java - Access values of hashmap

I am having a MAP, Map map = new HashMap ();

public class Records 
{
    String countryName;
    long numberOfDays;


    public String getCountryName() {
        return countryName;
    }
    public void setCountryName(String countryName) {
        this.countryName = countryName;
    }
    public long getNumberOfDays() {
        return numberOfDays;
    }

    public void setNumberOfDays(long numberOfDays) {
        this.numberOfDays = numberOfDays;
    }

    public Records(long days,String cName)
    {
        numberOfDays=days;
        countryName=cName;
    }


    public Records()
    {
        this.countryName=countryName;
        this.numberOfDays=numberOfDays;
    }

I have implemented the methods for map, now please tell me How do I access all the values that are present in the hashmap. I need to show them on UI in android ?

Answer

You can use Map#entrySet method, if you want to access the keys and values parallely from your HashMap: -

Map map = new HashMap ();

//Populate HashMap

for(Map.Entry entry: map.entrySet()) {
    System.out.println(entry.getKey() + " : " + entry.getValue());
}

Also, you can override toString method in your Record class, to get String Representation of your instances when you print them in for-each loop.

UPDATE: -

If you want to sort your Map on the basis of key in alphabetical order, you can convert your Map to TreeMap. It will automatically put entries sorted by keys: -

    Map treeMap = new TreeMap(map);

    for(Map.Entry entry: treeMap.entrySet()) {
        System.out.println(entry.getKey() + " : " + entry.getValue());


    }

For more detailed explanation, see this post: - how to sort Map values by key in Java