com.github.restdriver.serverdriver.polling

Class Poller

java.lang.Object

com.github.restdriver.serverdriver.polling.Poller

public abstract class Poller
extends Object

For making asynchronous assertions.

For typical use, create an anonymous subclass inline, and implement the poll() method:

 new Poller( times(10), every(100, MILLISECONDS) ) {
     public void poll() {
         assertThat(someMethodCall(), is("Success"));
     }
 };
 
 

This assertion will be called a number of times (configurable by using the different constructors). The first poll is tried immediately, so if you specify 3 attempts with 1 second pause, the total execution time will be about 2 seconds.

This class catches any AssertionError thrown in the first n-1 attempts. If any other kind of Exception is encountered, or an AssertionError is thrown at the last attempt then it will be thrown immediately and your test will fail. All AssertionErrors except the last are swallowed.

For debugging purposes you may call loudly() in your poll method, and interim AssertionErrors will be logged to System.out rather than being simply ignored.

Constructor Summary

Constructors

Constructor and Description
Poller() Creates a new Poller set to repeat the poll() once per second for ten seconds.
Poller(int times) Creates a new Poller set to repeat the poll() once per second for the specified number of times.
Poller(int times, TimeDuration pollPeriod) Creates a new Poller set to repeat the poll() once every sleepDuration timeUnits for the specified number of times.

Method Summary

Methods

Modifier and Type	Method and Description
static TimeDuration	every(long duration, TimeUnit unit) For helping your fluent interface, this simply creates a TimeDuration object in a more natural way.
protected void	loudly() Call this method in your poll() implementation (before any assertions) to enable logging of intermediate assertions to System.out.
abstract void	poll() Override this method with some kind of assertion that will be re-run according to the polling schedule.
static int	times(int count) For helping you define your fluent interface.

Methods inherited from class java.lang.Object

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

Constructor Detail

Poller

public Poller()

Creates a new Poller set to repeat the poll() once per second for ten seconds.

Poller

public Poller(int times)

Creates a new Poller set to repeat the poll() once per second for the specified number of times.

Parameters:

times - The number of times to poll.

Poller

public Poller(int times,
      TimeDuration pollPeriod)

Creates a new Poller set to repeat the poll() once every sleepDuration timeUnits for the specified number of times.

Parameters:

times - The number of times to try.

pollPeriod - The duration of the sleep between each poll.

Method Detail

loudly

protected final void loudly()

Call this method in your poll() implementation (before any assertions) to enable logging of intermediate assertions to System.out.

poll

public abstract void poll()

Override this method with some kind of assertion that will be re-run according to the polling schedule. Any AssertionError thrown will be swallowed unless this is the last attempt. Any other kind of Exception will be thrown immediately.
For debugging, intermediate AssertionErrors can be logged to sysout by calling loudly() in this method.

times

public static int times(int count)

For helping you define your fluent interface. This method simply returns its argument but allows calls like new Poller( times(4) ) then it is clear what the 4 refers to, rather than just saying new Poller(4) which is ambiguous. 4 what? elephants?

Parameters:

count - a number

Returns:

count

every

public static TimeDuration every(long duration,
                 TimeUnit unit)

For helping your fluent interface, this simply creates a TimeDuration object in a more natural way. For an example of usage, see the documentation for Poller.

Parameters:

duration - the duration

unit - the TimeUnit

Returns:

the new TimeDuration.