添加方法到 Java 8 流

Question

在使用 Java 8 Streams, I some times find that Stream doesn't have a particular method that I desire (e.g. takeWhile(), dropWhile(), skipLast()). How do I create my own stream class which has the additional methods with out re-writing the entire Java 8 Stream 架构时？

我知道 StreamEx library and know that it has takeWhile() and dropWhile(). As of writing this, it doesn't have skipLast(). I have filed an issue 这个方法。

一个可接受的解决方案是展示如何扩展 Java 8 Stream or StreamEx。

Answer 1

自版本 0.5.4 StreamEx library has a chain() 方法。这允许创建可以轻松插入的辅助方法。

public static <T> UnaryOperator<StreamEx<T>> skipLast(int n)
{
   return(stream -> skipLast(stream, n));
}

private static StreamEx<T> skipLast(Stream<T> input, int n)
{
   // implement the real logic of skipLast
}

有了上面的内容，现在可以写...

StreamEx.
   of(input).
   chain(skipLast(10)).
   forEach(System.out::println);

添加方法到 Java 8 流

Add a Method to Java 8 Stream

java

java-stream

streamex