title: Android. How to access a class from another file to MainActivity
body: <p>I created a separate java class called SetIP.java with just a simple print:</p>
  
  <pre><code>package com.myname.appname;
  
  import android.util.Log;
  
  public class SetIP {
  
      public void hello(){
          Log.d("System", "Hello World!");
      }
  }
  </code></pre>
  
  <p>In the MainActivity I try to call it by:</p>
  
  <pre><code>public class MainActivity extends AppCompatActivity {
  
      SetIP setip = new SetIP();
      setip.hello();
     // OnCreate and Stuff
  }
  </code></pre>
  
  <p>But the error said cannot resolve symbol 'Hello'. Please help. Thanks</p>