Part 2 – Entity – Coding in Flow

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In part 2 of the Architecture Components tutorial, we will set up a new Android Studio project, add the Room and Lifecycle dependencies and then create our Note class.
By annotating this Java class with @Entity, we can let room generate all the necessary code to create an SQLite table for this object, as well as columns for all it’s fields. With @PrimaryKey and autoGenerate = true, we can turn an integer member variable into an autoincrementing primary key, which we can use to uniquely identify each row in the table. In the past we would have to do all of this in an SQLiteOpenHelper with plain SQL statements.
Lastly we create a constructor, getters and setters and then Room takes care of creating all the boilerplate code at runtime. We can also specify the tableName if it should be different than the class name.
There are some more annotations and settings, like @Ignore and @ColumnInfo, which you can learn more about in the documentation below.

AndroidX refactoring table:
developer.android.com/topic/libraries/support-library/refactor

Entity documentation:
developer.android.com/training/data-storage/room/defining-data

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Links & DependenciesNote.java

“Adding Components” page with dependencies & instructions:

developer.android.com/topic/libraries/architecture/adding-components

CardView & Design Support Library:

developer.android.com/topic/libraries/support-library/packages#v7-cardview

developer.android.com/topic/libraries/support-library/packages#design

package com.codinginflow.architectureexample;

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

@Entity(tableName = "note_table")
public class Note {

    @PrimaryKey(autoGenerate = true)
    private int id;

    private String title;

    private String description;

    private int priority;

    public Note(String title, String description, int priority) {
        this.title = title;
        this.description = description;
        this.priority = priority;
    }

    public void setId(int id) {
        this.id = id;
    }

    public int getId() {
        return id;
    }

    public String getTitle() {
        return title;
    }

    public String getDescription() {
        return description;
    }

    public int getPriority() {
        return priority;
    }
}