title: No setter/getter for Firebase objects
body: <p>This is my Java class:</p>
  
  <pre><code>public class OnlineMatch{
  
  private FacebookUser firstplayer;
  private FacebookUser secondplayer;
  
  
  public OnlineMatch(){
  
  }
  
  
  public OnlineMatch(FacebookUser firstplayer, FacebookUser secondplayer) {
      this.firstplayer = firstplayer;
      this.secondplayer = secondplayer;
  }
  
  public FacebookUser getFirstplayer() {
      return firstplayer;
  }
  
  public void setFirstplayer(FacebookUser firstplayer) {
      this.firstplayer = firstplayer;
  }
  
  public FacebookUser getSecondplayer() {
      return secondplayer;
  }
  
  public void setSecondplayer(FacebookUser secondplayer) {
      this.secondplayer = secondplayer;
  }
  </code></pre>
  
  <p>}</p>
  
  <p>I can create objects correctly and uploaded to Firebase. The db structure is as follow:
  <a href="https://i.stack.imgur.com/jdNie.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/jdNie.png" alt="Screenshot taken from firebase panel control"></a></p>
  
  <p>Then I try to print the values of my OnlineMatch objects (Kotlin code):</p>
  
  <pre><code>val match = dataSnapshot.child("multiplayer").getValue(OnlineMatch::class.java)
              if(match!=null){
                  System.out.println(match)
              }
  </code></pre>
  
  <p>Here I get this output on the Android Studio console:</p>
  
  <p>9548-19548/app.simone W/ClassMapper: No setter/field for -KqV44f4FUxV8ZDuqL4Y found on class app.simone.multiplayer.model.OnlineMatch</p>
  
  <p>08-01 19:14:38.816 19548-19548/app.simone W/ClassMapper: No setter/field for -KqV3sAPXPcYrtr61cDy found on class app.simone.multiplayer.model.OnlineMatch</p>
  
  <p>08-01 19:14:38.816 19548-19548/app.simone W/ClassMapper: No setter/field for -KqV2BGH7Z-Y9RxnPGpt found on class app.simone.multiplayer.model.OnlineMatch</p>