如何通过其键格式化地图数据

Question

I'm trying to format the data inside my HashMap according to their key.

I have a loop which prints data in the following format

icon: "rain"
windBearing: 239
ozone: 339.89
precipType: "rain"
humidity: 0.82
moonPhase: 0.98
windSpeed: 7.37
summary: "Light rain starting in the evening."
visibility: 16.09
cloudCover: 0.62
pressure: 1011.49
dewPoint: 1.26
time: 08-03-2016 00:00:00
temperatureMax: 8.09

All of this data is stored in a HashMap with key (for example) icon and value "rain".

How can I format all of this data according to their keys? I tried something like this

private Map formatter(Map data) {
    String tmp;
    for(int i = 0; i < data.size(); i++) {
        if(data.containsKey("temperatureMax")) {
            tmp = String.format("%s c TEST", data.get("temperatureMax"));
            data.put("temperatureMax", tmp);
        }
    }
    return data;
}

I thought something like this would format 8.09 to simply 8, but it didn't do anything. (I attempted to do what the answer here How to update a value, given a key in a java hashmap? states)

This is where I acquire the data.

public Map dailyReport() {
    FIODaily daily = new FIODaily(fio);
    //In case there is no daily data available
    if (daily.days() < 0) {
        System.out.println("No daily data.");
    } else {
        System.out.println("\nDaily:\n");
    }
    //Print daily data
    for (int i = 0; i < daily.days(); i++) {
        String[] value = daily.getDay(i).getFieldsArray();
        System.out.println("Day #" + (i + 1));
        for (String key : value) {
            System.out.println(key + ": " + daily.getDay(i).getByKey(key));
            dailyData.put(key, daily.getDay(i).getByKey(key));
            formatter(dailyData);
        }
        System.out.println("\n");
    }
    return dailyData;
}

Answer 1

You should iterate through your map keys using the keySet() function of Map

for (String name:data.keySet()) {
    if (name.equals("temperatureMax")) {
        //Do your formatting
    }
}