java求助 Multimap

wyc1122wyc

使用 Multimap 接收到数据后，格式为

需求是 计算每个key中元素出现的次数

封心棒棒糖

[Java] 纯文本查看 复制代码

  @Test
  public void test8() {
    Multimap<Integer, List<String>> map = ArrayListMultimap.create();
    map.put(1, Arrays.stream(new String[]{"帅哥", "舔狗"}).toList());
    map.put(4, Arrays.stream(new String[]{"渣男", "普信男", "舔狗"}).toList());
    map.put(5, Arrays.stream(new String[]{"帅哥", "美女", "浪漫", "美女", "浪漫", "美女", "浪漫", "渣女"}).toList());
    Map<Integer, Map<String, Integer>> result = new HashMap<>();
    map.forEach((k, v) -> {
      Map<String, Integer> map1 = new HashMap<>();
      v.forEach(vv -> {
        if (!map1.containsKey(vv)) {
          map1.put(vv, Collections.frequency(v, vv));
        }
      });
      result.put(k, map1);
    });
    System.out.println(result);
  }

qwe12079

谢谢兄弟

kds0221

Multimap和HashMap有什么区别？？

unmask

[Java] 纯文本查看 复制代码

@Test
public void test01() {
    Multimap<Integer, List<String>> map = ArrayListMultimap.create();
    map.put(1, Arrays.stream(new String[] { "帅哥", "舔狗" }).toList());
    map.put(4, Arrays.stream(new String[] { "渣男", "普信男", "舔狗" }).toList());
    map.put(5, Arrays.stream(new String[] { "帅哥", "美女", "浪漫", "美女", "浪漫", "美女", "浪漫", "渣女" }).toList());

    Map<Integer, Map<String, Long>> ret = map.entries().stream().reduce(new HashMap<Integer, Map<String, Long>>(),
            (m, kv) -> {
                m.put(kv.getKey(), kv.getValue().stream()
                        .collect(Collectors.groupingBy(k -> k, Collectors.counting())));
                return m;
            }, (m1, m2) -> null);
    System.out.println(ret);
}