Use file sharing for cross-process communication in Android

I. Serialization of objects using serializable

Importjava.io.Serializable; Public  class User implements Serializable{    Private Static Final LongSerialversionuid =1LPrivateString username;PrivateString password; PublicStringGetUserName() {returnUsername } Public void Setusername(String username) { This. Username = Username; } PublicStringGetPassword() {returnPassword } Public void SetPassword(String password) { This. Password = password; }}

Serialversionuid is a UID that is written to a file when serializing an object, and is intended to prevent the addition or deletion of some fields or the modification of a type, resulting in a different version of the class and a recovery error when the object is being deserialized for recovery.
Serialization Process:

 user user = new  User ();        User.setusername ( "Zhangsan" );        User.setpassword ( "123" );        ObjectOutputStream os = null ; try  {OS = new  objectoutputstream (new  FILEOUTPU            TStream (Getfilesdir () + "Cache.txt" ));        Os.writeobject (user); } catch  (exception  e) {e.printstacktrace ()        ;            }finally  {try  {os.close ();            } catch  (IOException e) {e.printstacktrace (); }        }

Deserialization recovery process:

        isnull;        try {            isnew ObjectInputStream(new FileInputStream(getFilesDir()+"cache.txt"));            is.readObject();            tv.setText(newUser.getUsername());        catch (Exception e) {            e.printStackTrace();        finally{            try {                is.close();            catch (IOException e) {                e.printStackTrace();            }        }

Ii. using parcelable to serialize objects

ImportAndroid.os.Parcel;Importandroid.os.Parcelable; Public  class Student implements parcelable{    PrivateString username;PrivateString password; Public Student(){    } PublicStringGetUserName() {returnUsername } Public void Setusername(String username) { This. Username = Username; } PublicStringGetPassword() {returnPassword } Public void SetPassword(String password) { This. Password = password; }@Override     Public int describecontents() {return 0; }@Override     Public void Writetoparcel(Parcel dest,intFlags) {dest.writestring (username);    dest.writestring (password); } Public Static FinalParcelable.creator<student> Creator =NewCreator<student> () {@Override         PublicStudent[]NewArray(intSize) {return NewStudent[size]; }@Override         PublicStudentCreatefromparcel(Parcel Source) {return NewStudent (source); }    };Private Student(Parcel Source)        {username = source.readstring ();    Password = source.readstring (); }}

The Writetoparcel method is serialized and implemented by the write method of the parcel. The CREATOR is implemented by the parcel Read method, which enables deserialization.

This allows the Parcelable object to be passed through the intent,bundle.

Intent Intent = new Intent ();Intent. SetClass(mainactivity. this, secondactivity. Class);Bundle bundle = new Bundle ();Student Student = new Student ();Student. Setusername("Lisi");Student. SetPassword("456");Bundle. Putparcelable("Student", student);Intent. Putextras(bundle);StartActivity (Intent);

Serializable requires a large number of I/O operations and requires that the serialized object be stored on the device or network for transmission.
Parcelable is a serialized way of Android, which is cumbersome to use, but highly efficient.

Note: This object must be of type parcelable or serializable when there are objects in the Parcelable object.
The serialization method is as follows:

//user为Serializableprivate User user;dest.writeSerializable(user);user = (User) source.readSerializable();//teacher为Parcelableprivate0);//传递当前线程的上下文类加载器teacher = source.readParcelable(Thread.currentThread().getContextClassLoader());

Use file sharing for cross-process communication in Android