Java8 list根據對象某個屬性去重

1. 添加方法：

import java.util.concurrent.ConcurrentHashMap;
import java.util.function.Function;
import java.util.function.Predicate;
import java.util.stream.Collectors;

private static <T> Predicate<T> distinctByKey(Function<? super T, Object> keyExtractor) {
        Map<Object, Boolean> seen = new ConcurrentHashMap<>();
        return t -> seen.putIfAbsent(keyExtractor.apply(t), Boolean.TRUE) == null;
    }

2. 使用：

facultyRetList = facultyList.stream().filter(distinctByKey(Faculty::getId)).collect(Collectors.toList());