title: Spring REST Controller returns JSON with empty data
body: <p>I have a simple Spring Boot web application. I'm trying to receive some data from server. The Controller returns a collection, but the browser receives empty JSON - the number of curly brackets is equals to the number of objects from server, but its content is empty.</p>
  
  <pre><code>@RestController
  public class EmployeeController {
  
  @Autowired
  private EmployeeManagerImpl employeeManagerImpl;
  
      @RequestMapping(path="/employees", method = RequestMethod.GET)
      public Iterable&lt;Employee&gt; getAllEmployees() {
          Iterable&lt;Employee&gt; employeesIterable = employeeManagerImpl.getAllEmployees();
          return employeesIterable;
      }
  }
  </code></pre>
  
  <p>The method fires and a browser shows:</p>
  
  <p><a href="https://i.stack.imgur.com/yYQxo.png" rel="noreferrer"><img src="https://i.stack.imgur.com/yYQxo.png" alt="enter image description here"></a></p>
  
  <p>Nothing more in the console. Any ideas?</p>
  
  <p>EDIT:
  Employee.java</p>
  
  <pre><code>@Entity
  public class Employee implements Serializable{
  
      private static final long serialVersionUID = -1723798766434132067L;
  
      @Id
      @Getter @Setter 
      @GeneratedValue
      private Long id;
  
      @Getter @Setter
      @Column(name = "first_name")
      private String firstName;
  
      @Getter @Setter
      @Column(name = "last_name")
      private String lastName;
  
      @Getter @Setter
      private BigDecimal salary;
  
      public Employee(){
  
      }
  }
  </code></pre>