Stream (Java Platform SE 8 )
https://docs.oracle.com/javase/8/docs/api/java/util/stream/Stream.html
Java 8 – 从一个 Stream中过滤null值_wangmm0218的博客-CSDN博客_filter(objects::nonnull)
https://blog.csdn.net/wangmuming/article/details/72747183
Java 8 Streams filter examples - Mkyong.com
https://mkyong.com/java8/java-8-streams-filter-examples/
原文：https://www.cnblogs.com/rgqancy/p/13209769.html