java map access by key code example

Example 1: java map get the key from value

public static <T, E> Set<T> getKeyByValue(Map<T, E> map, E value) {
    return map.entrySet()
              .stream()
              .filter(entry -> Objects.equals(entry.getValue(), value))
              .map(Map.Entry::getKey)
              .collect(Collectors.toSet());
}

Example 2: hashmap get value java

//Import Hashmap
import java.util.HashMap;
   
    HashMap<String, String> dir = new HashMap<String, String>();
//Add key, values  
    dir.put("hi", "hello");
	dir.put("wow", "amazing");
//print value for hi.
    System.out.println(dir.get("hi");