The code snippet
allows user to iterate through the contents of a map with String ,
ArrayList entryset
The solution
provides an easy way to iterate through the map. The solution can be
used in phonebook examples, where many contact numbers can be stored
against a single user.
import java.io.IOException;
import java.util.*;
public class NewClass1 {
public static void main(String[] args) throws IOException {
Map<String, List> numMap = new HashMap<String, List>();
numMap.put("Key1", new ArrayList(Arrays.asList("K1V1", "K1V2", "K1V3")));
numMap.put("Key2", new ArrayList(Arrays.asList("K2V1", "K2V2", "K2V3")));
numMap.put("Key3", new ArrayList(Arrays.asList("K3V3", "K3V2", "K3V3")));
numMap.put("Key4", new ArrayList(Arrays.asList("K4V1", "K4V2", "K4V3")));
Iterator itr = numMap.entrySet().iterator();
while (itr.hasNext()) {
Map.Entry keyValue = (Map.Entry) itr.next();
System.out.println("Key: " + keyValue.getKey());
/* Iterate through the list of each key */
List value = (List) keyValue.getValue();
for (int i = 0; i < value.size(); i++) {
if (value != null) {
if (value.get(i) != null) {
System.out.println("Value: " + value.get(i));
}
}
}
}
}
}