public class Hash_Map_Demo {
public static void main(String[] args)
{
// Creating an empty HashMap
HashMap<String, Integer> hash_map = new HashMap<String, Integer>();
// Mapping int values to string keys
hash_map.put("Geeks", 10);
hash_map.put("4", 15);
hash_map.put("Geeks", 20);
hash_map.put("Welcomes", 25);
hash_map.put("You", 30);
// Displaying the HashMap
System.out.println("The Mappings are: " + hash_map);
// Checking for the emptiness of Map
System.out.println("Is the map empty? " + hash_map.isEmpty());
}
}
public class HashMapDemo {
public static void main(String args[]) {
// create hash map
HashMap newmap = new HashMap();
// populate hash map
newmap.put(1, "tutorials");
newmap.put(2, "point");
newmap.put(3, "is best");
// check if map is empty
boolean val = newmap.isEmpty();
// check the boolean value
System.out.println("Is hash map empty: " + val);
}
}
public class HashMapIsEmptyOrNot {
public static void main(String[] args) {
// creating empty HashMap object of type <String, String>
HashMap<String, String> hashMap = new HashMap<String, String>();
// checking empty even before adding any Key-Value pairs
boolean isEmpty1 = hashMap.isEmpty();
System.out.println("1. Checking Empty"
+ " before adding any entries : " + isEmpty1);
// adding key-value pairs to HashMap object
hashMap.put("Google", "Sundar Pichai");
hashMap.put("Facebook", "Mark Zuckerberg");
hashMap.put("LinkedIn", "Reid Hoffman");
hashMap.put("Apple", "Steve Jobs");
hashMap.put("Microsoft", "Bill Gates");
// checking empty adding few entries
boolean isEmpty2 = hashMap.isEmpty();
System.out.println("\n2. Checking Empty"
+ " before adding any entries : " + isEmpty2);
}
}
public class HashMapEmptyExample {
public static void main(String args[]) {
// Creating a HashMap of int keys and String values
HashMap<Integer, String> hashmap = new HashMap<Integer, String>();
// Checking whether HashMap is empty or not
/* isEmpty() method signature and description -
* public boolean isEmpty(): Returns true if this map
* contains no key-value mappings.
*/
System.out.println("Is HashMap Empty? "+hashmap.isEmpty());
// Adding Key and Value pairs to HashMap
hashmap.put(11,"Apple");
hashmap.put(22,"Banana");
hashmap.put(33,"Mango");
hashmap.put(44,"Pear");
hashmap.put(55,"PineApple");
// Checking again whether HashMap is Empty or not
System.out.println("Is HashMap Empty? "+hashmap.isEmpty());
}
}
public class HashMapIsEmptyExample {
public static void main(String args[]) throws InterruptedException {
// declare the hashmap
HashMap<String, String> mapStudent = new HashMap<>();
// put contents of our HashMap
mapStudent.put("12487912", "Shyra Travis");
mapStudent.put("45129987", "Sharon Wallace");
// check if the HashMap is empty or not
if (!mapStudent.isEmpty()) {
// printing the key value pairs available
// if the hashmap is not empty
for (String s : mapStudent.keySet()) {
System.out.println("Student with id # " + s + " is " + mapStudent.get(s));
}
}
}
}
public Aggregator createInternal(Aggregator parent, boolean collectsFromSingleBucket, List<PipelineAggregator> pipelineAggregators,
Map<String, Object> metaData) throws IOException {
HashMap<String, VS> valuesSources = new HashMap<>();
for (Map.Entry<String, ValuesSourceConfig<VS>> config : configs.entrySet()) {
VS vs = config.getValue().toValuesSource(context.getQueryShardContext());
if (vs != null) {
valuesSources.put(config.getKey(), vs);
}
}
if (valuesSources.isEmpty()) {
return createUnmapped(parent, pipelineAggregators, metaData);
}
return doCreateInternal(valuesSources, parent, collectsFromSingleBucket, pipelineAggregators, metaData);
}
protected JSONObject getChartData() {
JSONObject data = new JSONObject();
JSONObject values = new JSONObject();
HashMap<String, Integer> map = getValues(new HashMap<String, Integer>());
if (map == null || map.isEmpty()) {
// Null = skip the chart
return null;
}
for (Map.Entry<String, Integer> entry : map.entrySet()) {
JSONArray categoryValues = new JSONArray();
categoryValues.add(entry.getValue());
values.put(entry.getKey(), categoryValues);
}
data.put("values", values);
return data;
}
public static HashMap<Profile, Float> getPercentages(HashMap<Profile, Double> distances, int informationSetSize) {
Map<Profile, Float> result = new HashMap<Profile, Float>();
if (distances.isEmpty() || distances == null) {
return new HashMap<Profile, Float>();
} else {
for (Map.Entry<Profile, Double> entry : distances.entrySet()) {
Profile profile = entry.getKey();
Double distance = entry.getValue();
// Calculate the percentage for the current distance
// The maximum distance is sqrt(informationSetSize) because we have
// 0-1 vectors
// REMARK: Euclidean Distance Theory
float maxDistance = (float) Math.sqrt(informationSetSize);
float percentage = (float) (maxDistance - distance) * 100 / maxDistance;
// put the percentage in Map formatted with two decimals.
result.put(profile, (float) (Math.round(percentage * 100.0) / 100.0));
}
}
// return the HashMap sorted by value (DESC)
return (HashMap<Profile, Float>) MapUtil.sortByValueDESC(result);
}
protected JSONObject getChartData() {
JSONObject data = new JSONObject();
JSONObject values = new JSONObject();
HashMap<String, Integer> map = getValues(new HashMap<String, Integer>());
if (map == null || map.isEmpty()) {
// Null = skip the chart
return null;
}
for (Map.Entry<String, Integer> entry : map.entrySet()) {
JSONArray categoryValues = new JSONArray();
categoryValues.add(entry.getValue());
values.put(entry.getKey(), categoryValues);
}
data.put("values", values);
return data;
}
private String createCanonicalParameterString(HashMap<String, String> params) {
String paramString = "";
if (params != null && !params.isEmpty()) {
TreeMap<String, String> sortedMap = new TreeMap<String, String>(params);
for (Map.Entry<String, String> entry : sortedMap.entrySet()) {
paramString = paramString + entry.getKey() + "=" + entry.getValue();
if (!sortedMap.lastKey().equals(entry.getKey())) {
paramString = paramString + "&";
}
}
}
return paramString;
}