DataManager Library

A simple, efficient, and flexible data management library for Java and Android. Easily store, retrieve, and manipulate data using JSON serialization with support for type safety, pagination, and file-based persistence.

Features

• JSON Serialization/Deserialization: Easily convert objects to and from JSON format.

• File-based Data Storage: Store objects, strings, integers, booleans, lists, and more in local storage.

• Batch Data Handling: Efficiently save and load lists in batches to optimize memory usage.

• On Data Change Listener: Listen to changes in data to update your app in real time.

• Type-Safe Operations: Work with strongly-typed objects and use generics for flexibility.

• Customizable Converter: NEW in version 2.8! You can choose from the following built-in converters:

  • GsonConverter: Uses the Google Gson library for serialization and deserialization.

  You can also create your own converter by implementing the DataManager.Converter interface, allowing for even greater flexibility in handling data.

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Installation

To include this library in your project, simply clone this repository and build the project, or you can manually add the source code to your project.

Follow these steps to integrate the DataManager library into your project:

Step 1: Add the JitPack Repository

Add the JitPack repository to your root settings.gradle file:

dependencyResolutionManagement {
    repositoriesMode.set(RepositoriesMode.FAIL_ON_PROJECT_REPOS)
    repositories {
        mavenCentral()
        maven { url 'https://jitpack.io' }
    }
}

Step 2: Add the Dependency

Add the following dependency to your module-level build.gradle file:

implementation 'com.github.Jumman04:DataManager:3.0'

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Usage

1. Initializing the DataManager

You can initialize the DataManager with a custom converter:

DataManager dataManager = DataManagerFactory.create(getFilesDir(), new GsonConverter());

2. Storing Data

Store simple data types or complex objects:

dataManager.putString("user_name","John Doe");
dataManager.

putInt("user_age",30);

Store a list of objects:

List<String> fruits = Arrays.asList("Apple", "Banana", "Cherry");
dataManager.

putList("fruits",fruits);

3. Retrieving Data

Retrieve data with a specified key:

String userName = dataManager.getString("user_name", "Default Name");
int userAge = dataManager.getInt("user_age", 0);

Retrieve a list of data:

// Retrieve the full list of fruits (not recommended for very large datasets)
List<String> fruitsFull = dataManager.getFullList("fruits", String.class);

// Retrieve a paginated list of fruits (page 1)
PaginatedData<String> fruitsPage = dataManager.getPagedList("fruits", String.class, 1);

4. Data Change Listener

You can register a listener to detect when data changes:

dataManager.addDataObserver(new DataObserver() {
    @Override
    public void onDataChange (String key){
        // Handle data change for the specific key
    }

    @Override
    public void onError (Throwable error){
        // Handle error if necessary
        System.err.println("Error occurred for key '" + key + "': " + error.getMessage());
    }
});

5. Creating a Custom Converter

To create your own converter, implement the DataManager.Converter interface as follows:

public class MyCustomConverter implements DataManager.Converter {
    @Override
    public <T> String toJson(T data) {
        return // Implement serialization logic
    }

    @Override
    public <T> T fromJson(String json, Type typeOfT) {
        return // Implement deserialization logic
    }

    @Override
    public <T> T fromReader(Reader json, Type typeOfT) {
        return // Implement deserialization logic from a Reader
    }
}

You can then use your custom converter when initializing the DataManager:

DataManager dataManager = DataManagerFactory.create(getFilesDir(), new MyCustomConverter());

Methods Overview

Return Type	Method Name	Description
String	getRawString(String key)	Retrieves the raw JSON string associated with the key.
<T>	getObject(String key, Type type)	Retrieves an object of the specified type.
<T> List<T>	getFullList(String key, Type type)	Retrieves the full list of objects (⚠️ not recommended for large datasets).
<T>	PaginatedData<T> getPagedList(String key, Type type, int page)	Retrieves a paginated subset of the list.
String	getString(String key)	Retrieves a String value or null if not found.
String	getString(String key, String defValue)	Retrieves a String value with a fallback default.
int	getInt(String key)	Retrieves an int value or 0 if not found.
int	getInt(String key, int defValue)	Retrieves an int value with a fallback default.
long	getLong(String key)	Retrieves a long value or 0L if not found.
long	getLong(String key, long defValue)	Retrieves a long value with a fallback default.
float	getFloat(String key)	Retrieves a float value or 0.0f if not found.
float	getFloat(String key, float defValue)	Retrieves a float value with a fallback default.
boolean	getBoolean(String key)	Retrieves a boolean value or false if not found.
boolean	getBoolean(String key, boolean defValue)	Retrieves a boolean value with a fallback default.
<T>	fromJson(String value, Type typeOfT)	Converts a JSON string to an object of the specified type.
<T>	fromReader(Reader json, Type typeOfT)	Converts JSON from a Reader to an object of the specified type.
String	toJson(Object object)	Converts an object to a JSON string.
Type	getParameterized(Type rawType, Type... typeArguments)	Constructs a parameterized generic type.
void	saveString(String key, String value)	Saves a String value.
void	saveInt(String key, int value)	Saves an int value.
void	saveLong(String key, long value)	Saves a long value.
void	saveFloat(String key, float value)	Saves a float value.
void	saveBoolean(String key, boolean value)	Saves a boolean value.
void	saveObject(String key, Object value)	Saves an object.
<E>	saveList(String key, List<E> value)	Saves a full list.
<E>	saveList(String key, List<E> value, int maxArraySize)	Saves a list with a maximum size (for paging).
void	appendToList(String key, Object element)	Appends an element to the end of the list.
void	appendToList(String key, Object element, boolean removeDuplicate)	Appends an element, optionally removing duplicates.
void	appendToList(String key, int index, Object element)	Inserts an element at a specific index.
void	appendToList(String key, int index, Object element, boolean removeDuplicate)	Inserts at index with optional duplicate removal.
void	removeFromList(String key, int index)	Removes an element at a specific index from the list.
void	remove(String key)	Removes the item associated with the key.
void	clear()	Clears all stored data.
boolean	contains(String key)	Checks if a key exists in storage.
void	addDataObserver(DataObserver observer)	Registers a data observer for change notifications.
void	removeDataObserver(DataObserver observer)	Unregisters a data observer.

For more methods, refer to the documentation.

Contributing

We welcome contributions from the community! If you'd like to contribute, please fork the repository, make your changes, and submit a pull request.

License

This project is licensed under the MIT License - see the LICENSE file for details.

Support

For any issues, please open an issue on GitHub, and we will get back to you as soon as possible.

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Created with ❤️ by Jummania