Android Difference between Parcelable and Serializable

Question

Why does Android provide 2 interfaces for serializing objects  Do Serializable objects interopt with Android Binder and AIDL files

User · Answer

There is some performance issue regarding to marshaling and unmarshaling. Parcelable is twice faster than Serializable.

Please go through the following link:

http://www.3pillarglobal.com/insights/parcelable-vs-java-serialization-in-android-app-development

User · Answer

Parcelable is sort of a standard in Android development  But not because of speed Parcelable is recommended approach for data transfers  But if you use serializable correctly as shown in this repo  you will see that serializable is sometimes even faster then parcelable  Or at least timings are comparable  Is Parcelable faster then Serializable  No  if serialization is done right   Usual Java serialization on an average Android device  if done right    is about 3 6 times faster than Parcelable for writes and about 1 6 times faster for reads  Also it proves that Java Serialization  if done right  is fast storage mechanism that gives acceptable results even with relatively large object graphs of 11000 objects with 10 fields each    The sidenote is that usually everybody who blindly states that  quot Parcelable is mush faster quot  compares it to default automatic serialization  which uses much reflection inside  This is unfair comparison  because Parcelable uses manual  and very complicated  procedure of writing data to the stream  What is usually not mentioned is that standard Java Serializable according to the docs can also be done in a manual way  using writeObject   and readObject   methods  For more info see JavaDocs  This is how it should be done for the best performance   So  if serializable is faster and easier to implement  why android has parcelable at all  The reason is native code  Parcelable is created not just for interprocess communication  It also can be used for intercode communication  You can send and recieve objects from C   native layer  That s it  What should you choose  Both will work good  But I think that Parcelable is better choice since it is recommended by google and as you can see from this thread is much more appreciated

User · Answer

In Android we cannot just pass objects to activities  To do this the objects must either implement Serializable or Parcelable interface   Serializable  Serializable is a standard Java interface  You can just implement Serializable interface and add override methods  The problem with this approach is that reflection is used and it is a slow process  This method creates a lot of temporary objects and causes quite a bit of garbage collection  However  Serializable interface is easier to implement   Look at the example below  Serializable       MyObjects Serializable class  import java io Serializable  import java util ArrayList  import java util TreeMap   import android os Parcel  import android os Parcelable   public class MyObjects implements Serializable        private String name      private int age      public ArrayList lt String gt  address       public MyObjects String name  int age  ArrayList lt String gt  address            super            this name   name          this age   age          this address   address             public ArrayList lt String gt  getAddress             if    address    null               return address          else             return new ArrayList lt String gt                public String getName             return name             public String getAge             return age                 MyObjects instance MyObjects mObjects   new MyObjects  name    age    Address array here        Passing MyObjects instance via intent Intent mIntent   new Intent FromActivity this  ToActivity class   mIntent putExtra  UniqueKey   mObjects   startActivity mIntent          Getting MyObjects instance Intent mIntent   getIntent    MyObjects workorder    MyObjects     mIntent getSerializableExtra  UniqueKey      Parcelable  Parcelable process is much faster than Serializable  One of the reasons for this is that we are being explicit about the serialization process instead of using reflection to infer it  It also stands to reason that the code has been heavily optimized for this purpose   Look at the example below  Parcelable       MyObjects Parcelable class  import java util ArrayList   import android os Parcel  import android os Parcelable   public class MyObjects implements Parcelable        private int age      private String name      private ArrayList lt String gt  address       public MyObjects String name  int age  ArrayList lt String gt  address            this name   name          this age   age          this address   address             public MyObjects Parcel source            age   source readInt            name   source readString            address   source createStringArrayList                Override     public int describeContents             return 0              Override     public void writeToParcel Parcel dest  int flags            dest writeInt age           dest writeString name           dest writeStringList address              public int getAge             return age             public String getName             return name             public ArrayList lt String gt  getAddress             if    address    null               return address          else             return new ArrayList lt String gt                public static final Creator lt MyObjects gt  CREATOR   new Creator lt MyObjects gt               Override         public MyObjects   newArray int size                return new MyObjects size                       Override         public MyObjects createFromParcel Parcel source                return new MyObjects source                             MyObjects instance MyObjects mObjects   new MyObjects  name    age    Address array here        Passing MyOjects instance Intent mIntent   new Intent FromActivity this  ToActivity class   mIntent putExtra  UniqueKey   mObjects   startActivity mIntent          Getting MyObjects instance Intent mIntent   getIntent    MyObjects workorder    MyObjects  mIntent getParcelableExtra  UniqueKey      You can pass ArrayList of Parcelable objects as below      Array of MyObjects ArrayList lt MyObjects gt  mUsers      Passing MyOjects instance Intent mIntent   new Intent FromActivity this  ToActivity class   mIntent putParcelableArrayListExtra  UniqueKey   mUsers   startActivity mIntent          Getting MyObjects instance Intent mIntent   getIntent    ArrayList lt MyObjects gt  mUsers   mIntent getParcelableArrayList  UniqueKey      Conclusion   Parcelable is faster than Serializable interface Parcelable interface takes more time to implement compared to Serializable interface Serializable interface is easier to implement  Serializable interface creates a lot of temporary objects and causes quite a bit of garbage collection Parcelable array can be passed via Intent in android

User · Answer

Implementation of parcelable can be faster if you use paracelable plugin in android studio  search for Android Parcelable code generator

User · Answer

Serializable  Serializable is a markable interface or we can call as an empty interface  It doesn   t have any pre-implemented methods  Serializable is going to convert an object to byte stream  So the user can pass the data between one activity to another activity  The main advantage of serializable is the creation and passing data is very easy but it is a slow process compare to parcelable   Parcelable  Parcel able is faster than serializable  Parcel able is going to convert object to byte stream and pass the data between two activities  Writing parcel able code is little bit complex compare to serialization  It doesn   t create more temp objects while passing the data between two activities

User · Answer

In Parcelable  developers write custom code for marshalling and unmarshalling so it creates fewer garbage objects in comparison to Serialization  The performance of Parcelable over Serialization dramatically improves  around two times faster   because of this custom implementation  Serializable is a marker interface  which implies that user cannot marshal the data according to their requirements  In Serialization  a marshaling operation is performed on a Java Virtual Machine  JVM  using the Java reflection API  This helps identify the Java object s member and behavior  but also ends up creating a lot of garbage objects  Due to this  the Serialization process is slow in comparison to Parcelable  Edit  What is the meaning of marshalling and unmarshalling  In few words   quot marshalling quot  refers to the process of converting the data or the objects into a byte-stream  and  quot unmarshalling quot  is the reverse process of converting the byte-stream back to their original data or object  The conversion is achieved through  quot serialization quot   http   www jguru com faq view jsp EID 560072

User · Answer

Parcelable much faster than serializable with Binder  because serializable use reflection and cause many GC  Parcelable is design to optimize to pass object    Here s link to reference   http   www developerphil com parcelable-vs-serializable

User · Answer

you can use the serializable objects in the intents but at the time of making serialize a Parcelable object it can give a serious exception like NotSerializableException  Is it not recommended using serializable with  Parcelable   So it is better to extends Parcelable with the  object that you want to use with bundle and intents  As this Parcelable is android specific so it doesn t have any side effects

User · Answer

The Serializable interface can be used the same way as the Parcelable one  resulting in  not much  better performances  Just overwrite those two methods to handle manual marshalling and unmarshalling process   private void writeObject java io ObjectOutputStream out      throws IOException private void readObject java io ObjectInputStream in      throws IOException  ClassNotFoundException   Still  it seems to me that when developing native Android  using the Android api is the way to go   See     https   bitbucket org afrishman androidserializationtest  https   docs oracle com javase 7 docs api java io Serializable html

User · Answer

If you want to be a good citizen  take the extra time to implement   Parcelable since it will perform 10 times faster and use less   resources       However  in most cases  the slowness of Serializable won   t be   noticeable  Feel free to use it  but  remember that serialization is   an expensive operation so keep it to a minimum       If you are trying to pass a list with thousands of serialized objects    it is possible that the whole process will take more than a second  It   can make transitions or rotation from portrait to lanscape feel very   sluggish    Source to this point  http   www developerphil com parcelable-vs-serializable

User · Answer

1  Serializable   see http   docs oracle com javase 7 docs api java io Serializable html  Interface of what    is a standard Java interface   Speed   slower than Parcelable   2  Parcelable   see http   developer android com reference android os Parcelable html  Interface of what    is android os interface   which means Google developped Parcelable for better performance on android    Speed   faster   because it is optimized for usage on android development      In Conclusion  Be aware that Serializable is a standard Java interface  and Parcelable is for Android Development

User · Answer

Parcelable vs Serializable I refer these two   For Java and Kotlin  1  Java  Serializable  the Simplicity     What is Serializable       Serializable is a standard Java interface  It is not a part of the   Android SDK  Its simplicity is its beauty  Just by implementing this   interface your POJO will be ready to jump from one Activity to   another    public class TestModel implements Serializable    String name   public TestModel String name        this name   name     public String getName         return name     public void setName String name        this name   name         The beauty of serializable is that you only need to implement the    Serializable interface on a class and its children  It is a marker    interface  meaning that there is no method to implement  Java will    simply do its best effort to serialize it efficiently  The problem with this approach is that reflection is used and it is a    slow process  This mechanism also tends to create a lot of temporary objects and cause quite a bit of garbage collection    Parcelable  The Speed     What is Parcelable       Parcelable is another interface  Despite its rival  Serializable in   case you forgot   it is a part of the Android SDK  Now  Parcelable was   specifically designed in such a way that there is no reflection when   using it  That is because we are being really explicit for the   serialization process    public class TestModel implements Parcelable     String name   public TestModel String name  String id        this name   name     protected TestModel Parcel in        this name   in readString         public String getName         return name     public void setName String name        this name   name      Override public int describeContents         return 0      Override public void writeToParcel Parcel dest  int flags        dest writeString this name       public static final Parcelable Creator lt TestModel gt  CREATOR   new Parcelable Creator lt TestModel gt           Override     public TestModel createFromParcel Parcel source            return new TestModel source               Override     public TestModel   newArray int size            return new TestModel size                Now  The winner is    The results of the tests conducted by Philippe Breault show that Parcelable is more than 10x faster than Serializable  Some other Google engineers stand behind this statement as well      According to them  the default Serializable approach is slower than   Parcelable  And here we have an agreement between the two parties    BUT  it is unfair to compare these two at all  Because with Parcelable   we are actually writing custom code  Code specifically created for   that one POJO  Thus  no garbage is created and the results are better    But with the default Serializable approach  we rely on the automatic   serialization process of Java  The process is apparently not custom at   all and creates lots of garbage  Thus  the worse results    Stop Stop      Before making decision     Now  there is another approach  The whole automatic process behind Serializable can be replaced by custom code which uses writeObject    amp    readObject   methods  These methods are specific  If we want to rely   on the Serializable approach in combination with custom serialization   behavior  then we must include these two methods with the same exact   signature as the one below     private void writeObject java io ObjectOutputStream out   throws IOException    private void readObject java io ObjectInputStream in       throws IOException  ClassNotFoundException    private void readObjectNoData        throws ObjectStreamException    And now a comparison between Parcelable and custom Serializable seems fair  The results may be surprising  The custom Serializable approach is more than 3x faster for writes and 1 6x faster for reads than Parcelable   Edited -----  2  Kotlinx Serialization  Kotlinx Serialization Library   For Kotlin serialization need to add below dependency and plugin  implementation  org jetbrains kotlinx kotlinx-serialization-runtime 0 9 1   apply plugin   kotlinx-serialization    Your build gradle file   apply plugin   com android application   apply plugin   kotlin-android   apply plugin   kotlin-android-extensions  apply plugin   kotlinx-serialization   android       compileSdkVersion 28     defaultConfig           applicationId  com example smile kotlinxretrosample          minSdkVersion 16         targetSdkVersion 28         versionCode 1         versionName  1 0          testInstrumentationRunner  android support test runner AndroidJUnitRunner            buildTypes           release               minifyEnabled false             proguardFiles getDefaultProguardFile  proguard-android txt     proguard-rules pro                     dependencies       implementation fileTree dir   libs   include      jar        implementation  org jetbrains kotlin kotlin-stdlib-jdk7  kotlin version      implementation  org jetbrains kotlinx kotlinx-serialization-runtime 0 9 1      implementation  com android support appcompat-v7 28 0 0      implementation  com android support constraint constraint-layout 1 1 3      implementation  com android support design 28 0 0      implementation  com squareup retrofit2 retrofit 2 5 0      implementation  com squareup okhttp3 okhttp 3 12 0      testImplementation  junit junit 4 12      androidTestImplementation  com android support test runner 1 0 2      androidTestImplementation  com android support test espresso espresso-core 3 0 2      Serializing is done quite easily  you need to annotate the intended class with the  Serializable annotation as below  import kotlinx serialization Serializable  Serializable class Field       var count  Int   0     var name  String          Two more annotations to note are transient and optional  Using transient will have the serializer ignore that field and using optional will allow the serializer not to break if a field is missing  but at the same time a default value will need to be provided    Optional var isOptional  Boolean   false  Transient var isTransient  Boolean   false   Note  This can as well work with data classes      Now to actually use this in action let   s take an example of how to   convert a JSON to object and back    fun toObject stringValue  String   Field           return JSON parse Field serializer    stringValue             fun toJson field  Field   String             Notice we call a serializer method which is autogenerated from our class            once we have added the annotation to it         return JSON stringify Field serializer    field          For more

User · Answer

Serializable is a standard Java interface   You simply mark a class Serializable by implementing the interface  and Java will automatically serialize it in certain situations     Parcelable is an Android specific interface where you implement the serialization yourself   It was created to be far more efficient that Serializable  and to get around some problems with the default Java serialization scheme     I believe that Binder and AIDL work with Parcelable objects     However  you can use Serializable objects in Intents

User · Answer

I am late in answer  but posting with hope that it will help others   In terms of Speed  Parcelable  gt  Serializable  But  Custom Serializable is exception  It is almost in range of Parcelable or even more faster   Reference   https   www geeksforgeeks org customized-serialization-and-deserialization-in-java   Example     Custom Class to be serialized  class MySerialized implements Serializable         String deviceAddress    MyAndroid-04         transient String token    AABCDS      sensitive information which I do not want to serialize      private void writeObject ObjectOutputStream oos  throws Exception           oos defaultWriteObject            oos writeObject  111111    token      Encrypted token to be serialized            private void readObject ObjectInputStream ois  throws Exception           ois defaultReadObject             token     String  ois readObject    subString 6       Decrypting token

User · Answer

I m actually going to be the one guy advocating for the Serializable  The speed difference is not so drastic any more since the devices are far better than several years ago and also there are other  more subtle differences  See my blog post on the issue for more info

[android] Android: Difference between Parcelable and Serializable?

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