Android - How to pass HashMap<String,String> between activities?

Question

How to pass the detail HashMap to another Activity?

HashMap<String,String> detail = new HashMap<String, String>();
detail.add("name","paresh");
detail.add("surname","mayani");
detail.add("phone","99999");
......
......

Solution 1

This is pretty simple, All Collections objects implement Serializable (sp?) interface which means they can be passed as Extras inside Intent

Use putExtra(String key, Serializable obj) to insert the HashMap and on the other Activity use getIntent().getSerializableExtra(String key), You will need to Cast the return value as a HashMap though.

Solution 2

Solution:

Sender Activity:

HashMap<String, String> hashMap= adapter.getItem(position);
Intent intent = new Intent(SourceActivity.this, DestinationActivity.class);
intent.putExtra("hashMap", hashMap);
startActivity(intent);

Receiver Activity:

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

Solution 3

i used this to pass my HashMap

startActivity(new Intent(currentClass.this,toOpenClass.class).putExtra("hashMapKey", HashMapVariable));

and on the receiving activity write

HashMap<String,String> hm = (HashMap<String,String>) getIntent().getExtras().get("hashMapKey");

cuz i know my hashmap contains string as value.

Solution 4

An alternative is if the information is something that might be considered "global" to the application, to then use the Application class. You simply extend it and then define your custom class in your manifest using the <application> tag. Use this sparingly, though. The urge to abuse it is high.

View more solutions

Comments

[Pankaj Kumar]

stackoverflow.com/questions/4154744/… this will help you. And in another way make your HashMap as public and static, set its values in caller activity and use its values into called activity. And before adding values to your HashMap, clear its previous values.

[Paresh Mayani]

@pankaj i am not getting anything from the above link code

[Pekka]

@Tanmay please don't change the OP's code. Add a comment or answer outlining the change instead. (Rejected edit)

[Tanmay Mandal]

@Pekka No problem.I just wanted to make sure the right thing

[Pankaj Kumar]

Can you prefer to make your hashMap as public static? I can explain it.

[Vikas Patidar]

@PM- Paresh Mayani: This might be helpful for you: stackoverflow.com/questions/2906925/… I dont found any direct method to do this instead of creating static HashMap

[Paresh Mayani]

@Vikas i already know that how do we pass values, arraylist , object from one activity to another, but i dont know this only. Thanx

[Vikas Patidar]

@PM Paresh Mayani: As per your question, I really don't think you need to pass the HashMap instead simply your can do this by putting an ArrayList<String> in intent and on the other activity you can obtain the value form those positions , assuming that you know which data is stored at the perticular position.

[Paresh Mayani]

thanx for the support, and "new" information , but i just need to pass HashMap between two activities i.e. From activity A to activity B

[Nitish Hardeniya]

I figured. Just wanted to offer it as an alternative.

[Yeung]

Excause me. What if I can have a HaspMap<String, Object>? Can it be serialize? The value Objects are just int, String or float type. No custom Object type.

[Paresh Mayani]

Are you sure that you are able to get HashMap<String, String> using getExtras.get("key") ?

[MetaSnarf]

yeah...as long as you passed "HashMap<String,String>" to the receiving activity

[Miha_x64]

Keep in mind, that the map will not be serialized. It will be parcelized by internals if possible. And then you will get a HashMap on the other side, despite you've put LinkedHashMap or any other map.

[Anish Kumar]

Hey hi, I am getting parcel error at runtime. java.lang.RuntimeException: Parcel: unable to marshal value I am passing HaspMap<String, JSONArray>

[arlomedia]

"You will need to Cast the return value" -- that's what I was missing.

[temirbek]

I'm getting "Unchecked cast" warning

[Aba]

The "Unchecked cast" warning is basically saying "you're on your own" ;)

[Abubakar]

@anish bcz JSONArray is not serializable.

[Anish Kumar]

Thanks mate, though it is a late reply, appreciated your help. :) @Abubakar