title: Possible reason for "Error:cannot generate view binders java.lang.NullPointerException"
body: <p>I am using Android Studio for my Android projects. I faced an issue when builds crash with strange stacktrace, like this:</p>
  
  <pre><code>Error:Execution failed for task ':app:compileDevDebugJavaWithJavac'.
   java.lang.RuntimeException: failure, see logs for details.
    cannot generate view binders java.lang.NullPointerException
      at android.databinding.tool.reflection.ModelMethod.isBoxingConversion(ModelMethod.java:155)
      at android.databinding.tool.store.SetterStore.isBetterParameter(SetterStore.java:946)
      at android.databinding.tool.store.SetterStore.getBestSetter(SetterStore.java:838)
  </code></pre>
  
  <p>and it was seemed that the databinding became broken as whole.</p>
  
  <p>I made refactoring before and moved classes between packages.</p>