AndroidでPOSTデータをPHPに送信

Question

POSTデータをPHPスクリプトに送信して結果を表示する方法をお探しです。$ usernameのPOSTデータをPHPに送信します。 これは私のPHPファイルです：

<?php 

    ...// connect 

      $username = $_POST['txtUsername'];// this data 

    $mysqli->query("SET NAMES 'utf8'"); 
    $sql="SELECT * FROM $username"; 
    $result=$mysqli->query($sql); 
    while($e=mysqli_fetch_assoc($result)){ 
    $output[]=$e; 
    } 

    print(json_encode($output)); 
    $mysqli->close(); 

    ?> 

私の活動：
DataParser.class

public class DataParser extends AsyncTask<Void,Void,Integer>{ 

Context c; 
ListView lv; 
String jsonData; 

ProgressDialog pd; 
ArrayList<Spacecraft> spacecrafts = new ArrayList<>(); 

public DataParser(Context c, ListView lv, String jsonData) { 
    this.c = c; 
    this.lv = lv; 
    this.jsonData = jsonData; 
} 

@Override 
protected void onPreExecute() { 
    super.onPreExecute(); 

    pd= new ProgressDialog(c); 
    pd.setTitle("Parse"); 
    pd.setMessage("Parsing..Please wait"); 
    pd.show(); 
} 

@Override 
protected Integer doInBackground(Void... voids) { 
    return this.parseData(); 
} 

@Override 
protected void onPostExecute(Integer result) { 
    super.onPostExecute(result); 


    pd.dismiss(); 
    if (result==0){ 
     Toast.makeText(c,"Unable to parse",Toast.LENGTH_SHORT).show(); 
    } 
    else { 
     CustomAdapter adapter = new CustomAdapter(c,spacecrafts); 
     lv.setAdapter(adapter); 
    } 
} 
private int parseData(){ 
    try { 
     JSONArray ja = new JSONArray(jsonData); 
     JSONObject jo = null; 

    spacecrafts.clear(); 
     Spacecraft s=null; 


     for (int i=0;i<ja.length();i++){ 
      jo=ja.getJSONObject(i); 
      int id = jo.getInt("id"); 
      String name =jo.getString("name"); 
      String send =jo.getString("send"); 
      String comment =jo.getString("comment"); 
      String date =jo.getString("date"); 

      s=new Spacecraft(); 
      s.setId(id); 
      s.setName(name); 
      s.setSend(send); 
      s.setComment(comment); 
      s.setDate(date); 

      spacecrafts.add(s); 
     } 


     return 1; 
    } catch (JSONException e) { 
     e.printStackTrace(); 
    } 

    return 0; 
}} 

MainActivity：

public class MainActivity extends AppCompatActivity implements AsyncResponse { 

String urlAddress="http://mysite/myphp.php"; 

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

    final ListView lv = (ListView) findViewById(R.id.lv) ; 

    Intent intent = getIntent(); 
    final String username = intent.getStringExtra("location"); 

    Downloader d = new Downloader(MainActivity.this,urlAddress,lv); 
    d.execute(); 

そしてDownloader.class：

public class Downloader extends AsyncTask<Void,Void,String> { 

Context c; 
String urlAddress; 
ListView lv; 

ProgressDialog pd; 
public Downloader(Context c, String urlAddress, ListView lv) { 
    this.c = c; 
    this.urlAddress = urlAddress; 
    this.lv = lv; 
} 

@Override 
protected void onPreExecute() { 
    super.onPreExecute(); 

    pd = new ProgressDialog(c); 
    pd.setTitle("Fetch"); 
    pd.setMessage("Fetching...Please wait"); 
    pd.show(); 
} 

@Override 
protected String doInBackground(Void... voids) { 
    return this.downloadData(); 
} 

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

    pd.dismiss(); 

    if(s==null){ 
     Toast.makeText(c,"Unsuccessful,Null,returned",Toast.LENGTH_SHORT).show(); 
    } 
    else { 
    DataParser parser = new DataParser(c,lv,s); 
     parser.execute(); 

    } 

} 


private String downloadData(){ 
    HttpURLConnection con = Connector.connect(urlAddress); 
    if (con==null){ 
     return null; 
    } 
    InputStream is=null; 
    try { 

     is=new BufferedInputStream(con.getInputStream()); 
     BufferedReader br = new BufferedReader(new InputStreamReader(is)); 

    String line = null; 
     StringBuffer response = new StringBuffer(); 

     if (br!=null){ 
      while ((line=br.readLine())!=null){ 
       response.append(line+"\n"); 
      } 

      br.close(); 
     } 
     else {return null;} 
     return response.toString(); 

    } catch (IOException e) { 
     e.printStackTrace(); 
    } 
    finally { 
     if(is != null){ 
      try { 
       is.close(); 
      } catch (IOException e) { 
       e.printStackTrace(); 
      } 
     } 
    } 

    return null; 
}} 

私を助けてください、ありがとう！

Answer 1

提供したコードに基づいて、データをダウンロードしているように見えますが、データを投稿しているようではありません。

HTTP POST経由でデータを送信できる方法はいくつかあります。 Google IO Volley APIを使用してみると、ネットワーク通話のロジックが大事になります。例えば

：

RequestQueue queue = Volley.newRequestQueue(this); 
String url = "https://myurl.com"; 
JsonRequest postRequest = new StringRequest(Request.Method.POST, url, 
    new Response.Listener<String>() 
    { 
     @Override 
     public void onResponse(JSONObject response) 
     { 
      Log.d(TAG, response.toString()); 
     } 
    }, 
    new Response.ErrorListener() 
    { 
     @Override 
     public void onErrorResponse(VolleyError error) 
     { 
      Log.e(TAG, error.toString()); 
     } 
    }) 
    {  
    @Override 
    protected Map<String, String> getParams() 
    { 
     Map<String, String> params = new HashMap<String, String>(); 
     params.put("txtUsername", "mUsername");    
     return params; 
    } 
    @Override 
    public Map<String, String> getHeaders() throws AuthFailureError 
    {     
     Map<String, String> headers = new HashMap<String, String>(); 
     headers.put("Content-Type", "application/x-www-form-urlencoded"); 
     return headers; 
    } 
}; 
queue.add(postRequest); 

また、ポストを実行するために、独自のAsyncTaskを書くことができます。次に例を示します。次に

public class PostRequestAsyncTask extends AsyncTask<Void, Void, String 
{ 
    Context context; 
    Map<String, String> postParams; 

    /** 
    * Overridden constructor 
    */ 
    public PostRequestAsyncTask(Context context, Map<String, String> postParams) 
    { 
     this.context = context; 
     this.postParams = new LinkedHashMap<String, String>(postParams); 
    } 

    /** 
    * Default constructor 
    */ 
    public PostRequestAsyncTask() {} 

    public byte[] generatePostData() 
    { 
     StringBuilder postData = new StringBuilder(); 
     for (Map.Entry<String, String> dParam : postParams.entrySet()) 
     { 
      if (postData.length() != 0) 
       postData.append('&'); 
      try { 
       postData.append(URLEncoder.encode(dParam.getKey(), "UTF-8")); 
       postData.append('='); 
       postData.append(URLEncoder.encode(String.valueOf(dParam.getValue()), "UTF-8")); 
      } 
      catch (UnsupportedEncodingException e) 
      { 
       e.printStackTrace(); 
      } 
     } 
     byte[] postDataBytes = null; 
     try 
     { 
      postDataBytes = postData.toString().getBytes("UTF-8"); 
     } 
     catch (UnsupportedEncodingException e) 
     { 
      e.printStackTrace(); 
     } 
     return postDataBytes; 
    } 

    @Override 
    protected String doInBackground(Void... params) 
    { 
     /* Set params */ 
     byte[] postDataBytes = generatePostData(); 

     /* Set headers and write */ 
     URL url = null; 
     HttpURLConnection conn = null; 
     try 
     { 
      url = new URL("https://myurl.com"); 
      conn = (HttpURLConnection) url.openConnection(); 
      conn.setRequestMethod("POST"); 
      conn.setRequestProperty("Content-Type", "application/x-www-form-urlencoded"); 
      conn.setRequestProperty("Content-Length", String.valueOf(postDataBytes.length)); 
      conn.setDoOutput(true); 
      conn.getOutputStream().write(postDataBytes); 
     } 
     catch (MalformedURLException | IOException e) 
     { 
      e.printStackTrace(); 
     } 

     /* Retrieve response */ 
     Reader in = null; 
     String response = new String(); 
     try 
     { 
      in = new BufferedReader(new InputStreamReader(conn.getInputStream(), "UTF-8")); 
      response = ""; 
      for (int c = in.read(); c != -1; c = in.read()) 
      { 
       response += (char) c; 
      } 
     } 
     catch (IOException e) 
     { 
      e.printStackTrace(); 
     } 
     return response; 
    } 

    @Override 
    protected void onPostExecute(String resp) { 
     super.onPostExecute(resp); 
     JSONObject jsonResponse = null; 
     try 
     { 
      jsonResponse = new JSONObject(resp); 
      //do something with your json response 
     } 
     catch (JSONException e) 
     { 
      e.printStackTrace(); 
     } 
    } 
} 

そうのようなあなたのAsyncTaskを実行します。

Map<String, String> postParams = new LinkedHashMap<>(); 
postParams.put("txtUserName", "mUsername"); 
new PostRequestAsyncTask(MyActivity.this, postParams).execute();