Java8 lamda表达式

1. 将list转为map

public Map<String, AClass> getLarkMap(List<AClass> aList) {
   return aList.stream().collect(Collectors.toMap(AClass::getUrl, a -> a, (k1, k2) -> k2));
}

　　

2. 将list中感兴趣的内容过滤出来

public List<AClass> getLarkList(String url, List<AClass> aList) {
   return aList.stream().filter(AClass -> AClass.getUrl().equals(url)).collect(Collectors.toList());
}