通过Asynctask将字符串发布到外部URL

Question

目前，我正在通过外部URL检索数据，该URL使用PHP脚本并返回JSON值。工作很好。

但如何发送用于查询的字符串，以便在PHP脚本中执行以下操作：

$name = $_POST['name']; //this was sent from the Android app. How do I send this from the app.
$sql = "SELECT name FROM tablename WHERE category = '$name'";
$result = mysqli_query($con, $sql) or die("Error in Selecting");

注意：我不想使用凌空抽射。

我的AsyncTask扩展类，它当前不向URL发送任何值。

class BackgroundTask extends AsyncTask<Void,Void,String> {

        final String jsonUrl = "http://example.com/getdata.php";

        @Override
        protected String doInBackground(Void... params) {
            try {
                URL url = new URL(jsonUrl);
                HttpURLConnection httpURLConnection = (HttpURLConnection)url.openConnection();
                InputStream in = httpURLConnection.getInputStream();
                BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(in));
                StringBuilder stringBuilder = new StringBuilder();

                while ((jsonString = bufferedReader.readLine()) != null){
                    stringBuilder.append(jsonString+"\n");
                }

                bufferedReader.close();
                in.close();
                httpURLConnection.disconnect();
                return stringBuilder.toString().trim();

            } catch (Exception e) {
                e.printStackTrace();
            }

            return null;
        }

        @Override
        protected void onPostExecute(String s) {
            super.onPostExecute(s);

            products = new ArrayList<>();

            try {
                jsonObject = new JSONObject(s);
                String category = jsonObject.getString("viewProduct");
                JSONArray jsonArray = new JSONArray(category);

                for(int x=0; x < jsonArray.length(); x++){
                    JSONObject jsonPart = jsonArray.getJSONObject(x);
                    products.add(jsonPart.getString("name"));
                }

                adapter = new ArrayAdapter<>(MainActivity.this, android.R.layout.simple_list_item_1, android.R.id.text1, products);
                productListView.setAdapter(adapter);

            } catch (JSONException e) {
                e.printStackTrace();
            }
        }
    }

Answer 1

如果您只是在讨论将数据作为POST请求的主体发送,那么可以使用如下方法：

HttpURLConnection conn= (HttpURLConnection) url.openConnection();           
conn.setDoOutput( true );
conn.setRequestMethod( "POST" );
conn.setRequestProperty( "Content-Length", Integer.toString( postDataLength ));
try {
   DataOutputStream wr = new DataOutputStream( conn.getOutputStream());
   wr.write( postData );
} catch (IOException ex) {}