Communication from Java to Javascript

package com.example.myapp;

import android.os.Bundle;
import android.app.Activity;
import android.webkit.WebView;

public class WebViewActivity extends Activity {
    
    private Webview webView;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
       super.onCreate(savedInstanceState);

       webView = new WebView(this);
       webView.getSettings().setJavaScriptEnabled(true);

       setContentView(webView);

       webView.loadUrl("http://example.com");

       /*
        * Invoke Javascript function
        */
       webView.loadUrl("javascript:testJsFunction('Hello World!')");
    }

   /**
    * Invoking a Javascript function
    */
   public void doSomething() {
     this.webView.loadUrl("javascript:testAnotherFunction('Hello World Again!')");
   }
}