Class ResourcesDownloader

java.lang.Object
org.apache.jmeter.protocol.http.sampler.ResourcesDownloader

public class ResourcesDownloader extends Object
Manages the parallel http resources download.
A shared thread pool is used by all the sample.
A sampler will usually do the following
 
   // list of AsynSamplerResultHolder to download
   List<Callable<AsynSamplerResultHolder>> list = ...

   // max parallel downloads
   int maxConcurrentDownloads = ...

   // get the singleton instance
   ResourcesDownloader resourcesDownloader = ResourcesDownloader.getInstance();

   // schedule the downloads and wait for the completion
   List<Future<AsynSamplerResultHolder>> retExec =
           resourcesDownloader.invokeAllAndAwaitTermination(maxConcurrentDownloads, list);

 
the call to invokeAllAndAwaitTermination will block until the downloads complete or get interrupted
the Future list only contains task that have been scheduled in the threadpool.
The status of those futures are either done or cancelled

Future enhancements:
  • this implementation should be replaced with a NIO async download in order to reduce the number of threads needed
Since:
3.0
  • Method Details

    • getInstance

      public static ResourcesDownloader getInstance()
    • shrink

      public void shrink()
      this method will try to shrink the thread pool size as much as possible it should be called at the end of a test
    • invokeAllAndAwaitTermination

      public List<Future<ResourcesDownloader.AsynSamplerResultHolder>> invokeAllAndAwaitTermination(int maxConcurrentDownloads, List<Callable<ResourcesDownloader.AsynSamplerResultHolder>> list) throws InterruptedException
      This method will block until the downloads complete or it get interrupted the Future list returned by this method only contains tasks that have been scheduled in the threadpool.
      The status of those futures are either done or cancelled
      Parameters:
      maxConcurrentDownloads - max concurrent downloads
      list - list of resources to download
      Returns:
      list tasks that have been scheduled
      Throws:
      InterruptedException - when interrupted while waiting