How to determine the type of an extra in a bundle held by intent?

Question

I am trying to pass arbitrary data to a BroadcastReceiver through its Intent.

So I might do something like the following

intent.putExtra("Some boolean", false);
intent.putExtra("Some char", 'a');
intent.putExtra("Some String", "But don't know what it will be");
intent.putExtra("Some long", 15134234124125);

And then pass this to the BroadcastReceiver

I want to iterate through Intent.getExtras() with something like keySet(), but I would also like to be able to get the value of the key without having to hard-code calls to methods like .getStringExtra(), or .getBooleanExtra().

How does a person do this?

Answer 1

You can use the following code to get an object of any time from the Intent:

Bundle bundle = intent.getExtras();
Object value = bundle.get("key");

Then you can determine value's real type using Object's methods.

Answer 2

You can browse thye keys without knowing the type of the values using keySet(). It returns you a set of String that you can iterate on (see doc).

But for the values, it is normal that you have to use a typed method (getStringExtra(), getBooleanExtra(), etc): this is caused by the fact Java itself is typed.

If you would like to send data of arbitrary types to your BroadcastReceiver, you should either:

• convert all your extras to Strings before sending them, and retrieve all of them as Strings :

  intent.putExtra("Some boolean", "false");
  intent.putExtra("Some char", "a");
  intent.putExtra("Some String", "But don't know what it will be");
  intent.putExtra("Some long", "15134234124125");
  

• or use the get() method of the Bundle that returns Objects (see doc):

  Object o = bundle.get(key)