听起来最好的方法是使用map.entrySet()来遍历条目，因为map.containsValue()可能会这样做。

听起来最好的方法是使用map.entrySet()来遍历条目，因为map.containsValue()可能会这样做。

让我们看看我的例子

Map<String, String> mapPeopleAndCountry = new HashMap<>();
mapPeopleAndCountry.put("Matis", "Lithuania");
mapPeopleAndCountry.put("Carlos", "Honduras");
mapPeopleAndCountry.put("Teboho", "Lesotho");
mapPeopleAndCountry.put("Marielos", "Honduras");


List<String> peopleInHonduras = mapPeopleAndCountry.keySet()
    .stream()
    .filter(r -> mapPeopleAndCountry.get(r)
                .equals("Honduras"))
    .stream(Collectors.toList());

// will return ["Carlos", "Marielos"]

注:未经测试，可能含有错别字

在java8

map.entrySet().stream().filter(entry -> entry.getValue().equals(value))
    .forEach(entry -> System.out.println(entry.getKey()));

/**
 * This method gets the Key for the given Value
 * @param paramName
 * @return
 */
private String getKeyForValueFromMap(String paramName) {
    String keyForValue = null;
    if(paramName!=null)) {
        Set<Entry<String,String>> entrySet = myMap().entrySet();
        if(entrySet!=null && entrySet.size>0) {
            for(Entry<String,String> entry : entrySet) {
                if(entry!=null && paramName.equalsIgnoreCase(entry.getValue())) {
                    keyForValue = entry.getKey();
                }
            }
        }
    }
    return keyForValue;
}

for(int key: hm.keySet()) {
    if(hm.get(key).equals(value)) {
        System.out.println(key); 
    }
}