Answer

Here is one possible solution:

public class ShadowingDemo {
  private String x = "x";
  public void printX(){
    System.out.println(x);   
    String x = "y";
    System.out.println(x);   
  }
}

If you run new ShadowingDemo().printX();, it will print x first, then y because the local variable x in the following line shadows the x instance variable:

String x = "y";

Please note that shadowing can be a source of a defect or can be used for the benefit of the program. Without it, you would be not able to use a local variable identifier that is already used by an instance variable. And here is another example of a case where variable shadowing helps:

private String x = "x";
public void setX(String x) {
  this.x = x;
}

The x local variable (parameter) shadows the x instance variable. It allows using the same identificator for a local variable name that has been already used for an instance variable name. To avoid possible confusion, it is recommended to refer to an instance variable using the keyword this as we did in the example above.