co.cask.cdap.data2.dataset2

Class SingleTypeModule

java.lang.Object

co.cask.cdap.data2.dataset2.SingleTypeModule

All Implemented Interfaces:

co.cask.cdap.api.dataset.module.DatasetModule

public class SingleTypeModule
extends Object
implements co.cask.cdap.api.dataset.module.DatasetModule

Wraps implementation of Dataset into a DatasetModule. This allows for easier implementation of simple datasets without requiring to implement DatasetDefinition, DatasetAdmin, etc. when the implementation uses existing dataset types. NOTE: all admin ops of the dataset will be delegated to embedded datasets; DatasetProperties will be propagated to embedded datasets as well NOTE: must have exactly one constructor with parameter types of (DatasetSpecification, [0..n] @EmbeddedDataset Dataset)

Example of usage:

 // ...

datasetFramework.addModule("myModule", new SingleTypeModule(SimpleKVTable.class));

// ...


@DatasetType("KVTable")
public class SimpleKVTable extends AbstractDataset implements KeyValueTable {
  private static final byte[] COL = new byte[0];

  private final Table table;

  public SimpleKVTable(DatasetSpecification spec,
                       @EmbeddedDataset("data") Table table) {
    super(spec.getTransactionAwareName(), table);
    this.table = table;
  }

  public void put(String key, String value) throws Exception {
    table.put(Bytes.toBytes(key), COL, Bytes.toBytes(value));
  }

  public String get(String key) throws Exception {
    byte[] value = table.get(Bytes.toBytes(key), COL);
    return value == null ? null : Bytes.toString(value);
  }
}

 
 

See DatasetType and EmbeddedDataset for more details on their usage.

Constructor Summary

Constructors

Constructor and Description
SingleTypeModule(Class<? extends co.cask.cdap.api.dataset.Dataset> dataSetClass)

Method Summary

Methods

Modifier and Type	Method and Description
Class<? extends co.cask.cdap.api.dataset.Dataset>	getDataSetClass()
void	register(co.cask.cdap.api.dataset.module.DatasetDefinitionRegistry registry)

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

SingleTypeModule

public SingleTypeModule(Class<? extends co.cask.cdap.api.dataset.Dataset> dataSetClass)

Method Detail

getDataSetClass

public Class<? extends co.cask.cdap.api.dataset.Dataset> getDataSetClass()

register

public void register(co.cask.cdap.api.dataset.module.DatasetDefinitionRegistry registry)

Specified by:

register in interface co.cask.cdap.api.dataset.module.DatasetModule