffer buffer = new StringBuffer();
String line = "";
while ((line = reader.readLine()) != null) {
buffer.append(line);
}
return buffer.toString();

}
catch (MalformedURLException e) {
e.printStackTrace();
}
catch (IOException e) {
e.printStackTrace();
}
finally {
if (connection != null) {
connection.disconnect();
}
try {
if (reader != null) {
reader.close();
}
}
catch (Exception e) {
e.printStackTrace();
}
}//end of finally

return null;
}
@Override
protected void onPostExecute(String result) {
super.onPostExecute(result);
tv.setText(result);
}

Answer 1

为了解决此问题，您需要将 Node.js 服务器与 SSL 证书或安全 https 一起运行。对于本地测试，您应该只尝试使用相同的本地网络。 尝试更新请求中的以下参数，看看它是否有效

Access-Control-Allow-Origin: *
Access-Control-Allow-Methods: POST, GET, PUT, OPTIONS
Access-Control-Allow-Headers: Content-Type