Package org.springframework.batch.poller

# Class DirectPoller<S>

java.lang.Object
org.springframework.batch.poller.DirectPoller<S>

Type Parameters:
  `S` - the type of the result

All Implemented Interfaces:
  `Poller<S>`

public class DirectPoller<S> extends Object implements Poller<S>
A `Poller` that uses the callers thread to poll for a result as soon as it is asked for. This is often appropriate if you expect a result relatively quickly, or if there is only one such result expected (otherwise it is more efficient to use a background thread to do the polling).

Author:
  Dave Syer

- ## Constructor Summary

  Constructors
  Constructor
  Description
  `DirectPoller(long interval)`

- ## Method Summary

  Modifier and Type
  Method
  Description
  `Future<S>`
  `poll(Callable<S> callable)`
  Get a future for a non-null result from the callback.

  ### Methods inherited from class java.lang.Object

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

- ## Constructor Details

  - ### DirectPoller

    public DirectPoller(long interval)

- ## Method Details

  - ### poll

    public Future<S> poll(Callable<S> callable) throws Exception
    Get a future for a non-null result from the callback. Only when the result is asked for (using `Future.get()` or `Future.get(long, TimeUnit)` will the polling actually start.
    Specified by:
      `poll` in interface `Poller<S>`
    Parameters:
      `callable` - a `Callable` to use to retrieve a result
    Returns:
      a future which itself can be used to get the result
    Throws:
      `Exception` - allows for checked exceptions
    See Also:
      - `Poller.poll(Callable)`