Uploaded image for project: 'JDK'
  1. JDK
  2. JDK-8022237

j.u.s.BaseStream.onClose() has an issue in implementation or requires spec clarification

    XMLWordPrintable

Details

    • Bug
    • Status: Closed
    • P2
    • Resolution: Fixed
    • None
    • 8
    • core-libs

    Description

      Specification for the method BaseStream.onClose()

      http://download.java.net/lambda/b101/docs/api/java/util/stream/BaseStream.html#onClose(java.lang.Runnable)

      gives an impression that method returns not (always) the same stream and handlers are associated each with separate stream in the chain, being aware only of the "parent" handlers in the chain.

      While the implementation shows that it doesn't matter which of the streams in the chain is being triggered for closing - all the listeners are notified. Please see the following code:

      import java.util.stream.BaseStream;
      import java.util.stream.Stream;

      public class OnClose {

          public static void main(String[] args) {

              final Stream s = Stream.empty();

              BaseStream c1 = s.onClose(() -> {
                  System.out.println("handler 1");
              });

              BaseStream c2 = c1.onClose(() -> {
                  System.out.println("handler 2");
              });

              BaseStream c3 = c2.onClose(() -> {
                  System.out.println("handler 3");
              });

              // all the handlers will be called
              c1.close();
          }

      }

      the output will be:

      handler 1
      handler 2
      handler 3


      This looks like either a bug in implementation or behavior not clearly described by the specification.




      Attachments

        Activity

          People

            henryjen Henry Jen
            dbessono Dmitry Bessonov
            Votes:
            0 Vote for this issue
            Watchers:
            3 Start watching this issue

            Dates

              Created:
              Updated:
              Resolved: