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Show network error in android

I created an application with webview. if I have any actions and the network is disconnected, I want to display one warning. I tried the following,

added this to the oncreate method.

public class AndroidNetTestActivity extends Activity { public static WebView webview; private Handler mHandler = new Handler(); private boolean isConnected = true; final String offlineMessageHtml = "Net is disconnected"; final String timeoutMessageHtml = "Connection timed out"; @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.main); webview=(WebView)findViewById(R.id.webview); webview.getSettings().setJavaScriptEnabled(true); webview.loadUrl("file:///android_asset/www/index.htm"); webview.addJavascriptInterface(new MyJavaScriptInterface(), "Android"); isConnected=isNetworkAvailable(); webview.setNetworkAvailable(isConnected); webview.setWebViewClient(new WebViewClient() { @Override public boolean shouldOverrideUrlLoading(WebView view, String url) { isConnected=isNetworkAvailable(); if (isConnected) { // return false to let the WebView handle the URL return false; } else { // show the proper "not connected" message view.loadData(offlineMessageHtml, "text/html", "utf-8"); // return true if the host application wants to leave the current // WebView and handle the url itself return true; } } @Override public void onReceivedError (WebView view, int errorCode, String description, String failingUrl) { if (errorCode == ERROR_TIMEOUT) { view.stopLoading(); // may not be needed view.loadData(timeoutMessageHtml, "text/html", "utf-8"); } } }); webview.setWebChromeClient(new WebChromeClient()); } final class MyJavaScriptInterface { public void ProcessJavaScript(final String scriptname, final String args) { mHandler.post(new Runnable() { public void run() { //ToDo } }); } } public boolean isNetworkAvailable() { Context context = getApplicationContext(); ConnectivityManager connectivity = (ConnectivityManager) context.getSystemService(Context.CONNECTIVITY_SERVICE); if (connectivity == null) { //boitealerte(this.getString(R.string.alert),"getSystemService rend null"); } else { NetworkInfo[] info = connectivity.getAllNetworkInfo(); if (info != null) { for (int i = 0; i < info.length; i++) { if (info[i].getState() == NetworkInfo.State.CONNECTED) { return true; } } } } return false; } }

if I press the login button, it should show an error message if the network is unavailable.

but it does not work. please check my code and tell me what i did wrong

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ok ... I updated your code. just look

 import android.app.Activity; import android.app.AlertDialog; import android.content.Context; import android.content.DialogInterface; import android.graphics.Bitmap; import android.net.ConnectivityManager; import android.net.NetworkInfo; import android.os.Bundle; import android.os.Handler; import android.webkit.WebView; import android.webkit.WebViewClient; import android.widget.Toast; public class AndroidNetTestActivity extends Activity { public static WebView webview; private Handler mHandler = new Handler(); private boolean isConnected = true; final String offlineMessageHtml = "Net is disconnected"; final String timeoutMessageHtml = "Connection timed out"; @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.full_screen_image_layout); webview=(WebView)findViewById(R.id.webview); webview.getSettings().setJavaScriptEnabled(true); webview.loadUrl("http://www.google.com"); webview.addJavascriptInterface(new MyJavaScriptInterface(), "Android"); isConnected=isNetworkAvailable(); webview.setNetworkAvailable(isConnected); webview.setWebViewClient(new WebViewClient() { /* (non-Javadoc) * @see android.webkit.WebViewClient#onPageStarted(android.webkit.WebView, java.lang.String, android.graphics.Bitmap) */ @Override public void onPageStarted(WebView view, String url, Bitmap favicon) { System.out.println("page loading started"); // TODO Auto-generated method stub if(!isNetworkAvailable2()) { showInfoMessageDialog("network not available"); System.out.println("network not available"); return; } else System.out.println("network available"); super.onPageStarted(view, url, favicon); } @Override public boolean shouldOverrideUrlLoading(WebView view, String url) { isConnected=isNetworkAvailable2(); if (isConnected) { // return false to let the WebView handle the URL return false; } else { // show the proper "not connected" message // view.loadData(offlineMessageHtml, "text/html", "utf-8"); // return true if the host application wants to leave the current // WebView and handle the url itself return true; } } @Override public void onReceivedError (WebView view, int errorCode, String description, String failingUrl) { if (errorCode == ERROR_TIMEOUT) { view.stopLoading(); // may not be needed // view.loadData(timeoutMessageHtml, "text/html", "utf-8"); } } }); //webview.setWebChromeClient(new WebChromeClient()); } final class MyJavaScriptInterface { public void ProcessJavaScript(final String scriptname, final String args) { mHandler.post(new Runnable() { public void run() { //ToDo } }); } } private void showInfoMessageDialog(String meaasge) { AlertDialog alertDialog = new AlertDialog.Builder( AndroidNetTestActivity.this).create(); alertDialog.setTitle("Connectivity"); alertDialog.setMessage(meaasge); alertDialog.setButton("OK", new DialogInterface.OnClickListener() { public void onClick(DialogInterface dialog, int which) { dialog.cancel(); } }); //alertDialog.setIcon(R.drawable.error); alertDialog.show(); } private boolean isNetworkAvailable2() { System.out.println("isNetworkAvailable2 called"); NetworkInfo info = (NetworkInfo) ((ConnectivityManager) getApplicationContext() .getSystemService(Context.CONNECTIVITY_SERVICE)) .getActiveNetworkInfo(); if (info == null || !info.isAvailable() || !info.isConnected()) return false; else return true; } public boolean isNetworkAvailable() { Context context = getApplicationContext(); ConnectivityManager connectivity = (ConnectivityManager) context.getSystemService(Context.CONNECTIVITY_SERVICE); if (connectivity == null) { //boitealerte(this.getString(R.string.alert),"getSystemService rend null"); } else { NetworkInfo[] info = connectivity.getAllNetworkInfo(); if (info != null) { for (int i = 0; i < info.length; i++) { if (info[i].getState() == NetworkInfo.State.CONNECTED) { return true; } } } } return false; } }
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u can check your internet connection like this

  boolean check=checkConnection(); if(check==true){ Toast.makeText( this, "Internet is Connected", Toast.LENGTH_LONG).show(); } else{ Toast.makeText( this, "Failed to connect to internet.", Toast.LENGTH_LONG).show(); } and here is a method of checkConnection protected boolean checkConnection(){ ConnectivityManager conMan = (ConnectivityManager) getSystemService(Context.CONNECTIVITY_SERVICE); NetworkInfo networkInfo = conMan.getActiveNetworkInfo(); final boolean connected = networkInfo != null && networkInfo.isAvailable() && networkInfo.isConnected(); if ( !connected) { Toast.makeText( this, "Failed to connect to internet.", Toast.LENGTH_LONG).show(); return false; } return true; }

Just make it work for me

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