java中的finagle

java中的finagle - Function，Function1等(finagle in java - Function, Function1 etc)

如何在Java中使用finagle的Future对象的flatMap方法创建Function1对象？

试过这个：

Function1<String, String> f = new Function1<String, String>() { @Override public String apply(String s) { return null; } };

但它不起作用：

错误：（22,73）java：不是抽象的，并且不会覆盖抽象方法而是scala.Function1中的$ mcVJ $ sp（scala.Function1）

How do I create Function1 object for use in flatMap method of finagle's Future object in Java?

Tried this:

Function1<String, String> f = new Function1<String, String>() { @Override public String apply(String s) { return null; } };

But it doesn't work:

Error:(22, 73) java: is not abstract and does not override abstract method andThen$mcVJ$sp(scala.Function1) in scala.Function1

最满意答案

为了完整起见，这是我上面两个月的评论的答案。

首先是一些进口：

import scala.Function1; import scala.runtime.AbstractFunction1;

现在你只需要定义apply方法：

Function1<String, String> f = new AbstractFunction1<String, String>() { public String apply(String s) { return s; } };

但是，如果您正在使用Finagle， Twitter的Util库也提供了类似的帮助类：

import com.twitter.util.Function; import scala.Function1;

接着：

Function1<String, String> f = new Function<String, String>() { public String apply(String s) { return s; } };

后一种选择可能更好 - 我从未真正喜欢使用scala.runtime东西。

For the sake of completeness, here's the answer from my two month-old comment above.

First for some imports:

import scala.Function1; import scala.runtime.AbstractFunction1;

And now you only have to define the apply method:

Function1<String, String> f = new AbstractFunction1<String, String>() { public String apply(String s) { return s; } };

If you're using Finagle, though, Twitter's Util library also provides a similar helper class:

import com.twitter.util.Function; import scala.Function1;

And then:

Function1<String, String> f = new Function<String, String>() { public String apply(String s) { return s; } };

This latter option is probably better—I've never really liked explicitly using stuff from scala.runtime.