Open another application from your own (intent)

Question

I have work it like this,

/** Open another app.
 * @param context current Context, like Activity, App, or Service
 * @param packageName the full package name of the app to open
 * @return true if likely successful, false if unsuccessful
 */
public static boolean openApp(Context context, String packageName) {
    PackageManager manager = context.getPackageManager();
    try {
        Intent i = manager.getLaunchIntentForPackage(packageName);
        if (i == null) {
            return false;
            //throw new ActivityNotFoundException();
        }
        i.addCategory(Intent.CATEGORY_LAUNCHER);
        context.startActivity(i);
        return true;
    } catch (ActivityNotFoundException e) {
        return false;
    }
}

Example usage:

openApp(this, "com.google.android.maps.mytracks");

Hope it helps someone.

Firstly, the concept of "application" in Android is slightly an extended one.

An application - technically a process - can have multiple activities, services, content providers and/or broadcast listeners. If at least one of them is running, the application is up and running (the process).

So, what you have to identify is how do you want to "start the application".

Ok... here's what you can try out:

1. Create an intent with action=MAIN and category=LAUNCHER
2. Get the PackageManager from the current context using context.getPackageManager
3. packageManager.queryIntentActivity(<intent>, 0) where intent has category=LAUNCHER, action=MAIN or packageManager.resolveActivity(<intent>, 0) to get the first activity with main/launcher
4. Get theActivityInfo you're interested in
5. From the ActivityInfo, get the packageName and name
6. Finally, create another intent with with category=LAUNCHER, action=MAIN, componentName = new ComponentName(packageName, name) and setFlags(Intent.FLAG_ACTIVITY_NEW_TASK)
7. Finally, context.startActivity(newIntent)

    Intent intent = new Intent(Intent.ACTION_MAIN);
    intent.setComponent(ComponentName.unflattenFromString("com.google.android.maps.mytracks/com.google.android.apps.mytracks.MyTracks"));
    intent.addCategory(Intent.CATEGORY_LAUNCHER);
    startActivity(intent);

EDIT :

as suggested in comments, add one line before startActivity(intent);

intent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);

If you already have the package name you wish to activate, you can use the following code which is a bit more generic:

PackageManager pm = context.getPackageManager();
Intent appStartIntent = pm.getLaunchIntentForPackage(appPackageName);
if (null != appStartIntent)
{
    context.startActivity(appStartIntent);
}

I found that it works better for cases where the main activity was not found by the regular method of start the MAIN activity.

This is the code of my solution base on MasterGaurav solution:

private void  launchComponent(String packageName, String name){
    Intent launch_intent = new Intent("android.intent.action.MAIN");
    launch_intent.addCategory("android.intent.category.LAUNCHER");
    launch_intent.setComponent(new ComponentName(packageName, name));
    launch_intent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);

    activity.startActivity(launch_intent);
}

public void startApplication(String application_name){
    try{
        Intent intent = new Intent("android.intent.action.MAIN");
        intent.addCategory("android.intent.category.LAUNCHER");

        intent.addFlags(Intent.FLAG_ACTIVITY_NO_ANIMATION);
        List<ResolveInfo> resolveinfo_list = activity.getPackageManager().queryIntentActivities(intent, 0);

        for(ResolveInfo info:resolveinfo_list){
            if(info.activityInfo.packageName.equalsIgnoreCase(application_name)){
                launchComponent(info.activityInfo.packageName, info.activityInfo.name);
                break;
            }
        }
    }
    catch (ActivityNotFoundException e) {
        Toast.makeText(activity.getApplicationContext(), "There was a problem loading the application: "+application_name,Toast.LENGTH_SHORT).show();
    }
}

Using the solution from inversus, I expanded the snippet with a function, that will be called when the desired application is not installed at the moment. So it works like: Run application by package name. If not found, open Android market - Google play for this package.

public void startApplication(String packageName)
{
    try
    {
        Intent intent = new Intent("android.intent.action.MAIN");
        intent.addCategory("android.intent.category.LAUNCHER");

        intent.addFlags(Intent.FLAG_ACTIVITY_NO_ANIMATION);
        List<ResolveInfo> resolveInfoList = getPackageManager().queryIntentActivities(intent, 0);

        for(ResolveInfo info : resolveInfoList)
            if(info.activityInfo.packageName.equalsIgnoreCase(packageName))
            {
                launchComponent(info.activityInfo.packageName, info.activityInfo.name);
                return;
            }

        // No match, so application is not installed
        showInMarket(packageName);
    }
    catch (Exception e) 
    {
        showInMarket(packageName);
    }
}

private void launchComponent(String packageName, String name)
{
    Intent intent = new Intent("android.intent.action.MAIN");
    intent.addCategory("android.intent.category.LAUNCHER");
    intent.setComponent(new ComponentName(packageName, name));
    intent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);

    startActivity(intent);
}

private void showInMarket(String packageName)
{
    Intent intent = new Intent(Intent.ACTION_VIEW, Uri.parse("market://details?id=" + packageName));
    intent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
    startActivity(intent);
}

And it is used like this:

startApplication("org.teepee.bazant");