TreeMap keys does not display in ascending order

Question

I am using Treemap to get key value pair in ascending order.

I have key value pair as

key  |  Value

 2      Rooney 
 7      Ronaldo
 20     Persie
 1      Pele
 10     Ramires

I have used Map.Entry and also advanced for loop to iterate key value.

Problem is that the output is not in proper ascending order as i want.

Output 

key  |  Value

 1      Pele
 10     Ramires     
 2      Rooney
 20     Persie 
 7      Ronaldo

Actual output as I want to display is shown below.

Output 

    key  |  Value

     1      Pele          
     2      Rooney
     7      Ronaldo
     10     Ramires
     20     Persie

Thanks in advance for your answers.

Answer 1

Change key to int. If you use string, the map will be sorted in the lexicographical order.