This is my code, but I had an error in logcat
com.example.norhanom.example2 E/AndroidRuntime: FATAL EXCEPTION: main com.example.norhanom.example2 E/AndroidRuntime: Process: com.example.norhanom.example2, PID: 26334 com.example.norhanom.example2 E/AndroidRuntime: java.lang.NullPointerException: Attempt to invoke virtual method 'java.lang.String java.lang.String.toString()' on a null object reference com.example.norhanom.example2 E/AndroidRuntime: at com.example.norhanom.example2.MainActivity$2.onErrorResponse(MainActivity.java:68) com.example.norhanom.example2 E/AndroidRuntime: at com.android.volley.Request.deliverError(Request.java:564) com.example.norhanom.example2 E/AndroidRuntime: at com.android.volley.ExecutorDelivery$ResponseDeliveryRunnable.run(ExecutorDelivery.java:101) com.example.norhanom.example2 E/AndroidRuntime: at android.os.Handler.handleCallback(Handler.java:815) com.example.norhanom.example2 E/AndroidRuntime: at android.os.Handler.dispatchMessage(Handler.java:104) com.example.norhanom.example2 E/AndroidRuntime: at android.os.Looper.loop(Looper.java:207) com.example.norhanom.example2 E/AndroidRuntime: at android.app.ActivityThread.main(ActivityThread.java:5777) com.example.norhanom.example2 E/AndroidRuntime: at java.lang.reflect.Method.invoke(Native Method) com.example.norhanom.example2 E/AndroidRuntime: at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:789) com.example.norhanom.example2 E/AndroidRuntime: at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:679) com.example.norhanom.example2 I/Process: Sending signal. PID: 26334 SIG: 9
MainActivity
package com.example.norhanom.example2;
import android.app.ProgressDialog;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;
import android.widget.Toast;
import com.android.volley.Request;
import com.android.volley.RequestQueue;
import com.android.volley.Response;
import com.android.volley.VolleyError;
import com.android.volley.toolbox.JsonObjectRequest;
import com.android.volley.toolbox.StringRequest;
import com.android.volley.toolbox.Volley;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;
public class MainActivity extends AppCompatActivity implements
View.OnClickListener {
private EditText editTextBarcodeNumber;
private Button buttonGet;
private TextView textViewResult;
private ProgressDialog loading;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
editTextBarcodeNumber = (EditText) findViewById(R.id.editTextbc);
buttonGet = (Button) findViewById(R.id.button);
textViewResult = (TextView) findViewById(R.id.textViewResult);
buttonGet.setOnClickListener(this);
}
private void getData() {
String bc = editTextBarcodeNumber.getText().toString().trim();
if (bc.equals("")) {
Toast.makeText(this, "Please enter the barcode number",
Toast.LENGTH_LONG).show();
return;
}
loading = ProgressDialog.show(this,"Please
wait...","Fetching...",false,false);
String url =
Config.DATA_URL+editTextBarcodeNumber.getText().toString().trim();
StringRequest stringRequest = new StringRequest(url, new
Response.Listener<String>() {
@Override
public void onResponse(String response) {
loading.dismiss();
showJSON(response);
}
},
new Response.ErrorListener() {
@Override
public void onErrorResponse(VolleyError error) {
Toast.makeText(MainActivity.this,error.getMessage().toString(),Toast.LENGTH_LONG).show();
}
});
RequestQueue requestQueue = Volley.newRequestQueue(this);
requestQueue.add(stringRequest);
}
private void showJSON(String response){
String name="";
String StatusProduct="";
String ExpiredDate = "";
try {
JSONObject jsonObject = new JSONObject(response);
JSONArray result = jsonObject.getJSONArray(Config.JSON_ARRAY);
JSONObject halal_data = result.getJSONObject(0);
name = halal_data.getString(Config.KEY_NAME);
StatusProduct = halal_data.getString(Config.KEY_STATUSPRODUCT);
ExpiredDate = halal_data.getString(Config.KEY_EXPIREDDATE);
} catch (JSONException e) {
e.printStackTrace();
}
textViewResult.setText("Name:\t" + name + "\nStatus of Product:\t" +
StatusProduct + "\nExpired Date:\t"+ ExpiredDate);
}
@Override
public void onClick(View v) {
getData();
}
}
Config.java
package com.example.norhanom.example2;
public class Config {
public static final String DATA_URL =
"http://192.168.1.7/android/getData.php?BarcodeNumber=";
public static final String KEY_NAME = "Name";
public static final String KEY_STATUSPRODUCT = "StatusProduct";
public static final String KEY_EXPIREDDATE = "ExpiredDate";
public static final String JSON_ARRAY = "result";
}
activity
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin"
android:paddingBottom="@dimen/activity_vertical_margin"
tools:context=".MainActivity">
<Button
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="GET"
android:id="@+id/button"
android:layout_below="@+id/editTextbc"
android:layout_centerHorizontal="true"
android:layout_marginTop="46dp" />
<EditText
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:inputType="number"
android:ems="10"
android:id="@+id/editTextbc"
android:text="enter the barcode number"
android:layout_alignParentTop="true"
android:layout_centerHorizontal="true"
android:layout_marginTop="55dp" />
<TextView
android:id="@+id/textViewResult"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:layout_below="@+id/button"
android:layout_alignParentLeft="true"
android:layout_alignParentStart="true"
android:layout_marginTop="55dp" />
[enter image description here][1]
