title: Is it possible to store HashMap to MongoDB / ArangoDB, where HashMap's KEY is custom Java Object and VALUE also custom Java Object
body: <p>Is it possible to store HashMap to MongoDB / ArangoDB, where HashMap's KEY is custom Java Object and VALUE also custom Java Object. </p>
  
  <pre><code>`Class Customer {
      private String customerName;
      private String customerAddress;
      private HashMap&lt;ContactPerson, Address&gt; customerConacts;    
  }`
  
  `class ContactPerson {
      private String name;
      private String mailId;
  }`
  
  `class Address {
      private String houseNo;
      private String street;
  }`
  </code></pre>
  
  <p>Here, I want to store Customer object to MongoDB / ArangoDB and using Spring data. Is it possible to store Customer Objects into DB?.</p>