How to send hashmap value to another activity using an intent

Question

How to send HashMap value from one Intent to second Intent?

Also, how to retrieve that HashMap value in the second Activity?

Answer 1

Java's HashMap class extends the Serializable interface, which makes it easy to add it to an intent, using the Intent.putExtra(String, Serializable) method.

In the activity/service/broadcast receiver that receives the intent, you then call Intent.getSerializableExtra(String) with the name that you used with putExtra.

For example, when sending the intent:

HashMap<String, String> hashMap = new HashMap<String, String>();
hashMap.put("key", "value");
Intent intent = new Intent(this, MyOtherActivity.class);
intent.putExtra("map", hashMap);
startActivity(intent);

And then in the receiving Activity:

protected void onCreate(Bundle bundle) {
    super.onCreate(savedInstanceState);

    Intent intent = getIntent();
    HashMap<String, String> hashMap = (HashMap<String, String>)intent.getSerializableExtra("map");
    Log.v("HashMapTest", hashMap.get("key"));
}

Answer 2

I hope this must work too.

in the sending activity

Intent intent = new Intent(Banks.this, Cards.class);
intent.putExtra("selectedBanksAndAllCards", (Serializable) selectedBanksAndAllCards);
startActivityForResult(intent, 50000);

in the receiving activity

Intent intent = getIntent();
HashMap<String, ArrayList<String>> hashMap = (HashMap<String, ArrayList<String>>) intent.getSerializableExtra("selectedBanksAndAllCards");

when I am sending a HashMap like following,

Map<String, ArrayList<String>> selectedBanksAndAllCards = new HashMap<>();

Hope it would help for someone.