我测试了您的代码并正常工作。我添加了一个小演示,它用另一种方式打印地图中的所有数据:
ConcurrentHashMap<String, Integer> map = new ConcurrentHashMap<String, Integer>();map.put("A", 1);map.put("B", 2);map.put("C", 3);for (String key : map.keySet()) { System.out.println(key + " " + map.get(key));}for (Map.Entry<String, Integer> entry : map.entrySet()) { String key = entry.getKey().toString(); Integer value = entry.getValue(); System.out.println("key, " + key + " value " + value);}


