co.cask.cdap.common.collect

Class FirstNCollector<Element>

java.lang.Object

co.cask.cdap.common.collect.FirstNCollector<Element>

Type Parameters:

Element - Type of element.

All Implemented Interfaces:

Collector<Element>

public class FirstNCollector<Element>
extends Object
implements Collector<Element>

This collector is used for collecting the first N elements, it returns false after N elements have been collected.

Constructor Summary

Constructors

Constructor and Description
FirstNCollector(int n)

Method Summary

Methods

Modifier and Type	Method and Description
boolean	addElement(Element element) collect one element.
<T extends Collection<? super Element>> T	finish(T collection) Finish collection of elements and add all collected elements into the given Collection.

Methods inherited from class java.lang.Object

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

Constructor Detail

FirstNCollector

public FirstNCollector(int n)

Method Detail

addElement

public boolean addElement(Element element)

Description copied from interface: Collector

collect one element.

Specified by:

addElement in interface Collector<Element>

Parameters:

element - the element to collect

Returns:

whether more elements need to be collected

finish

public <T extends Collection<? super Element>> T finish(T collection)

Description copied from interface: Collector

Finish collection of elements and add all collected elements into the given Collection.

Specified by:

finish in interface Collector<Element>

Type Parameters:

T - Type of collection

Parameters:

collection - Collection for storing collected elements.

Returns:

The same Collection instance given in the parameter.