Getting started

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Gradle dependency:

repositories {
	jcenter()
}
    
dependencies {
	compile 'com.github.andreyrage:leftdb:1.5'
}

Getting started

1. Create helper:

public class DbHelper extends LeftDBUtils {
	private static volatile DbHelper sInstance;

	private DbHelper() {
		...
	}

	public static DbHelper getInstance(Context context) {
		DbHelper localInstance = sInstance;
		if (localInstance == null) {
			synchronized (DbHelper.class) {
				localInstance = sInstance;
				if (localInstance == null) {
					sInstance = localInstance = new DbHelper();
					localInstance.setDBContext(context, "sample.sqlite", 1);
				}
			}
		}
		return localInstance;
	}
    
	@Override
	public void onCreate(SQLiteDatabase db) {
		super.onCreate(db);
		createTable(db, SimpleEntity.class);
	}
    
    ...
}

Also need override serializeObject(Object object) and deserializeObject(String string, Class tClass, final Type genericType). In these methods need realize serialization object to string and deserialization from string to object if you want use annotation @ColumnDAO.

For example you can do it with gson:

	private final Gson mGson = new Gson();

	...

	@Override
	protected String serializeObject(Object object) {
		return mGson.toJson(object);
	}

	@Override
	protected <T> T deserializeObject(String string, Class<T> tClass, final Type genericType) {
		return mGson.fromJson(string, genericType);
	}

or with jackson:

	private final ObjectMapper mMapper = new ObjectMapper()
		.configure(DeserializationConfig.Feature.FAIL_ON_UNKNOWN_PROPERTIES, false);

	...

	@Override
	protected String serializeObject(Object object) {
		try {
			return mMapper.writeValueAsString(object);
		} catch (IOException e) {
			e.printStackTrace();
		}
		return null;
	}

	@Override
	protected <T> T deserializeObject(String string, Class<T> tClass, final Type genericType) {
		try {
			return mMapper.readValue(string, new TypeReference<Object>() {
				@Override public Type getType() {
					return genericType;
				}
			});
		} catch (IOException e) {
			e.printStackTrace();
		}
		return null;
	}

2. Create entity with default constructor:

public class SimpleEntity {

	@ColumnAutoInc private Long id;
	@ColumnName("name") private String entityName;
	@ColumnDAO private Properties properties;

	public SimpleEntity() {
	}
    
	...
}

More for creating entities read here.

3. Now you can save and restore objects from database.

For example:

DbHelper dbHelper = DbHelper.getInstance(this);

SimpleEntity simpleEntity = new SimpleEntity();

dbHelper.add(simpleEntity); //save in the database

List<SimpleEntity> entities 
    = dbHelper.getAll(SimpleEntity.class); //get all SimpleEntity objects from database
  
dbHelper.delete(simpleEntity); //delete object from database

To execute in not UI thread you can use AsyncCall:

AsyncCall.make(new AsyncCall.Call<List<SimpleEntity>>() {
	@Override
	public List<SimpleEntity> call() {
		return dbHelper.getAll(SimpleEntity.class)
	}
}, new AsyncCall.Do<List<SimpleEntity>>() {
	@Override
	public void doNext(List<SimpleEntity> simpleEntities) {
		// returned result to UI thread
	}
}).call();