我的Android應用未從服務器獲得任何響應

Question

我是Android的初學者。 實際上，我正在嘗試從服務器接收數據並檢查輸入的用戶名和密碼是否正確，但是沒有收到任何顯示“錯誤匹配”的響應事件。 我還檢查了JSON輸出，如果輸入“ Hello”作為名稱並輸入“ Hi”作為密碼，則假設顯示成功，但是單擊按鈕時未顯示任何內容。 我還在Manifest.xml添加了Internet權限。

MainActivity.java

public class MainActivity extends AppCompatActivity {
 private static final String REGISTER_URL = "http://192.168.43.218/define_testing.php";
 EditText username,pass;
 Button login;
 @Override
 protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    login = (Button) findViewById(R.id.login);
    username=(EditText)findViewById(R.id.username);
    pass=(EditText)findViewById(R.id.password);
    login.setOnClickListener(
            new View.OnClickListener() {
                @Override
                public void onClick(View v) {
                 StringRequest request=new StringRequest(REGISTER_URL, new Response.Listener<String>() {
                        @Override
                        public void onResponse(String response) {
                            try {
                                JSONObject jsO= new JSONObject(response);

                                JSONArray array = null;

                                array = jsO.getJSONArray("result");

                                    JSONObject obj = array.getJSONObject(0);
                                    String name= obj.getString("name");
                                    String password=obj.getString("password");

                                    String enterName=username.getText().toString();
                                    String enterPass=pass.getText().toString();
                                    if(name.equals(enterName) && password.equals(enterPass)){
                                        Toast.makeText(getApplicationContext(),"Success",Toast.LENGTH_SHORT).show();
                                    }
                                    else {
                                        Toast.makeText(getApplicationContext(),"Wrong Match",Toast.LENGTH_SHORT).show();
                                    }



                            }
                            catch (JSONException e1) {
                                e1.printStackTrace();
                            }
                        }},new Response.ErrorListener() {
                        @Override
                        public void onErrorResponse(VolleyError error) {
                            Toast.makeText(getApplicationContext(),"Internet Problem",Toast.LENGTH_SHORT).show();
                        }
                    });
                    RequestQueue requestQueue= Volley.newRequestQueue(getApplicationContext());
                    requestQueue.add(request);
                }
            }
    );


   }

 }

PHP腳本

<?php
 require ('connection.php');

  $name  = 'Hello';

 $sql = "SELECT * FROM new_one_user_information WHERE username='".$name."'";

 $r = mysqli_query($connect,$sql);

 $res = mysqli_fetch_array($r);

$result = array();

array_push($result,array(
"name"=>$res['username'],
"password"=>$res['password']
      )
     );

echo json_encode(array("result"=>$result));


 mysqli_close($connect);
 ?>

該PHP腳本的輸出為：

Connection Established
{"result":[{"name":"Hello","password":"Hi"}]}

logcat錯誤：

org.json.JSONException: Value Connection of type java.lang.String cannot be converted to JSONObject
  at org.json.JSON.typeMismatch(JSON.java:111)
  at org.json.JSONObject.<init>(JSONObject.java:159)
  at org.json.JSONObject.<init>(JSONObject.java:172)
  at com.example.srinu.stackview2.MainActivity.checkIt(MainActivity.java:85)
  at com.example.srinu.stackview2.MainActivity$1$1.onResponse(MainActivity.java:68)
  at com.example.srinu.stackview2.MainActivity$1$1.onResponse(MainActivity.java:50)
  at com.android.volley.toolbox.StringRequest.deliverResponse(StringRequest.java:67)
  at com.android.volley.toolbox.StringRequest.deliverResponse(StringRequest.java:30)
  at com.android.volley.ExecutorDelivery$ResponseDeliveryRunnable.run(ExecutorDelivery.java:99)
  at android.os.Handler.handleCallback(Handler.java:733)
  at android.os.Handler.dispatchMessage(Handler.java:95)
  at android.os.Looper.loop(Looper.java:136)
  at android.app.ActivityThread.main(ActivityThread.java:5001)
  at java.lang.reflect.Method.invokeNative(Native Method)
  at java.lang.reflect.Method.invoke(Method.java:515)
  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:785)
  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:601)
  at dalvik.system.NativeStart.main(Native Method)

Answer 1

必需的connection.php文件內必須有“已建立連接”消息。

這就是為什么php響應不是有效的json的原因。