How do I pass an object from one activity to another on Android

Question

I need to be able to use one object in multiple activities within my app  and it needs to be the same object  What is the best way to do this    I have tried making the object  public static  so it can be accessed by other activities  but for some reason this just isn t cutting it  Is there another way of doing this

User · Accepted Answer

When you are creating an object of intent, you can take advantage of following two methods for passing objects between two activities.

putParcelable

putSerializable

You can have your class implement either Parcelable or Serializable. Then you can pass around your custom classes across activities. I have found this very useful.

Here is a small snippet of code I am using

CustomListing currentListing = new CustomListing();
Intent i = new Intent();
Bundle b = new Bundle();
b.putParcelable(Constants.CUSTOM_LISTING, currentListing);
i.putExtras(b);
i.setClass(this, SearchDetailsActivity.class);
startActivity(i);

And in newly started activity code will be something like this...

Bundle b = this.getIntent().getExtras();
if (b != null)
    mCurrentListing = b.getParcelable(Constants.CUSTOM_LISTING);

User · Answer

It depends on the type of data you need access to   If you have some kind of data pool that needs to persist across Activitys then Erich s answer is the way to go   If you just need to pass a few objects from one activity to another then you can have them implement Serializable and pass them in the extras of the Intent to start the new Activity

User · Answer

You can create a subclass of Application and store your shared object there   The Application object should exist for the lifetime of your app as long as there is some active component   From your activities  you can access the application object via getApplication

User · Answer

Maybe it s an unpopular answer  but in the past I ve simply used a class that has a static reference to the object I want to persist through activities   So   public class PersonHelper       public static Person person      I tried going down the Parcelable interface path  but ran into a number of issues with it and the overhead in your code was unappealing to me

User · Answer

Your object can also implement the Parcelable interface  Then you can use the Bundle putParcelable   method and pass your object between activities within intent   The Photostream application uses this approach and may be used as a reference

User · Answer

This answer is specific to situations where the objects to be passed has nested class structure  With nested class structure  making it Parcelable or Serializeable is a bit tedious  And  the process of serialising an object is not efficient on Android  Consider the example below   class Myclass        int a    class SubClass             int b          With Google s GSON library  you can directly parse an object into a JSON formatted String and convert it back to the object format after usage  For example   MyClass src   new MyClass    Gson gS   new Gson    String target   gS toJson src      Converts the object to a JSON String   Now you can pass this String across activities as a StringExtra with the activity intent   Intent i   new Intent FromActivity this  ToActivity class   i putExtra  MyObjectAsString   target     Then in the receiving activity  create the original object from the string representation   String target   getIntent   getStringExtra  MyObjectAsString    MyClass src   gS fromJson target  MyClass class      Converts the JSON String to an Object   It keeps the original classes clean and reusable  Above of all  if these class objects are created from the web as JSON objects  then this solution is very efficient and time saving   UPDATE    While the above explained method works for most situations  for obvious performance reasons  do not rely on Android s bundled-extra system to pass objects around  There are a number of solutions makes this process flexible and efficient  here are a few  Each has its own pros and cons    Eventbus Otto

[android] How do I pass an object from one activity to another on Android?

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