java – 使用Android发送HTTP Post请求

我一直试图从SO和其他网站上的大量例子中学习,但我无法弄清楚为什么我一起攻击的例子不起作用.我正在构建一个小概念验证应用程序来识别语音并将其作为POST请求发送到node.js服务器.语音识别我已经确认工作,服务器正在接收来自常规浏览器访问的连接,因此我认为问题出在应用程序本身.我错过了一些小而愚蠢的东西吗？没有错误被抛出,但服务器永远不会识别连接.提前感谢任何建议或帮助.

相关Java(主要活动和必要的AsyncTask)：

protected void onActivityResult(int requestCode, int resultCode, Intent data) {
    if (requestCode == 1001) {
        if (resultCode == RESULT_OK) {
            ArrayList textMatchList = data.getStringArrayListExtra(RecognizerIntent.EXTRA_RESULTS);
            if (!textMatchList.isEmpty()) {
                String topMatch = textMatchList.get(0);
                PostTask pt = new PostTask();
                pt.execute(topMatch);
            }
        }
    }
}

private class PostTask extends AsyncTask {
    @Override
    protected String doInBackground(String... data) {
        try {
            URL url = new URL("http://:3000");
            HttpURLConnection conn = (HttpURLConnection) url.openConnection();
            conn.setReadTimeout(10000);
            conn.setConnectTimeout(15000);
            conn.setRequestMethod("POST");
            conn.setDoOutput(true);
            ContentValues values = new ContentValues();
            values.put("data", data[0]);
            OutputStream os = conn.getOutputStream();
            BufferedWriter writer = new BufferedWriter(new OutputStreamWriter(os, "UTF-8"));
            StringBuilder sb = new StringBuilder();
            sb.append(URLEncoder.encode("data", "UTF-8"));
            sb.append("=");
            sb.append(URLEncoder.encode(data[0], "UTF-8"));
            writer.write(sb.toString());
            writer.flush();
            writer.close();
            os.close();
            conn.connect();
            return "Text sent: " + data[0];
        } catch (IOException e) {
            e.printStackTrace();
            return "LOL NOPE";
        }
    }
}

服务器JS：

var http = require('http');
const PORT=3000;

function handleRequest(request, response){
    response.end('It Works!! Path Hit: ' + request.url);
    console.log("Request got.");
}

var server = http.createServer(handleRequest);
server.listen(PORT, '0.0.0.0');
console.log("Listening on 3000...");