Develop Reference

Android Studio web app opens a blank page for Wordpress website. How to fix?

This is the MainActivity.java code in my web app that give a blank Wordpress page when I open the app.
It happens only for Wordpress.
Other websites work just fine.
They open as they should.
Thank you for your help.
The code is below:
package com.sdvjuridic.sdv;
import androidx.appcompat.app.AppCompatActivity;
import android.graphics.Bitmap;
import android.os.Bundle;
import android.webkit.WebSettings;
import android.webkit.WebView;
import android.webkit.WebViewClient;
public class MainActivity extends AppCompatActivity {
private WebView mywebView;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
mywebView=(WebView) findViewById(R.id.webview);
mywebView.setWebViewClient(new WebViewClient());
mywebView.loadUrl("https://www.sdvjuridic.wordpress.com/");
WebSettings webSettings=mywebView.getSettings();
webSettings.setJavaScriptEnabled(true);
}
public class mywebClient extends WebViewClient{
#Override
public void onPageStarted(WebView view, String url, Bitmap favicon){
super.onPageStarted(view,url,favicon);
}
#Override
public boolean shouldOverrideUrlLoading(WebView view,String url){
view.loadUrl(url);
return true;
}
}
#Override
public void onBackPressed(){
if(mywebView.canGoBack()) {
mywebView.goBack();
}
else{
super.onBackPressed();
}
}
}

This code is the fix:
package com.sdvjuridic.sdv;
import androidx.appcompat.app.AppCompatActivity;
import android.graphics.Bitmap;
import android.net.http.SslError;
import android.os.Bundle;
import android.webkit.SslErrorHandler;
import android.webkit.WebSettings;
import android.webkit.WebView;
import android.webkit.WebViewClient;
public class MainActivity extends AppCompatActivity {
private WebView mywebView;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
mywebView=(WebView) findViewById(R.id.webview);
mywebView.setWebViewClient(new SSLTolerentWebViewClient());
mywebView.loadUrl("https://www.sdvjuridic.wordpress.com/");
WebSettings webSettings=mywebView.getSettings();
webSettings.setJavaScriptEnabled(true);
}
public class mywebClient extends WebViewClient{
#Override
public void onPageStarted(WebView view, String url, Bitmap favicon){
super.onPageStarted(view,url,favicon);
}
#Override
public boolean shouldOverrideUrlLoading(WebView view,String url){
view.loadUrl(url);
return true;
}
#Override
public void onReceivedSslError(WebView view, SslErrorHandler handler, SslError error) {
handler.proceed(); // Ignore SSL certificate errors
}
}
#Override
public void onBackPressed(){
if(mywebView.canGoBack()) {
mywebView.goBack();
}
else{
super.onBackPressed();
}
}
// SSL Error Tolerant Web View Client
private class SSLTolerentWebViewClient extends WebViewClient {
#Override
public void onReceivedSslError(WebView view, SslErrorHandler handler, SslError error) {
handler.proceed(); // Ignore SSL certificate errors
}
}
}

Non static method error on back button

I am trying to add a back button to app but when i add the code i get the "Non static method 'canGoBack() cannot be referenced from a static context" error. I have read several stack articles about this error but have not been able to solve it. Any ideas please?
package com.test;
import org.json.JSONException;
import org.json.JSONObject;
import android.app.Activity;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.content.IntentFilter;
import android.os.Bundle;
import android.support.v4.content.LocalBroadcastManager;
import android.util.Log;
import android.view.KeyEvent;
import android.view.Menu;
import android.view.View;
import android.view.View.OnClickListener;
import android.webkit.WebSettings;
import android.webkit.WebView;
import android.webkit.WebViewClient;
import android.widget.Button;
import android.widget.Toast;
import com.parse.ParseInstallation;
import com.parse.ParsePush;
import com.parse.ParseQuery;
import com.parse.PushService;
public class MainActivity extends Activity implements OnClickListener {
private Button push;
private BroadcastReceiver mBroadcastReceiver = new BroadcastReceiver() {
#Override
public void onReceive(Context context, Intent intent) {
Toast.makeText(getApplicationContext(), "onReceive invoked!", Toast.LENGTH_LONG).show();
}
};
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
PushService.setDefaultPushCallback(this, MainActivity.class);
Button back = (Button) findViewById(R.id.back);
WebView webView = (WebView) findViewById(R.id.webView1);;
webView.getSettings().setJavaScriptEnabled(true);
webView.loadUrl("http://www.xxxxx.xxxxxx.xxxxx.xxxx// ");
webView.setWebViewClient(new WebViewClient());
push = (Button)findViewById(R.id.senPushB);
push.setOnClickListener(this);
}
private class Callback extends WebViewClient {
#Override
public boolean shouldOverrideUrlLoading(WebView view, String url) {
return (true);
}
}
#Override
public void onBackPressed()
{
if(WebView.canGoBack()){
WebView.goBack();
}else{
super.onBackPressed();
}
}
#Override
public void onPause() {
super.onPause();
LocalBroadcastManager.getInstance(this).unregisterReceiver(mBroadcastReceiver);
}
#Override
public void onResume() {
super.onResume();
LocalBroadcastManager.getInstance(this).registerReceiver(mBroadcastReceiver, new IntentFilter(MyCustomReceiver.intentAction));
}
#Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.activity_main, menu);
return true;
}
#Override
public void onClick(View v) {
JSONObject obj;
try {
obj = new JSONObject();
obj.put("alert", "hello!");
obj.put("action", MyCustomReceiver.intentAction);
obj.put("customdata","My message");
ParsePush push = new ParsePush();
ParseQuery query = ParseInstallation.getQuery();
// Push the notification to Android users
query.whereEqualTo("deviceType", "android");
push.setQuery(query);
push.setData(obj);
push.sendInBackground();
} catch (JSONException e) {
e.printStackTrace();
}
}
}

Try changing:
#Override
public void onBackPressed()
{
if(WebView.canGoBack()){
WebView.goBack();
}else{
super.onBackPressed();
}
}
to:
#Override
public void onBackPressed()
{
WebView webView = (WebView) findViewById(R.id.webView1);
if(webView.canGoBack()){
webView.goBack();
}else{
super.onBackPressed();
}
}
Explanation:
You should call canGoBack() and goBack() for the webview instance that you're using (move to the previous view). This is also why the method is declared at the instance level and not at the class level (static)

canGoBack is an instance (non-static) method. It can only be called on an instance of the WebView class. WebView is the class. Calling WebView.function() only works if function is a static function. You need to get the instance of the WebView and call it on that.
For the record, the difference between a static and instance method- a static method may not use any non-static data. An instance method can. Static data only has 1 copy per class. Non-static data has 1 copy per instance of the class.

Android WebView Tab Browsing with Cookies

My app has a 3-tabbed ActionBar layout. The 3 tabs are Dashboard, Feed and Messages.
When you click any of the three, the application is supposed to create a WebView of www.flyalaskava.org/incog/mobile/ which - if you do not have an active session for - will display an image and a "log-in with facebook" button.
The problem is, when I load the first tab (Dashboard) and cliek Log-In with Facebook, it logs me in - but as soon as I click onto another tab, I lose my session and am re-prompted.
Please keep in mind that currently all of these are using the same php file and that the log-in system works perfectly outside of Android. Sorry if this is a newbie question - any help is appreciated.
package com.example.testing;
import android.app.ActionBar;
import android.app.FragmentTransaction;
import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentActivity;
import android.support.v4.app.NavUtils;
import android.view.Gravity;
import android.view.LayoutInflater;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.view.ViewGroup;
import android.widget.TextView;
import android.webkit.WebView;
import android.webkit.WebViewClient;
import android.net.ConnectivityManager;
import android.net.NetworkInfo;
import android.app.AlertDialog;
import android.app.Dialog;
import android.content.DialogInterface;
import com.handmark.pulltorefresh.library.PullToRefreshWebView;
public class Main extends FragmentActivity implements ActionBar.TabListener {
PullToRefreshWebView mPullRefreshWebView;
WebView mWebView;
/**
* The serialization (saved instance state) Bundle key representing the
* current tab position.
*/
private static final String STATE_SELECTED_NAVIGATION_ITEM = "selected_navigation_item";
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
mPullRefreshWebView = (PullToRefreshWebView) findViewById(R.id.pull_refresh_webview);
mWebView = mPullRefreshWebView.getRefreshableView();
mWebView.getSettings().setJavaScriptEnabled(true);
mWebView.setWebViewClient(new SampleWebViewClient());
mWebView.loadUrl("http://www.google.com");
// Set up the action bar to show tabs.
final ActionBar actionBar = getActionBar();
actionBar.setNavigationMode(ActionBar.NAVIGATION_MODE_TABS);
// For each of the sections in the app, add a tab to the action bar.
actionBar.addTab(actionBar.newTab().setText(R.string.title_section1)
.setTabListener(this));
actionBar.addTab(actionBar.newTab().setText(R.string.title_section2)
.setTabListener(this));
actionBar.addTab(actionBar.newTab().setText(R.string.title_section3)
.setTabListener(this));
}
private static class SampleWebViewClient extends WebViewClient {
#Override
public boolean shouldOverrideUrlLoading(WebView view, String url) {
view.loadUrl(url);
return true;
}
}
#Override
public void onRestoreInstanceState(Bundle savedInstanceState) {
// Restore the previously serialized current tab position.
if (savedInstanceState.containsKey(STATE_SELECTED_NAVIGATION_ITEM)) {
getActionBar().setSelectedNavigationItem(
savedInstanceState.getInt(STATE_SELECTED_NAVIGATION_ITEM)
);
}
}
#Override
public void onSaveInstanceState(Bundle outState) {
// Serialize the current tab position.
outState.putInt(STATE_SELECTED_NAVIGATION_ITEM, getActionBar()
.getSelectedNavigationIndex());
}
#Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.activity_main, menu);
return true;
}
public boolean onOptionsItemSelected(MenuItem item) {
switch (item.getItemId()) {
case R.id.menu_settings:
displayAlert();
break;
case R.id.menu_exit:
displayExit();
break;
default:;
}
return(super.onOptionsItemSelected(item));
}
public void displayAlert() {
new AlertDialog.Builder(this)
.setMessage("This Application was created by Grant Adkins")
.setTitle("About")
.setCancelable(false)
.setNeutralButton(android.R.string.ok,
new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int whichButton){
dialog.cancel();
}
}
)
.show();
}
public void displayExit() {
new AlertDialog.Builder(this).setMessage("Exit the application")
.setTitle("Are you sure?")
.setCancelable(false)
.setNeutralButton(android.R.string.no,
new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int whichButton){
dialog.cancel();
}
}).setPositiveButton(android.R.string.yes,
new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int whichButton){
finish();
}
}
)
.show();
}
public boolean isOnline() {
ConnectivityManager cm =
(ConnectivityManager) getSystemService(CONNECTIVITY_SERVICE);
NetworkInfo netInfo = cm.getActiveNetworkInfo();
if (netInfo != null && netInfo.isConnectedOrConnecting()) {
return true;
}
String summary = "<html><body>No Network Connection.</body></html>";
mWebView.loadData(summary, "text/html", null);
return false;
}
#Override
public void onTabSelected(ActionBar.Tab tab, FragmentTransaction fragmentTransaction) {
// When the given tab is selected, show the tab contents in the
// container view
int page = tab.getPosition() + 1;
if(page == 1) {
/// eventually is going to load index.php?content=dashboard
mWebView.loadUrl("http://www.flyalaskava.org/incog/mobile/");
isOnline();
} else if (page == 2) {
/// eventually is going to load index.php?content=messages
mWebView.loadUrl("http://www.flyalaskava.org/incog/mobile/");
isOnline();
} else if (page == 3) {
/// eventually is going to load index.php?content=feed
mWebView.loadUrl("http://www.flyalaskava.org/incog/mobile/");
isOnline();
} else {
mWebView.loadUrl("http://www.google.com");
isOnline();
}
}
#Override
public void onTabUnselected(ActionBar.Tab tab, FragmentTransaction fragmentTransaction) {
}
#Override
public void onTabReselected(ActionBar.Tab tab, FragmentTransaction fragmentTransaction) {
}
/**
* A dummy fragment representing a section of the app, but that simply
* displays dummy text.
*/
public static class DummySectionFragment extends Fragment {
/**
* The fragment argument representing the section number for this
* fragment.
*/
public static final String ARG_SECTION_NUMBER = "section_number";
public DummySectionFragment() {
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
// Create a new TextView and set its text to the fragment's section
// number argument value.
TextView textView = new TextView(getActivity());
textView.setGravity(Gravity.CENTER);
textView.setText(
Integer.toString(getArguments().getInt(ARG_SECTION_NUMBER))
);
return textView;
}
}
}`
*\\\\\\\\UPDATE\\\\\\*
I found this article which seems to be a similar problem, maybe because im using mWebView.loadUrl("http://www.flyalaskava.org/incog/mobile/"); it is acting like a new browser, is there any way to change urls without using that method.
Here is a picture of the problem.

Add the following lines after having created your WebView :
CookieSyncManager.createInstance(mWebView.getContext()).sync();
CookieManager.getInstance().acceptCookie();

Consider using a Service instead of cookies. A Service will allow you to maintain a connection to your server in the background of your application. Services are easily referenced once created (read about Services and Intents). The Service would then act as your session to your server.

Android enable back button in webview

I'm using the following code to display a webview in my Android app.
package com.company.myapp;
import com.google.android.apps.analytics.GoogleAnalyticsTracker;
import android.app.Activity;
import android.os.Bundle;
import android.view.View;
import android.view.Window;
import android.webkit.WebChromeClient;
import android.webkit.WebView;
import android.webkit.WebViewClient;
import android.widget.Toast;
public class ArticlesActivity extends Activity {
/** Initialize the Google Analytics Tracker */
GoogleAnalyticsTracker tracker;
/** Called when the activity is first created. */
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
getWindow().requestFeature(Window.FEATURE_PROGRESS);
getWindow().setFeatureInt(Window.FEATURE_PROGRESS, Window.PROGRESS_VISIBILITY_ON);
WebView webview = new WebView(this);
setContentView(webview);
setProgressBarVisibility(true);
webview.getSettings().setJavaScriptEnabled(true);
webview.setScrollBarStyle(View.SCROLLBARS_INSIDE_OVERLAY);
final Activity activity = this;
tracker = GoogleAnalyticsTracker.getInstance();
// Start the tracker, updating google every 20 seconds
tracker.start((String) getText(R.string.analyticsID), 20, this);
webview.setWebChromeClient(new WebChromeClient() {
public void onProgressChanged(WebView view, int progress) {
activity.setProgress(progress * 100 );
}
});
webview.setWebViewClient(new WebViewClient() {
public void onReceivedError(WebView view, int errorCode, String description, String failingUrl) {
Toast.makeText(activity, "Oh no! " + description, Toast.LENGTH_SHORT).show();
}
});
webview.loadUrl("http://www.google.com");
}
#Override
public void onResume() {
tracker.trackPageView("ArticlesActivity");
super.onResume();
}
#Override
protected void onDestroy() {
super.onDestroy();
// Stop the tracker when it is no longer needed.
tracker.stop();
}
}
I would need to enable the back button to step back if history exists instead of just exiting the webview.
I've tried many different code examples such as this but can't get any to work. The app just shuts down when the back button is pressed.
Here's my code with the back button code but it just crashes the app when then back button is pressed:
package com.company.myapp;
import com.google.android.apps.analytics.GoogleAnalyticsTracker;
import android.app.Activity;
import android.os.Bundle;
import android.view.View;
import android.view.Window;
import android.webkit.WebChromeClient;
import android.webkit.WebView;
import android.webkit.WebViewClient;
import android.widget.Toast;
public class ArticlesActivity extends Activity {
WebView webview;
/** Initialize the Google Analytics Tracker */
GoogleAnalyticsTracker tracker;
/** Called when the activity is first created. */
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
getWindow().requestFeature(Window.FEATURE_PROGRESS);
getWindow().setFeatureInt(Window.FEATURE_PROGRESS, Window.PROGRESS_VISIBILITY_ON);
WebView webview = new WebView(this);
setContentView(webview);
setProgressBarVisibility(true);
webview.getSettings().setJavaScriptEnabled(true);
webview.setScrollBarStyle(View.SCROLLBARS_INSIDE_OVERLAY);
final Activity activity = this;
tracker = GoogleAnalyticsTracker.getInstance();
// Start the tracker, updating google every 20 seconds
tracker.start((String) getText(R.string.analyticsID), 20, this);
webview.setWebChromeClient(new WebChromeClient() {
public void onProgressChanged(WebView view, int progress) {
activity.setProgress(progress * 100 );
}
});
webview.setWebViewClient(new WebViewClient() {
public void onReceivedError(WebView view, int errorCode, String description, String failingUrl) {
Toast.makeText(activity, "Oh no! " + description, Toast.LENGTH_SHORT).show();
}
});
webview.loadUrl("http://www.google.com");
}
#Override
public boolean onKeyDown(int keyCode, KeyEvent event) {
if (keyCode == KeyEvent.KEYCODE_BACK) {
webview.goBack();
return true;
}
return super.onKeyDown(keyCode, event);
}
#Override
public void onResume() {
tracker.trackPageView("ArticlesActivity");
super.onResume();
}
#Override
protected void onDestroy() {
super.onDestroy();
// Stop the tracker when it is no longer needed.
tracker.stop();
}
}
Could someone help me with a solution?

Got it! Your problem in this line
WebView webview = new WebView(this);
Instead of using your member variable you are creating a variable inside function, and hence your member variable is null inside onKeyDown function.
Just replace it with
webview = new WebView(this);

Error when checking Internet Connection in Android

The idea is when there is no internet connection available, show my custom dialog to users which indicates there is no connection. Otherwise, when page is loading in WebView, show a ProgressDialog to show that page is loading and dismiss when loading is done. When there is an internet connection this code works, but if there is no, it crashes and I can't find where the error is.
package com.tariknotebook;
import android.app.Activity;
import android.app.Dialog;
import android.app.ProgressDialog;
import android.content.Context;
import android.graphics.Bitmap;
import android.net.ConnectivityManager;
import android.net.NetworkInfo;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.webkit.WebView;
import android.webkit.WebViewClient;
import android.widget.Button;
public class NoteBook extends Activity {
/** Called when the activity is first created. */
WebView web;
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
web = (WebView) findViewById(R.id.browserMine);
web.setWebViewClient(new HelloWebViewClient());
web.getSettings().setJavaScriptEnabled(true);
}
#Override
protected void onStart() {
// TODO Auto-generated method stub
super.onStart();
web.loadUrl("http://m.seslisozluk.com");
}
ProgressDialog dialog;
Dialog connDialog;
#Override
protected Dialog onCreateDialog(int id) {
switch(id)
{
case 1:
dialog = ProgressDialog.show(NoteBook.this, "Loading",
"Loading.. Please wait.");
break;
case 2:
connDialog = new Dialog(getApplicationContext());
connDialog.setContentView(R.layout.connection);
connDialog.setTitle("No Internet Connection");
Button closeButton = (Button) findViewById(R.id.closeButton);
closeButton.setOnClickListener(new closeButtonOnClickListener());
connDialog.show();
break;
}
return super.onCreateDialog(id);
}
private class closeButtonOnClickListener implements OnClickListener
{
public void onClick(View v) {
connDialog.dismiss();
};
}
private class HelloWebViewClient extends WebViewClient {
#Override
public boolean shouldOverrideUrlLoading(WebView view, String url) {
view.loadUrl(url);
return true;
}
#Override
public void onPageStarted(WebView view, String url, Bitmap favicon) {
// TODO Auto-generated method stub
super.onPageStarted(view, url, favicon);
ConnectivityManager conStatus = (ConnectivityManager) view.getContext().getApplicationContext().getSystemService(Context.CONNECTIVITY_SERVICE);
if(conStatus.getActiveNetworkInfo().isConnected() && conStatus.getActiveNetworkInfo() != null)
showDialog(1);
else
showDialog(2);
}
#Override
public void onPageFinished(WebView view, String url) {
// TODO Auto-generated method stub
super.onPageFinished(view, url);
dialog.dismiss();
}
}
}
And this is the error log as well :

When you post error messages, you should tell us which line of the source corresponds.
By pasting your code into a text editor, I believe line 83 is:
if(conStatus.getActiveNetworkInfo().isConnected() && conStatus.getActiveNetworkInfo() != null)
This strongly suggests that conStatus is null and you are trying to call a method of non-existent object.
You should check that it's non-null first.