Class BodyOutputStream

  • All Implemented Interfaces:
    java.io.Closeable, java.io.Flushable, java.lang.AutoCloseable
    Direct Known Subclasses:
    BufferedBodyOutputStream, ChunkedBodyOutputStream

    abstract class BodyOutputStream
    extends java.io.OutputStream
    TODO consider exposing the mode as part of the API, so the user can make decisions based on the mode

    An extension of OutputStream that adds method that allow to use the stream asynchronously. It is inspired by and works in a very similar way as Servlet asynchronous streams introduced in Servlet 3.1.

    The stream supports 2 modes SYNCHRONOUS and ASYNCHRONOUS. The stream is one of the following 3 states:

    • UNDECIDED
    • SYNCHRONOUS
    • ASYNCHRONOUS
    UNDECIDED is an initial mode and it commits either to SYNCHRONOUS or ASYNCHRONOUS. Once it commits to one of these 2 modes it cannot change to the other. The mode it commits to is decided based on the first use of the stream. If setWriteListener(WriteListener) is invoked before any of the write methods, it commits to ASYNCHRONOUS mode and similarly if any of the write methods is invoked before setWriteListener(WriteListener), it commits to SYNCHRONOUS mode.
    • Method Summary

      All Methods Instance Methods Abstract Methods 
      Modifier and Type Method Description
      abstract boolean isReady()
      Returns true if data can be written without blocking else returns false.
      abstract void setWriteListener​(WriteListener writeListener)
      Instructs the stream to invoke the provided WriteListener when it is possible to write.
      • Methods inherited from class java.io.OutputStream

        close, flush, nullOutputStream, write, write, write
      • Methods inherited from class java.lang.Object

        clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
    • Constructor Detail

      • BodyOutputStream

        BodyOutputStream()
    • Method Detail

      • setWriteListener

        public abstract void setWriteListener​(WriteListener writeListener)
        Instructs the stream to invoke the provided WriteListener when it is possible to write.

        If the stream is in UNDECIDED state, invoking this method will commit the stream to ASYNCHRONOUS mode.

        Parameters:
        writeListener - the WriteListener that should be notified when it's possible to write.
        Throws:
        java.lang.IllegalStateException - if one of the following conditions is true
        • the stream has already committed to SYNCHRONOUS mode.
        • setWriteListener is called more than once within the scope of the same request.
        java.lang.NullPointerException - if writeListener is null
      • isReady

        public abstract boolean isReady()
        Returns true if data can be written without blocking else returns false.

        If the stream is in ASYNCHRONOUS mode and the user attempts to write to it even though this method returns false, an IllegalStateException is thrown.

        Returns:
        true if data can be obtained without blocking, otherwise returns false.