Dialog

org.eclipse.jface.dialogs.Dialog

public class MyDialog extends Dialog {
   private Label label;
   private Text text;
 
   protected MyDialog(Shell parentShell) {
      super(parentShell);
   }
 
   @Override
   protected Control createDialogArea(Composite parent) {
      Composite composite = (Composite) super.createDialogArea(parent);
 
      label = new Label(parent, SWT.LEFT);
      label.setText("Bitte geben Sie ihren Text ein");
 
      text = new Text(composite, SWT.LEFT);
      return composite;
   }
 
   @Override
   public void okPressed() {
      String str = text.getText();
 
      System.out.println(str);
      close();
   }
}

Aufruf des Dialogs:

MyDialog dialog = new MyDialog(Display.getCurrent().getShell());
if (dialog.open() == Window.OK) {
   // mach irgendwas
}