Check if the activity exists on Android.

You can use the getActivityInfo method of the PackageManager class to determine if an Activity exists. First, you need to obtain an instance of the PackageManager, then call the getActivityInfo method, passing in the full class name of the Activity and the GET_ACTIVITIES flag of the PackageManager. If the Activity exists, it will return an ActivityInfo object; otherwise, it will throw a PackageManager.NameNotFoundException exception.

The following is an example code:

String activityClassName = "com.example.myapp.MainActivity";
PackageManager packageManager = getPackageManager();
try {
    ActivityInfo activityInfo = packageManager.getActivityInfo(new ComponentName(this, activityClassName), PackageManager.GET_ACTIVITIES);
    // Activity存在
    // 可以执行相关操作
} catch (PackageManager.NameNotFoundException e) {
    // Activity不存在
    // 可以执行其他操作
}

Please make sure to replace “com.example.myapp.MainActivity” in the example code with the full class name of the Activity you want to check.