0
kann ich meine Anwendung auf einem Emulator ohne Probleme laufen, aber wenn ich versuche, es auf einem Telefon zu spielen bekomme ich diesen FehlerNullpointer bei der Verwendung von Layout
„Kann Aktivität ComponentInfo starten {br.com. pedro.pedrodaumas/br.com.pedro.pedrodaumas.MainActivity}: java.lang.NullPointerException: Versuch, die virtuelle Methode 'void android.widget.ListView.setAdapter (android.widget.ListAdapter)' für eine Nullobjekt-Referenz aufzurufen ".
Soweit ich weiß, ich sollte in der Lage movieListView = (ListView) findViewById(R.id.movieListView); mit einem incluce auf meinem activity_main zugreifen zu können, wie diese, die ich habe:
<include android:id="@+id/content" layout="@layout/content_main" />
Also ich bin nicht sicher, warum Ich erhalte diesen Fehler.
MainActivity.java
package br.com.pedro.pedrodaumas;
import android.annotation.TargetApi;
import android.content.Context;
import android.content.Intent;
import android.os.AsyncTask;
import android.os.Build;
import android.os.Bundle;
import android.support.design.widget.FloatingActionButton;
import android.support.design.widget.Snackbar;
import android.support.design.widget.TextInputEditText;
import android.support.v7.app.AppCompatActivity;
import android.support.v7.widget.Toolbar;
import android.text.Layout;
import android.view.LayoutInflater;
import android.view.View;
import android.view.Menu;
import android.view.MenuItem;
import android.view.ViewGroup;
import android.view.Window;
import android.view.inputmethod.InputMethodManager;
import android.widget.AdapterView;
import android.widget.LinearLayout;
import android.widget.ListView;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.net.HttpURLConnection;
import java.net.URL;
import java.net.URLEncoder;
import java.util.ArrayList;
import java.util.List;
public class MainActivity extends AppCompatActivity {
private List<Movie> movieList = new ArrayList<>();
private MovieArrayAdapter movieArrayAdapter;
private ListView movieListView;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
movieListView = (ListView) findViewById(R.id.movieListView);
movieArrayAdapter = new MovieArrayAdapter(this, movieList);
movieListView.setAdapter(movieArrayAdapter);
Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
setSupportActionBar(toolbar);
FloatingActionButton fab = (FloatingActionButton) findViewById(R.id.fab);
fab.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
TextInputEditText search_bar;
search_bar = (TextInputEditText) findViewById(R.id.search_bar);
URL url = createURL(search_bar.getText().toString());
if(url != null){
dismissKeyboard(search_bar);
GetMovieTask getLocalMovieTask = new GetMovieTask();
getLocalMovieTask.execute(url);
}else {
Snackbar.make(findViewById(R.id.coordinatorLayout), R.string.invalid_url,
Snackbar.LENGTH_LONG).show();
}
}
});
movieListView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
switch (position) {
default:
Movie review = movieArrayAdapter.getItem(position);
Intent nextActivity = new Intent(MainActivity.this, ShortReview.class);
nextActivity.putExtra("summary", review.getsummary());
startActivity(nextActivity);
break;
}
}
});
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.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);
}
private void dismissKeyboard (View view){
InputMethodManager imm = (InputMethodManager)getSystemService(Context.INPUT_METHOD_SERVICE);
imm.hideSoftInputFromWindow(view.getWindowToken(),0);
}
private URL createURL (String movie){
String apiKey = getString (R.string.api_key);
String baseUrl = getString(R.string.nyt_url);
try{
String urlString = baseUrl + "?api_key=" + apiKey + "&query=" + URLEncoder.encode (movie, "UTF-8");
return new URL(urlString);
}
catch(Exception e){
e.printStackTrace();
}
return null;
}
private class GetMovieTask extends AsyncTask<URL, Void, JSONObject> {
@TargetApi(Build.VERSION_CODES.KITKAT)
@Override
protected JSONObject doInBackground(URL... params) {
HttpURLConnection connection = null;
try {
connection = (HttpURLConnection) params[0].openConnection();
int response = connection.getResponseCode();
if (response == HttpURLConnection.HTTP_OK){
StringBuilder builder = new StringBuilder();
try (BufferedReader reader = new BufferedReader(new InputStreamReader(connection.getInputStream()))){
String line;
while ((line = reader.readLine()) != null){
builder.append(line);
}
}
catch (IOException e){
Snackbar.make(findViewById(R.id.coordinatorLayout), R.string.read_error, Snackbar.LENGTH_LONG).show();
e.printStackTrace();
}
return new JSONObject(builder.toString());
}
}
catch (Exception e){
Snackbar.make(findViewById(R.id.coordinatorLayout), R.string.connect_error, Snackbar.LENGTH_LONG).show();
e.printStackTrace();
}
finally{
if (connection != null){
connection.disconnect();
}
}
return null;
}
protected void onPostExecute(JSONObject movie) {
convertJSONToArrayList (movie);
movieArrayAdapter.notifyDataSetChanged();
movieListView.smoothScrollToPosition(0);
}
}
private void convertJSONToArrayList (JSONObject forecast){
movieList.clear();
try{
JSONArray results = forecast.getJSONArray("results");
for (int i = 0; i < results.length(); i++) {
JSONObject movie = results.getJSONObject(i);
if(movie.isNull("multimedia")){
movieList.add(new Movie(movie.getString("display_title"),
movie.getString("publication_date"),
"image", movie.getString("summary_short")));
}else {
JSONObject multimedia = movie.getJSONObject("multimedia");
movieList.add(new Movie(movie.getString("display_title"),
movie.getString("publication_date"),
multimedia.getString("src"), movie.getString("summary_short")));
}
}
if(results.length() == 0){
Snackbar.make(findViewById(R.id.coordinatorLayout), R.string.no_movie,
Snackbar.LENGTH_LONG).show();
}
}
catch (JSONException e){
e.printStackTrace();
}
}
}
Movie.java
package br.com.pedro.pedrodaumas;
public class Movie {
public final String title;
public final String publication_date;
public final String iconURL;
public final String short_summary ;
public Movie(String title,String publication_date, String iconName, String short_summary) {
this.title = title;
this.publication_date = publication_date;
this.iconURL = iconName;
this.short_summary = short_summary;
}
public String getsummary() {
return short_summary;
}
}
MovieArrayAdapter.java
package br.com.pedro.pedrodaumas;
import android.annotation.TargetApi;
import android.content.Context;
import android.content.Intent;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.os.AsyncTask;
import android.os.Build;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ArrayAdapter;
import android.widget.ImageView;
import android.widget.TextView;
import java.io.InputStream;
import java.net.HttpURLConnection;
import java.net.URL;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
public class MovieArrayAdapter extends ArrayAdapter<Movie> {
private static class ViewHolder{
ImageView movieImage;
TextView description;
TextView publication_date;
}
private Map<String, Bitmap> bitmaps = new HashMap<>();
public MovieArrayAdapter (Context context, List<Movie>
forecast){
super (context, -1, forecast);
}
public View getView(int position, View convertView, ViewGroup parent) {
Movie review = getItem (position);
ViewHolder viewHolder;
if (convertView == null){
viewHolder = new ViewHolder();
LayoutInflater inflater = LayoutInflater.from(getContext());
convertView = inflater.inflate(R.layout.complete_review, parent, false);
viewHolder.movieImage = (ImageView)convertView.findViewById(R.id.movieImage);
viewHolder.description = (TextView)convertView.findViewById(R.id.description);
viewHolder.publication_date = (TextView)convertView.findViewById(R.id.publication_date);
convertView.setTag(viewHolder);
}
else{
viewHolder = (ViewHolder)convertView.getTag();
}
if(review.iconURL == "image"){
viewHolder.movieImage.setImageResource(R.drawable.ic_import_contacts_white_24dp);
}
else{
new LoadImageTask (viewHolder.movieImage).execute (review.iconURL);
}
viewHolder.description.setText(review.title);
viewHolder.publication_date.setText(review.publication_date);
return convertView;
}
private class LoadImageTask extends AsyncTask<String, Void, Bitmap> {
private ImageView imageView;
public LoadImageTask (ImageView imageView){
this.imageView = imageView;
}
@TargetApi(Build.VERSION_CODES.KITKAT)
@Override
protected Bitmap doInBackground(String... params) {
Bitmap bitmap = null;
HttpURLConnection connection = null;
try{
URL url = new URL(params[0]);
connection = (HttpURLConnection) url.openConnection();
try(InputStream inputStream = connection.getInputStream()){
bitmap = BitmapFactory.decodeStream(inputStream);
bitmaps.put (params[0], bitmap);
}
catch (Exception e){
e.printStackTrace();
}
}
catch (Exception e){
e.printStackTrace();
}
finally{
connection.disconnect();
}
return bitmap;
}
protected void onPostExecute(Bitmap bitmap) {
imageView.setImageBitmap(bitmap);
}
}
}
Activity_main.xml
<?xml version="1.0" encoding="utf-8"?>
<android.support.design.widget.CoordinatorLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:fitsSystemWindows="true"
tools:context="br.com.pedro.pedrodaumas.MainActivity"
android:id="@+id/coordinatorLayout">
<android.support.design.widget.AppBarLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:theme="@style/AppTheme.AppBarOverlay">
<android.support.v7.widget.Toolbar
android:id="@+id/toolbar"
android:layout_width="match_parent"
android:layout_height="?attr/actionBarSize"
android:background="?attr/colorPrimary"
app:popupTheme="@style/AppTheme.PopupOverlay"
android:elevation="@dimen/toolbar_elevation" />
</android.support.design.widget.AppBarLayout>
<android.support.design.widget.FloatingActionButton
android:id="@+id/fab"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="top|end"
android:layout_marginTop="@dimen/fab_magin_top"
android:layout_marginEnd="@dimen/fab_margin"
android:layout_marginBottom="@dimen/fab_margin"
android:layout_marginStart="@dimen/fab_margin"
app:elevation="@dimen/rested_button_elevation"
android:src="@drawable/ic_action_search" />
<include android:id="@+id/content"
layout="@layout/content_main" />
</android.support.design.widget.CoordinatorLayout>
Content_main.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:paddingBottom="@dimen/activity_vertical_margin"
android:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin"
app:layout_behavior="@string/appbar_scrolling_view_behavior"
tools:context="br.com.pedro.pedrodaumas.MainActivity"
tools:showIn="@layout/activity_main"
android:orientation="vertical">
<android.support.design.widget.TextInputLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:id="@+id/view">
<android.support.design.widget.TextInputEditText android:layout_width="match_parent"
android:layout_height="wrap_content"
android:id="@+id/search_bar"
android:singleLine="true"
android:hint="@string/hint_text"
android:elevation="@dimen/rested_search_elevation"
tools:targetApi="lollipop" />
</android.support.design.widget.TextInputLayout>
<ListView
android:layout_width="match_parent"
android:layout_height="0dp"
android:id="@+id/movieListView"
android:layout_weight="1" />
</LinearLayout>
Fehlermeldung
07-28 21:18:00.812 5123-5123/br.com.pedro.pedrodaumas E/Zygote: no v2
07-28 21:18:00.822 5123-5123/br.com.pedro.pedrodaumas I/SELinux: Function: selinux_compare_spd_ram, SPD-policy is existed. and_ver=SEPF_SM-J110M_5.1.1 ver=48
07-28 21:18:00.822 5123-5123/br.com.pedro.pedrodaumas I/SELinux: Function: selinux_compare_spd_ram , priority [1] , priority version is VE=SEPF_SM-J110M_5.1.1_0048
07-28 21:18:00.822 5123-5123/br.com.pedro.pedrodaumas E/SELinux: [DEBUG] get_category: variable seinfo: default sensitivity: NULL, cateogry: NULL
07-28 21:18:00.822 5123-5123/br.com.pedro.pedrodaumas I/art: Late-enabling -Xcheck:jni
07-28 21:18:00.842 5123-5123/br.com.pedro.pedrodaumas I/SAMP: ActivityThread() - SAMP_ENABLE : true
07-28 21:18:00.862 5123-5123/br.com.pedro.pedrodaumas W/ResourcesManager: getTopLevelResources: null for user 0
07-28 21:18:01.012 5123-5123/br.com.pedro.pedrodaumas W/ResourcesManager: getTopLevelResources: null for user 0
07-28 21:18:01.022 5123-5123/br.com.pedro.pedrodaumas D/DisplayManager: DisplayManager()
07-28 21:18:01.022 5123-5123/br.com.pedro.pedrodaumas W/ResourcesManager: getTopLevelResources: null for user 0
07-28 21:18:01.092 5123-5123/br.com.pedro.pedrodaumas W/art: Before Android 4.1, method android.graphics.PorterDuffColorFilter android.support.graphics.drawable.VectorDrawableCompat.updateTintFilter(android.graphics.PorterDuffColorFilter, android.content.res.ColorStateList, android.graphics.PorterDuff$Mode) would have incorrectly overridden the package-private method in android.graphics.drawable.Drawable
07-28 21:18:01.172 5123-5123/br.com.pedro.pedrodaumas D/PhoneWindow: *FMB* installDecor mIsFloating : false
07-28 21:18:01.172 5123-5123/br.com.pedro.pedrodaumas D/PhoneWindow: *FMB* installDecor flags : -2139029248
07-28 21:18:01.362 5123-5138/br.com.pedro.pedrodaumas I/art: Background partial concurrent mark sweep GC freed 3506(700KB) AllocSpace objects, 0(0B) LOS objects, 27% free, 5MB/7MB, paused 7.831ms total 22.235ms
07-28 21:18:01.372 5123-5123/br.com.pedro.pedrodaumas I/TextInputLayout: EditText added is not a TextInputEditText. Please switch to using that class instead.
07-28 21:18:01.412 5123-5123/br.com.pedro.pedrodaumas D/AndroidRuntime: Shutting down VM
07-28 21:18:01.412 5123-5123/br.com.pedro.pedrodaumas E/AndroidRuntime: FATAL EXCEPTION: main
Process: br.com.pedro.pedrodaumas, PID: 5123
java.lang.RuntimeException: Unable to start activity ComponentInfo{br.com.pedro.pedrodaumas/br.com.pedro.pedrodaumas.MainActivity}: java.lang.NullPointerException: Attempt to invoke virtual method 'void android.widget.ListView.setAdapter(android.widget.ListAdapter)' on a null object reference
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2697)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2771)
at android.app.ActivityThread.access$900(ActivityThread.java:177)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1432)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:135)
at android.app.ActivityThread.main(ActivityThread.java:5912)
at java.lang.reflect.Method.invoke(Native Method)
at java.lang.reflect.Method.invoke(Method.java:372)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1405)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1200)
Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'void android.widget.ListView.setAdapter(android.widget.ListAdapter)' on a null object reference
at br.com.pedro.pedrodaumas.MainActivity.onCreate(MainActivity.java:44)
at android.app.Activity.performCreate(Activity.java:6178)
at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1118)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2650)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2771)
at android.app.ActivityThread.access$900(ActivityThread.java:177)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1432)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:135)
at android.app.ActivityThread.main(ActivityThread.java:5912)
at java.lang.reflect.Method.invoke(Native Method)
at java.lang.reflect.Method.invoke(Method.java:372)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1405)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1200)
07-28 21:29:10.422 8489-8489/br.com.pedro.pedrodaumas W/art: Before Android 4.1, method android.graphics.PorterDuffColorFilter android.support.graphics.drawable.VectorDrawableCompat.updateTintFilter(android.graphics.PorterDuffColorFilter, android.content.res.ColorStateList, android.graphics.PorterDuff$Mode) would have incorrectly overridden the package-private method in android.graphics.drawable.Drawable
07-28 21:29:10.522 8489-8489/br.com.pedro.pedrodaumas D/PhoneWindow: *FMB* installDecor mIsFloating : false
07-28 21:29:10.522 8489-8489/br.com.pedro.pedrodaumas D/PhoneWindow: *FMB* installDecor flags : -2139029248
07-28 21:29:10.612 8489-8489/br.com.pedro.pedrodaumas I/TextInputLayout: EditText added is not a TextInputEditText. Please switch to using that class instead.
07-28 21:29:10.612 8489-8489/br.com.pedro.pedrodaumas D/AndroidRuntime: Shutting down VM
07-28 21:29:10.612 8489-8489/br.com.pedro.pedrodaumas E/AndroidRuntime: FATAL EXCEPTION: main
Process: br.com.pedro.pedrodaumas, PID: 8489
java.lang.RuntimeException: Unable to start activity ComponentInfo{br.com.pedro.pedrodaumas/br.com.pedro.pedrodaumas.MainActivity}: java.lang.NullPointerException: Attempt to invoke virtual method 'void android.widget.ListView.setAdapter(android.widget.ListAdapter)' on a null object reference
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2697)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2771)
at android.app.ActivityThread.access$900(ActivityThread.java:177)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1432)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:135)
at android.app.ActivityThread.main(ActivityThread.java:5912)
at java.lang.reflect.Method.invoke(Native Method)
at java.lang.reflect.Method.invoke(Method.java:372)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1405)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1200)
Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'void android.widget.ListView.setAdapter(android.widget.ListAdapter)' on a null object reference
at br.com.pedro.pedrodaumas.MainActivity.onCreate(MainActivity.java:44)
at android.app.Activity.performCreate(Activity.java:6178)
at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1118)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2650)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2771)
at android.app.ActivityThread.access$900(ActivityThread.java:177)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1432)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:135)
at android.app.ActivityThread.main(ActivityThread.java:5912)
at java.lang.reflect.Method.invoke(Native Method)
at java.lang.reflect.Method.invoke(Method.java:372)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1405)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1200)
Sie sollen Ihre Frage ein [MCVE] machen –
das genaue Problem hightlight ich glaube, das Problem ist, weil Sie 'activity_main' in dem Haupt aufblasen Aktivität, aber der Name Ihres Hauptlayouts ist 'Content_main.xml', verwenden Sie stattdessen setContentView (R.layout.Content_main.xml) – diogojme
Ich habe das schon versucht und ich gebe den gleichen Fehler =/ Sorry cricket_007 Ich dachte, dieser Titel war gut, hoffe, das ist besser ^^ –