If the application is only for Android, you do not have to use Phonegap, since one of its premises is that with the same code you can create an app for various platforms.
You can do in Java Pure, it will be simple maintenance if you already have the site hosted on some server.
You will use the WebView component.
Create an android project normally and in the file
MainActivity.java
Put this code below:
import android.app.Activity;
import android.content.Context;
import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
public class MainActivity extends Activity {
private Button button;
public void onCreate(Bundle savedInstanceState) {
final Context context = this;
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
button = (Button) findViewById(R.id.buttonUrl);
button.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View arg0) {
Intent intent = new Intent(context, WebViewActivity.class);
startActivity(intent);
}
});
}
}
In the file
WebViewActivity.java
Place this code:
import android.app.Activity;
import android.os.Bundle;
import android.webkit.WebView;
public class WebViewActivity extends Activity {
private WebView webView;
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.webview);
webView = (WebView) findViewById(R.id.webView1);
webView.getSettings().setJavaScriptEnabled(true);
//webView.loadUrl("http://www.google.com");
String customHtml = "<html><body><h1>Hello, WebView</h1></body></html>";
webView.loadData(customHtml, "text/html", "UTF-8");
}
}
On this site Android WebView example you will find more complete and complex examples and you can improve your application.