Clone a TreeMap in Java

This example shows how to copy elements from a Map to a TreeMap using the putAll() method. You can copy the items from another data collection in TreeMap.

javacoder package. TreeMap; 
import java.util.TreeMap; 
 
public class TreeMapCopy {
 
 public static void main(String a[]){
 TreeMap hmap = new TreeMap(); 
 //add key-value pairs
 hmap.put("1", "value1"); 
 hmap.put("2", "value2"); 
 hmap.put("3","value3"); 
 System.out.println(hmap); 
 TreeMap subMap = new TreeMap(); 
 subMap.put("s1", "S1 value"); 
 subMap.put("s2", "S2 value"); 
 hmap.putAll(subMap); 
 System.out.println(hmap); 
 }
}

Runtime:

{1=value1, 2=value2, 3=value3}
{1=value1, 2=value2, 3=value3, s1=Value S1,  s2=S2 value}