使用流获取 Map 的最大值

Question

我有一个名为 Test 的课程。这个类有一个名为 getNumber 的方法，它返回一个 int 值。

public class Test{
     .
     .
     .
     .
     public int getNumber(){
          return number;
     }
}

我还有一个 HashMap ，它的键是 Long ，值是一个 Test 对象。

Map<Long, Test> map = new HashMap<Long, Test>(); 

I want to print the key and also getNumber which has a maximum getNumber using a Stream Line code.

I can print the maximum Number via below lines

final Comparator<Test> comp = (p1, p2) -> Integer.compare(p1.getNumber(), p2.getNumber());

map.entrySet().stream().map(m -> m.getValue())
     .max(comp).ifPresent(d -> System.out.println(d.getNumber()));

However my question is How can I return the key of the maximum amount? Can I do it with one round using stream?

Answer 1

如果我理解正确的话：

Entry<Long, Test> entry = map.entrySet()
            .stream()
            .max(Map.Entry.comparingByValue(Comparator.comparingInt(Test::getNumber)))
            .get();