draenei

Another one ORM for Cassandra but with distributed cache and analytics utils from package

Project exists in R&D mode

Add it to your project

Gradle

compile 'com.fnklabs:fnklabs-draenei:0.1.2'

Or as git submodule (preferred)

git submodule add https://github.com/fnklabs/draenei.git draenei

Annotations

There are several annotations that make help your to mark your entity

Column

Column name, value is optional by default will use field name as value

class User {
    @Column(name = "value")
    private String name;
    
    @Column
    private String surname;
}

PrimaryKey

Each entity must contains at least one primary key (partition key).

class User {
    @PrimaryKey
    @Column
    private String email;

    @Column(name = "value")
    private String name;
    
    @Column
    private String surname;
}

Entity can contains several partition keys in this case you must set order value for each primary key

class User {
    @PrimaryKey
    @Column
    private String email;
    
    @PrimaryKey(order = 1)
    @Column
    private String email;

    @Column(name = "value")
    private String name;
    
    @Column
    private String surname;
}

By default all primary keys belong to partition group if you want to mark some primary keys as clustering set PrimaryKey.isPartitionKey = false

class User {
    @PrimaryKey
    @Column
    private String email;
    
    @PrimaryKey(isPartitionKey = false, order = 1)
    @Column
    private String phone;

    @Column(name = "value")
    private String name;
    
    @Column
    private String surname;
}

Enumerated

To use enum fields you must set Enumerated.enumType value (need for serialization, deserialization). In current implementation all enum fields stored as text values

class User {
    @Enumerated(enumType = UserRole.class)
    @Column
    private UserRole surname;
}

enum UserRole{
    ADMINISTRATOR,
    CUSTOMER
}

Table

@Table(name = "user", fetchSize = 100, readConsistencyLevel = ConsistencyLevel.QUORUM, writeConsistencyLevel = ConsistencyLevel.QUORUM)
class User {
    @PrimaryKey
    @Column
    private String email;

}

All other fields in Table annotation is optional and not used in current implementation

Entity (Complete class)

All field values read and write though getters and setters so you must define them

@Table(name = "user")
class User {
    @PrimaryKey
    @Column
    private String email;

    public String getEmail() {
        return email;
    }
    
    public void setEmail(String email) {
        this.email = email;
    }
}

DataProvider

There are two several implementation of DataProvider:

1. com.fnklabs.draenei.orm.DataProvider (base implementation)
2. com.fnklabs.draenei.orm.CacheableDataProvider (use data grid for caching)

DataProvider

Create your first dataProvider

public class UserDataProvider extends DataProvider<User> {
    public User(CassandraClientFactory cassandraClientFactory, ExecutorService executorService) {
        super(User.class, cassandraClientFactory, executorService);
    }
}

Saving data

public class Example {
    private static CassandraClientFactory = // implement CassandraClientFactory;
    private static ExecutorService = // retrieve executor service for data provider;
    
    public static void main(String[] args) {
        UserDataProvider dataProvider = new UserDataProvider(cassandraClientFactory, executorService);
        
        User user = new User();
        user.setEmail("test@example.com");
        
        ListenableFuture<Boolean> saveFuture = dataProvider.saveAsync(user);
    }
}

Find data

When calling find method you must provide all partition keys

public class Example {
    private static CassandraClientFactory = // implement CassandraClientFactory;
    private static ExecutorService = // retrieve executor service for data provider;
    
    public static void main(String[] args) {
        UserDataProvider dataProvider = new UserDataProvider(cassandraClientFactory, executorService);
        
        List<User> users = dataProvider.find("test@example.com"); // sync
        ListenableFuture<List<User>> findUsersFuture = dataProvider.findAsync("test@example.com"); // async
        
        // retrieving only one record
        
        User user = dataProvider.findOne("test@example.com"); // sync
        ListenableFuture<User> findUserFuture = dataProvider.findOneAsync("test@example.com"); // async
    }
}

Removing data

To remove data you must provide entity object

public class Example {
    private static CassandraClientFactory = // implement CassandraClientFactory;
    private static ExecutorService = // retrieve executor service for data provider;
    
    public static void main(String[] args) {
        UserDataProvider dataProvider = new UserDataProvider(cassandraClientFactory, executorService);
        
        User user = new User();
        user.setEmail("test@example.com");
        
        ListenableFuture<Boolean> removeFuture = dataProvider.removeAsync(user);
    }
}

CacheableDataProvider

Analytics

Load data from cassandra into cache

Compute operations