user/src/com/google/gwt/user/tools/AppClassTemplate.javasrc

package @clientPackage;

import com.google.gwt.core.client.EntryPoint;
import com.google.gwt.user.client.ui.Button;
import com.google.gwt.user.client.ui.ClickListener;
import com.google.gwt.user.client.ui.Label;
import com.google.gwt.user.client.ui.RootPanel;
import com.google.gwt.user.client.ui.Widget;

/**
 * Entry point classes define <code>onModuleLoad()</code>.
 */
public class @className implements EntryPoint {

  /**
   * This is the entry point method.
   */
  public void onModuleLoad() {
    final Button button = new Button("Click me");
    final Label label = new Label();

    button.addClickListener(new ClickListener() {
      public void onClick(Widget sender) {
        if (label.getText().equals(""))
          label.setText("Hello World!");
        else
          label.setText("");
      }
    });

    // Assume that the host HTML has elements defined whose
    // IDs are "slot1", "slot2".  In a real app, you probably would not want
    // to hard-code IDs.  Instead, you could, for example, search for all 
    // elements with a particular CSS class and replace them with widgets.
    //
    RootPanel.get("slot1").add(button);
    RootPanel.get("slot2").add(label);
  }
}