guava - What is difference between LinkedHashSet and FilterSet(Guava)

Question

When I trace legacy code, I found something very strange. I can get all the data values from LinkedHashSet, not from the other(FilterSet).

Although data can be seen in unfiltered, but in iteration, I cannot get the required data. Is it because of the predicate? How to get all the data from unfiltered ones?

I found that guava is used in the implementation of utilities class in my project.

What is the difference of these two sets? Any help is greatly appreciated.

Set<A<? extends B, ?>> attributes;

Answer 1

Sets.filter返回一个名为的私有实现类型FilteredSet，它是另一个集合的视图，将其输出限制为仅具有某些特定属性的原始集合的元素。

故意没有办法取出未经过滤的原始数据。