Getting Error while using Generic Dao in room with java

Question

when I try to use Generic Dao in android Room I get this Erro :

Cannot use unbound generics in query methods. It must be bound to a type through base Dao class.

import android.arch.lifecycle.LiveData;
import android.arch.persistence.room.Dao;
import android.arch.persistence.room.Delete;
import android.arch.persistence.room.Insert;
import android.arch.persistence.room.RawQuery;
import android.arch.persistence.room.Update;

import java.util.List;

@Dao
public interface BaseDaoAccess<T> {
    @Insert
    Long Insert(T entity);

    @Update
    void Update(T entity);
    @Delete
    void Delete(T entity);

    @RawQuery
    LiveData<List<T>> RowQuery(String query);

}

Meaning that your T type must be declared at compile time otherwise your DAO won't get generated. — Jeel Vankhede
– Jeel Vankhede, Commented May 11, 2019 at 4:48

chrylis -cautiouslyoptimistic- · Accepted Answer · 2019-05-11 05:51:43Z

1

Due to type erasure, Java can't tell at runtime what T you mean. You can provide this information by creating a subtype that has the T bound to a specific type, such as this:

public interface CarDao extends BaseDaoAccess<Car> { }

answered May 11, 2019 at 5:51

chrylis -cautiouslyoptimistic-

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