java - 为什么这个断言不起作用 - assertThat(foo, is(not(null)));

Question

此断言编译但失败，即使我知道 foo 不为 null 的事实:

import static org.hamcrest.Matchers.is;  // see http://stackoverflow.com/a/27256498/2848676
import static org.hamcrest.Matchers.not;
import static org.hamcrest.MatcherAssert.assertThat;

...

assertThat(foo, is(not(null)));

Answer 1

根据经验，我发现这反而有效:

assertThat(foo, is(not(nullValue())));