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

Question

I am trying to work on sending an object of my customer class from one Activity and display it in another Activity   The code for the customer class   public class Customer        private String firstName  lastName  Address      int Age       public Customer String fname  String lname  int age  String address             firstName   fname          lastName   lname          Age   age          Address   address             public String printValues              String data   null           data    First Name      firstName     Last Name      lastName             Age       Age     Address       Address           return data            I want to send its object from one Activity to another and then display the data on the other Activity   How can I achieve that

User · Answer

We can pass the object from one activity to another activity:

SupplierDetails poSuppliersDetails = new SupplierDetails();

Inside poSuppliersDetails we have some values. Now I am sending this object to target activity:

Intent iPODetails = new Intent(ActivityOne.this, ActivityTwo.class);
iPODetails.putExtra("poSuppliersDetails", poSuppliersDetails);

How to get this in ACtivityTwo:

private SupplierDetails supplierDetails;
    supplierDetails =(SupplierDetails) getIntent().getSerializableExtra("poSuppliersDetails");

User · Answer

You could also write the object s data into temporary Strings and ints  and pass them to the activity  Of course that way  you get the data transported  but not the object itself   But if you just want to display them  and not use the object in another method or something like that  it should be enough  I did it the same way to just display data from one object in another activity   String fName temp     yourObject getFname    String lName temp     yourObject getLname    String age temp       yourObject getAge    String address temp   yourObject getAddress     Intent i   new Intent this  ToClass class   i putExtra  fname   fName temp   i putExtra  lname   lName temp   i putExtra  age   age temp   i putExtra  address   address temp    startActivity i     You could also pass them in directly instead of the temp ivars  but this way it s clearer  in my opinion  Additionally  you can set the temp ivars to null so that they get cleaned by the GarbageCollector sooner   Good luck   On a side note  override toString   instead of writing your own print method   As mentioned in the comments below  this is how you get your data back in another activity   String fName   getIntent   getExtras   getInt  fname

User · Answer

I am using parcelable to send data from one activity to another acivity  Here is my code that works fine in my project   public class Channel implements Serializable  Parcelable                    private static final long serialVersionUID   4861597073026532544L       private String cid      private String uniqueID      private String name      private String logo      private String thumb                    return The cid             public String getCid             return cid                         param cid            The cid to set             public void setCid String cid            this cid   cid                         return The uniqueID             public String getUniqueID             return uniqueID                         param uniqueID            The uniqueID to set             public void setUniqueID String uniqueID            this uniqueID   uniqueID                         return The name             public String getName             return name                         param name                   The name to set             public void setName String name            this name   name                         return the logo             public String getLogo             return logo                         param logo            The logo to set             public void setLogo String logo            this logo   logo                         return the thumb             public String getThumb             return thumb                         param thumb            The thumb to set             public void setThumb String thumb            this thumb   thumb              public Channel Parcel in            super            readFromParcel in              public static final Parcelable Creator lt Channel gt  CREATOR   new Parcelable Creator lt Channel gt              public Channel createFromParcel Parcel in                return new Channel in                      public Channel   newArray int size                 return new Channel size                         public void readFromParcel Parcel in            String   result   new String 5           in readStringArray result            this cid   result 0           this uniqueID   result 1           this name   result 2           this logo   result 3           this thumb   result 4              public int describeContents             return 0             public void writeToParcel Parcel dest  int flags             dest writeStringArray new String     this cid  this uniqueID                  this name  this logo  this thumb              In activityA use it like this   Bundle bundle   new Bundle    bundle putParcelableArrayList  channel   ArrayList lt Channel gt   channels   Intent intent   new Intent ActivityA this ActivityB class   intent putExtras bundle   startActivity intent     In ActivityB use it like this to get data   Bundle getBundle   this getIntent   getExtras    List lt Channel gt  channelsList   getBundle getParcelableArrayList  channel

User · Answer

Create two methods in your custom Class like this  public class Qabir        private int age      private String name       Qabir               Qabir int age String name           this age age  this name name                   method for sending object     public String toJSON            return   age     age     name      name                       method for get back original object     public void initilizeWithJSONString String jsonString            JSONObject json                  try               json  new JSONObject jsonString                age json getInt  age                name json getString  name              catch  JSONException e                e printStackTrace                         Now in your sender Activity do like this  Qabir q  new Qabir 22  KQ        Intent in new Intent this SubActivity class   in putExtra  obj   q toJSON     startActivity  in     And in your receiver Activity  Qabir q  new Qabir    q initilizeWithJSONString getIntent   getStringExtra  obj

User · Answer

I know that static is bad  but it seems that we re forced to use it here  The problem with parceables seriazables is that the two activities have duplicate instances of the same object   waste of memory and CPU   public class IntentMailBox       static Queue lt Object gt  content   new LinkedList lt Object gt            Calling activity  IntentMailBox content add level   Intent intent   new Intent LevelsActivity this  LevelActivity class   startActivity intent       Called activity  note that onCreate   and onResume   may be called multiple times when the system destroys and recreates activities   if  IntentMailBox content size   gt 0      level    Level  IntentMailBox content poll    else        Here you reload what you have saved in onPause      Another way is to declare a static field of the class that you want to pass in that very class  It will serve only for this purpose  Don t forget that it can be null in onCreate  because your app package has been unloaded from memory by system and reloaded later  Bearing in mind that you still need to handle activity lifecycle  you may want to write all the data straight to shared preferences  painful with complex data structures as it is

User · Answer

As mentioned in the comments  this answer breaks encapsulation and tightly couples components  which is very likely not what you want  The best solution is probably making your object Parcelable or Serializable  as other responses explain  Having said that  the solution solves the problem  So if you know what you are doing   Use a class with static fields   public class Globals       public static Customer customer   new Customer        Inside the activities you can use   Activity From   Globals customer   myCustomerFromActivity    Activity Target   myCustomerTo   Globals customer    It s an easy way to pass information for activities

User · Answer

Hello all I see a lot of good options but I was wondering why Binding hasn t been used      Passing a reference to an object just seems more efficient to me than serializing and desterilizing objects  but I have not done a deep dive to see if that is what is going on behind the scenes    Creating a Binder is simple enough     public class MyBinder extends Binder        private Object myObject       public MyBinder Object object            myObject   object             public Object getObject             return myObject             And creating the parcelable to use it isn t that bad ether   public class MyParcelable implements Parcelable        private Object myObject       public MyParcelable                public MyParcelable Parcel parcel            myObject     MyBinder parcel readStrongBinder    getObject               public void setObject Object object            myObject   object             public Object getObject             return myObject             public void writeToParcel Parcel parcel  int flags            parcel writeStrongBinder new MyBinder myObject               public int describeContents             return myObject    null   0   1             public static final Parcelable Creator lt MyParcelable gt  CREATOR   new Parcelable Creator lt MyParcelable gt               public MyParcelable createFromParcel Parcel parcel                return new MyParcelable parcel                      public MyParcelable   newArray int length                return new MyParcelable length                         This logic is really cool because you are actually passing a reference from activity to activity      I would advise checking for nulls and if the instanceof Binder is MyBinder    and to implement this you just     Send it off  Object myObject    some object   MyParcelable myParcelable   new MyParcelable    myParcelable setObject myObject    intent putExtra  MyParcelable   myParcelable     Get it back  myParcelable    MyParcelable  getIntent   getExtras   getParcelable  MyParcelable    myObject   myParcelable getObject      Heck someone could get all crazy and make this sucker a true generic

User · Answer

Using global static variables is not good software engineering practice   Converting an object s fields into primitive data types can be a hectic job   Using serializable is OK  but it s not performance-efficient on the Android platform   Parcelable is specifically designed for Android and you should use it  Here is a simple example  Passing custom objects between Android activities   You can generate Parcelable code for you class using this site

User · Answer

Android Activity objects can be destroyed and reconstituted  So  you will need to use another approach to look them - or any object they create    -  up  That is  you could pass as static class reference but then the object handle  Java calls these  quot references quot   as does SmallTalk  but they are not references in the sense of C or assembly  will be possibly invalid later because a  quot feature quot  of Android OE is any Activity can be annihilated and reconstituted later  The original question asked  quot How to pass object from one activity to another in Android quot  and nobody has answered that  For sure  you can serialized  Serializable  Parcelable  to from JSON  and pass a copy of the object s data and a new object having the same data could be created  but it will NOT have the same references handles   Also  many others mentioned you can store the reference in a static store  And that will work unless Android decides to onDestroy your Activity  So  to really solve the original question you would need a static lookup plus each object will update its reference when if it is recreated  E g  each Android Activity would relist itself if its onCreate is called  You can also see how some people use the task list to search out an Activity by name   system is temporarily destroying this instance of the activity to save space  getRunningTasks  the task list is effectively a specialized listing of the most recent object instance of each Activity   For reference   Stopped   quot The activity is completely obscured by another activity  the activity is now in the  quot background quot    A stopped activity is also still alive  the Activity object is retained in memory  it maintains all state and member information  but is not attached to the window manager   However  it is no longer visible to the user and it can be killed by the system when memory is needed elsewhere  quot  onDestroy  quot system is temporarily destroying this instance of the activity to save space  quot   So  the Message Bus is a workable solution  It basically  quot punts quot   Rather than try to have references to objects  then you re-architect your design to use MessagePassing instead of SequentialCode  Exponentially harder to debug  but it lets you ignore these sort of OperatingEnvironment understandings  Effectively  each object method access is inverted so the caller posts a Message and the object itself defines a handler for that message  Lots more code but can make it robust with the Android OE restrictions  If all you want is the top Activity  typical thing in Android apps due to  quot Context quot  being needed everywhere   then you can just have each Activity lists itself as  quot top quot  in the static global space whenever its onResume is called  Then your AlertDialog or whatever which needs a context can just grab it from there  Also  its a bit yucky to use a global but can simplifying passing a Context up and down everywhere and  for sure  when you use a MessageBus then IT IS global anyways

User · Answer

I had always wondered why this can t be as simple as calling into a method of the other activity  I recently wrote a utility library that makes it almost as simple as that  You can check it out here https   github com noxiouswinter gnlib android wiki gnlauncher     GNLauncher makes sending objects data to an Activity from another Activity etc as easy as calling a function in tha Activity with the required data as parameters  It introduces type safety and removes all the hastles of having to serialize  attaching to the intent using string keys and undoing the same at the other end   Usage  Define an interface with the methods you want to call on the Activity to launch   public interface IPayload       public void sayHello String name  int age       Implement the above interface on the Activity to launch into  Also notify GNLauncher when the activity is ready   public class Activity 1 extends Activity implements IPayload         Override     protected void onCreate Bundle savedInstanceState            super onCreate savedInstanceState             Notify GNLauncher when the Activity is ready           GNLauncher get   ping this               Override     public void sayHello String name  int age            Log d  gnlib test    Hello     name       nYour age is      age             In the other Activity  get a proxy to the above Activity and call any method with the desired parameters   public class Activity 2 extends Activity       public void onClick View v              IPayload GNLauncher get   getProxy this  IPayload class  Activity 1 class   sayHello name  age             The first activity will be launched and the method called into with the required parameters   Prerequisites  Please refer to https   github com noxiouswinter gnlib android wiki prerequisites for information on how to add the dependencies

User · Answer

Pass one activity to another   startActivity new Intent getBaseContext   GetActivity class  putExtra  passingkey   passingvalue       Get values   String myvalue  getIntent   getExtras  passingkey

User · Answer

This question is also discussed in another Stack Overflow question  Please have a look at a solution to Passing data through intent using Serializable  The main point is about using Bundle object which stores the necessary data inside Intent    Bundle bundle   new Bundle      bundle putSerializable key1  value1    bundle putSerializable key2  value2    bundle putSerializable key3  value3     intent putExtras bundle     To extract values    Bundle bundle   new Bundle      for  String key   bundle keySet       value   bundle getSerializable key         Advantage of Serializable is its simplicity  However  you should consider using Parcelable method if you need many data to be transferred  because Parcelable is specifically designed for Android and it is more efficient than Serializable  You can create Parcelable class using    an online tool - parcelabler a plugin for Android Studio - Android Parcelable code generator

User · Answer

Create your own class Customer as following   import import java io Serializable  public class Customer implements Serializable       private String name      private String city       public Customer                    public Customer String name  String city                this name  name          this city city            public String getName                  return name            public void setName String name                 this name   name            public String getCity                  return city            public void setCity String city                 this city  city             In your onCreate   method   Override protected void onCreate Bundle savedInstanceState         super onCreate savedInstanceState        setContentView R layout activity top        Customer cust new Customer        cust setName  abc        cust setCity  xyz         Intent intent new Intent abc this xyz class       intent putExtra  bundle  cust       startActivity intent        In xyz activity class you need to use the following code   Intent intent getIntent    Customer cust  Customer intent getSerializableExtra  bundle    textViewName setText cust getName     textViewCity setText cust getCity

User · Answer

It is impossible to serialize any type of object  For Example you can not serialize delegate methods or interfaces that carry code instead of data  So I have written a  Box  class you can use to pass any type of data without Serialization   1- for putting Data to Intent Use   Intent I   new Intent this  YourActivity class   CustomClass Date   new CustomClass    Box Add I   Name   Data     2- for retrieving Data from Intent   CustomClass Data   Box Get getIntent     Name      3- for removing data after use  add this method to your activity    Override protected void onDestroy         Box Remove getIntent         super onDestroy        4- and add this code to your project   package ir namirasoft Utility   import android content Intent   import java util HashMap  import java util Vector   public class Box          Number     private static int Number   1       public static int NextNumber             return Number                      private static String  Intent Identifier     Intent Identifier       private static HashMap lt Integer  Vector lt Integer gt  gt  DeleteList   new HashMap lt Integer  Vector lt Integer gt  gt         private static HashMap lt Integer  HashMap lt String  Object gt  gt  ObjectList   new HashMap lt Integer  HashMap lt String  Object gt  gt          public static int GetIntent Identifier Intent I            int Intent Identifier   I getIntExtra  Intent Identifier  0           if  Intent Identifier    0              I putExtra  Intent Identifier  Intent Identifier   NextNumber             return Intent Identifier             public static void Add Intent I  String Name  Object O            int Intent Identifier   GetIntent Identifier I           synchronized  ObjectList                if   ObjectList containsKey Intent Identifier                   ObjectList put Intent Identifier  new HashMap lt String  Object gt                  ObjectList get Intent Identifier  put Name  O                        public static  lt T gt  T Get Intent I  String Name            int Intent Identifier   GetIntent Identifier I           synchronized  DeleteList                DeleteList remove Intent Identifier                     return  T  ObjectList get Intent Identifier  get Name              public static void Remove final Intent I            final int Intent Identifier   GetIntent Identifier I           final int ThreadID   NextNumber            synchronized  DeleteList                if   DeleteList containsKey Intent Identifier                   DeleteList put Intent Identifier  new Vector lt Integer gt                  DeleteList get Intent Identifier  add ThreadID                     new Thread new Runnable                  Override             public void run                     try                       Thread sleep 60   1000                     catch  InterruptedException e                                      synchronized  DeleteList                        if  DeleteList containsKey Intent Identifier                           if  DeleteList get Intent Identifier  contains ThreadID                               synchronized  ObjectList                                    ObjectList remove Intent Identifier                                                                            start                 Box class is Thread-Safe

User · Answer

While calling an activity   Intent intent   new Intent fromClass this toClass class  putExtra  myCustomerObj  customerObj     In toClass java receive the activity by   Customer customerObjInToClass   getIntent   getExtras   getParcelable  myCustomerObj      Please make sure that customer class implements parcelable  public class Customer implements Parcelable        private String firstName  lastName  address      int age          all your getter and setter methods         public Customer Parcel in             readFromParcel  in               public static final Parcelable Creator CREATOR   new Parcelable Creator             public LeadData createFromParcel Parcel in                 return new Customer  in                       public Customer   newArray int size                return new Customer size                           Override     public void writeToParcel Parcel dest  int flags             dest writeString firstName           dest writeString lastName           dest writeString address           dest writeInt age              private void readFromParcel Parcel in              firstName   in  readString            lastName    in  readString            address     in  readString            age         in  readInt

User · Answer

Crete a class like bean class and implement the Serializable interface  Then we can pass it through the intent method  for example   intent putExtra  class   BeanClass     Then get it from the other activity  for example    BeanClass cb   intent getSerializableExtra  class

User · Answer

There are a couple of ways by which you can access variables or objects in other classes or Activity   A  Database  B  Shared preferences   C  Object serialization   D  A class which can hold common data can be named as Common Utilities  It depends on you   E  Passing data through Intents and Parcelable Interface   It depends upon your project needs   A  Database  SQLite is an open source database which is embedded into Android  SQLite supports standard relational database features like SQL syntax  transactions and prepared statements   Tutorials  B  Shared preferences  Suppose you want to store username  So there will now be two things  a key username  value value   How to store      Create object of SharedPreferences   SharedPreferences sharedPref   PreferenceManager getDefaultSharedPreferences this       Now get Editor  SharedPreferences Editor editor   sharedPref edit        Put your value  editor putString  userName    stackoverlow        Commits your edits  editor commit      Using putString    putBoolean    putInt    putFloat    and putLong   you can save your desired dtatype   How to fetch  SharedPreferences sharedPref   PreferenceManager getDefaultSharedPreferences this   String userName   sharedPref getString  userName    Not Available      http   developer android com reference android content SharedPreferences html  C  Object serialization  Object serlization is used if we want to save an object state to send it over a network or you can use it for your purpose also   Use Java beans and store in it as one of his fields and use getters and setter for that   JavaBeans are Java classes that have properties  Think of properties as private instance variables  Since they re private  the only way they can be accessed from outside of their class is through methods in the class  The methods that change a property s value are called setter methods  and the methods that retrieve a property s value are called getter methods   public class VariableStorage implements Serializable         private String inString       public String getInString             return inString             public void setInString String inString            this inString   inString            Set the variable in your mail method by using  VariableStorage variableStorage   new VariableStorage    variableStorage setInString inString     Then use object serialzation to serialize this object and in your other class deserialize this object   In serialization an object can be represented as a sequence of bytes that includes the object s data as well as information about the object s type and the types of data stored in the object   After a serialized object has been written into a file  it can be read from the file and deserialized  That is  the type information and bytes that represent the object and its data can be used to recreate the object in memory   If you want tutorial for this refer to    Serialization in Java  blog post  Get variable in other classes  Stack Overflow    D  CommonUtilities  You can make a class by yourself which can contain common data which you frequently need in your project   Sample  public class CommonUtilities        public static String className    CommonUtilities        E  Passing data through intents  Please refer the tutorial Android     Parcel data to pass between Activities using Parcelable classes for this option of passing data

User · Answer

Yeah  using a static object is by far the easiest way of doing this with custom non-serialisable objects

User · Answer

I made a singleton helper class that holds temporary objects   public class IntentHelper        private static IntentHelper  instance      private Hashtable lt String  Object gt   hash       private IntentHelper              hash   new Hashtable lt String  Object gt                private static IntentHelper getInstance             if  instance  null                 instance   new IntentHelper                      return  instance             public static void addObjectForKey Object object  String key            getInstance    hash put key  object              public static Object getObjectForKey String key            IntentHelper helper   getInstance            Object data   helper  hash get key           helper  hash remove key           helper   null          return data            Instead of putting your objects within Intent  use IntentHelper   IntentHelper addObjectForKey obj   key      Inside your new Activity  you can get the object   Object obj    Object  IntentHelper getObjectForKey  key      Bear in mind that once loaded  the object is removed to avoid unnecessary references

User · Answer

One option could be letting your custom class implement the Serializable interface and then you can pass object instances in the intent extra using the putExtra Serializable    variant of the Intent putExtra   method   Pseudocode     To pass  intent putExtra  MyClass   obj       To retrieve object in second Activity getIntent   getSerializableExtra  MyClass      Note  Make sure each nested class of your main custom class has implemented Serializable interface to avoid any serialization exceptions  For example    class MainClass implements Serializable        public MainClass           public static class ChildClass implements Serializable            public ChildClass

User · Answer

Above answers almost all correct but for those who doesn t undestand those answers Android has powerfull class Intent with help of it you share data between not only activity but another components of Android  broadcasr receiver  servises for content provide we use ContetnResolver class no Intent   In your activity you build intent  Intent intent   new Intent context SomeActivity class   intent putExtra  key  value   startActivity intent     In your receving activity you have  public class SomeActivity extends AppCompactActivity        public void onCreate                         SomeObject someObject   getIntent   getExtras   getParceable  key               You have to implement Parceable or Serializable interface on your object in order to share between activities  It is hard to implement Parcealbe  rather than Serializable interface on object that s why android has plugin especially for this Download it and use it

User · Answer

I found a simple  amp  elegant method    NO Parcelable NO Serializable NO Static Field No Event Bus   Method 1  Code for the first activity       final Object objSent   new Object        final Bundle bundle   new Bundle        bundle putBinder  object value   new ObjectWrapperForBinder objSent        startActivity new Intent this  SecondActivity class  putExtras bundle                Log d TAG   original object     objSent     Code for the second activity       final Object objReceived     ObjectWrapperForBinder getIntent   getExtras   getBinder  object value    getData        Log d TAG   received object     objReceived     you will find objSent  amp  objReceived have the same hashCode  so they are identical   But why can we pass a java object in this way   Actually  android binder will create global JNI reference for java object and release this global JNI reference when there are no reference for this java object  binder will save this global JNI reference in the Binder object    CAUTION  this method ONLY work unless the two activities run in the same process  otherwise throw ClassCastException at  ObjectWrapperForBinder getIntent   getExtras   getBinder  object value      class ObjectWrapperForBinder  defination  public class ObjectWrapperForBinder extends Binder        private final Object mData       public ObjectWrapperForBinder Object data            mData   data             public Object getData             return mData            Method 2   for the sender     use custom native method to add your java object to JNI global reference table via JNIEnv  NewGlobalRef  put the return integer  actually  JNIEnv  NewGlobalRef return jobject  which is a pointer  we can cast it to int safely  to your Intent via Intent  putExtra   for the receiver   get integer from    Intent via Intent  getInt   use custom native method to    restore your java object from    JNI global reference table  via JNIEnv  NewLocalRef  remove item from JNI global reference table via JNIEnv  DeleteGlobalRef      But Method 2 has a little but serious issue  if the receiver fail to restore the java object  for example  some exception happen before restore the java object  or the receiver Activity does not exist at all   then the java object will become an orphan or memory leak   Method 1  don t have this issue  because android binder will handle this exception  Method 3  To invoke the java object remotely  we will create a data contract interface to describe the java object  we will use the aidl file  IDataContract aidl  package com example objectwrapper  interface IDataContract       int func1 String arg1       int func2 String arg1       Code for the first activity      final IDataContract objSent   new IDataContract Stub               Override         public int func2 String arg1  throws RemoteException                  TODO Auto-generated method stub             Log d TAG   func2   arg1     arg1               return 102                      Override         public int func1 String arg1  throws RemoteException                  TODO Auto-generated method stub             Log d TAG   func1   arg1     arg1               return 101                       final Bundle bundle   new Bundle        bundle putBinder  object value   objSent asBinder         startActivity new Intent this  SecondActivity class  putExtras bundle        Log d TAG   original object     objSent     Code for the second activity   change the android process attribute in AndroidManifest xml to a non-empty process name to  make sure the second activity run in another process      final IDataContract objReceived   IDataContract Stub asInterface getIntent   getExtras   getBinder  object value         try           Log d TAG   received object     objReceived      func1       objReceived func1  test1        func2       objReceived func2  test2           catch  RemoteException e               TODO Auto-generated catch block         e printStackTrace            In this way  we can pass an interface between two activities even though they run in different process  and call the interface method remotely  Method 4  method 3 seem not simple enough because we must implement an aidl interface  If you just want to do simple task and the method return value is unnecessary  we can use android os Messenger  Code for the first activity  sender    public class MainActivity extends Activity       private static final String TAG    MainActivity        public static final int MSG OP1   1      public static final int MSG OP2   2       public static final String EXTRA MESSENGER    messenger        private final Handler mHandler   new Handler               Override         public void handleMessage Message msg                   TODO Auto-generated method stub             Log e TAG   handleMessage   msg     msg               switch  msg what                case MSG OP1                   break              case MSG OP2                  break               default                   break                            super handleMessage msg                          Override     protected void onCreate Bundle savedInstanceState            super onCreate savedInstanceState           setContentView R layout activity main            startActivity new Intent this  SecondActivity class  putExtra EXTRA MESSENGER  new Messenger mHandler               Code for the second activity   receiver     public class SecondActivity extends Activity         Override     protected void onCreate Bundle savedInstanceState            super onCreate savedInstanceState           setContentView R layout activity second            final Messenger messenger   getIntent   getParcelableExtra MainActivity EXTRA MESSENGER           try               messenger send Message obtain null  MainActivity MSG OP1  101  1001   10001                 messenger send Message obtain null  MainActivity MSG OP2  102  1002   10002               catch  RemoteException e                   TODO Auto-generated catch block             e printStackTrace                         All the Messenger send will execute in a Handler asynchronously and sequentially   Actually  android os Messenger is also an aidl interface  if you have the android source code  you can find a file named IMessenger aidl   package android os   import android os Message        hide    oneway interface IMessenger       void send in Message msg

User · Answer

In my experience there are three main solutions  each with their disadvantages and advantages    Implementing Parcelable Implementing Serializable Using a light-weight event bus library of some sort  for example  Greenrobot s EventBus or Square s Otto    Parcelable - fast and Android standard  but it has lots of boilerplate code and requires hard-coded strings for reference when pulling values out the intent  non-strongly typed    Serializable - close to zero boilerplate  but it is the slowest approach and also requires hard-coded strings when pulling values out the intent  non-strongly typed    Event Bus - zero boilerplate  fastest approach  and does not require hard-coded strings  but it does require an additional dependency  although usually lightweight   40 nbsp KB   I posted a very detailed comparison around these three approaches  including efficiency benchmarks

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Implement your class with Serializable  Let s suppose that this is your entity class   import java io Serializable    SuppressWarnings  serial     With this annotation we are going to hide compiler warnings public class Deneme implements Serializable        public Deneme double id  String name            this id   id          this name   name             public double getId             return id             public void setId double id            this id   id             public String getName             return this name             public void setName String name            this name   name             private double id      private String name      We are sending the object called dene from X activity to Y activity  Somewhere in X activity   Deneme dene   new Deneme 4  Mustafa    Intent i   new Intent this  Y class   i putExtra  sampleObject   dene   startActivity i     In Y activity we are getting the object   Intent i   getIntent    Deneme dene    Deneme i getSerializableExtra  sampleObject      That s it

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Use gson to convert your object to JSON and pass it through intent  In the new Activity convert the JSON to an object   In your build gradle  add this to your dependencies  implementation  com google code gson gson 2 8 4    In your Activity  convert the object to json-string   Gson gson   new Gson    String myJson   gson toJson vp   intent putExtra  myjson   myjson     In your receiving Activity  convert the json-string back to the original object   Gson gson   new Gson    YourObject ob   gson fromJson getIntent   getStringExtra  myjson    YourObject class     For Kotlin it s quite the same  Pass the data  val gson   Gson   val intent   Intent this  YourActivity  class java  intent putExtra  identifier   gson toJson your object   startActivity intent    Receive the data  val gson   Gson   val yourObject   gson fromJson lt YourObject gt  intent getStringExtra  identifier    YourObject  class java

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Pass object from one activity to another activity        1  source activity  Intent ii   new Intent examreport select this                      BarChartActivity class                ii putExtra  IntentExamResultDetail                        Serializable  your List lt ArraList lt String gt  gt  object here               startActivity ii      2  destination acitivity  List lt ArrayList lt String gt  gt  aa    List lt ArrayList lt String gt  gt   getIntent                getSerializableExtra  IntentExamResultDetail

User · Answer

I used to set object with Pacelable or Serializable to transfer  but whenever I add other variables to object model   I have to register it all  It s so nconvenient    It s super easy to transfer object between activities or fragments    Android DataCache

User · Answer

If you choose use the way Samuh describes  remember that only primitive values can be sent  That is  values that are parcable  So  if your object contains complex objects these will not follow  For example  variables like Bitmap  HashMap etc    These are tricky to pass by the intent   In general I would advice you to send only primitive datatypes as extras  like String  int  boolean etc  In your case it would be  String fname  String lname  int age  and String address   My opinion  More complex objects are better shared by implementing a ContentProvider  SDCard  etc  It s also possible to use a static variable  but this may fastly lead to error-prone code     But again  it s just my subjective opinion

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You can try to use that class  The limitation is that it can t be used outside of one process   One activity    final Object obj1   new Object     final Intent in   new Intent     in putExtra EXTRA TEST  new Sharable obj1      Other activity   final Sharable s   in getExtras   getParcelable EXTRA TEST   final Object obj2   s obj     public final class Sharable implements Parcelable        private Object mObject       public static final Parcelable Creator  lt  Sharable  gt  CREATOR   new Parcelable Creator  lt  Sharable  gt               public Sharable createFromParcel Parcel in                 return new Sharable  in                         Override         public Sharable   newArray int size                return new Sharable size                         public Sharable final Object obj            mObject   obj             public Sharable Parcel in             readFromParcel  in               Object obj             return mObject               Override     public int describeContents             return 0               Override     public void writeToParcel final Parcel out  int flags            final long val   SystemClock elapsedRealtime            out writeLong val           put val  mObject              private void readFromParcel final Parcel in             final long val   in  readLong            mObject   get val                         private static final HashMap  lt  Long  Object  gt  sSharableMap   new HashMap  lt  Long  Object  gt   3        synchronized private static void put long key  final Object obj            sSharableMap put key  obj              synchronized private static Object get long key            return sSharableMap remove key

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The best way is to have a class  call it Control  in your application that will hold a static variable of type  Customer   in your case   Initialize the variable in your Activity A   For example   Control Customer   CustomerClass    Then go to Activity B and fetch it from Control class  Don t forget to assign a null after using the variable  otherwise memory will be wasted

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public class MyClass implements Serializable      Here is your instance variable     Now you want to pass the object of this class in startActivity  Simply use this   Bundle b   new Bundle    b putSerializable  name   myClassObject   intent putExtras b     This works here because MyClass implements Serializable

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Start another activity from this activity and pass parameters via Bundle Object  Intent intent   new Intent getBaseContext    YourActivity class   intent putExtra  USER NAME    xyz gmail com    startActivity intent     Retrive data on another activity  YourActivity   String s   getIntent   getStringExtra  USER NAME      This is ok for simple kind of data type  But if u want to pass complex data in between activity  U need to serialize it first   Here we have Employee Model  class Employee      private String empId      private int age      print Double salary       getters        setters        You can use Gson lib provided by google to serialize the complex data  like this  String strEmp   new Gson   toJson emp   Intent intent   new Intent getBaseContext    YourActivity class   intent putExtra  EMP   strEmp   startActivity intent    Bundle bundle   getIntent   getExtras    String empStr   bundle getString  EMP                Gson gson   new Gson                Type type   new TypeToken lt Employee gt                    getType                Employee selectedEmp   gson fromJson empStr  type

[java] How to pass an object from one activity to another on Android

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