The example above shows how to navigate through all the elements of a TreeMap. First, you can retrieve all the keys by calling the ketSet() which returns a list of keys as a set of objects. By reading each element of the set, you can retrieve the corresponding values from TreeMap.

import java.util.Set; 
import java.util.TreeMap; 
 
public class Parcours_treemap {
 
 public static void main(String a[]){
 TreeMap< String, String> tm = new TreeMap< String, String> (); 
 //add key-value pairs
 tm.put("first", "element1"); 
 tm.put("second", "element2"); 
 tm.put("third","element3"); 
 
 Set< String> keys = tm.keySet(); 
 
 for(String key: keys){
 System.out.println("The value of "+key+" is: "+tm.get(key)); 
 }
 }
}

Running this code gives:

The value for second is: element2
The value for first is: element1
The value for third is: element3

Browse TreeMap using Iterator

In this example, we browse the TreeMpa list with Iterator and Map.Entry.

import java.util.Iterator; 
import java.util.Set; 
import java.util.TreeMap; 
import java.util.Map; 
 
public class TreeMap_iterator {
 
 public static void main(String a[]){
 // Create a TreeMap
 TreeMap< String, String> tmap = new TreeMap< String, String> (); 
 
 // Add key-value pairs to TreeMap
 tmap.put("Key1","element1"); 
 tmap.put("Key2","element2"); 
 tmap.put("Key3","element3"); 
 tmap.put("Key4","element4"); 
 
 // Get all inputs
 Set set = tmap.entrySet(); 
 
 // Get iterator to browse the list
 Iterator it = set.iterator(); 
 
 // Show key-value peers
 while(it.hasNext()) {
 Map.Entry mentry = (Map.Entry)it.next(); 
 System.out.print("key: "+mentry.getKey() + " - "); 
 System.out.println("Value: "+mentry.getValue()); 
 } 
 }
}

This code returns this result after execution:

key: Key1 - Value: element1
key: Key2 - Value: element2
key: Key3 - Value: element3
key:  Key4 - Value: element4

References:
Java Doc: Iterator
Java Doc: Map.Entry