java - 通量处理器 : retrieve last emitted value on subscribe like rx's Subject

Question

目前，FluxProcessor 订阅仅检索订阅后发出的那些值。但我想在订阅时检索 Flux 中的最后一个值，例如，像 RX 的 Subject 那样。

我有这样的设置:

FluxProcessor<Integer, Integer> processor = DirectProcessor.<Integer>create().serialize();
FluxSink<Integer> sink = processor.sink();

sink.next(1);

stateProcessor.subscribe(System.out:println);

sink.next(2);

输出是:

1

期望的输出:

1
2

Answer 1

使用ReplayProcessor修复了它。它能够存储 N 个最后发出的值以供进一步订阅。对于同一示例:

FluxProcessor<Integer, Integer> processor = ReplayProcessor.<Integer>create(1).serialize(); //1 is the history size
FluxSink<Integer> sink = processor.sink();

sink.next(1);

stateProcessor.subscribe(System.out:println);

sink.next(2);

打印:

1
2