we can use to Collections.syncroniseMap() to synchronize 
the HashMap

By implementing  comparable interface we can sort the 
HashMap

import java.util.ArrayList;
import java.util.Collections;
import java.util.Comparator;
import java.util.HashMap;
import java.util.Map;

public class format {
	public static void main(String args[]) {
		Map<String, Person> people = new 
HashMap<String, Person>();
		Person jim = new Person("Jim", 25);
		Person scott = new Person("Scott", 28);
		Person anna = new Person("Anna", 23);
		people.put(jim.getName(), jim);
		people.put(scott.getName(), scott);
		people.put(anna.getName(), anna); 
		// not yet sorted 
		ArrayList<Person> peopleByAge = new 
ArrayList<Person>(people.values());
		Collections.sort(peopleByAge, new 
Comparator<Person>()
				{        
			public int compare(Person o1, 
Person o2) 
				{      
				return o1.getAge() - 
o2.getAge();      
				}    
			});   
		for (Person p : peopleByAge) {   
			System.out.println(p.getName() 
+ "\t" + p.getAge()); 
			}
				}
}
class Person
{
	String name = null;
	int age;
	Person()
	{
		
	}
	Person(String name,int age)
	{
		this.name=name;
		this.age=age;
	}
	public String getName()
	{
		return this.name;
	}
	public int getAge()
	{
		return this.age;
	}
}