Android app runs only on emulator but not on device
Question
I have created an application that fetches contents from an online MySQL Database. I have used JSON Parser for that. My app works fine on the emulator but on my mobile device it is no able to fetch the contents.
This is my code till now: AllPapersActivity.java
package com.papershare.bhanu;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import org.apache.http.NameValuePair;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;
import android.app.ListActivity;
import android.app.ProgressDialog;
import android.content.Intent;
import android.os.AsyncTask;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.widget.AdapterView;
import android.widget.AdapterView.OnItemClickListener;
import android.widget.ListAdapter;
import android.widget.ListView;
import android.widget.SimpleAdapter;
import android.widget.TextView;
public class AllPapersActivity extends ListActivity {
// Progress Dialog
private ProgressDialog pDialog;
// Creating JSON Parser object
JSONParser jParser = new JSONParser();
ArrayList<HashMap<String, String>> papersList;
// url to get all papers list
private static String url_all_papers = "http://kidessential.esy.es/android_connect_paper/get_all_papers.php";
// JSON Node names
private static final String TAG_SUCCESS = "success";
private static final String TAG_paperS = "papers";
private static final String TAG_PID = "pid";
private static final String TAG_NAME = "name";
private static final String TAG_DESCRIPTION = "description";
// papers JSONArray
JSONArray papers = null;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.all_papers);
// Hashmap for ListView
papersList = new ArrayList<HashMap<String, String>>();
// Loading papers in Background Thread
new LoadAllpapers().execute();
// Get listview
ListView lv = getListView();
// on seleting single paper
// launching Edit paper Screen
lv.setOnItemClickListener(new OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> parent, View view,
int position, long id) {
// getting values from selected ListItem
String description = ((TextView) view.findViewById(R.id.description)).getText()
.toString();
// Starting new intent
Intent in = new Intent(getApplicationContext(),
WebViewer.class);
// sending pid to next activity
in.putExtra(TAG_DESCRIPTION, description);
// starting new activity and expecting some response back
startActivityForResult(in, 100);
}
});
}
// Response from Edit paper Activity
@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
super.onActivityResult(requestCode, resultCode, data);
// if result code 100
if (resultCode == 100) {
// if result code 100 is received
// means user edited/deleted paper
// reload this screen again
Intent intent = getIntent();
finish();
startActivity(intent);
}
}
/**
* Background Async Task to Load all paper by making HTTP Request
* */
class LoadAllpapers extends AsyncTask<String, String, String> {
/**
* Before starting background thread Show Progress Dialog
* */
@Override
protected void onPreExecute() {
super.onPreExecute();
pDialog = new ProgressDialog(AllPapersActivity.this);
pDialog.setMessage("Loading papers. Please wait...");
pDialog.setIndeterminate(false);
pDialog.setCancelable(false);
pDialog.show();
}
/**
* getting All papers from url
* */
protected String doInBackground(String... args) {
// Building Parameters
List<NameValuePair> params = new ArrayList<NameValuePair>();
// getting JSON string from URL
JSONObject json = jParser.makeHttpRequest(url_all_papers, "GET", params);
// Check your log cat for JSON reponse
Log.d("All papers: ", json.toString());
try {
// Checking for SUCCESS TAG
int success = json.getInt(TAG_SUCCESS);
if (success == 1) {
// papers found
// Getting Array of papers
papers = json.getJSONArray(TAG_paperS);
// looping through All papers
for (int i = 0; i < papers.length(); i++) {
JSONObject c = papers.getJSONObject(i);
// Storing each json item in variable
String id = c.getString(TAG_PID);
String name = c.getString(TAG_NAME);
String descrip = c.getString(TAG_DESCRIPTION);
// creating new HashMap
HashMap<String, String> map = new HashMap<String, String>();
// adding each child node to HashMap key => value
map.put(TAG_PID, id);
map.put(TAG_NAME, name);
map.put(TAG_DESCRIPTION, descrip);
// adding HashList to ArrayList
papersList.add(map);
}
} else {
// no papers found
// Launch Add New paper Activity
Intent i = new Intent(getApplicationContext(),
NewPapersActivity.class);
// Closing all previous activities
i.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
startActivity(i);
}
} catch (JSONException e) {
e.printStackTrace();
}
return null;
}
/**
* After completing background task Dismiss the progress dialog
* **/
protected void onPostExecute(String file_url) {
// dismiss the dialog after getting all papers
pDialog.dismiss();
// updating UI from Background Thread
runOnUiThread(new Runnable() {
public void run() {
/**
* Updating parsed JSON data into ListView
* */
ListAdapter adapter = new SimpleAdapter(
AllPapersActivity.this, papersList,
R.layout.list_item,
new String[] { TAG_PID,TAG_NAME, TAG_DESCRIPTION},
new int[] { R.id.pid, R.id.name, R.id.description});
// updating listview
setListAdapter(adapter);
}
});
}
}
}
and this is JSONParser.java
package com.papershare.bhanu;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.UnsupportedEncodingException;
import java.util.List;
import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.NameValuePair;
import org.apache.http.client.ClientProtocolException;
import org.apache.http.client.entity.UrlEncodedFormEntity;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.client.utils.URLEncodedUtils;
import org.apache.http.impl.client.DefaultHttpClient;
import org.json.JSONException;
import org.json.JSONObject;
import android.util.Log;
public class JSONParser {
static InputStream is = null;
static JSONObject jObj = null;
static String json = "";
// constructor
public JSONParser() {
}
// function get json from url
// by making HTTP POST or GET mehtod
public JSONObject makeHttpRequest(String url, String method,
List<NameValuePair> params) {
// Making HTTP request
try {
// check for request method
if(method.equals("POST")){
// request method is POST
// defaultHttpClient
DefaultHttpClient httpClient = new DefaultHttpClient();
HttpPost httpPost = new HttpPost(url);
httpPost.setEntity(new UrlEncodedFormEntity(params));
HttpResponse httpResponse = httpClient.execute(httpPost);
HttpEntity httpEntity = httpResponse.getEntity();
is = httpEntity.getContent();
}else if(method.equals("GET")){
// request method is GET
DefaultHttpClient httpClient = new DefaultHttpClient();
String paramString = URLEncodedUtils.format(params, "utf-8");
url += "?" + paramString;
HttpGet httpGet = new HttpGet(url);
HttpResponse httpResponse = httpClient.execute(httpGet);
HttpEntity httpEntity = httpResponse.getEntity();
is = httpEntity.getContent();
}
} catch (UnsupportedEncodingException e) {
e.printStackTrace();
} catch (ClientProtocolException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
try {
BufferedReader reader = new BufferedReader(new InputStreamReader(
is, "iso-8859-1"), 8);
StringBuilder sb = new StringBuilder();
String line = null;
while ((line = reader.readLine()) != null) {
sb.append(line + "\n");
}
is.close();
json = sb.toString();
} catch (Exception e) {
Log.e("Buffer Error", "Error converting result " + e.toString());
}
// try parse the string to a JSON object
try {
jObj = new JSONObject(json);
} catch (JSONException e) {
Log.e("JSON Parser", "Error parsing data " + e.toString());
}
// return JSON String
return jObj;
}
}
As you can see I am hosting my php files in my hostinger account and I also have my MySQL database also created. Here is the logcat when the app is run in USB Debugging mode.
03-22 16:42:23.268: D/dalvikvm(531): Not late-enabling CheckJNI (already on)
03-22 16:42:23.508: I/dalvikvm(531): Turning on JNI app bug workarounds for target SDK version 8...
03-22 16:42:24.228: I/dalvikvm(531): threadid=3: reacting to signal 3
03-22 16:42:24.238: I/dalvikvm(531): Wrote stack traces to '/data/anr/traces.txt'
03-22 16:42:24.648: I/dalvikvm(531): threadid=3: reacting to signal 3
03-22 16:42:24.698: D/dalvikvm(531): GC_FOR_ALLOC freed 64K, 2% free 12613K/12867K, paused 261ms
03-22 16:42:24.718: I/dalvikvm(531): Wrote stack traces to '/data/anr/traces.txt'
03-22 16:42:24.738: I/dalvikvm-heap(531): Grow heap (frag case) to 15.890MB for 3686416-byte allocation
03-22 16:42:24.858: D/dalvikvm(531): GC_CONCURRENT freed 1K, 2% free 16212K/16519K, paused 4ms+14ms
03-22 16:42:25.058: D/dalvikvm(531): GC_FOR_ALLOC freed 0K, 2% free 16212K/16519K, paused 31ms
03-22 16:42:25.118: I/dalvikvm-heap(531): Grow heap (frag case) to 22.140MB for 6554896-byte allocation
03-22 16:42:25.148: I/dalvikvm(531): threadid=3: reacting to signal 3
03-22 16:42:25.199: I/dalvikvm(531): Wrote stack traces to '/data/anr/traces.txt'
03-22 16:42:25.237: D/dalvikvm(531): GC_CONCURRENT freed 0K, 2% free 22613K/22983K, paused 5ms+5ms
03-22 16:42:25.618: D/(531): HostConnection::get() New Host Connection established 0x17c018, tid 531
03-22 16:42:25.728: I/dalvikvm(531): threadid=3: reacting to signal 3
03-22 16:42:25.738: I/dalvikvm(531): Wrote stack traces to '/data/anr/traces.txt'
03-22 16:42:26.328: I/dalvikvm(531): threadid=3: reacting to signal 3
03-22 16:42:26.338: I/dalvikvm(531): Wrote stack traces to '/data/anr/traces.txt'
03-22 16:58:22.478: I/dalvikvm(531): threadid=3: reacting to signal 3
03-22 16:58:22.518: I/dalvikvm(531): Wrote stack traces to '/data/anr/traces.txt'
03-22 16:58:22.958: I/dalvikvm(531): threadid=3: reacting to signal 3
03-22 16:58:23.117: I/dalvikvm(531): Wrote stack traces to '/data/anr/traces.txt'
03-22 16:58:24.167: I/dalvikvm(531): threadid=3: reacting to signal 3
03-22 16:58:24.178: I/dalvikvm(531): Wrote stack traces to '/data/anr/traces.txt'
03-22 17:01:32.008: W/System.err(531): org.apache.http.conn.HttpHostConnectException: Connection to http://10.0.2.2 refused
03-22 17:01:32.008: W/System.err(531): at org.apache.http.impl.conn.DefaultClientConnectionOperator.openConnection(DefaultClientConnectionOperator.java:183)
03-22 17:01:32.008: W/System.err(531): at org.apache.http.impl.conn.AbstractPoolEntry.open(AbstractPoolEntry.java:164)
03-22 17:01:32.008: W/System.err(531): at org.apache.http.impl.conn.AbstractPooledConnAdapter.open(AbstractPooledConnAdapter.java:119)
03-22 17:01:32.008: W/System.err(531): at org.apache.http.impl.client.DefaultRequestDirector.execute(DefaultRequestDirector.java:360)
03-22 17:01:32.008: W/System.err(531): at org.apache.http.impl.client.AbstractHttpClient.execute(AbstractHttpClient.java:555)
03-22 17:01:32.008: W/System.err(531): at org.apache.http.impl.client.AbstractHttpClient.execute(AbstractHttpClient.java:487)
03-22 17:01:32.008: W/System.err(531): at org.apache.http.impl.client.AbstractHttpClient.execute(AbstractHttpClient.java:465)
03-22 17:01:32.038: W/System.err(531): at com.papershare.bhanu.JSONParser.makeHttpRequest(JSONParser.java:62)
03-22 17:01:32.048: W/System.err(531): at com.papershare.bhanu.AllPapersActivity$LoadAllpapers.doInBackground(AllPapersActivity.java:128)
03-22 17:01:32.048: W/System.err(531): at com.papershare.bhanu.AllPapersActivity$LoadAllpapers.doInBackground(AllPapersActivity.java:1)
03-22 17:01:32.048: W/System.err(531): at android.os.AsyncTask$2.call(AsyncTask.java:264)
03-22 17:01:32.048: W/System.err(531): at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:305)
03-22 17:01:32.058: W/System.err(531): at java.util.concurrent.FutureTask.run(FutureTask.java:137)
03-22 17:01:32.058: W/System.err(531): at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1076)
03-22 17:01:32.058: W/System.err(531): at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:569)
03-22 17:01:32.058: W/System.err(531): at java.lang.Thread.run(Thread.java:856)
03-22 17:01:32.068: W/System.err(531): Caused by: java.net.ConnectException: failed to connect to /10.0.2.2 (port 80): connect failed: ETIMEDOUT (Connection timed out)
03-22 17:01:32.068: W/System.err(531): at libcore.io.IoBridge.connect(IoBridge.java:114)
03-22 17:01:32.078: W/System.err(531): at java.net.PlainSocketImpl.connect(PlainSocketImpl.java:192)
03-22 17:01:32.078: W/System.err(531): at java.net.PlainSocketImpl.connect(PlainSocketImpl.java:459)
03-22 17:01:32.078: W/System.err(531): at java.net.Socket.connect(Socket.java:842)
03-22 17:01:32.078: W/System.err(531): at org.apache.http.conn.scheme.PlainSocketFactory.connectSocket(PlainSocketFactory.java:119)
03-22 17:01:32.078: W/System.err(531): at org.apache.http.impl.conn.DefaultClientConnectionOperator.openConnection(DefaultClientConnectionOperator.java:144)
03-22 17:01:32.088: W/System.err(531): ... 15 more
03-22 17:01:32.088: W/System.err(531): Caused by: libcore.io.ErrnoException: connect failed: ETIMEDOUT (Connection timed out)
03-22 17:01:32.097: W/System.err(531): at libcore.io.Posix.connect(Native Method)
03-22 17:01:32.097: W/System.err(531): at libcore.io.BlockGuardOs.connect(BlockGuardOs.java:85)
03-22 17:01:32.097: W/System.err(531): at libcore.io.IoBridge.connectErrno(IoBridge.java:127)
03-22 17:01:32.097: W/System.err(531): at libcore.io.IoBridge.connect(IoBridge.java:112)
03-22 17:01:32.108: W/System.err(531): ... 20 more
03-22 17:01:32.108: E/Buffer Error(531): Error converting result java.lang.NullPointerException
03-22 17:01:32.108: E/JSON Parser(531): Error parsing data org.json.JSONException: End of input at character 0 of
03-22 17:01:32.117: W/dalvikvm(531): threadid=11: thread exiting with uncaught exception (group=0x409c01f8)
03-22 17:01:32.147: E/AndroidRuntime(531): FATAL EXCEPTION: AsyncTask #1
03-22 17:01:32.147: E/AndroidRuntime(531): java.lang.RuntimeException: An error occured while executing doInBackground()
03-22 17:01:32.147: E/AndroidRuntime(531): at android.os.AsyncTask$3.done(AsyncTask.java:278)
03-22 17:01:32.147: E/AndroidRuntime(531): at java.util.concurrent.FutureTask$Sync.innerSetException(FutureTask.java:273)
03-22 17:01:32.147: E/AndroidRuntime(531): at java.util.concurrent.FutureTask.setException(FutureTask.java:124)
03-22 17:01:32.147: E/AndroidRuntime(531): at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:307)
03-22 17:01:32.147: E/AndroidRuntime(531): at java.util.concurrent.FutureTask.run(FutureTask.java:137)
03-22 17:01:32.147: E/AndroidRuntime(531): at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1076)
03-22 17:01:32.147: E/AndroidRuntime(531): at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:569)
03-22 17:01:32.147: E/AndroidRuntime(531): at java.lang.Thread.run(Thread.java:856)
03-22 17:01:32.147: E/AndroidRuntime(531): Caused by: java.lang.NullPointerException
03-22 17:01:32.147: E/AndroidRuntime(531): at com.papershare.bhanu.AllPapersActivity$LoadAllpapers.doInBackground(AllPapersActivity.java:131)
03-22 17:01:32.147: E/AndroidRuntime(531): at com.papershare.bhanu.AllPapersActivity$LoadAllpapers.doInBackground(AllPapersActivity.java:1)
03-22 17:01:32.147: E/AndroidRuntime(531): at android.os.AsyncTask$2.call(AsyncTask.java:264)
03-22 17:01:32.147: E/AndroidRuntime(531): at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:305)
03-22 17:01:32.147: E/AndroidRuntime(531): ... 4 more
03-22 17:01:32.808: I/dalvikvm(531): threadid=3: reacting to signal 3
03-22 17:01:32.838: I/dalvikvm(531): Wrote stack traces to '/data/anr/traces.txt'
03-22 17:01:34.098: I/dalvikvm(531): threadid=3: reacting to signal 3
03-22 17:01:34.118: I/dalvikvm(531): Wrote stack traces to '/data/anr/traces.txt'
03-22 17:01:35.828: E/WindowManager(531): Activity com.papershare.bhanu.AllPapersActivity has leaked window com.android.internal.policy.impl.PhoneWindow$DecorView@41fe6a18 that was originally added here
03-22 17:01:35.828: E/WindowManager(531): android.view.WindowLeaked: Activity com.papershare.bhanu.AllPapersActivity has leaked window com.android.internal.policy.impl.PhoneWindow$DecorView@41fe6a18 that was originally added here
03-22 17:01:35.828: E/WindowManager(531): at android.view.ViewRootImpl.<init>(ViewRootImpl.java:344)
03-22 17:01:35.828: E/WindowManager(531): at android.view.WindowManagerImpl.addView(WindowManagerImpl.java:267)
03-22 17:01:35.828: E/WindowManager(531): at android.view.WindowManagerImpl.addView(WindowManagerImpl.java:215)
03-22 17:01:35.828: E/WindowManager(531): at android.view.WindowManagerImpl$CompatModeWrapper.addView(WindowManagerImpl.java:140)
03-22 17:01:35.828: E/WindowManager(531): at android.view.Window$LocalWindowManager.addView(Window.java:537)
03-22 17:01:35.828: E/WindowManager(531): at android.app.Dialog.show(Dialog.java:278)
03-22 17:01:35.828: E/WindowManager(531): at com.papershare.bhanu.AllPapersActivity$LoadAllpapers.onPreExecute(AllPapersActivity.java:118)
03-22 17:01:35.828: E/WindowManager(531): at android.os.AsyncTask.executeOnExecutor(AsyncTask.java:561)
03-22 17:01:35.828: E/WindowManager(531): at android.os.AsyncTask.execute(AsyncTask.java:511)
03-22 17:01:35.828: E/WindowManager(531): at com.papershare.bhanu.AllPapersActivity.onCreate(AllPapersActivity.java:58)
03-22 17:01:35.828: E/WindowManager(531): at android.app.Activity.performCreate(Activity.java:4465)
03-22 17:01:35.828: E/WindowManager(531): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1049)
03-22 17:01:35.828: E/WindowManager(531): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1920)
03-22 17:01:35.828: E/WindowManager(531): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:1981)
03-22 17:01:35.828: E/WindowManager(531): at android.app.ActivityThread.access$600(ActivityThread.java:123)
03-22 17:01:35.828: E/WindowManager(531): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1147)
03-22 17:01:35.828: E/WindowManager(531): at android.os.Handler.dispatchMessage(Handler.java:99)
03-22 17:01:35.828: E/WindowManager(531): at android.os.Looper.loop(Looper.java:137)
03-22 17:01:35.828: E/WindowManager(531): at android.app.ActivityThread.main(ActivityThread.java:4424)
03-22 17:01:35.828: E/WindowManager(531): at java.lang.reflect.Method.invokeNative(Native Method)
03-22 17:01:35.828: E/WindowManager(531): at java.lang.reflect.Method.invoke(Method.java:511)
03-22 17:01:35.828: E/WindowManager(531): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:784)
03-22 17:01:35.828: E/WindowManager(531): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:551)
03-22 17:01:35.828: E/WindowManager(531): at dalvik.system.NativeStart.main(Native Method)
03-22 17:06:32.377: I/Process(531): Sending signal. PID: 531 SIG: 9
Please tell where in my code this 10.0.2.2 is creating problem while running this app on the mobile device
2 answers
solution1
3 ACCPTED 2015-03-22 11:48:33
It looks like you are trying to access a localhost web service on your local network. You should know that such a web service can only be accessed by an emulator on a computer which is presumably on the same local network as the server. A real device cannot access a web service on a local network.
To test your app on a real device, you need to expose your web service through a public URL, which can be accessed on a public network. Do this and it will work.
solution2
0 2015-03-22 12:12:17
10.0.2.2 can only be used if your app runs on an emulator. For a real device change to the local ip address of the server in your wlan.
The technical post webpages of this site follow the CC BY-SA 4.0 protocol. If you need to reprint, please indicate the site URL or the original address.Any question please contact:yoyou2525@163.com.
Related Question
Expo app runs on ios and emulator but not on android device
App runs on emulator but not on device
.NET MAUI app only runs on emulator or device connected to USB debugger
Android app runs perfectly in emulator but not on device due to external DB
Xamarin Forms/Android map app runs on emulator, but crashes on physical device
Android Hash code Mismatch : onFacebookError on actual device, app runs on emulator
Android Studio app runs on real device but won't run on an emulator
Run Android app Only on Physical Device not Emulator
Android runs on device but crashes on emulator
App runs well on emulator and fails on device
Related Tags