Archive for category How to

Another common requirement is to send an email from your application. At first, this looks easy. You use an ACTION_SEND Intent as demonstrated by the example on OpenIntents…

Intent sendIntent = new Intent(Intent.ACTION_SEND);
sendIntent.putExtra(Intent.EXTRA_TEXT, "email text");
sendIntent.putExtra(Intent.EXTRA_SUBJECT, "Subject");
sendIntent.setType("message/rfc822");
startActivity(Intent.createChooser(sendIntent, "Title:"));

However, this sends the email via the Android mail app in the phone, prompting you which email app if you have more than one configured. So, how do you send an email silently? It turns out that there’s no official way to send an email directly (via SMTP). The Google rationale is that, for security reasons, the user needs to know (and confirm) that the application is sending an email on their behalf.

However, what if you still want to send silent emails? One option is to port a 100% Java SMTP library. You might try JavaMail. There’s a .jar file on the Google groups but I wouldn’t use it if I were you as it doesn’t respect the original source code license and you don’t really know what you are including.

There’s another attempt at putting together bits and pieces with more details how to go about this yourself but it’s really lots of hacking which most people might like to avoid. Someone else has also claimed to port gnu inetlib.

If you want a cleaner way of sending via SMTP, without polluting your application with lots of unwanted classes, then one solution might be to get your server to do it via a simple php script and send up the information via a http GET or POST.

Many apps end up opening a web page at some point. This is often useful to allow changeable information to shown, such as a help screen, that can be maintained on a web server in light of questions from users.

I have come across three ways to do this. The first is to create a android.webkit.WebView and call loadUrl() . You can see this being used in com.android.browser.BrowserActivity where selecting home causes the URL, set up in your settings, to be shown…

            case R.id.homepage_menu_id:
                TabControl.Tab current = mTabControl.getCurrentTab();
                if (current != null) {
                    dismissSubWindow(current);
                    current.getWebView().loadUrl(mSettings.getHomePage());
                }
                break;

The above technique is flexible in that you can even use it to call some JavaScript instead.

But what if the server requires you to use a http POST rather than GET? You can use the commons http client and loadDataWithBaseURL as shown on the Google groups.

A second way to show a URL, but in the built-in web browser rather than within your application, is to use an intent…

Intent myIntent = new Intent(Intent.VIEW_ACTION,
   ContentURI.create("http://www.myurl.com"));
startActivity(myIntent);

Finally,you can also create a TextView with the property android:autoLink=”web”. When the user selects a link in the TextView it will open in the built-in browser application.