Java扫描仪上的占位符

在控制台中，如何在扫描仪上放置一个占位符？

我举个例子

public class main {
  string name;
  public void main(){
   name = " default ";
  }

 public void modif(){
  Scanner sc = new Scanner(System.in);
  String str = sc.nextLine(); // At this moment i want in the console the current value of name. The user can delete it, and replace it with the new name. Or just modify it
  this.name=str;
 }
}

非常感谢阅读我，对不起我的英语