title: how to write One to One mapping using Xml , in java?
body: <p>how to write one-to-one  mapping using xml,for the below class ?
              in account table customerId has to come.first one is Account class 
              and second class is customer class.</p>
  
  <pre><code>public class Account {
          private int customerId;
          private int accountNumber;
          private double balance;
          private String typeOfAccount;
          private Customer customer;
      }
  
  
      public class Customer {
          private int customerID;
          private String name;
          private String email;
          private String phoneNumber;
  
      }
  </code></pre>