title: abstractlist protobuf java
body: <p>I have an object containing a list sent from a C# client to a Java server. The serialization with protobuf work perfectly and the object is received perfectly in Java. But the class generated with protoc.exe (can we call it a proto class?) have a list that i can't modify. Basically, I have to add some values in it before returning it to C#, but when I try to add a value, i have an exception :</p>
  
  <pre><code>Exception in thread "main" java.lang.UnsupportedOperationException
      at java.util.AbstractList.add(AbstractList.java:148)
      at java.util.AbstractList.add(AbstractList.java:108)
      ...
  </code></pre>
  
  <p>Here's how i'm adding values:</p>
  
  <pre><code>MyProtoObject.MyResult result = MyProtoObject.MyResut.NewBuilder()
          .setId(1)
          .setValue(9.135)
          .build();
  MyObject.getResultList().add(result);
  </code></pre>
  
  <p>How can i insert values in it?</p>