EDIT: For those struggling with this, checkout this link. Follow it carefully, but it does work! The crucial part is using keytool to generate your SHA1 hash against your debug keystore. Also, don't forget to add one for release too!
I've been trying to setup Google Maps Android API v2 and after setting everything up as said I'm getting this runtime exception ClassNotFound:
01-02 16:29:07.927: E/AndroidRuntime(12508): FATAL EXCEPTION: main
01-02 16:29:07.927: E/AndroidRuntime(12508): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.app/com.example.app.MapActivity}: android.view.InflateException: Binary XML file line #6: Error inflating class fragment
01-02 16:29:07.927: E/AndroidRuntime(12508): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1659)
01-02 16:29:07.927: E/AndroidRuntime(12508): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:1675)
01-02 16:29:07.927: E/AndroidRuntime(12508): at android.app.ActivityThread.access$1500(ActivityThread.java:121)
01-02 16:29:07.927: E/AndroidRuntime(12508): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:943)
01-02 16:29:07.927: E/AndroidRuntime(12508): at android.os.Handler.dispatchMessage(Handler.java:99)
01-02 16:29:07.927: E/AndroidRuntime(12508): at android.os.Looper.loop(Looper.java:130)
01-02 16:29:07.927: E/AndroidRuntime(12508): at android.app.ActivityThread.main(ActivityThread.java:3701)
01-02 16:29:07.927: E/AndroidRuntime(12508): at java.lang.reflect.Method.invokeNative(Native Method)
01-02 16:29:07.927: E/AndroidRuntime(12508): at java.lang.reflect.Method.invoke(Method.java:507)
01-02 16:29:07.927: E/AndroidRuntime(12508): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:866)
01-02 16:29:07.927: E/AndroidRuntime(12508): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:624)
01-02 16:29:07.927: E/AndroidRuntime(12508): at dalvik.system.NativeStart.main(Native Method)
01-02 16:29:07.927: E/AndroidRuntime(12508): Caused by: android.view.InflateException: Binary XML file line #6: Error inflating class fragment
01-02 16:29:07.927: E/AndroidRuntime(12508): at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:581)
01-02 16:29:07.927: E/AndroidRuntime(12508): at android.view.LayoutInflater.rInflate(LayoutInflater.java:623)
01-02 16:29:07.927: E/AndroidRuntime(12508): at android.view.LayoutInflater.inflate(LayoutInflater.java:408)
01-02 16:29:07.927: E/AndroidRuntime(12508): at android.view.LayoutInflater.inflate(LayoutInflater.java:320)
01-02 16:29:07.927: E/AndroidRuntime(12508): at android.view.LayoutInflater.inflate(LayoutInflater.java:276)
01-02 16:29:07.927: E/AndroidRuntime(12508): at com.android.internal.policy.impl.PhoneWindow.setContentView(PhoneWindow.java:227)
01-02 16:29:07.927: E/AndroidRuntime(12508): at android.app.Activity.setContentView(Activity.java:1657)
01-02 16:29:07.927: E/AndroidRuntime(12508): at com.example.app.MapActivity.onCreate(MapActivity.java:11)
01-02 16:29:07.927: E/AndroidRuntime(12508): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1047)
01-02 16:29:07.927: E/AndroidRuntime(12508): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1623)
01-02 16:29:07.927: E/AndroidRuntime(12508): ... 11 more
01-02 16:29:07.927: E/AndroidRuntime(12508): Caused by: java.lang.ClassNotFoundException: android.view.fragment in loader dalvik.system.PathClassLoader[/data/app/com.example.app-1.apk]
01-02 16:29:07.927: E/AndroidRuntime(12508): at dalvik.system.PathClassLoader.findClass(PathClassLoader.java:240)
01-02 16:29:07.927: E/AndroidRuntime(12508): at java.lang.ClassLoader.loadClass(ClassLoader.java:551)
01-02 16:29:07.927: E/AndroidRuntime(12508): at java.lang.ClassLoader.loadClass(ClassLoader.java:511)
01-02 16:29:07.927: E/AndroidRuntime(12508): at android.view.LayoutInflater.createView(LayoutInflater.java:471)
01-02 16:29:07.927: E/AndroidRuntime(12508): at android.view.LayoutInflater.onCreateView(LayoutInflater.java:549)
01-02 16:29:07.927: E/AndroidRuntime(12508): at com.android.internal.policy.impl.PhoneLayoutInflater.onCreateView(PhoneLayoutInflater.java:66)
01-02 16:29:07.927: E/AndroidRuntime(12508): at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:568)
01-02 16:29:07.927: E/AndroidRuntime(12508): ... 20 more
Has anyone ever come across this before?
XML:
<?xml version="1.0" encoding="utf-8"?>
<fragment xmlns:android="http://schemas.android.com/apk/res/android"
android:id="#+id/map"
android:layout_width="match_parent"
android:layout_height="match_parent"
class="com.google.android.gms.maps.MapFragment"/>
MapActivity:
import android.os.Bundle;
import android.app.Activity;
public class MapActivity extends Activity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_map);
}
}
Your Activity needs to extend FragmentActivity from the support library
Try this code working perfect help full to you.
XML
<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"
tools:context=".MainActivity" >
<fragment
android:id="#+id/map"
android:layout_width="match_parent"
android:layout_height="match_parent"
class="com.google.android.gms.maps.SupportMapFragment"/>
</RelativeLayout>
Java
package com.example.androidmapsv2;
import com.google.android.gms.common.ConnectionResult;
import com.google.android.gms.common.GooglePlayServicesUtil;
import com.google.android.gms.maps.GoogleMap;
import com.google.android.gms.maps.SupportMapFragment;
import android.app.AlertDialog;
import android.os.Bundle;
import android.support.v4.app.FragmentActivity;
import android.support.v4.app.FragmentManager;
import android.view.Menu;
import android.view.MenuItem;
import android.widget.Toast;
public class MainActivity extends FragmentActivity {
final int RQS_GooglePlayServices = 1;
private GoogleMap myMap;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
FragmentManager myFragmentManager = getSupportFragmentManager();
SupportMapFragment mySupportMapFragment
= (SupportMapFragment)myFragmentManager.findFragmentById(R.id.map);
myMap = mySupportMapFragment.getMap();
}
#Override
protected void onResume() {
// TODO Auto-generated method stub
super.onResume();
int resultCode = GooglePlayServicesUtil.isGooglePlayServicesAvailable(getApplicationContext());
if (resultCode == ConnectionResult.SUCCESS){
Toast.makeText(getApplicationContext(),
"isGooglePlayServicesAvailable SUCCESS",
Toast.LENGTH_LONG).show();
}else{
GooglePlayServicesUtil.getErrorDialog(resultCode, this, RQS_GooglePlayServices);
}
}
}
Did you run on AVD? if yes try on real devices
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Edit the question to include desired behavior, a specific problem or error, and the shortest code necessary to reproduce the problem. This will help others answer the question.
Closed 7 years ago.
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I have a trouble in my app retrieving my data from parse.com
I just wanted to recover data from website in an ArrayList made with a custom class, for using later in my app
Here is code but I can't test it on my emulator because my app crashes on boot, despite I don't have coding errors
PS: I'm very new in android coding, so any help is well accepted!
final int duration = Toast.LENGTH_SHORT;
ParseQuery<ParseObject> queryP = ParseQuery.getQuery("Menu");
queryP.orderByAscending("Id");
queryP.findInBackground(new FindCallback<ParseObject>() {
#Override
public void done(List<ParseObject> MenuList, ParseException e) {
int Id_c;
String Image_c;
String Name_c;
String Description_c;
String Type_c;
Double Cost_c;
ArrayList<Plate> FullMenu = new ArrayList<Plate>();
Plate plate;
if (e == null) {
for (ParseObject plate_o : MenuList) {
Id_c = plate_o.getInt("Id");
Image_c = plate_o.getString("Image");
Name_c = plate_o.getString("Name");
Description_c = plate_o.getString("Description");
Type_c = plate_o.getString("Type");
Cost_c = plate_o.getDouble("Cost");
String text = Name_c;
Toast toast = Toast.makeText(getApplicationContext(), text, duration);
toast.show();
FullMenu.add(Id_c, new Plate(Id_c, Image_c, Name_c, Description_c, Type_c, Cost_c));
plate = FullMenu.get(Id_c);
if (plate.getId() % 5 == 0) {
text = plate.getName();
toast = Toast.makeText(getApplicationContext(), text, duration);
toast.show();
}
}
}
else {
String text = "The get request failed.";
Toast toast = Toast.makeText(getApplicationContext(), text, duration);
toast.show();
}
}
});
And here is my logcat
01-02 19:18:58.916 4406-4406/mycompany.restaurantapp I/art: Not late-enabling -Xcheck:jni (already on)
01-02 19:18:58.916 4406-4406/mycompany.restaurantapp I/art: Late-enabling JIT
01-02 19:18:58.918 4406-4406/mycompany.restaurantapp I/art: JIT created with code_cache_capacity=2MB compile_threshold=1000
01-02 19:18:58.962 4406-4406/mycompany.restaurantapp W/System: ClassLoader referenced unknown path: /data/app/mycompany.restaurantapp-2/lib/x86
01-02 19:18:59.401 4406-4438/mycompany.restaurantapp D/OpenGLRenderer: Use EGL_SWAP_BEHAVIOR_PRESERVED: true
01-02 19:18:59.446 4406-4406/mycompany.restaurantapp D/: HostConnection::get() New Host Connection established 0xa335d700, tid 4406
01-02 19:18:59.542 4406-4438/mycompany.restaurantapp D/: HostConnection::get() New Host Connection established 0xa335d8d0, tid 4438
01-02 19:18:59.556 4406-4438/mycompany.restaurantapp I/OpenGLRenderer: Initialized EGL, version 1.4
01-02 19:18:59.703 4406-4438/mycompany.restaurantapp W/EGL_emulation: eglSurfaceAttrib not implemented
01-02 19:18:59.704 4406-4438/mycompany.restaurantapp W/OpenGLRenderer: Failed to set EGL_SWAP_BEHAVIOR on surface 0xad79f160, error=EGL_SUCCESS
01-02 19:19:04.799 4406-4406/mycompany.restaurantapp D/AndroidRuntime: Shutting down VM
01-02 19:19:04.799 4406-4406/mycompany.restaurantapp E/AndroidRuntime: FATAL EXCEPTION: main
01-02 19:19:04.799 4406-4406/mycompany.restaurantapp E/AndroidRuntime: Process: mycompany.restaurantapp, PID: 4406
01-02 19:19:04.799 4406-4406/mycompany.restaurantapp E/AndroidRuntime: java.lang.IndexOutOfBoundsException: Invalid index 1, size is 0
01-02 19:19:04.799 4406-4406/mycompany.restaurantapp E/AndroidRuntime: at java.util.ArrayList.throwIndexOutOfBoundsException(ArrayList.java:255)
01-02 19:19:04.799 4406-4406/mycompany.restaurantapp E/AndroidRuntime: at java.util.ArrayList.add(ArrayList.java:147)
01-02 19:19:04.799 4406-4406/mycompany.restaurantapp E/AndroidRuntime: at mycompany.restaurantapp.MainActivity$1.done(MainActivity.java:91)
01-02 19:19:04.799 4406-4406/mycompany.restaurantapp E/AndroidRuntime: at mycompany.restaurantapp.MainActivity$1.done(MainActivity.java:69)
01-02 19:19:04.799 4406-4406/mycompany.restaurantapp E/AndroidRuntime: at com.parse.ParseTaskUtils$2$1.run(ParseTaskUtils.java:115)
01-02 19:19:04.799 4406-4406/mycompany.restaurantapp E/AndroidRuntime: at android.os.Handler.handleCallback(Handler.java:739)
01-02 19:19:04.799 4406-4406/mycompany.restaurantapp E/AndroidRuntime: at android.os.Handler.dispatchMessage(Handler.java:95)
01-02 19:19:04.799 4406-4406/mycompany.restaurantapp E/AndroidRuntime: at android.os.Looper.loop(Looper.java:148)
01-02 19:19:04.799 4406-4406/mycompany.restaurantapp E/AndroidRuntime: at android.app.ActivityThread.main(ActivityThread.java:5417)
01-02 19:19:04.799 4406-4406/mycompany.restaurantapp E/AndroidRuntime: at java.lang.reflect.Method.invoke(Native Method)
01-02 19:19:04.799 4406-4406/mycompany.restaurantapp E/AndroidRuntime: at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:726)
01-02 19:19:04.799 4406-4406/mycompany.restaurantapp E/AndroidRuntime: at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:616)
01-02 19:19:11.067 4406-4406/? I/Process: Sending signal. PID: 4406 SIG: 9
FullMenu.add(Id_c, new Plate(Id_c, Image_c, Name_c, Description_c, Type_c, Cost_c));
The wrong line. You're trying to add the element to empty ArrayList at certain position. Try to make it like this
FullMenu.add(new Plate(Id_c, Image_c, Name_c, Description_c, Type_c, Cost_c));
If you want to have an access by id as key you should use Map structure.
I'm getting a NullPointerException while trying to start an Activity which contains a ListView .
In the getView method of the adapter class, the exception happens when the setText function of a textView is being called .
The code bellow is my adapter class:
public class QuestionsListAdapter extends ArrayAdapter<Question> {
Context context;
List<Question> questions;
public QuestionsListAdapter(Context context, List<Question> questions){
super(context, R.layout.list_item_question, questions);
this.context = context;
this.questions = questions;
}
#Override
public View getView(int position, View convertView, ViewGroup parent) {
LayoutInflater vi = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
View view = vi.inflate(R.layout.list_item_question, null);
Question question = questions.get(position);
TextView tv = (TextView) view.findViewById(R.id.question_list_item_string);
Log.i(TableCreator.LOG_TAG, question.toString()); //this works fine and the string is not null .
tv.setText(question.toString()+""); //NULL POINTER EXCEPTION .
return view;
}
}
As you see, I've logged the string in the logcat and it works just fine, but the next line makes the mistake .
And this is the logcat output:
05-27 13:24:02.979 5325-5325/org.kabiri.operationcheklist I/Operation Checklist﹕ |-Question-> id:1 summary:mySummary comment:myComment solution:mySolution ownerList:dummyOwner
05-27 13:24:02.979 5325-5325/org.kabiri.operationcheklist D/AndroidRuntime﹕ Shutting down VM
05-27 13:24:02.979 5325-5325/org.kabiri.operationcheklist W/dalvikvm﹕ threadid=1: thread exiting with uncaught exception (group=0xb0f5f648)
05-27 13:24:02.979 5325-5325/org.kabiri.operationcheklist E/AndroidRuntime﹕ FATAL EXCEPTION: main
java.lang.NullPointerException
at org.kabiri.operationchecklist.adapter.QuestionsListAdapter.getView(QuestionsListAdapter.java:43)
at android.widget.AbsListView.obtainView(AbsListView.java:2177)
at android.widget.ListView.makeAndAddView(ListView.java:1840)
at android.widget.ListView.fillDown(ListView.java:675)
at android.widget.ListView.fillFromTop(ListView.java:736)
at android.widget.ListView.layoutChildren(ListView.java:1655)
at android.widget.AbsListView.onLayout(AbsListView.java:2012)
at android.view.View.layout(View.java:14289)
at android.view.ViewGroup.layout(ViewGroup.java:4562)
at android.widget.LinearLayout.setChildFrame(LinearLayout.java:1671)
at android.widget.LinearLayout.layoutVertical(LinearLayout.java:1525)
at android.widget.LinearLayout.onLayout(LinearLayout.java:1434)
at android.view.View.layout(View.java:14289)
at android.view.ViewGroup.layout(ViewGroup.java:4562)
at android.widget.FrameLayout.onLayout(FrameLayout.java:448)
at android.view.View.layout(View.java:14289)
at android.view.ViewGroup.layout(ViewGroup.java:4562)
at android.support.v7.internal.widget.ActionBarOverlayLayout.onLayout(ActionBarOverlayLayout.java:502)
at android.view.View.layout(View.java:14289)
at android.view.ViewGroup.layout(ViewGroup.java:4562)
at android.widget.FrameLayout.onLayout(FrameLayout.java:448)
at android.view.View.layout(View.java:14289)
at android.view.ViewGroup.layout(ViewGroup.java:4562)
at android.widget.LinearLayout.setChildFrame(LinearLayout.java:1671)
at android.widget.LinearLayout.layoutVertical(LinearLayout.java:1525)
at android.widget.LinearLayout.onLayout(LinearLayout.java:1434)
at android.view.View.layout(View.java:14289)
at android.view.ViewGroup.layout(ViewGroup.java:4562)
at android.widget.FrameLayout.onLayout(FrameLayout.java:448)
at android.view.View.layout(View.java:14289)
at android.view.ViewGroup.layout(ViewGroup.java:4562)
at android.view.ViewRootImpl.performLayout(ViewRootImpl.java:1976)
at android.view.ViewRootImpl.performTraversals(ViewRootImpl.java:1730)
at android.view.ViewRootImpl.doTraversal(ViewRootImpl.java:1004)
at android.view.ViewRootImpl$TraversalRunnable.run(ViewRootImpl.java:5481)
at android.view.Choreographer$CallbackRecord.run(Choreographer.java:749)
at android.view.Choreographer.doCallbacks(Choreographer.java:562)
at android.view.Choreographer.doFrame(Choreographer.java:532)
at android.view.Choreographer$FrameDisplayEventReceiver.run(Choreographer.java:735)
at android.os.Handler.handleCallback(Handler.java:730)
at android.os.Handler.dispatchMessage(Handler.java:92)
at android.os.Looper.loop(Looper.java:137)
at android.app.ActivityThread.main(ActivityThread.java:5103)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:525)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:737)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:553)
at dalvik.system.NativeStart.main(Native Method)
The logcat shows that the error happens on this line of my adapter class:
tv.setText(question.toString()+"");
I really appreciate your help .
You already know where the problem is!
tv.setText(question.toString()+"");
is causing the NPE that means the TextView tv is null. And that means that the line
TextView tv = (TextView) view.findViewById(R.id.question_list_item_string);
is not able to find the TextView. Check the question_list_item_string id and make sure it matches the id in your list_item_question.xml file
I am trying to create an app that lets the user click a button and it will display a random month. I have created a string array in my strings.xml file. Bellow is my main.java, strings.xml and activity.xml. I try to run the app and it just force closes.
package com.example.datebutton;
import android.app.Activity;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.TextView;
import android.graphics.Color;
public class Main extends Activity
{
Button btn;
#Override
public void onCreate(Bundle b)
{
super.onCreate(b);
setContentView(R.layout.activity_main);
btn = (Button) findViewById(R.id.btn1);
final String[] months = getResources().getStringArray(R.array.Months);
final TextView tv =(TextView)findViewById(R.id.text1);
btn.setOnClickListener(new View.OnClickListener()
{
public void onClick(View v)
{
int rand = (int) (Math.random() * 12);
tv.setText(months[rand]);
}
});
}
}
here is my activity.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
>
<Button
android:id="#+id/btn1"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:onClick="updateMonth"
android:text="#string/app_name" />
<TextView
android:id="#+id/text1"
android:layout_width="68dp"
android:layout_height="wrap_content"
android:layout_gravity="center"
android:gravity="center_vertical"
android:text="#array/Months" />
</LinearLayout>
here is my strings.xml
<?xml version="1.0" encoding="utf-8"?>
<resources>
<string name="app_name">DateButton</string>
<string-array name="Months">
<item>January</item>
<item>Feburary</item>
<item>March</item>
<item>April</item>
<item>May</item>
<item>June</item>
<item>July</item>
<item>August</item>
<item>September</item>
<item>October</item>
<item>November</item>
<item>December</item>
</string-array>
</resources>
I'm still getting errors and the app still says unfortunately your app closed. The logcat is below.
09-11 16:55:17.472: W/Resources(1638): Converting to string: TypedValue{t=0x1/d=0x7f0c0000 a=-1 r=0x7f0c0000}
09-11 16:55:17.512: D/AndroidRuntime(1638): Shutting down VM
09-11 16:55:17.512: W/dalvikvm(1638): threadid=1: thread exiting with uncaught exception (group=0xb3a8fba8)
09-11 16:55:17.532: E/AndroidRuntime(1638): FATAL EXCEPTION: main
09-11 16:55:17.532: E/AndroidRuntime(1638): Process: com.example.datebutton, PID: 1638
09-11 16:55:17.532: E/AndroidRuntime(1638): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.datebutton/com.example.datebutton.Main}: java.lang.ClassCastException: android.widget.TextView cannot be cast to android.widget.Button
09-11 16:55:17.532: E/AndroidRuntime(1638): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2195)
09-11 16:55:17.532: E/AndroidRuntime(1638): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2245)
09-11 16:55:17.532: E/AndroidRuntime(1638): at android.app.ActivityThread.access$800(ActivityThread.java:135)
09-11 16:55:17.532: E/AndroidRuntime(1638): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1196)
09-11 16:55:17.532: E/AndroidRuntime(1638): at android.os.Handler.dispatchMessage(Handler.java:102)
09-11 16:55:17.532: E/AndroidRuntime(1638): at android.os.Looper.loop(Looper.java:136)
09-11 16:55:17.532: E/AndroidRuntime(1638): at android.app.ActivityThread.main(ActivityThread.java:5017)
09-11 16:55:17.532: E/AndroidRuntime(1638): at java.lang.reflect.Method.invokeNative(Native Method)
09-11 16:55:17.532: E/AndroidRuntime(1638): at java.lang.reflect.Method.invoke(Method.java:515)
09-11 16:55:17.532: E/AndroidRuntime(1638): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:779)
09-11 16:55:17.532: E/AndroidRuntime(1638): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:595)
09-11 16:55:17.532: E/AndroidRuntime(1638): at dalvik.system.NativeStart.main(Native Method)
09-11 16:55:17.532: E/AndroidRuntime(1638): Caused by: java.lang.ClassCastException: android.widget.TextView cannot be cast to android.widget.Button
09-11 16:55:17.532: E/AndroidRuntime(1638): at com.example.datebutton.Main.onCreate(Main.java:24)
09-11 16:55:17.532: E/AndroidRuntime(1638): at android.app.Activity.performCreate(Activity.java:5231)
09-11 16:55:17.532: E/AndroidRuntime(1638): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1087)
09-11 16:55:17.532: E/AndroidRuntime(1638): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2159)
09-11 16:55:17.532: E/AndroidRuntime(1638): ... 11 more
You forgot to add the line: setContentView(R.layout.activity); before trying to instantiate your button object btn.
To use layout in you Activity you have to connect them both together. Below is how your code should look like:
#Override
public void onCreate(Bundle b) {
super.onCreate(b);
setContentView(R.layout.activity);
btn = (Button) findViewById(R.id.btn1);
final String[] months = getResources().getStringArray(R.array.Months);
final TextView tv =(TextView)findViewById(R.id.text1);
btn.setOnClickListener(new View.OnClickListener(){
public void onClick(View v) {
int r, g, b;
int rand = (int) (Math.random() * 12);
tv.setText(months[rand]);
}
});
}
in the last few days I tried to develop android applications with no success, for some reason my application keep crashing.
the application keeps throwing few exceptions that I didn't succeeded to handle with.
MainActivity.java :
package com.mobIce.digicoin.digitalcoin;
import android.support.v7.app.ActionBarActivity;
import android.support.v7.app.ActionBar;
import android.support.v4.app.Fragment;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.view.ViewGroup;
import android.os.Build;
import android.widget.ArrayAdapter;
import android.widget.ListAdapter;
import android.widget.ListView;
import android.widget.TextView;
import java.util.ArrayList;
import java.util.List;
public class MainActivity extends ActionBarActivity {
private List<Coin> coins;
public MainActivity(){
coins = new ArrayList<Coin>();
}
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
if (savedInstanceState == null) {
getSupportFragmentManager().beginTransaction()
.add(R.id.container, new PlaceholderFragment())
.commit();
populateCoins();
populateListView();
}
}
private void populateCoins() {
coins.add(new Coin("Bitcoin", "650", "4", "http://coinmarketcap.com/img/Bitcoin.png"));
coins.add(new Coin("Dogecoin", "100", "400", "http://coinmarketcap.com/img/Bitcoin.png"));
coins.add(new Coin("fafaf", "8065", "400", "http://coinmarketcap.com/img/Bitcoin.png"));
}
private void populateListView() {
ArrayAdapter<Coin> adapter = new MyListAdapter();
ListView list = (ListView) findViewById(R.id.coinsListView);
list.setAdapter(adapter);
}
#Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.main, menu);
return true;
}
#Override
public boolean onOptionsItemSelected(MenuItem item) {
// Handle action bar item clicks here. The action bar will
// automatically handle clicks on the Home/Up button, so long
// as you specify a parent activity in AndroidManifest.xml.
int id = item.getItemId();
if (id == R.id.action_settings) {
return true;
}
return super.onOptionsItemSelected(item);
}
/**
* A placeholder fragment containing a simple view.
*/
public static class PlaceholderFragment extends Fragment {
public PlaceholderFragment() {
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.fragment_main, container, false);
return rootView;
}
}
private class MyListAdapter extends ArrayAdapter<Coin> {
public MyListAdapter()
{
super(MainActivity.this, R.layout.coin_layout, coins);
}
#Override
public View getView(int position, View convertView, ViewGroup parent){
View itemView = convertView;
if(itemView == null)
itemView = getLayoutInflater().inflate(R.layout.coin_layout, parent, false);
//find the coin to work with.
Coin currentCoin = coins.get(position);
//fill the view
try{
TextView coinName = (TextView) itemView.findViewById(R.id.coinName);
coinName.setText(currentCoin.getName());
TextView coinPrice = (TextView) itemView.findViewById(R.id.coinPrice);
coinPrice.setText(currentCoin.getPrice());
TextView coinPercentage = (TextView) itemView.findViewById(R.id.coinPercentage);
coinPercentage.setText(currentCoin.getPercentage());
}
catch (NullPointerException e){ }
return itemView;
}
}
}
activity_main.xml:
<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:id="#+id/container"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context="com.mobIce.digicoin.digitalcoin.MainActivity"
tools:ignore="MergeRootFrame" />
fragment_main.xml:
<LinearLayout
android:orientation="horizontal"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
xmlns:android="http://schemas.android.com/apk/res/android">
<ListView
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:id="#+id/coinsListView"
android:paddingLeft="30dp" />
</LinearLayout>
coin_layout.xml:
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent" android:layout_height="match_parent"
android:padding="8dp">
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textAppearance="?android:attr/textAppearanceLarge"
android:text="coinName"
android:id="#+id/coinName"
android:layout_alignParentTop="true"
android:layout_toRightOf="#+id/coinIcon"
android:layout_marginTop="35dp"
android:layout_marginLeft="20dp" />
<ImageView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="#+id/coinIcon"
android:maxHeight="80dp"
android:maxWidth="80dp"
android:minHeight="80dp"
android:minWidth="80dp"
android:src="#drawable/dogecoin"
android:longClickable="false"
android:focusable="false"
android:focusableInTouchMode="false"
android:baselineAlignBottom="false"
android:clickable="false"
android:adjustViewBounds="true"
android:layout_alignParentTop="true"
android:layout_alignParentLeft="true"
android:layout_alignParentStart="true" />
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textAppearance="?android:attr/textAppearanceLarge"
android:text="Large Text"
android:id="#+id/coinPrice"
android:layout_marginLeft="35dp"
android:layout_alignTop="#+id/coinIcon"
android:layout_toRightOf="#+id/coinName"
android:layout_marginTop="25dp" />
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textAppearance="?android:attr/textAppearanceMedium"
android:text="Medium Text"
android:id="#+id/coinPercentage"
android:layout_below="#+id/coinPrice"
android:layout_alignLeft="#+id/coinPrice"
android:layout_alignStart="#+id/coinPrice" />
</RelativeLayout>
logcat trace:
03-17 08:59:33.977 1107-1107/com.mobIce.digicoin.digitalcoin D/AndroidRuntime﹕ Shutting down VM
03-17 08:59:33.977 1107-1107/com.mobIce.digicoin.digitalcoin W/dalvikvm﹕ threadid=1: thread exiting with uncaught exception (group=0xb1a38ba8)
03-17 08:59:33.987 1107-1107/com.mobIce.digicoin.digitalcoin E/AndroidRuntime﹕ FATAL EXCEPTION: main
Process: com.mobIce.digicoin.digitalcoin, PID: 1107
java.lang.RuntimeException: Unable to start activity ComponentInfo{com.mobIce.digicoin.digitalcoin/com.mobIce.digicoin.digitalcoin.MainActivity}: java.lang.NullPointerException
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2195)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2245)
at android.app.ActivityThread.access$800(ActivityThread.java:135)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1196)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:136)
at android.app.ActivityThread.main(ActivityThread.java:5017)
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:779)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:595)
at dalvik.system.NativeStart.main(Native Method)
Caused by: java.lang.NullPointerException
at com.mobIce.digicoin.digitalcoin.MainActivity.populateListView(MainActivity.java:47)
at com.mobIce.digicoin.digitalcoin.MainActivity.onCreate(MainActivity.java:36)
at android.app.Activity.performCreate(Activity.java:5231)
at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1087)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2159)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2245)
at android.app.ActivityThread.access$800(ActivityThread.java:135)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1196)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:136)
at android.app.ActivityThread.main(ActivityThread.java:5017)
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:779)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:595)
at dalvik.system.NativeStart.main(Native Method)
03-17 09:04:09.857 1149-1149/com.mobIce.digicoin.digitalcoin D/AndroidRuntime﹕ Shutting down VM
03-17 09:04:09.857 1149-1149/com.mobIce.digicoin.digitalcoin W/dalvikvm﹕ threadid=1: thread exiting with uncaught exception (group=0xb1a38ba8)
03-17 09:04:09.867 1149-1149/com.mobIce.digicoin.digitalcoin E/AndroidRuntime﹕ FATAL EXCEPTION: main
Process: com.mobIce.digicoin.digitalcoin, PID: 1149
java.lang.RuntimeException: Unable to start activity ComponentInfo{com.mobIce.digicoin.digitalcoin/com.mobIce.digicoin.digitalcoin.MainActivity}: java.lang.NullPointerException
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2195)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2245)
at android.app.ActivityThread.access$800(ActivityThread.java:135)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1196)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:136)
at android.app.ActivityThread.main(ActivityThread.java:5017)
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:779)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:595)
at dalvik.system.NativeStart.main(Native Method)
Caused by: java.lang.NullPointerException
at com.mobIce.digicoin.digitalcoin.MainActivity.populateListView(MainActivity.java:50)
at com.mobIce.digicoin.digitalcoin.MainActivity.onCreate(MainActivity.java:39)
at android.app.Activity.performCreate(Activity.java:5231)
at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1087)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2159)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2245)
at android.app.ActivityThread.access$800(ActivityThread.java:135)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1196)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:136)
at android.app.ActivityThread.main(ActivityThread.java:5017)
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:779)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:595)
at dalvik.system.NativeStart.main(Native Method)
03-17 09:06:36.697 1192-1192/com.mobIce.digicoin.digitalcoin D/AndroidRuntime﹕ Shutting down VM
03-17 09:06:36.697 1192-1192/com.mobIce.digicoin.digitalcoin W/dalvikvm﹕ threadid=1: thread exiting with uncaught exception (group=0xb1a38ba8)
03-17 09:06:36.717 1192-1192/com.mobIce.digicoin.digitalcoin E/AndroidRuntime﹕ FATAL EXCEPTION: main
Process: com.mobIce.digicoin.digitalcoin, PID: 1192
java.lang.RuntimeException: Unable to start activity ComponentInfo{com.mobIce.digicoin.digitalcoin/com.mobIce.digicoin.digitalcoin.MainActivity}: java.lang.NullPointerException
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2195)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2245)
at android.app.ActivityThread.access$800(ActivityThread.java:135)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1196)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:136)
at android.app.ActivityThread.main(ActivityThread.java:5017)
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:779)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:595)
at dalvik.system.NativeStart.main(Native Method)
Caused by: java.lang.NullPointerException
at com.mobIce.digicoin.digitalcoin.MainActivity.populateListView(MainActivity.java:50)
at com.mobIce.digicoin.digitalcoin.MainActivity.onCreate(MainActivity.java:39)
at android.app.Activity.performCreate(Activity.java:5231)
at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1087)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2159)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2245)
at android.app.ActivityThread.access$800(ActivityThread.java:135)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1196)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:136)
at android.app.ActivityThread.main(ActivityThread.java:5017)
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:779)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:595)
at dalvik.system.NativeStart.main(Native Method)
03-17 09:13:38.647 1239-1239/com.mobIce.digicoin.digitalcoin D/AndroidRuntime﹕ Shutting down VM
03-17 09:13:38.647 1239-1239/com.mobIce.digicoin.digitalcoin W/dalvikvm﹕ threadid=1: thread exiting with uncaught exception (group=0xb1a38ba8)
03-17 09:13:38.747 1239-1239/com.mobIce.digicoin.digitalcoin E/AndroidRuntime﹕ FATAL EXCEPTION: main
Process: com.mobIce.digicoin.digitalcoin, PID: 1239
java.lang.RuntimeException: Unable to start activity ComponentInfo{com.mobIce.digicoin.digitalcoin/com.mobIce.digicoin.digitalcoin.MainActivity}: java.lang.NullPointerException
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2195)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2245)
at android.app.ActivityThread.access$800(ActivityThread.java:135)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1196)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:136)
at android.app.ActivityThread.main(ActivityThread.java:5017)
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:779)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:595)
at dalvik.system.NativeStart.main(Native Method)
Caused by: java.lang.NullPointerException
at com.mobIce.digicoin.digitalcoin.MainActivity.populateListView(MainActivity.java:50)
at com.mobIce.digicoin.digitalcoin.MainActivity.onCreate(MainActivity.java:37)
at android.app.Activity.performCreate(Activity.java:5231)
at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1087)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2159)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2245)
at android.app.ActivityThread.access$800(ActivityThread.java:135)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1196)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:136)
at android.app.ActivityThread.main(ActivityThread.java:5017)
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:779)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:595)
at dalvik.system.NativeStart.main(Native Method)
03-17 09:13:45.127 1239-1239/com.mobIce.digicoin.digitalcoin I/Process﹕ Sending signal. PID: 1239 SIG: 9
03-17 09:19:34.847 1285-1285/com.mobIce.digicoin.digitalcoin D/AndroidRuntime﹕ Shutting down VM
03-17 09:19:34.847 1285-1285/com.mobIce.digicoin.digitalcoin W/dalvikvm﹕ threadid=1: thread exiting with uncaught exception (group=0xb1a38ba8)
03-17 09:19:34.857 1285-1285/com.mobIce.digicoin.digitalcoin E/AndroidRuntime﹕ FATAL EXCEPTION: main
Process: com.mobIce.digicoin.digitalcoin, PID: 1285
java.lang.RuntimeException: Unable to start activity ComponentInfo{com.mobIce.digicoin.digitalcoin/com.mobIce.digicoin.digitalcoin.MainActivity}: java.lang.NullPointerException
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2195)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2245)
at android.app.ActivityThread.access$800(ActivityThread.java:135)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1196)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:136)
at android.app.ActivityThread.main(ActivityThread.java:5017)
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:779)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:595)
at dalvik.system.NativeStart.main(Native Method)
Caused by: java.lang.NullPointerException
at com.mobIce.digicoin.digitalcoin.MainActivity.populateListView(MainActivity.java:50)
at com.mobIce.digicoin.digitalcoin.MainActivity.onCreate(MainActivity.java:37)
at android.app.Activity.performCreate(Activity.java:5231)
at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1087)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2159)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2245)
at android.app.ActivityThread.access$800(ActivityThread.java:135)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1196)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:136)
at android.app.ActivityThread.main(ActivityThread.java:5017)
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:779)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:595)
at dalvik.system.NativeStart.main(Native Method)
03-17 09:20:11.987 1285-1285/com.mobIce.digicoin.digitalcoin I/Process﹕ Sending signal. PID: 1285 SIG: 9
Your coinsListView is in the fragment layout and not in activity layout. You cannot access it with findViewById() in populateListView() called from activity onCreate(). Instead, move the list view population to the fragment's onCreateView() after the inflation, calling findViewById() on the rootView layout you just inflated.
I have two String arrays, latitude and longitude
I want to draw polylines on the map, the documentation says, that it's as easy as pie. And it is. If I add polylines manually like this, it works:
PolylineOptions rectOptions = new PolylineOptions()
.add(new LatLng(37.35, -122.0))
.add(new LatLng(37.45, -122.0))
.add(new LatLng(37.45, -122.2))
But the problem starts when I'm trying to loop adding polylines:
rectOptions = new PolylineOptions();
for(int i = 0; i<latitude.length(); i++){
rectOptions.add(new LatLng(Long.getLong(latitude[i]), Long.getLong(longitude[i])));
// Log.d("coordinates", latitude[i]+"|"+longitude[i]);
}
I get a java.lang.NullPointerException And I don't know why. I know the problem is in the rectOptions.add() method, because Log.d("coordinates", latitude[i]+"|"+longitude[i]); works fine in the same loop.
Here's the output of LogCat:
01-02 11:59:27.380: E/AndroidRuntime(25146): FATAL EXCEPTION: main
01-02 11:59:27.380: E/AndroidRuntime(25146): java.lang.NullPointerException
01-02 11:59:27.380: E/AndroidRuntime(25146): at com.shniv.MainActivity$1.onClick(MainActivity.java:82)
01-02 11:59:27.380: E/AndroidRuntime(25146): at android.view.View.performClick(View.java:3519)
01-02 11:59:27.380: E/AndroidRuntime(25146): at android.view.View$PerformClick.run(View.java:14140)
01-02 11:59:27.380: E/AndroidRuntime(25146): at android.os.Handler.handleCallback(Handler.java:605)
01-02 11:59:27.380: E/AndroidRuntime(25146): at android.os.Handler.dispatchMessage(Handler.java:92)
01-02 11:59:27.380: E/AndroidRuntime(25146): at android.os.Looper.loop(Looper.java:137)
01-02 11:59:27.380: E/AndroidRuntime(25146): at android.app.ActivityThread.main(ActivityThread.java:4456)
01-02 11:59:27.380: E/AndroidRuntime(25146): at java.lang.reflect.Method.invokeNative(Native Method)
01-02 11:59:27.380: E/AndroidRuntime(25146): at java.lang.reflect.Method.invoke(Method.java:511)
01-02 11:59:27.380: E/AndroidRuntime(25146): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:787)
01-02 11:59:27.380: E/AndroidRuntime(25146): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:554)
01-02 11:59:27.380: E/AndroidRuntime(25146): at dalvik.system.NativeStart.main(Native Method)