23. Sorting Map By Key - prabhatrocks07/Core-Java-Programming GitHub Wiki

public class SortMapByKey {

public static void main(String[] args) {
	Map<String, String> map = new HashMap<String, String>();
	map.put("2", "B");
	map.put("1", "A");
	map.put("4", "D");
	map.put("3", "C");
	map.put("7", "C");
	map.put("5", "z");
	map.put("6", "b");
	map.put("8", "a");
	map.put("9", "x");
	
	System.out.println("Unsorted Map........");
	printMap(map);
	System.out.println("Sorted Map ..... By Key");
	Map<String, String> treeMap = new TreeMap<>(map);
	printMap(treeMap);
}

private static void printMap(Map<String, String> map) {
	/*for (Entry<String, String> entry : map.entrySet()) {
		System.out.println("Key : " + entry.getKey() + " Value : " + entry.getValue());
	}*/
	// Java 8
            map.forEach((k, v) -> System.out.println(k + " : " + v));

}

}