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I have generic problem,

I have LiveData<List<User>>, object User implement IEntity.

How to cast LiveData<List<User>> to LiveData<List<IEntity>>?

  package cz.roomlivedata.entity;
  import  android.arch.persistence.room.Entity;
  import android.arch.persistence.room.Index; 
  import android.arch.persistence.room.PrimaryKey;

  @Entity(indices = {@Index(value = "id", unique = true)}) 
  public class User implements IEntity {

  @PrimaryKey(autoGenerate = true) public int id;

  private String name;

  private String name; public User(String name) { this.name = name; } 

  public String getName() { return name; } 

  public void setName(String name) { this.name = name; } 
}

code

Radesh
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motorcb
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  • add User class code – Radesh Nov 11 '18 at 10:21
  • You say that "User *implements* IEntity" not "... *extends* IEntitiy". But without the latter, you can't add anything from one List to the other – Bö macht Blau Nov 11 '18 at 14:34
  • @Radesh `
    package cz.roomlivedata.entity;

import android.arch.persistence.room.Entity;
import android.arch.persistence.room.Index;
import android.arch.persistence.room.PrimaryKey;

@Entity(indices = {@Index(value = "id", unique = true)})
public class User implements IEntity {

    @PrimaryKey(autoGenerate = true)
    public int id;

    private String name;

    public User(String name) {
        this.name = name;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }
}
    `     – motorcb Nov 11 '18 at 18:07
  • @motorcb did your problem solved? – Radesh Nov 17 '18 at 14:22
  • This is a good question sadly with no good answer – Richard Muvirimi Oct 24 '20 at 16:16

1 Answers1

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This is how I removed while using kotlin.

abstract class X

class Y: X()

fun getValues(): MutableLiveData<out List<X>> {
    return MutableLiveData<List<Y>>()
}

out keyword helped me. So basically what in and out keyword does have to be done in java manually.

niketshah09
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