kotlin uses Parcelize annotations to simplify Parcelable writing

Posted by dennismcdougall on Wed, 15 Jul 2020 16:22:56 +0200

kotlin uses Parcelize annotations to simplify Parcelable writing

Parcelize Note

kotlin added support for parcelable at version 1.1.4

The Android extension now includes an automated generator that implements Parcelable.The generator automatically creates the writeToParcel ()/ createFromParcel () method by declaring the serialized properties in the main constructor and adding a @Parcelize comment

Demand Environment

Kotlin version 1.1.4 or higher

Start using

stayBuild.gradleAdd support in

apply plugin: 'kotlin-android-extensions'
....
androidExtensions {
    experimental = true
}

Entity Class

Student.kt

@Parcelize
data class Student(val id: String, val name: String, val grade: String) : Parcelable

Comparing Java entity classes

Student.java

public class Student implements Parcelable{
        private String id;
        private String name;
        private String grade;

        // Constructor
        public Student(String id, String name, String grade){
            this.id = id;
            this.name = name;
            this.grade = grade;
       }
       // Getter and setter methods
       .........
       .........

       // Parcelling part
       public Student(Parcel in){
           String[] data = new String[3];

           in.readStringArray(data);
           // the order needs to be the same as in writeToParcel() method
           this.id = data[0];
           this.name = data[1];
           this.grade = data[2];
       }

       @Оverride
       public int describeContents(){
           return 0;
       }

       @Override
       public void writeToParcel(Parcel dest, int flags) {
           dest.writeStringArray(new String[] {this.id,
                                               this.name,
                                               this.grade});
       }
       public static final Parcelable.Creator CREATOR = new Parcelable.Creator() {
           public Student createFromParcel(Parcel in) {
               return new Student(in); 
           }

           public Student[] newArray(int size) {
               return new Student[size];
           }
       };
   }