LiteStore

The Solution for Standalone Application Persistence

LiteStore is the solution for standalone application persistence. It allows you to persist your application-generated data on-device. No SQL knowledge is required; it's all Java-based.

Features

• Data persistence
• Data retrieval
• Indexed retrieval
• Data update
• Data deletion

How it works

LiteStore creates a .dat file with the name of your persisting class in the user application data directory. It then creates an index of this data to facilitate the retrieval of this data. By default, only the primary key of the storable classes is indexed, but you can also create custom indexes for improved and customized querying.

Code Examples

Preparing a class for storage

To store your application data, you must annotate the classes whose instances you want to be persisted with the @Storable and the primary key with @Key.

import annotations.dev.hangalito.litestore.Key;
import annotations.dev.hangalito.litestore.Storable;

@Storable
public class MyClass {
    @Key
    private int id;
    // other fields
}

Storing the storable instances

You start by initializing the datasource after its instantiation, then you pass the instance you want to be persisted. Note that you must initialize the datasource before calling other methods. By doing so, you ensure that the index is loaded and you have the correct data. Calling a persistence-related method (save, update, delete, findAll, and findBy) will result in DatasourceNotInitializedException

import storage.dev.hangalito.litestore.Datasource;

void main() {
    Datasource<MyClass, Integer> ds = new Datasource<>();
    ds.init(MyClass.class);

    MyClass mc = new MyClass();
    ds.save(mc);
}

Retrieving all data

You can retrieve all your data by calling the findAll method. This method will never return null, if there is no saved data it will simply return an empty list.

import storage.dev.hangalito.litestore.Datasource;

void main() {
    Datasource<MyClass, Integer> ds = new Datasource<>();
    ds.init(MyClass.class);
    List<MyClass> myClassList = ds.findAll();
}

Creating and Retrieving by Custom Fields

To query by custom fields, say, by name on a User storable class, you start by creating an index on this field

import storage.dev.hangalito.litestore.Datasource;

void main() {
    Datasource<User, Long> ds = new Datasource<>();
    ds.init(User.class);
    ds.createIndex("name");
}

then you can query in this field the following way

void main() {
    Datasource<User, Long> ds = new Datasource<>();
    ds.init(User.class);
    ds.findBy("name", "John");
}   

Updating Data

LiteStore also lets you update your saved instances. You can do it as shown below

import storage.dev.hangalito.litestore.Datasource;

void main() {
    Datasource<User, Long> ds = new Datasource<>();
    ds.init(User.class);

    User user = new User();
    user.setName("John");
    ds.save(user);

    user.setName("Dee");
    ds.update(user.getId(), user);
}

Deleting Data

You can delete data simply by calling the delete method in the Datasource passing the instance you want to delete.

import storage.dev.hangalito.litestore.Datasource;

void main() {
    Datasource<User, Long> ds = new Datasource<>();
    ds.init(User.class);

    ds.findByIndex(100L).ifPresent(user -> ds.delete(user));
}

This code snippet retrieves the user with ID of 100 and then deletes it from the datasource.