Android : java class only declaration no definition

New to Java and debugging the WebView android app which does not update properly. To find out what happens in onDraw() of WebView the source code here http://grepcode.com/file/repository.grepcode.com/java/ext/com.google.android/android/4.2.2_r1/android/webkit/WebView.java?av=f

shows the onDraw() class calls

 mProvider.init(javaScriptInterfaces, privateBrowsing);

the mProvider.init(...) is here http://grepcode.com/file/repository.grepcode.com/java/ext/com.google.android/android/4.2.2_r1/android/webkit/WebViewProvider.java#WebViewProvider.init%28java.util.Map%2Cboolean%29

But only declaration is present no definition. In c++ the definitions are in cpp files. Is there any equivalent in java ?.