刚刚尝试这个code。 ：）

 公共类MainActivity扩展AppCompatActivity { @覆盖
 保护无效的onCreate（捆绑savedInstanceState）{
  super.onCreate（savedInstanceState）;
  的setContentView（R.layout.activity_main）;
  新的测试（）执行（）;
 }
 // AsyncTask的
 Test类扩展的AsyncTask＆LT;字符串，太虚，字符串＆GT; {  @覆盖
  保护字符串doInBackground（字符串... PARAMS）{
   在的InputStream = NULL;
   串QueryResult中=;
   网址URL =新的URL（http://www.android.com/）;
   HttpURLConnection类的URLConnection =（HttpURLConnection类）url.openConnection（）;
   尝试{
    在的InputStream =新的BufferedInputStream（urlConnection.getInputStream（））;
    QueryResult中= readStream（上）;
   } {最后
    urlConnection.disconnect（）;
   }
   返回QueryResult中;  }
  私人字符串readStream（InputStream中的IStream）抛出IOException   //缓冲的读者可以让我们逐行读取
   尝试（面包屑的BufferedReader =
    新的BufferedReader（新的InputStreamReader（的IStream）））{
    StringBuilder的建设者=新的StringBuilder（）;
    串线;
    而（（行= bReader.readLine（））！= NULL）{//读取直到结束
     builder.append（线）;
    }
    返回builder.toString（）;
   }
  }
  保护无效onPostExecute（字符串数据）{
   //做进一步的事情
   吐司面包= Toast.makeText（getApplicationContext（），数据，
    Toast.LENGTH_SHORT）;
   toast.show（）;  } }}
 

I'm really confused, i'm trying to develop a simple function that allow me to send and receive data from a server.

The operation is as follows:

In an activity I execute an HTTP POST to a PHP file on a server, the "PHP file" gets the data that i send (tipically a string), and executes a query using the parameters sent over http.

Example:

My android app send a string with this value "PIPPO", in the PHP file there is a query, for example:

$value = PIPPO /* data received from android app*/ Select * from characters where(characters.name=".$value.")

p.s. all data use JSON format

The problem is: i always used a function (that works fine) but now all methods are deprecated, I can't find an alternative to the methods for the newest API.

This is my code:

public class ReadServer extends Activity {
 String result;
 public String readserver(String id_data, String data){
 try{
  HttpClient httpclient = new DefaultHttpClient();
  HttpPost httpPost = new HttpPost("myurl/queryMobile.php");
  StringBuilder builder = new StringBuilder();
  String json = "";
  //Build jsonObject
  JSONObject jsonObject = new JSONObject();
  jsonObject.accumulate(id_data, data);
  //Convert JSONObject to JSON to String
  json = jsonObject.toString();

  //Set json to StringEntity
  StringEntity se = new StringEntity(json);
  //Set httpPost Entity
  httpPost.setEntity(se);
  //Set some headers to inform server about the type of the content
  httpPost.setHeader("Accept", "application/json");
  httpPost.setHeader("Content-type", "application/json");

  //Execute POST request to the given URL
  HttpResponse httpResponse = httpclient.execute(httpPost);
  //Receive response as inputStream
  StatusLine statusLine = httpResponse.getStatusLine();
  int statusCode = statusLine.getStatusCode();
  //Convert input stream to string
  AlertDialog.Builder alertDialog;

  switch(statusCode){
  case 200:
  HttpEntity entity = httpResponse.getEntity();
  InputStream content = entity.getContent();
  BufferedReader reader = new BufferedReader(new InputStreamReader(content));
  String line="";
  try{
  while ((line = reader.readLine()) != null) {
  builder.append(line);
  result = builder.toString();
  }
  }catch(Exception e){
  alertDialog = new AlertDialog.Builder(this);
  alertDialog.setTitle("400 Bad Request");
  alertDialog.setMessage("Non è stato possibile soddisfare la tua richiesta, riprova più tardi.");
  alertDialog.show();
  }
  break;

Just try this code. :)

public class MainActivity extends AppCompatActivity {

 @Override
 protected void onCreate(Bundle savedInstanceState) {
  super.onCreate(savedInstanceState);
  setContentView(R.layout.activity_main);
  new Test().execute();
 }


 //AsyncTask 
 class Test extends AsyncTask < String, Void, String > {

  @Override
  protected String doInBackground(String...params) {
   InputStream in = null;
   String queryResult = "";
   URL url = new URL("http://www.android.com/");
   HttpURLConnection urlConnection = (HttpURLConnection) url.openConnection();
   try {
    InputStream in = new BufferedInputStream(urlConnection.getInputStream());
    queryResult = readStream( in );
   } finally {
    urlConnection.disconnect();
   }
   return queryResult;

  }
  private String readStream(InputStream iStream) throws IOException {

   //Buffered reader allows us to read line by line
   try (BufferedReader bReader =
    new BufferedReader(new InputStreamReader(iStream))) {
    StringBuilder builder = new StringBuilder();
    String line;
    while ((line = bReader.readLine()) != null) { //Read till end
     builder.append(line);
    }
    return builder.toString();
   }
  }
  protected void onPostExecute(String data) {
   // do further things 
   Toast toast = Toast.makeText(getApplicationContext(), data,
    Toast.LENGTH_SHORT);
   toast.show();

  }

 }

}